Shining light on tryptamine-derived isocyanides: access to constrained spirocylic scaffolds.

Dearomatization of indoles through a charge transfer complex constitutes a powerful tool for synthesizing three-dimensional constrained structures. However, the implementation of this strategy for the dearomatization of tryptamine-derived isocyanides to generate spirocyclic scaffolds remains underdeveloped. In this work, we have demonstrated the ability of tryptamine-derived isocyanides to form aggregates at higher concentration, enabling a single electron transfer step to generate carbon-based-radical intermediates. Optical, HRMS and computational studies have elucidated key aspects associated with the photophysical properties of tryptamine-derived isocyanides. The developed protocol is operationally simple, robust and demonstrates a novel approach to generate conformationally constrained spirocyclic scaffolds, compounds with high demand in various fields, including drug discovery.

Genetic variability of histidine-rich protein 2 repeat sequences: Misleading factor in true determination of Plasmodium falciparum in different population.

PURPOSE: Genetically diverse parasites enhances resistance against antimalarials, vaccines and host immune responses. The present study was designed to evaluate the role played by Plasmodium falciparum genetic diversity in predicting the real world malarial population. METHODS: Initially, the incidence pattern of all four northern Indian malarial species was examined using 18S rRNA gene and performed principal component analysis (PCA) based on frequencies of Plasmodium species. Consequently, genetic variance of Plasmodium falciparum histidine-rich protein-2 (Pfhrp2) gene among different malarial populations were compared using phylogenetic analysis. Multi-dimensional scaling was performed to assess genetic similarities and distances among studied populations. RESULTS: Of total 2168 patients screened, 561 patients with fever of unknown origin were included. 18S rRNA and Pfhrp2 genes were amplified in 78 and 45 samples, respectively. Among them 13.9%(78/561) patients had Plasmodium infection. Infections by P. falciparum, P. vivax and mixed infections were diagnosed among 47(60.2%) and 28(35.9%) and 3(3.8%) patients, respectively. We found eight types of Pfhrp2 amino acid sequence repeats among northern Indian population. The PCA findings were in line with genetic diversity and phylogenetic data. Temporal analysis showed the proportion of total diversity present in total subpopulation (ΔS/ΔT) was maximum for P. falciparum. CONCLUSIONS: Higher incidence of Pfhrp2 sequence variation through genetic recombination among multiple strains during sexual reproduction is potentially correlated with high transmission activity. This sequence variation might alter RDT detection sensitivities for different parasites by modulating the structure and frequency of antigenic epitopes.

A computational study of CuCrX2 (X = S, Se, Te) for intermediate band solar cell: Conceptual density functional theory approach.

Transition metals doped semiconductors have been extensively used as a greener alternative to lead-based solar cell materials. In this work, we have investigated the structure, electronic, optical, and thermo-chemical properties of CuCrX2 (X = S, Se, Te) by using the Conceptual Density Functional Theory (CDFT) approach. Different suitable exchange correlations have been used for the process of geometry optimization of systems in the study. Applied exchange correlations namely B3LYP and WB97XD demonstrate that the energy gap shows a decline from the atom S to Se to Te. HOMO-LUMO obtained from level B3LYP/LANL2DZ is in accordance with the stated data. The attained band gap directs that studied materials could be beneficial for further utilization in optoelectronic and photovoltaic devices. A comparative study has been made based on the selected exchange correlations for the analysis of investigated materials, which has not been explored commonly. The study reveals that B3LYP/LANL2DZ could be a better choice for a combination set of level and basis set for studying these types of compounds. CDFT-based global reactivity descriptors are computed and analyzed. The obtained band gap range indicates the desirable nature of CuCrX2 for further exploration in the application of Intermediate Band Solar cells.

A Cobalt Mediated Nitrene Transfer aza-Wittig Cascade Reaction To Access 1,3,4-Oxadiazole Scaffolds.

A cobalt(II) mediated three-component synthesis of 5-substituted-N-sulfonyl-1,3,4-oxadiazol-2(3H)-imines using sulfonyl azides, N-isocyaniminotriphenylphosphorane (NIITP), and carboxylic acids has been developed. This one-pot tandem reaction starts with a nitrene transfer to NIITP, followed by addition of the carboxylic acid to the in situ formed carbodiimide and subsequent intramolecular aza-Wittig reaction. Both the steric constraints of carboxylic acid and the stoichiometry of the employed cobalt salt determine the selectivity toward the two products, i.e. 5-substituted-N-sulfonyl-1,3,4-oxadiazol-2(3H)-imine versus 5-substituted-4-tosyl-2,4-dihydro-3H-1,2,4-triazol-3-one.

A systematic computational study of acridine derivatives through conceptual density functional theory.

A detailed computational analysis of acridine derivatives viz. acridone, 9-amino acridine hydrochloride hydrate, proflavin, acridine orange and acridine yellow is done in terms of conceptual density functional theory (CDFT). CDFT-based global descriptors-ionization potential, electron affinity, HOMO-LUMO gap, hardness, softness, electronegativity and electrophilicity index of acridine derivatives for ground state as well as excited state are estimated with the help of different hybrid functionals B3LYP/6-31G (d, p), B3LYP/6-311G (d, p), B3LYP/DGDZVP and B3LYP/LANL2DZ. Acridine derivatives show higher values of ionization potential and electron affinity in excited state as compared to ground state, indicating that these compounds are willing to accept electrons in excited state rather than donating electron. Acridone shows the maximum HOMO-LUMO energy gap in ground and excited state which implies that one-way electron transfer is most feasible with this compound. Our computed results emphasize the pronounced electron acceptor behaviour of the acridine derivatives in the excited state which has already been experimentally verified. It is observed that the trend in the computed values of the descriptors is not much improved on refinement of the basis set.

Challenges and future scope of exosomes in the treatment of cardiovascular diseases.

Exosomes are nanosized vesicles that carry biologically diverse molecules for intercellular communication. Researchers have been trying to engineer exosomes for therapeutic purposes by using different approaches to deliver biologically active molecules to the various target cells efficiently. Recent technological advances may allow the biodistribution and pharmacokinetics of exosomes to be modified to meet scientific needs with respect to specific diseases. However, it is essential to determine an exosome's optimal dosage and potential side effects before its clinical use. Significant breakthroughs have been made in recent decades concerning exosome labelling and imaging techniques. These tools provide in situ monitoring of exosome biodistribution and pharmacokinetics and pinpoint targetability. However, because exosomes are nanometres in size and vary significantly in contents, a deeper understanding is required to ensure accurate monitoring before they can be applied in clinical settings. Different research groups have established different approaches to elucidate the roles of exosomes and visualize their spatial properties. This review covers current and emerging strategies for in vivo and in vitro exosome imaging and tracking for potential studies.

A computational study of potential therapeutics for COVID-19 invoking conceptual density functional theory.

The pandemic, COVID-19, has caused social and economic disruption at a larger pace all over the world. Identification of an effective drug for the deadliest disease is still an exigency. One of the most promising approaches to combat the lethal disease is use of repurposed drugs. This study provides insights into some of the potential repurposed drugs viz. camostat mesylate, hydroxychloroquine, nitazoxanide, and oseltamivir in terms of the computational quantum chemical method. Properties of these compounds have been elucidated in terms of Conceptual Density Functional Theory (CDFT)-based descriptors, IR spectra, and thermochemical properties. Computed results specify that hydroxychloroquine is the most reactive drug among them. Thermochemical data reveals that camostat mesylate has the utmost heat capacity, entropy, and thermal energy. Our findings indicate that camostat mesylate and hydroxychloroquine may be investigated further as potential COVID-19 therapeutics. We anticipate that the current study will aid the scientific community to design and develop viable therapeutics against COVID-19.

mRNA modifications in cardiovascular biology and disease: with a focus on m6A modification.

Among several known RNA modifications, N6-methyladenosine (m6A) is the most studied RNA epitranscriptomic modification and controls multiple cellular functions during development, differentiation, and disease. Current research advancements have made it possible to examine the regulatory mechanisms associated with RNA methylation and reveal its functional consequences in the pathobiology of many diseases, including heart failure. m6A methylation has been described both on coding (mRNA) and non-coding RNA species including rRNA, tRNA, small nuclear RNA and circular RNAs. The protein components which catalyze the m6A methylation are termed methyltransferase or 'm6A writers'. The family of proteins that recognize this methylation are termed 'm6A readers' and finally the enzymes involved in the removal of a methyl group from RNA are known as demethylases or 'm6A erasers'. At the cellular level, different components of methylation machinery are tightly regulated by many factors to maintain the m6A methylation dynamics. The m6A methylation process impacts different stages of mRNA metabolism and the biogenesis of long non-coding RNA and miRNA. Although, mRNA methylation was initially described in the 1970s, its regulatory roles in various diseases, including cardiovascular diseases are broadly unexplored. Recent investigations suggest the important role of m6A mRNA methylation in both hypertrophic and ischaemic heart diseases. In the present review, we evaluate the significance of m6A methylation in the cardiovascular system, in cardiac homeostasis and disease, all of which may help to improve therapeutic intervention for the treatment of heart failure. RNA methylation in cardiovascular diseases: altered m6A RNA (coding and non-coding RNA) methylation is identified during different cardiovascular diseases. Increased cardiac hypertrophy is observed following METTL3 overexpression. In contrast, reduced FTO level was seen in mice following myocardial infarction. Increased cardiac fibroblasts activation or increased atherosclerotic plaques were also co-related with m6A RNA methylation.

Photoredox-catalyzed multicomponent Petasis reaction in batch and continuous flow with alkyl boronic acids.

Multicomponent reactions (MCRs) are ideal platforms for the generation of a wide variety of organic scaffolds in a convergent and atom-economical manner. Many strategies for the generation of highly substituted and diverse structures have been developed and among these, the Petasis reaction represents a viable reaction manifold for the synthesis of substituted amines via coupling of an amine, an aldehyde and a boronic acid (BA). Despite its synthetic utility, the inherent drawbacks associated with the traditional two-electron Petasis reaction have stimulated continuous research towards more facile and tolerant methodologies. In this regard, we present the use of free alkyl BAs as effective radical precursors in this MCR through a single-electron transfer mechanism under mild reaction conditions. We have further demonstrated its applicability to photo-flow reactors, facilitating the reaction scale-up for the rapid assembly of complex molecular structures.

Management of inflammation in cardiovascular diseases.

Cardiovascular disease is the leading cause of morbidity and mortality world-wide. Recently, the role of inflammation in the progression of diseases has significantly attracted considerable attention. In addition, various comorbidities, including diabetes, obesity, etc. exacerbate inflammation in the cardiovascular system, which ultimately leads to heart failure. Furthermore, cytokines released from specialized immune cells are key mediators of cardiac inflammation. Here, in this review article, we focused on the role of selected immune cells and cytokines (both pro-inflammatory and anti-inflammatory) in the regulation of cardiac inflammation and ultimately in cardiovascular diseases. While IL-1ß, IL-6, TNFα, and IFNγ are associated with cardiac inflammation; IL-10, TGFß, etc. are associated with resolution of inflammation and cardiac repair. IL-10 reduces cardiovascular inflammation and protects the cardiovascular system via interaction with SMAD2, p53, HuR, miR-375 and miR-21 pathway. In addition, we also highlighted recent advancements in the management of cardiac inflammation, including clinical trials of anti-inflammatory molecules to alleviate cardiovascular diseases.

Myofibroblast-Derived Exosome Induce Cardiac Endothelial Cell Dysfunction.

Background: Endothelial cells (ECs) play a critical role in the maintenance of vascular homeostasis and in heart function. It was shown that activated fibroblast-derived exosomes impair cardiomyocyte function in hypertrophic heart, but their effect on ECs is not yet clear. Thus, we hypothesized that activated cardiac fibroblast-derived exosomes (FB-Exo) mediate EC dysfunction, and therefore modulation of FB-exosomal contents may improve endothelial function. Methods and Results: Exosomes were isolated from cardiac fibroblast (FB)-conditioned media and characterized by nanoparticle tracking analysis and electron microscopy. ECs were isolated from mouse heart. ECs were treated with exosomes isolated from FB-conditioned media, following FB culture with TGF-ß1 (TGF-ß1-FB-Exo) or PBS (control) treatment. TGF-ß1 significantly activated fibroblasts as shown by increase in collagen type1 α1 (COL1α1), periostin (POSTN), and fibronectin (FN1) gene expression and increase in Smad2/3 and p38 phosphorylation. Impaired endothelial cell function (as characterized by a decrease in tube formation and cell migration along with reduced VEGF-A, Hif1α, CD31, and angiopoietin1 gene expression) was observed in TGF-ß1-FB-Exo treated cells. Furthermore, TGF-ß1-FB-Exo treated ECs showed reduced cell proliferation and increased apoptosis as compared to control cells. TGF-ß1-FB-Exo cargo analysis revealed an alteration in fibrosis-associated miRNAs, including a significant increase in miR-200a-3p level. Interestingly, miR-200a-3p inhibition in activated FBs, alleviated TGF-ß1-FB-Exo-mediated endothelial dysfunction. Conclusions: Taken together, this study demonstrates an important role of miR-200a-3p enriched within activated fibroblast-derived exosomes on endothelial cell biology and function.

Preparation of Cu cluster catalysts by simultaneous cooling-microwave heating: application in radical cascade annulation.

One of the hallmarks of microwave irradiation is its selective heating mechanism. In the past 30 years, alternative designs of chemical reactors have been introduced, where the microwave (MW) absorber occupies a limited reactor volume but the surrounding environment is MW transparent. This advantage results in a different heating profile or even the possibility to quickly cool down the system. Simultaneous cooling-microwave heating has been largely adopted for organic chemical transformations. However, to the best of our knowledge there are no reports of its application in the field of nanocluster synthesis. In this work, we propose an innovative one-pot procedure for the synthesis of Cu nanoclusters. The cluster nucleation was selectively MW-activated inside the pores of a highly ordered mesoporous substrate. Once the nucleation event occurred, the crystallization reaction was instantaneously quenched, precluding the growth events and favoring the production of Cu clusters with a homogenous size distribution. Herein, we demonstrated that Cu nanoclusters could be successfully adopted for radical cascade annulations of N-alkoxybenzamides, resulting in various tricyclic and tetracyclic isoquinolones, which are widely present in lots of natural products and bioactive compounds. Compared to reported homogeneous methods, supported Cu nanoclusters provide a better platform for a green, sustainable and efficient heterogeneous approach for the synthesis of tricyclic and tetracyclic isoquinolones, avoiding a variety of toxic waste/byproducts and metal contamination in the final products.

Polarizability: a promising descriptor to study chemical-biological interactions.

Recently, we have defined atomic polarizability, a Conceptual Density Functional Theory (CDFT)-based reactivity descriptor, through an empirical method. Though the method is empirical, it is competent enough to meet the criteria of periodic descriptors and exhibit relativistic effect. Since the atomic data are very accurate, we have applied them to determine molecular polarizability. Molecular polarizability is an electronic parameter and has an impact on chemical-biological interactions. Thus, it plays a pivotal role in explaining such interactions through Structure Activity Relationships (SAR). In the present work, we have explored the application of polarizability in the real field through investigation of chemical-biological interactions in terms of molecular polarizability. A Quantitative Structure-Activity Relationship (QSAR) model is constructed to account for electronic effects owing to polarizability in ligand-substrate interactions. The study involves the prediction of various biological activities in terms of minimum block concentration, relative biological response, inhibitory growth concentration or binding affinity. Superior results are presented for the predicted and observed activities which support the accuracy of the proposed polarizability-QSAR model. Further, the results are considered from a biological viewpoint in order to understand the mechanism of interactions. The study is performed to explore the efficacy of the computational model based on newly proposed polarizability and not to establish the finest QSAR. For future studies, it is suggested that the descriptor polarizability should be contrasted with the use of other drug-like descriptors.

ALKBH5 Regulates SPHK1-Dependent Endothelial Cell Angiogenesis Following Ischemic Stress.

BACKGROUND: Endothelial cells dysfunction has been reported in many heart diseases including acute myocardial infarction, and atherosclerosis. The molecular mechanism for endothelial dysfunction in the heart is still not clearly understood. We aimed to study the role of m6A RNA demethylase alkB homolog 5 (ALKBH5) in ECs angiogenesis during ischemic injury. METHODS AND RESULTS: ECs were treated with ischemic insults (lipopolysaccharide and 1% hypoxia) to determine the role of ALKBH5 in ECs angiogenesis. siRNA mediated ALKBH5 gene silencing was used for examining the loss of function. In this study, we report that ALKBH5 levels are upregulated following ischemia and are associated with maintaining ischemia-induced ECs angiogenesis. To decipher the mechanism of action, we found that ALKBH5 is required to maintain eNOS phosphorylation and SPHK1 protein levels. ALKBH5 silencing alone or with ischemic stress significantly increased SPHK1 m6A mRNA methylation. In contrast, METTL3 (RNA methyltransferase) overexpression resulted in the reduced expression of SPHK1. CONCLUSION: We reported that ALKBH5 helps in the maintenance of angiogenesis in endothelial cells following acute ischemic stress via reduced SPHK1 m6A methylation and downstream eNOS-AKT signaling.

Prevalence and Genetic Characterization of Cryptosporidium and Microsporidia Infecting Hematological Malignancy Patients.

PURPOSE: To evaluate the prevalence of Cryptosporidium and Microsporidia, associated risk factors and species identification in patients with haematological malignancies (HM). METHODS: A total of 148 consecutive patients with HM and 101 healthy subjects were evaluated for Cryptosporidium and Microsporidia using modified Kinyoun and modified Trichrome staining. Clinical, demographic and laboratory parameters were studied. The species of Cryptosporidium and Microsporidia were studied using PCR-RFLP. RESULTS: Of 148 HM patients initially screened, 47 were excluded from the final analysis due to inadequate clinical records. Patients with HM [n = 101, 63 (62.4%) male] more often had Cryptosporidium than healthy subjects [n = 101, 65 (74.4%) male] [3/101 (3%) vs. 0/101 (0%), p = 0.02]. Two of 101 (2%) HM patients and none of the healthy subjects had Microsporidia (p = 0.155). Diarrhea was more prevalent in HM patients with Cryptosporidium than those without [3, 100% vs. 39/96, 40.62%; p = 0.04). Both patients infected with Microsporidia presented with persistent diarrhea and fever. Cryptosporidium hominis was identified in all the three HM patients. Enterocytozoon bieneusi was identified in one HM patient infected with Microsporidia, which was classified as genotype Ind2. CONCLUSION: Cryptosporidium and Microsporidia may infect HM patients leading to overwhelming diarrhea. The commonest species of Cryptosporidium and Microsporidia found to infect HM patients are C. hominis and E. bieneusi.

Sequential and direct multicomponent reaction (MCR)-based dearomatization strategies.

Dearomatization strategies in a multicomponent fashion often result in complex heterocyclic frameworks, which have attracted the attention of chemists due to their natural product-like structures. The combination of these two processes can easily achieve extended molecular complexity and diversity from simple starting materials with high atom economy. Thus, this field has attracted extensive interest owing to its potential significance in both asymmetric catalysis and convenient build-up of libraries of molecules with novel three-dimensional scaffolds, which may find application in medicinal chemistry. Accordingly, a systematic review on this topic will provide the synthetic organic community with a conceptual overview and comprehensive understanding of the different multicomponent reaction (MCR) cascades involving dearomatization as the characteristic step. In addition, this review will help researchers to look at this promising area from a different perspective with respect to drug discovery, new MCR-based disconnections and often hidden opportunities.

Recent Developments in Transition-Metal Catalyzed Direct C-H Alkenylation, Alkylation, and Alkynylation of Azoles.

The transition metal-catalyzed C-H bond functionalization of azoles has emerged as one of the most important strategies to decorate these biologically important scaffolds. Despite significant progress in the C-H functionalization of various heteroarenes, the regioselective alkylation and alkenylation of azoles are still arduous transformations in many cases. This review covers recent advances in the direct C-H alkenylation, alkylation and alkynylation of azoles utilizing transition metal-catalysis. Moreover, the limitations of different strategies, chemoselectivity and regioselectivity issues will be discussed in this review.

Ligand-Enabled Palladium-Catalyzed Through-Space C-H Bond Activation via a Carbopalladation/1,4-Pd Migration/C-H Functionalization Sequence.

We report, herein, a palladium-catalyzed cascade comprising carbopalladation, 1,4-Pd-migration and C(sp2 )-C(sp2 ) bond formation to construct a variety of bis-heterocyclic frameworks in a single operational step. The methodology provides a direct approach to introduce an oxadiazole core at a remote location without any functional group obligation, with moderate to good yields.

Energy saving and Fuzzy-PID position control of electro-hydraulic system by leakage compensation through proportional flow control valve.

In this article, the focus is on the energy efficiency along with the position control of the linear actuator used in heavy earth moving equipment. It is quite evident that linear actuators are one of the critical machinery components used in the construction and mining activities like in booms of excavation equipment. The proposed work employed two different hydraulic circuits and a contrast has been carried out in terms of the energy efficiency. In one hydraulic circuit, the conventional proportional directional control valve (PDCV) is used for the position control. In another one, an innovative solution of using proportional flow control valve (PFCV) by creating artificial leakage between the two ends of the actuator is evaluated according to its energy efficiency. The extra flow coming from the pump during position control is by-passed by PFCV rather than the pressure relief valve in PDCV. This reduces the energy loss in the form of heat and increases the efficiency of the hydraulic circuit. The simulation of the hydraulic circuit is performed using MATLAB/Simulink and results are compared with the experiments and it is found that hydraulic circuit using PFCV is 8.5% more energy efficient than the conventional circuit using PDCV. The position control of the actuator is done using PID controller tuned by the fuzzy controller.

A novel approach for the energy recovery and position control of a hybrid hydraulic excavator.

The heavy earth moving machineries (HEMM) like hydraulic excavator play a major role in construction and mining industries. In this context, the energy saving strategies in hydraulic excavator needs to be addressed considering its vital importance. Since the hydraulic excavators are subjected to heavy loads, hence the opportunity to harness the potential gravitational energy (GPE) remains a key area which can be effectively explored in order to minimize the energy consumption in consideration with hydraulic excavator. In the projected system, the potential energy is stored as pressure energy in hydro-pneumatic accumulator. The upward movement of the boom is executed with the help of prime mover during the starting of the first duty cycle. In the latter duty cycles, the stored pressurized energy is utilized together with the prime mover energy capable to execute the upward movement of the boom. The position of the boom cylinder is controlled by using the conventional PID controller using proportional flow control valve (PFCV) and accumulator. The error between the actual position and demand position of the linear actuator is minimized along with attainment of superior controlled performance while utilizing Model Predictive Controller (MPC). The pressurized accumulator with PFCV has been utilized to cater the different position demands. This has been also justified both experimentally and analytically with the error in the permissible range of 2%. It has been observed that the proposed system is 10% more efficient in contrast to the conventional system.