Anti-bacterial activity of neoandrographolide derivatives: In silico interaction with the bacterial target

Natural products and their semi synthesized molecules have been used as efficient antibiotics since a long time. The present global health scenario has raised the demand for novel antimicrobial agents and drug targets that are effective against drug resistant pathogens, emerging infections etc. The current study has promoted the antibacterial activity of the glucoside labdane ‘neoandrographolide’, isolated from the methanolic extract of the medicinal plant Andrographis paniculata. Further modification at its glucoside hydroxyl groups to generate ester and acetonide derivatives was done and the antibacterial potential of these compounds was screened against common bacterial pathogens. Among various derivatives, 4?,6?-O-(4-methoxybenzylidene) neoandrographolide exhibited promising results. In addition, molecular modeling study of the active compound was also explored to identify its probable binding mode on the bacterial target. The present study reported antibacterial activity of neoandrographolide derivatives for first time and also the bioactive molecule, 4?,6?-O-(4-methoxybenzylidene) neoandrographolide was examined as a potent antibacterial agent against different strains.

Biological identification and molecular structure model analysis of Bx02 / 中国输血杂志

【Objective】 To identify two ABO discrepancy samples and explore the molecular mechanism. 【Methods】 The serological phenotype of the proband was determined with standard serological methods. ABO genotype was determined by polymerase chain reaction-sequence specific primer (PCR-SSP). Exon 6 and 7 of the ABO gene were amplified with PCR and sequence-based typing (SBT). The amplicon of exon 6 and 7 was also cloned and sequenced. Pymol software was used to simulate the 3D structural model and predict the effect of GTB protein mutation on the structure. The sample were collected from proband’s father and analyzed. 【Results】 The proband’s erythrocytes were detected with B antigens, along with the presence of anti-B in serum. The genotype O1/B of the proband was identified by PCR-SSP. Direct sequencing of the proband revealed 261delG/G, 297A/G in exon 6 and 526C/G, 646A/T, 657C/T, 681A/G, 703A/G, 771C/T, 796A/C, 803C/G, 829A/G, 905A/G, 930A/G, 1096A/G heterozygote in exon 7, which was assigned as Bx02/O02 genotype. Clone sequencing showed that a 905 A>G mutation in the ABO*B.01 allele. The 3D structure simulation suggested that Asp302Gly may cause the change of GTB enzyme activity or function. 【Conclusion】 Two cases of Bx02 allele were identified. Combined detection of serological and genotyping methods is important for identification of ABO blood group.

Antitumor activity of a novel HER3-targeting antibody-drug-conjugate / 药学学报

As a member of the human epidermal growth factor receptor (HER) family of receptor tyrosine kinases, HER3 is an aberrantly activator of the PI3K/AKT pathway. Studies have indicated that HER3 is related to the progression of a variety of tumor types such as breast cancer, non-small cell lung cancer (NSCLC), ovary cancer and colon cancer, and in acquired resistance to EGFR and HER2 therapies. However, the attempts to target HER3 with neutralizing antibodies are not ideal previously. This is most likely due to the fact that the antibodies targeting HER3 fail to completely block the heterodimerization of HER3 and other receptors. Antibody-drug conjugates (ADCs) can specifically bind to target cells and exert the highly cytotoxicity effect on cancer cells through chemical drugs. ADCs have been widely used in clinical cancer therapies. We analyzed and optimized the structure of the antigen-antibody complex between HER3 and antibody LmAb3 by computer-aided molecular simulation technology, and the key sites involved in antigen binding in LmAb3 were predicted by distance geometry and computer graphics technology. Then a novel anti-HER3 antibody FD001 was obtained by point mutation technology. The affinity measurement by ForteBio results showed that the affinity of FD001 is much higher than LmAb3, the KD values of FD001 and LmAb3 with HER3 were 1.48E-11 and 2.46E-10, respectively. Antibody drug conjugate FD001-DM1 is obtained by coupling FD001 to DM1 [emtansine, N2'-deacetyl-N2'-(3-mercapto-1-oxopropyl)-maytansine] by lysine coupling technology. The results of cell cytotoxicity experiments showed that FD001-DM1 could effectively inhibit the proliferation of HER3-positive HT-29 colon cancer cells, with EC50 value of 33.62 nmol·L-1. The in vivo xenografts therapy results showed that the tumor volume of the FD001-DM1 treatment group was about 25% of that of the control group, and there was no significant weight reduction of the mice. These results reveal that FD001-DM1 had good in vivo and in vitro anti-tumor activity with high safety, which may provide effective help for further exploration of HER3-targeted ADCs drugs. The mice in this study were used and treated in accordance with international laboratory animal care and use guidelines and approved by the Animal Ethics Committee of the Military Cognitive and Brain Science Institute of the Military Medical Research Institute.

Prediction of lipid nanoparticles for mRNA vaccines by the machine learning algorithm

Lipid nanoparticle (LNP) is commonly used to deliver mRNA vaccines. Currently, LNP optimization primarily relies on screening ionizable lipids by traditional experiments which consumes intensive cost and time. Current study attempts to apply computational methods to accelerate the LNP development for mRNA vaccines. Firstly, 325 data samples of mRNA vaccine LNP formulations with IgG titer were collected. The machine learning algorithm, lightGBM, was used to build a prediction model with good performance (R 2 > 0.87). More importantly, the critical substructures of ionizable lipids in LNPs were identified by the algorithm, which well agreed with published results. The animal experimental results showed that LNP using DLin-MC3-DMA (MC3) as ionizable lipid with an N/P ratio at 6:1 induced higher efficiency in mice than LNP with SM-102, which was consistent with the model prediction. Molecular dynamic modeling further investigated the molecular mechanism of LNPs used in the experiment. The result showed that the lipid molecules aggregated to form LNPs, and mRNA molecules twined around the LNPs. In summary, the machine learning predictive model for LNP-based mRNA vaccines was first developed, validated by experiments, and further integrated with molecular modeling. The prediction model can be used for virtual screening of LNP formulations in the future.

Modelagem Molecular (TD-DFT) aplicada na predição do fator de proteção solar de compostos naturais / Molecular Modeling (TD-DFT) applied to predict the sun protection factor of natural compounds

Na área da saúde pública, as doenças provocadas pela radiação solar têm ganho grande destaque, por serem cada vez mais comuns. Dentre as principais formas de prevenção a utilização de filtros solares são as mais comuns e de fácil acesso. Os filtros utilizados atuam por sua capacidade de refletir, absorver ou dispersar os raios solares ultravioletas (UV). A aplicação de métodos teóricos tornou-se indispensável no auxílio do planejamento de novos compostos com função terapêutica, em estudos de suas diferentes propriedades, buscando gerar, manipular e analisar representações realistas de estruturas moleculares obtidas a partir de cálculos de propriedades físico-químicas por meio da química computacional. Neste estudo, foram selecionados compostos naturais de origem vegetal (3-O-metilquercetina, ácido gálico, aloína, catequina, quercetina e resveratrol), os quais são descritos com propriedades fotoprotetoras, para os quais se aplicou métodos computacionais para predição dos espectros de absorção, por meio do método TD-DFT (Teoria funcional da densidade dependente do tempo). Foram avaliadas as principais transições eletrônicas dos compostos estudados e se as diferenças de energia HOMO e LUMO para os compostos que absorvem na faixa UV compreendem na UVA (320400 nm, 3.103.87 eV), UVB (290320 nm, 3.874.27 eV) ou na UVC (100290 nm, 4.2712.4 eV). Realizou-se a validação experimental para o método aplicado para o EMC, quercetina e resveratrol, demonstrando a eficácia. Após os estudos realizados concluímos que o resveratrol, teoricamente é um ótimo candidato a fotoprotetor. O estudo ofereceu informações relevantes sobre o poder de predição in silico para fotoprotetores, e se utilizado pode contribuir diminuindo de tempo e custos em pesquisas para desenvolver fármacos

In the area of public health, diseases caused by solar radiation have gained great prominence, as they are increasingly common. Among the main ways to prevent the use of sunscreens are the most common and easily accessible. The filters used act by their ability to reflect, absorb or scatter the sun's ultraviolet (UV) rays. The application of theoretical methods has become indispensable in helping to plan new compounds with therapeutic function, in studies of their different properties, seeking to generate, manipulate and analyze realistic representations of molecular structures obtained from calculations of physicochemical properties through computational chemistry. In this study, natural compounds of plant origin (3-O-methylquercetin, gallic acid, aloin, catechin, quercetin, and resveratrol) were selected, which are described with photoprotective properties, for which computational methods were applied to predict the absorption spectra, using the TD-DFT (Time-Dependent Density Functional Theory) method. The main electronic transitions of the studied compounds were evaluated and whether the differences in HOMO and LUMO energy for compounds that absorb in the UV range comprise UVA (320400 nm, 3.103.87 eV), UVB (290 320 nm, 3.87 4.27 eV) or UVC (100290 nm, 4.2712.4 eV). Experimental validation was carried out for the method applied for CME, quercetin, and resveratrol, demonstrating its effectiveness. After the studies carried out, we concluded that resveratrol, theoretically, is an excellent candidate for sunscreen. The study provided relevant information about the in silico predictive power for photoprotectors, and if used, it can contribute to reducing time and costs in research to develop drugs

Molecular modeling, synthesis, and evaluation of 1-(4-methoxybenzofuran-5-yl)-3-phenylpropane-1, 3-dione for its anxiolytic potentiality

The disabling mental illness anxiety is gradually affecting the modern society in any age group worldwide. The searchfor novel bioactive entity from herbal origin for different disorders has become the center of attraction significantlyfrom the past few decades. Gamma-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter known tobe responsible for the anxiolytic activity of most of the potent anxiolytic agents. All the available data of pongamol1-(4-methoxybenzofuran-5-yl)-3-phenylpropane-1, 3-dione (MPD) were based on natural or semi-synthetic source.The synthetic routes were using easily available source and quick, cost-effective, and high yielding process. MPD hastraditionally been acquired from natural sources mainly from the extracts of fruits of Pongamia pinnata and Pongamiaglabra, where the yield value and the yield time are the main drawbacks. Keeping in view of the above aspects in thepresent research, it was approached to synthesize and evaluate the anxiolytic potential 1-(methoxybenzofuran-5yl)-3-phenylpropane-1, 3-dione on experimental animals and docking procedure after its synthesis. The study of MPDon the gross behavior of mice showed a significant Central Nervous System (CNS) depressant effect. Furthermore,its anxiolytic activity was confirmed by observing its reduced locomotion of mice using actophotometer and elevatedplus-maze apparatus. The highest docking score was observed to be −3.22 than the diazepam (−3.21) against GammaAmino Butyric Acid-A (GABAA). The present study provides a promising anxiolytic agent, MPD, which has itspotency due to the GABAA receptor binding and causing the mitigation of the symptoms of anxiety.

Planejamento e desenvolvimento de ligantes não peptídicos com atividade agonista enviesada no receptor de angiotensina II tipo 1 empregando-se técnicas de modelagem molecular e ensaios in vitro / Drug design of non-peptidic biased agonists for angiotensin II type 1 receptor using molecular modeling techniques and in vitro tests

A insuficiência cardíaca (IC) é uma síndrome de elevada morbimortalidade, correspondendo a um grave problema de saúde pública. Uma das abordagens terapêuticas para IC consiste no uso de antagonistas do receptor de angiotensina II do tipo 1 (AT1R), conhecidos como sartanas. Estudos apontam que uma nova classe de compostos, os agonistas enviesados, é capaz de induzir a sinalização da via da ß-arrestina sem ativação da via da proteína G. Essa seletividade funcional é particularmente interessante, pois a via dependente da proteína G é responsável pelo aumento da pressão arterial, morte celular e fibrose tecidual, levando a hipertrofia cardíaca e progressão da IC. No entanto, a via da ß-arrestina está associada com renovação celular e aumento do inotropismo. Além disso, estudos in vivo sugerem que agonistas enviesados poderiam corresponder a uma terapia superior à dos antagonistas convencionais, que bloqueiam ambas as vias. Apesar do potencial terapêutico, esses compostos possuem estrutura peptídica e, por isso, tem sua administração restrita à via intravenosa. A resolução da estrutura cristalográfica do AT1R permitiu estudos de modelagem molecular mais acurados. Tendo isso em mente, nesse trabalho foram propostos agonistas enviesados de natureza não peptídica para o AT1R por meio de técnicas de modelagem molecular e validação das hipóteses levantadas por ensaios in vitro. Foram realizados estudos de dinâmica molecular com o AT1R (PDB ID: 4YAY) em uma bicamada lipídica e ensaios de ancoramento molecular da angiotensina II (AngII) e do ligante enviesado TRV027. As poses de ancoramento molecular selecionadas foram utilizadas em dinâmicas de complexo, que revelaram diferenças entre os sistemas apo (sem nenhum ligante) e holo (com o ligante no sitio de ligação). Nossos resultados sugerem que o TRV027 induz um padrão exclusivo de ligações de hidrogênio e de estrutura secundária, enquanto que a AngII afeta os resíduos do bolso hidrofóbico do sitio de ligação, principalmente a conformação do Trp2536.48. Com base nas simulações, três farmacóforos foram criados e utilizados de maneira complementar em triagens virtuais na base de dados ZINC15, resultando na seleção de cinco compostos. Um desses compostos apresentou afinidade pelo receptor AT1R e, ainda que estudos complementares de ativação de vias especificas sejam necessários para que o composto possa ser classificado como agonista enviesado, já se constitui em molécula potencialmente promissora. Além disso, esses estudos permitiram a proposição de estruturas inéditas que podem vir a ser hits no processo de desenvolvimento de agonistas enviesados para AT1R. Portanto, como continuidade desse trabalho, essas moléculas serão sintetizadas e investigadas quanto à possível interação com o receptor.

Heart Failure (HF) is a common syndrome with high morbimortality, being considered a serious public health problem. One of the therapeutic approaches for HF consists in the use of the sartan class, which are angiotensin II type 1 receptor (AT1R) antagonists. Recent studies have shown that a new class of compounds, known as biased agonists, is able to induce signaling via ß-arrestin without G-protein activation. This functional selectivity is particularly interesting since G-protein dependent signaling is responsible for cell death and cardiac tissue fibrosis, which leads to cardiac muscle hypertophy and HF progression. On the other hand, ß-arrestin signaling is associated with cellular renewal and increased inotropism. In vivo studies suggests that biased agonists could correspond to a superior therapy over conventional angiotensin II type 1 receptor antagonists, which blocks cell signaling as a whole, however their peptidic structure restricts their use to intravenous administration. Moreover, the AT1R crystal structure determination holds great promise for more accurate molecular modeling studies. With that being said, the aim of this work was to plan and develop new non-peptidic biased agonists for ATR1 employing molecular modeling techniques and in vitro tests for hypothesis validation. Molecular dynamics (MD) simulations of the refined AT1R crystal (PDB ID: 4YAY) embedded in a lipid bilayer and molecular docking studies with angiotensin II (AngII) and TRV027 (biased agonist) were conducted. Selected docking poses from both ligands underwent complex MD simulations revealing differences between apo (ligand free) and holo (ligand in the binding site) systems. Our results suggest that TRV027 induces an exclusive hydrogen bond and secondary structure pattern, while AngII affects the hydrophobic pocket conformation, mainly Trp253. Based on the simulations, three pharmacophore models were created and used in virtual screenings in the ZINC15 database, resulting in the selection of five compounds that were tested in vitro. One of the compounds displayed affinity for AT1R and is a promising molecule. Nonetheless, it needs further pathway activation characterization in order to be a classified as a biased agonist. Furthermore, these results have contributed significantly for the proposition of new structures that could be hits with biased agonist activity for AT1R. Thus, for future works, we point out the necessity for synthesis and characterization of this new compounds

Possible Metsulfuron Herbicide Detoxification by a Oryza sativa L. Glutathione S-transferase Enzyme

Abstract Rice (Oryza sativa L.) is one of the most important crops in the world, and it is considered the primary source of nutritional layout in developing countries in Asia. The glutathione S-transferases (GSTs) superfamily confers to rice protection against biotic and abiotic stress, and herbicide resistance. However, the three-dimensional structure of a GST Tau class, is unsolved. The objectives of this work were to develop a reliable comparative model for the s-transferase glutathione class Tau 4 from rice, and simulate docking interactions, against herbicides bentazon and metsulfuron. Results showed that the predicted model is reliable and has structural quality. Ramachandran plot set 91.9% of the residues in the most favored regions. All complexes showed negative binding energies values; and metsulfuron docked to the glutathione tripeptide, and it represents a possible insilico evidence of glutathione conjugation with this herbicide.

Synthesis and biological evaluation of a series of 2-(((5-akly/aryl-1-pyrazol-3-yl)methyl)thio)-5-alkyl-6-(cyclohexylmethyl)-pyrimidin-4(3)-ones as potential HIV-1 inhibitors

A series of 2-(((5-akly/aryl-1-pyrazol-3-yl)methyl)thio)-5-alkyl-6-(cyclohexylmethyl)-pyrimidin-4(3)-ones were synthesized and their anti-HIV-1 activities were evaluated. Most of these compounds were highly active against wild-type (WT) HIV-1 strain (IIIB) with EC values in the range of 0.0038-0.4759 μmol/L. Among those compounds, had an EC value of 3.8 nmol/L and SI (selectivity index) of up to 25,468 indicating excellent activity against WT HIV-1. anti-HIV-1 activity and resistance profile studies suggested that compounds and displayed potential anti-HIV-1 activity against laboratory adapted strains and primary isolated strains including different subtypes and tropism strains (ECs range from 4.3 to 63.6 nmol/L and 18.9-219.3 nmol/L, respectively). On the other hand, it was observed that those two compounds were less effective with EC values of 2.77 and 4.87 μmol/L for HIV-1A (K103N + Y181C). The activity against reverse transcriptase (RT) was also evaluated for those compounds. Both and obtained sub-micromolar IC values showing their potential in RT inhibition. The pharmacokinetics examination in rats indicated that compound has acceptable pharmacokinetic properties and bioavailability. Preliminary structure-activity relationships and molecular modeling studies were also discussed.

In silico investigation of possible caffeine interactions with common inflammation-related targets

Caffeine (CA) is a methylxanthine alkaloid widely used in anti-inflammatory drug associations due to itsvasoconstricting properties. Although CA is acknowledged to interact with a plethora of macromolecules inhuman organism, there was to the best of our knowledge, no survey regarding its possible interactions withcommon inflammation-related targets. Henceforth, this work was concerned in the investigation of CA possibleinteractions with cyclooxygenases-1 and -2 (COX-1 and COX-2), as well as prostaglandin H2 synthase-1and leukotriene A4 hydrolase through in silico approaches. CA molecule was studied as a ligand whereas theligand-macromolecules docking models were created through AutoDock Vina tools. Results showcased that,although the thermodynamic features of the best scoring models did not render enough information to affirmstable interaction between CA and the analyzed macromolecules, more studies are needed to shed light on thepossible role of methylxanthines towards inflammation targets.

Development of software for prediction and virtual screening of antioxidant activity of new synthesized azaheterocyclic compounds

Background: Increasing introduction of innovation technologies into medicine and pharmacology makes it possible to modify and develop further the methods of the development of new medicines. Such methods include virtual screening. In this article approaches to building software for virtual screening of nitric oxide (NO)scavengers in an important class of azaheterocyclic compounds are discussed.Methods: During the study period (from October 2017 to January 2019) the methods for the evaluation of antioxidant activity, as well as quantum-mechanical and statistical calculations were conducted. Quantum-mechanical calculations on HOMO (highest occupied molecular orbital) energy and LUMO (lowest unoccupied molecular orbital) energy descriptors have been conducted using program complex WinMopac 7.2.Results: Evaluation methods of antioxidant activity, quantum-mechanical and statistical calculations have been presented. The algorithm for computer program of virtual screening has been proposed. Prospects and benefits of computer modeling of agent activity are considered.Conclusions: Establishment of computer program for virtual screening will significantly reduce time and resources during researching new synthesized compounds. The algorithm for a computer program of virtual screening has been developed Predictable antioxidant activity data on nitric oxide radical (NO·)inhibition may be calculated in percentage using HOMO and LUMO as the input data for this program.

Mangostanaxanthone VIIII, a new xanthone from Garcinia mangostana pericarps, α-amylase inhibitory activity, and molecular docking studies

ABSTRACT A new xanthone: mangostanaxanthone VIIII [1,3,5,6,7-pentahydroxy-2-(3-methylbut-2-enyl)-8-(3-hydroxy-3-methylbut-1-enyl) xanthone] (5) and four known xanthones: mangostanaxanthones I (1) and II (2), γ-mangostin (3), and mangostanaxanthone VII (4) were separated and characterized from the acetone fraction of Garcinia mangostana L., Clusiaceae (mangosteen) pericarps. Their structures were established based on various spectroscopic analyses in addition to HRMS and comparison with the literature. The α-amylase inhibitory potential of the isolated metabolites was evaluated. Compounds 1, 2, and 5 had the highest activity with % inhibition 72.5, 86.5, and 81.8, respectively compared to acarbose (97.1%, reference α-amylase inhibitor). The molecular docking study of the tested metabolites was estimated to shade up the rational explanation of the α-amylase inhibitory activity results. Moreover, the pharmacokinetic parameters were assessed using Swiss ADME. It is noteworthy that 1, 2, and 5 had similar binding poses as the X-ray crystal structure of acarbose, whereas the other metabolites possessed different binding mode that decreased their inhibitory capacity. Thus, these data reinforced the health benefit of mangosteen as an alternative medicine to help lowering the postprandial glucose absorption. Therefore, it could have a good potential for the treatment of diabetes.

Planejamento, síntese e avaliação biológica de inibidores de falcipaína 2 como candidatos a antimaláricos / Design, synthesis and biological evaluation of falcipain 2 inhibitors as candidates for antimalarials

A malária, doença causada pelo protozoário do gênero Plasmodium, está entre as doenças que mais causam mortes os países subdesenvolvidosn. O hospedeiro é infectado por meio da picada do mosquito do gênero Anopheles, que introduz o parasita durante a hematofagia. As formas mais graves são causadas pelo Plasmodium vivax e o Plasmodium falciparum. As regiões mais afetadas por estas formas são África Subsaariana, Ásia, América Central e Sul. Desde o começo do século XXI, a Organização Mundial de Saúde (OMS) busca erradicar a doença, porém o P.falciparum se mostrou resistente aos fármacos antimaláricos existentes, dificultando a eficácia do tratamento. Isto, entre outros fatores, como mortalidade e alto índice de infecção, tornam necessárias novas pesquisas para a descoberta de novos fármacos mais seguros e eficazes contra a malária. Estudos têm mostrado como um alvo promissor para a criação de novos antimaláricos, a cisteína protease falcipaína, a qual se apresenta em três isoformas no parasita, sendo elas, falcipaína 1, 2 e 3. A falcipaína 2 está ligada com a hidrólise da hemoglobina, e seus inibidores vem sendo estudados como alternativas na busca de agentes antimaláricos. Derivados de semicarbazona, tais como o nitrofural e o hidroximetilnitrofural demonstraram atividade inibitória de cisteíno proteases parasitárias. Utilizando estratégias modernas de planejamento de fármacos e por meio da integração entre técnicas computacionais e experimentais, realizou-se o planejamento, síntese e avaliação biológica de compostos derivados dos ditiocarbazatos e tiossemicarbazonas, bioisosteros de semicarbazona, como inibidores da cisteíno protease falcipaína 2, no intuito de obter novos antimaláricos. Aplicaram-se técnicas de modelagem molecular em três séries de compostos (A, B e C), sendo a A e B derivados dos ditiocarbazatos e a C das tiossemicarbazonas. Estes estudos sugerem, três compostos da série A, quatro na série B e três na C com maior potencial para inibição da falcipaína 2. Isso devido aos resultados teóricos indicarem condições favoráveis ao ataque nucleofílico da cisteína 42 catalítica da falcipaína 2 às tiocarbonilass presentes nos compostos planejados. Estes derivados foram sintetizados, analisados por espectroscopia de ressonância magnética de 1H e 13C, espectroscopia de IV, ponto de fusão e pureza caracterizando sua formação. Após a obtenção, os compostos foram enviados para ensaios biológicos frente ao parasita P. falciparum. Os compostos testados não apresentaram inibição, porém é sabido que muitos inibidores enzimáticos não são ativos contra o parasita mesmo tendo alta potência contra a enzima, isto devido às barreiras a serem ultrapassadas até chegar ao alvo bioquímico, deste modo faz-se necessário ensaios contra a enzima para validar nossa hipótese

Malaria, a disease caused by the protozoan of the genus Plasmodium, is among the most deadly diseases in poor countries. The host is infected through the bite of the mosquito of the genus ,i>Anopheles, which introduces the parasite during hematophagy. The most severe forms are caused by Plasmodium vivax and Plasmodium falciparum. The regions most affected by these forms are Sub-Saharan Africa, Asia, Central and South America. Since the beginning of the 21st century, the World Health Organization (WHO) has sought to eradicate the disease, but P. falciparum has been resistant to antimalarial drugs treatment. Among other factors, such as mortality and high infection rates, new research is needed to find new, safer and more effective drugs against malaria. Studies have shown as a promising target for the creation of new antimalarial drugs, the cysteine protease falcipain, which is present in three isoforms in the parasite: falcipain 1, 2 and 3. Falcipain 2 is linked to the hydrolysis of hemoglobin, and its inhibitors have been studied as alternatives in the search for antimalarial agents. Derivatives of semicarbazone such as nitrofural and hydroxymethylnitrofural demonstrated inhibitory activity of parasitic cysteine proteases. Using modern strategies for drug design and the integration of computational and experimental techniques, the design, synthesis and biological evaluation of compounds derived from dithiocarbazates and thiossemicarbazones, semicarbazone biosynthesis as inhibitors of cysteine protease falcipain 2 were carried out in order to new antimalarials. Molecular modeling studies were performed in three series of compounds (A, B and C), with A and B being derived from dithiocarbazates and C from thiossemicarbazones. These studies suggest three compounds in the A series, four in the B series, and three in the C group with the greatest potential for inhibition of falcipain 2. This is due to the theoretical results indicating favorable conditions for the nucleophilic attack of the catalytic cysteine of falcipain 2 on thionyls present in the compounds planned. These derivatives were synthesized, analyzed by 1H and 13C magnetic resonance spectroscopy, IR spectroscopy and melting point, characterizing their formation. After being obtained, the compounds were sent for biological assays against the P. falciparum parasite. The compounds tested did not show inhibition, but it is known that many enzyme inhibitors are not active against the parasite even though they have high potency against the enzyme, this is due to the barriers to be overcome until reaching the biochemical target, thus enzyme to validate our hypothesis

Drug nanoclusters formed in confined nano-cages of CD-MOF: dramatic enhancement of solubility and bioavailability of azilsartan

Tremendous efforts have been devoted to the enhancement of drug solubility using nanotechnologies, but few of them are capable to produce drug particles with sizes less than a few nanometers. This challenge has been addressed here by using biocompatible versatile -cyclodextrin (-CD) metal-organic framework (CD-MOF) large molecular cages in which azilsartan (AZL) was successfully confined producing clusters in the nanometer range. This strategy allowed to improve the bioavailability of AZL in Sprague-Dawley rats by 9.7-fold after loading into CD-MOF. The apparent solubility of AZL/CD-MOF was enhanced by 340-fold when compared to the pure drug. Based on molecular modeling, a dual molecular mechanism of nanoclusterization and complexation of AZL inside the CD-MOF cages was proposed, which was confirmed by small angle X-ray scattering (SAXS) and synchrotron radiation-Fourier transform infrared spectroscopy (SR-FTIR) techniques. In a typical cage-like unit of CD-MOF, three molecules of AZL were included by the -CD pairs, whilst other three AZL molecules formed a nanocluster inside the 1.7 nm sized cavity surrounded by six -CDs. This research demonstrates a dual molecular mechanism of complexation and nanoclusterization in CD-MOF leading to significant improvement in the bioavailability of insoluble drugs.

Predicting complexation performance between cyclodextrins and guest molecules by integrated machine learning and molecular modeling techniques

Most pharmaceutical formulation developments are complex and ideal formulations are generally obtained after extensive experimentation. Machine learning is increasingly advancing many aspects in modern society and has achieved significant success in multiple subjects. Current research demonstrated that machine learning can be adopted to build up high-accurate predictive models in drugs/cyclodextrins (CDs) systems. Molecular descriptors of compounds and experimental conditions were employed as inputs, while complexation free energy as outputs. Results showed that the light gradient boosting machine provided significantly improved predictive performance over random forest and deep learning. The mean absolute error was 1.38 kJ/mol and squared correlation coefficient was 0.86. The evaluation of relative importance of molecular descriptors further demonstrated the key factors affecting molecular interactions in drugs/CD systems. In the specific ketoprofen-CD systems, machine learning model showed better predictive performance than molecular modeling calculation, while molecular simulation could provide structural, dynamic and energetic information. The integration of machine learning and molecular simulation could produce synergistic effect for interpreting and predicting pharmaceutical formulations. In conclusion, the developed predictive models were able to quickly and accurately predict the solubilizing capacity of CD systems. Current research has taken an important step toward the application of machine learning in pharmaceutical formulation design.

Structure analysis of capsid protein of Porcine circovirus type 2 from pigs with systemic disease

Abstract Economic losses with high mortality rate associated with Porcine circovirus type 2 (PCV2) is reported worldwide. PCV2 commercial vaccine was introduced in 2006 in U.S. and in 2008 in Brazil. Although PCV2 vaccines have been widely used, cases of PCV2 systemic disease have been reported in the last years. Eleven nursery or fattening pigs suffering from PCV2 systemic disease were selected from eight PCV2-vaccinated farms with historical records of PCV2 systemic disease in Southern Brazil. PCV2 genomes were amplified and sequenced from lymph node samples of selected pigs. The comparison among the ORF2 amino acid sequences of PCV2 isolates revealed three amino acid substitutions in the positions F57I, N178S and A190T, respectively. Using molecular modeling, a structural model for the capsid protein of PCV2 was built. Afterwards, the mutated residues positions were identified in the model. The structural analysis of the mutated residues showed that the external residue 190 is close to an important predicted region for antibodies recognition. Therefore, changes in the viral protein conformation might lead to an inefficient antibody binding and this could be a relevant mechanism underlying the recent vaccine failures observed in swine farms in Brazil.

Cytotoxic activity of abietane diterpenoids from roots of Salvia sahendica by HPLC-based activity profiling

ABSTRACT Screening of medicinal plants from Iranian flora against human cancer cell-lines have shown that an hexane extract from roots of Salvia sahendica Boiss. & Buhse, Lamiaceae, is active against human cervical cancer (HeLa) and colorectal adenocarcinoma (Caco-2) cell-lines at the test concentration of 100 µg/ml (100% inhibition). Cytotoxicity of the extract was localized with the aid of HPLC-time-based activity profiling adapted to the tetrazolium colorimetric bioassay. Four abietane-type diterpenoids in active time-windows were identified as cytotoxic compounds namely: sahandone (1), sahandol (2), 12-deoxy-salvipisone (3) and sahandinone (4). Compound 1 showed the highest toxicity against HeLa cells (IC50 = 5.6 ± 0.1 µg/ml), which was comparable with betulinic acid (IC50 = 4.3 ± 1.2 µg/ml), the positive control. Compound 2 was active against the HeLa cells (IC50 = 8.9 ± 0.7 µg/ml) but not the Caco-2 cell-line. Compounds 1, 3 and 4 exhibited moderate activity (IC50 = 22.9-41.4 µg/ml) against the Caco-2 cells. This study reveals that the HeLa cells are more sensitive to all tested compounds than the Caco-2 cells. In silico molecular docking study showed a rigid binding of the compounds to tyrosine kinase pp60src, and proved their cytotoxic activity.

A combinatorial approach to study hepatoprotective activity of Acanthus ilicifolius leaf extract against hepatocellular carcinoma(HCC) / 中国药理学与毒理学杂志

OBJECTIVE To study the bioactive phytochemicals in the leaves of A.ilicifolius against Hepatocellular carcinoma (HCC) through in silico, in vitro and in vivo studies. METHODS A. ilicifolius leaves were collected from Cuddalore District,Tamil Nadu,India.Authenticated by the Botanical Survey of India. The fresh leaves of A. ilicifolius were washed and shade dried at room temperature (28 ± 2)℃. The dried leaves were powdered by electrical blender.25 gms of A.ilicifolius leaf powder was used for methanol extraction in the Soxhlet apparatus.The Phytochemical compounds were analyzed by GC-MS and the structure was retrieved from PubChem.Totally,seven HCC target proteins were collected from literature, ligand and proteins were prepared for in silico molecular docking. HepG2 cell lines were used for in vitro (MTT assay). BALB/c mice were used for in vivo studies, the biochemical parameters and histopathological studies were carried out with standard procedure. RESULTS The phytochemical 26.27-Di (nor)-cholest-5, 7, 23-trien-22-ol, 3-methoxymethoxy exhibited maximum docking score against the HCC target protein C-Jun N-terminal kinase 1 (JNK 1) (-6.839798). MTT assay revealed that the extract at a concentration of 200 μg·mL-1,caused 60% cell death in HepG2 cell lines.Further animal studies using to injecting HCC induced BALB/c mice,restoration of haematological parameters and cells to normal was observed after 15 days of oral administration of the extract.These findings suggest the possibility of using A.ilicifolius leaves in the treatment of HCC.CONCLUSION The in silico,in vitro and in vivo studies indicated that the A.ilicifolius leaves had anticancereous activity against Hepatocellular carcinoma.There can be a possibility of synergistic activity of phytochemicals together against HCC.

Potenciais candidatos a novos agentes antineoplásicos: síntese e avaliação da atividade antitumoral de análogos ureídicos e tioureidicos da capsaicina / New potential antineoplastic candidates: synthesis and antitumoral evaluation of urea and thiourea capsaicin analogues

As neoplasias malignas, doenças mundialmente conhecidas como câncer, possuem um dos tratamentos mais onerosos, tóxicos e de baixa seletividade na terapêutica atual. Adicionalmente, o contínuo crescimento da incidência da doença também representa em uma grande problemática. Os produtos de origem natural se apresentam como alternativas para o tratamento de diversas doenças, incluindo o câncer. A capsaicina, produto natural proveniente das pimentas do gênero Capsicum, apresenta propriedades antineoplásicas, portanto, pode ser utilizada como protótipo para obtenção de análogos. Quatro séries foram planejadas e sintetizadas, obtendo-se compostos ureídicos e tioureídicos. A estratégia sintética se baseou na reação da piperonilamina ou vanililamina com isocianatos ou isotiocianatos, ligados a substituintes aromáticos ou alquílicos. Vinte e sete análogos foram sintetizados com rendimentos variando entre 22 a 90 %. Todos os compostos apresentaram aspecto sólido variando a cor de branco a levemente amarelados. Para a caracterização das substâncias obtidas foram utilizados dados de RMN 1H e 13C, ponto de fusão e a determinação de pureza foi realizada mediante HPLC. Todos os compostos foram submetidos a ensaios de avaliação da atividade citotóxica por redução do MTT contra linhagens de células cancerígenas e células sadias. Os compostos RPF652, RPF 512 - 514) apresentaram atividade comparável ou superior ao protótipo com valores de IC50 na faixa de micromolar. Os resultados apontados pela modelagem molecular indicam que descritores eletrônicos como Ehomo e Elumo podem estar associados à atividade do composto, ClogP (3,92) pode favorecer melhor permeabilidade na membrana celular, e o maior número de sítios de acepção de ligação de hidrogênio podem corroborar com a citotoxidade em linhagem A2058. Particularmente, o análogo RPF652 apresentou atividade pronunciada com valores de IC50 de 55, 67, e 87 µM contra as células A2058, SK-MEL 25, e U87, respectivamente, o que representa atividade de superior à capsaicina. Como uma tendência o composto RPF652 causou parada no ciclo de linhagem B-RAF B16F10 não levando a célula à morte. Porém esta linhagem não apresenta mutação no códon V600E. Em contraponto, o análogo RPF652 apresentou maior potência contra linhagem V600EB-RAF A2058 mutada, indicando possível seletividade em linhagens que apresentam a mutação no códon V600E da proteína B-RAF. Ademais, novos esforços devem ser concentrados no análogo RPF652 para melhor elucidação mecanística de sua atividade

Malignant neoplasms have one of the most expensive, non-selective and toxic treatment of present times. This situation, combined with the rising incidence rate, represents a major problem for humanity. The use of natural products can be an alternative for treatment of several diseases, including cancer. Capsaicin is a natural product derived from Capsicum peppers, with reported anticancer activity and can be used as prototype for the design of new molecules with remarkable activity. Capsaicin analogues were designed and synthesized in four series of derivatives, replacing the prototype amide bond with urea and thiourea functions. The synthetic approach builds the urea/ thiourea scaffold using the reaction of piperonyl/ vanilyl amine with alkyl and aryl isocyanides/ isothiocyanides. Twenty-seven new compounds were obtained with yields from 22 to 90 %, and were fully characterized using 1H and 13C NMR, the purity was determined by melting point and HPLC. All of the obtained compounds were evaluated in MTT cytotoxic assays against different cancer cell-lines (B16F10, A2058, SK-MEL 25 and U-87), and compared with healthy human cells (T75). Additionally, the most active compound was submitted to a cell cycle arrest assay. The thiourea derivative RPF652 was the most active compound, and the urea derivatives RPF512, RPF513 and RPF514 showed good micromolar IC50 values. This results, when correlated with several in silico-calculated properties for the obtained molecules, suggests that ClogP, Ehomo, Elumo and the number of hydrogen-bond acception sites may be correlated to the anticancer activity reported. RPF652 especially, showed IC50 values with superior activity and better selectivity index when compared with capsaicin. The cell-cycle assay of RPF652 showed significant arrest in V600E-codon B-RAF non-mutated cell lines (B16F10) without killing it. V600E-codon B-RAF mutated cells A2058, were significantly more sensitive to the compound. These findings may suggest some insights about the mechanism of action and targets of this compounds

Evaluation of the influence of fluoroquinolone chemical structure on stability: forced degradation and in silico studies

ABSTRACT Fluoroquinolones are a known antibacterial class commonly used around the world. These compounds present relative stability and they may show some adverse effects according their distinct chemical structures. The chemical hydrolysis of five fluoroquinolones was studied using alkaline and photolytic degradation aiming to observe the differences in molecular reactivity. DFT/B3LYP-6.31G* was used to assist with understanding the chemical structure degradation. Gemifloxacin underwent degradation in alkaline medium. Gemifloxacin and danofloxacin showed more degradation perceptual indices in comparison with ciprofloxacin, enrofloxacin and norfloxacin in photolytic conditions. Some structural features were observed which may influence degradation, such as the presence of five member rings attached to the quinolone ring and the electrostatic positive charges, showed in maps of potential electrostatic charges. These measurements may be used in the design of effective and more stable fluoroquinolones as well as the investigation of degradation products from stress stability assays.