Malignant mesothelioma tumours: molecular pathogenesis, diagnosis, and therapies accompanying clinical studies.

The pathetic malignant mesothelioma (MM) is a extremely uncommon and confrontational tumor that evolves in the mesothelium layer of the pleural cavities (inner lining- visceral pleura and outer lining- parietal pleura), peritoneum, pericardium, and tunica vaginalis and is highly resistant to standard treatments. In mesothelioma, the predominant pattern of lesions is a loss of genes that limit tumour growth. Despite the worldwide ban on the manufacture and supply of asbestos, the prevalence of mesothelioma continues to increase. Mesothelioma presents and behaves in a variety of ways, making diagnosis challenging. Most treatments available today for MM are ineffective, and the median life expectancy is between 10 and 12 months. However, in recent years, considerable progress has already been made in understanding the genetics and molecular pathophysiology of mesothelioma by addressing hippo signaling pathway. The development and progression of MM are related to many important genetic alterations. This is related to NF2 and/or LATS2 mutations that activate the transcriptional coactivator YAP. The X-rays, CT scans, MRIs, and PET scans are used to diagnose the MM. The MM are treated with surgery, chemotherapy, first-line combination chemotherapy, second-line treatment, radiation therapy, adoptive T-cell treatment, targeted therapy, and cancer vaccines. Recent clinical trials investigating the function of surgery have led to the development of innovative approaches to the treatment of associated pleural effusions as well as the introduction of targeted medications. An interdisciplinary collaborative approach is needed for the effective care of persons who have mesothelioma because of the rising intricacy of mesothelioma treatment. This article highlights the key findings in the molecular pathogenesis of mesothelioma, diagnosis with special emphasis on the management of mesothelioma.

Microscopic and physicochemical evaluation of Ruta angustifolia leaves.

Background: There are thousands of species of known medicinal plants in the world. Ruta angustifolia L. has been widely used in traditional medication for jaundice and liver disease. Previous studies have shown that R. angustifolia leaves can inhibit the hepatitis C virus in Huhit culture cells, reduce the value of NS3 protein, and possess a synergistic effect in combination with antiviral drugs. Therefore, this plant is potential to be developed as a drug candidate. Characteristics of plants including microscopic, physicochemical properties, and phytochemical profiles are necessary information to ensure the quality of raw material in drug development. Objective: This study was carried out to examine the microscopic and physicochemical including the standardized parameter of R. angustifolia leaves to fulfil the quality raw materials as traditional medicine. Methods: Simplicia of R. angustifolia leaves obtained from Jombang, East Java, were observed under a microscope and determined its physicochemical properties referred to the Materia Medica Indonesia V. The TLC and HPLC profiles of extract were determined as well. Results: Microscopic analysis were conducted by transfection sections and the presence of epidermis cells, palisade, mesophyll with stomata, and Ca-oxalate crystal were found. The standard parameter obtained value of loss of drying, extractive value in water and ethanol, and ash value. The TLC and HPLC profiles of leaves extract demonstrated to contain with flavonoid, terpenoids, and alkaloids. Conclusion: Ruta angustifolia obtained from Jombang, east Java, has a specific character in microscopic analysis. The physicochemical properties analysis of R. angustifolia leaves as a raw material met the requirements according to Materia Medica Indonesia V.

Chemical Profiles and In Vitro Cholinesterase Inhibitory Activities of the Flower Extracts of Cassia spectabilis.

Background: Cassia spectabilis is a flowering plant containing various metabolites that provide potential for pharmacological activities. The current study aimed to investigate the ethanolic and water extracts of C. spectabilis as cholinesterase inhibitor as one of the target treatments for Alzheimer's disease. The chemical composition of the extracts was also studied to determine which components are responsible for the bioactivity. Methods: The cholinesterase inhibitory activity assay was carried out by the modified Ellman's method against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). LC-MS/MS analysis was carried out to investigate the chemical profiles of the extracts, followed by a molecular networking study by GNPS. Results: Both extracts showed inhibition against AChE and BChE in a dose-dependent manner, with the higher potency exhibited by the ethanolic extract with IC50 values of 7.88 and 3.78 µg/mL. The chemical analysis and molecular networking study of the flower extracts revealed similarity between the ethanolic and water extracts. Piperidine alkaloids were identified in both extracts, while the sphingolipid compounds were found in the ethanolic extract. Conclusion: The water and ethanolic extracts of C. spectabilis flowers displayed potency for Alzheimer's disease treatment. The presence of piperidine alkaloids in the extract may be responsible for the cholinesterase inhibitory activity. The higher potency of the ethanolic extract compared to the water extract is possibly due to the higher amount of piperidine alkaloids in the ethanolic extract. Further study is needed to quantify the concentration of alkaloids in the extracts.

In vitro and in vivo antiplasmodial activities of leaf extracts from Sonchus arvensis L.

BACKGROUND: Malaria continues to be a global problem due to the limited efficacy of current drugs and the natural products are a potential source for discovering new antimalarial agents. Therefore, the aims of this study were to investigate phytochemical properties, cytotoxic effect, antioxidant, and antiplasmodial activities of Sonchus arvensis L. leaf extracts both in vitro and in vivo. METHODS: The extracts from S. arvensis L. leaf were prepared by successive maceration with n-hexane, ethyl acetate, and ethanol, and then subjected to quantitative phytochemical analysis using standard methods. The antimalarial activities of crude extracts were tested in vitro against Plasmodium falciparum 3D7 strain while the Peter's 4-day suppressive test model with P. berghei-infected mice was used to evaluate the in vivo antiplasmodial, hepatoprotective, nephroprotective, and immunomodulatory activities. The cytotoxic tests were also carried out using human hepatic cell lines in [3(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay. RESULT: The n-hexane, ethyl acetate, and ethanolic extracts of S. arvensis L. leaf exhibited good in vitro antiplasmodial activity with IC50 values 5.119 ± 3.27, 2.916 ± 2.34, and 8.026 ± 1.23 µg/mL, respectively. Each of the extracts also exhibited high antioxidant with low cytotoxic effects. Furthermore, the ethyl acetate extract showed in vivo antiplasmodial activity with ED50 = 46.31 ± 9.36 mg/kg body weight, as well as hepatoprotective, nephroprotective, and immunomodulatory activities in mice infected with P. berghei. CONCLUSION: This study highlights the antiplasmodial activities of S. arvensis L. leaf ethyl acetate extract against P. falciparum and P. berghei as well as the antioxidant, nephroprotective, hepatoprotective, and immunomodulatory activities with low toxicity. These results indicate the potential of Sonchus arvensis L. to be developed into a new antimalarial drug candidate. However, the compounds and transmission-blocking strategies for malaria control of S. arvensis L. extracts are essential for further study.

Antimalarial Activity of Extract and Fractions of Sauropus androgynus (L.) Merr.

Sauropus androgynus (L.) Merr., in the Indonesian local name known as "Katuk," is a tropical shrub plant of the family Euphorbiaceae. Based on genus and chemotaxonomic approaches, as well as in vitro testing of Plasmodium falciparum, leaves of S. androgynus are presumed to have an active compound content as an antimalarial. The current study aims to investigate the antimalarial activity of 96% ethanol extract and fractions of S. androgynus leaves. The ethanolic extract was fractionated using the vacuum liquid chromatography (VLC) method with three solvents of different polarities (n-hexane, chloroform, and 96% ethanol). The fraction obtained was then evaluated for antimalarial activity against P. falciparum 3D7 strain. The ethanolic extract was evaluated for antimalarial suppressive and prophylactic activity against P. berghei-infected mice, as well as inhibitory activity against the heme detoxification process in vitro. Fractionation of ethanolic extract resulted in seven combined fractions, with the most active fraction being FV (50% inhibitory concentration (IC50) = 2.042 µg/mL). The ethanolic extract showed good parasitic suppressive (therapeutic) activity with a median effective dose (ED50) value of 15.35 mg/kg body weight. In a prophylactic test, ethanolic extract showed parasite growth inhibitory activity of 67.74 ± 9.21% after the administration of 400 mg/kg body weight for 4 days before infection, and 65.30 ± 10.44% after the administration of 200 mg/kg body weight for 8 consecutive days (4 days before and after infection). The ethanolic extract also showed an effect in inhibiting the formation of ß-hematin of about 26.87-79.36% at a concentration of 0.1-4 mg/mL and an IC50 value of 0.479 mg/mL. The S. androgynus leaves were shown to have antimalarial activity in vitro and in vivo, where ethanolic extract were more active compared with the fraction obtained. The antimalarial properties of the extract showed a higher suppressive activity than prophylactic activity.

Advances in Hybrid Vesicular-based Drug Delivery Systems: Improved Biocompatibility, Targeting, Therapeutic Efficacy and Pharmacokinetics of Anticancer Drugs.

Anticancer drugs and diagnostics can be transported in nanoscale vesicles that provide a flexible platform. A hybrid nanoparticle, a nano assembly made up of many types of nanostructures, has the greatest potential to perform these two activities simultaneously. Nanomedicine has shown the promise of vesicular carriers based on lipopolymersomes, lipid peptides, and metallic hybrid nano-vesicle systems. However, there are significant limitations that hinder the clinical implementation of these systems at the commercial scale, such as low productivity, high energy consumption, expensive setup, long process durations, and the current cancer therapies described in this article. Combinatorial hybrid systems can be used to reduce the above limitations. A greater therapeutic index and improved clinical results are possible with hybrid nanovesicular systems, which integrate the benefits of many carriers into a single structure. Due to their unique properties, cell-based drug delivery systems have shown tremendous benefits in the treatment of cancer. Nanoparticles (NPs) can benefit significantly from the properties of erythrocytes and platelets, which are part of the circulatory cells and circulate for a long time. Due to their unique physicochemical properties, nanomaterials play an essential role in cell-based drug delivery. Combining the advantages of different nanomaterials and cell types gives the resulting delivery systems a wide range of desirable properties. NPs are nextgeneration core-shell nanostructures that combine a lipid shell with a polymer core. The fabrication of lipid-polymer hybrid NPs has recently undergone a fundamental shift, moving from a two-step to a one-step technique based on the joint self-assembly of polymers and lipids. Oncologists are particularly interested in this method as a combinatorial drug delivery platform because of its two-in-one structure. This article addresses various preparative methods for the preparation of hybrid nano-vesicular systems. It also discusses the cellular mechanism of hybrid nano-vesicular systems and describes the thorough knowledge of various hybrid vesicular systems.

Toxicological Evaluation and Protective Effects of Ethanolic Leaf Extract of Cassia spectabilis DC on Liver and Kidney Function of Plasmodium berghei-Infected Mice.

Currently, the presence of antimalarial drug resistance has become a major obstacle in the treatment of malaria. To overcome the problem, a series of studies are needed to find new antimalarial drugs from plants. Previously, 90% ethanolic extract of Cassia spectabilis DC (EECS) leaves have been reported to have antimalarial activity in vitro against Plasmodium falciparum and in vivo against Plasmodium berghei ANKA. The research is conducted to find out the toxicity and protective effects of EECS on the liver and kidneys of mice infected with P. berghei ANKA. The acute and subacute toxicity tests were carried out on healthy mice that were given EECS at a dose of 150 mg/kg BW. An antimalarial activity test was carried out at doses of 150 and 200 mg/kg BW in P. berghei-infected mice. Regarding hepatomegaly, further plasma levels of hepatic enzyme were analyzed, as well as histopathological observation of the liver to determine the effect of the extract on liver. The kidney was observed histopathologically as well. The acute toxicity test of EECS showed that there was no mouse died at the highest dose, indicating safe for the mice. The subacute toxicity based on the histology data showed no significant difference in the liver and kidney of mice between the tested group and the healthy group. The histological and enzymatic effect of EECS in mice infected with P. berghei showed the histological and enzymatic effect that improved liver function and the histopathological effect on kidneys with the highest activity at a dose of 200 mg/kg BW compared with the negative control. The results showed the EECS was not toxic in mice and repaired the liver and kidney functions of P. berghei ANKA-infected mice, indicating a good candidate for antimalarial drug development.

Growth, secondary metabolite production, and in vitro antiplasmodial activity of Sonchus arvensis L. callus under dolomite [CaMg(CO3)2] treatment.

Malaria is still a global health problem. Plasmodium is a single-cell protozoan parasite that causes malaria and is transmitted to humans through the female Anopheles mosquito. The previous study showed that Sonchus arvensis L. callus has antiplasmodial activity. Several treatments are needed for callus quality improvement for antimalarial compound production. This study aimed to examine the effect of dolomite [CaMg(CO3)2] on growth (morpho-anatomical structure and biomass), secondary metabolite production, and in vitro antiplasmodial activity of S. arvensis L. callus. In this study, leaf explants were grown in Murashige and Skoog medium with a combination of 2,4-dichlorophenoxyacetic acid (2,4-D, one mg/L) and 6-benzyl amino purine (BAP, 0.5 mg/L) with dolomite (50, 75, 100, 150, and 200 mg/L). The 21 days callus ethanolic and methanolic extract were analyzed by gas chromatography-mass spectrometry (GC-MS) and thin-layer chromatography (TLC). The antiplasmodial test was performed on a blood culture infected with Plasmodium falciparum strain 3D7 using the Rieckmann method. The results showed that dolomite significantly affected callus growth, metabolite profile, and in vitro antiplasmodial activity. Dolomite (150 mg/L) showed the highest biomass (0.590 ± 0.136 g fresh weight and 0.074 ± 0.008 g dry weight). GC-MS analysis detected four compounds from callus ethanolic extract. Pelargonic acid, decanoic acid, and hexadecanoic acid were major compounds. One new terpenoid compound is based on TLC analysis. S. arvensis L. callus has antiplasmodial activity with the IC50 value of 5.037 µg/mL. It was three times lower than leaf methanolic extract and five times lower than leaf ethanolic extract.

Exploration of several plants from Baung Forest on bone formation cell models.

OBJECTIVES: Osteoporosis is an ailment described by a skeletal degradation of bone skeletal dominating to increases the chance of fracture. In order to find out the bone formation agents from Baung Forest plants, this research analyzed the effects of 96% ethanol extract of several plants from Baung Forest on antioxidant activity and the effect of osteoblast differentiation-related to the bone formation on the most potent extract. METHODS: The antioxidant effect and osteoblast differentiation of 96% ethanol extracts were evaluated by measuring DPPH scavenging and alkaline phosphatase in p-nitrophenyl phosphate effects by the enzyme-linked immunosorbent assay (ELISA) reader method, respectively. RESULTS: The 96% ethanol extract of Elaeocarpus serratus L. from Baung Forest had the strongest DPPH radical scavenging as anti oxidant (82.17%) and stimulated osteoblast differentiation (116%). Then, this extract had been fractionated based on polarity to become hexane, ethyl acetate, butanol, and aqueous fractions. All the fractions stimulated their alkaline phosphatase (ALP) activity to 138.11 ± 9.72%, 108 ± 5.05%, 148.56 ± 8.47, and 144.58 ± 1.04, respectively. CONCLUSIONS: The extract and fractions of E. serratus L. can successfully inhibit DPPH radical scavenging value and increase ALP activities as markers of osteoblast functions.

Antiplasmodial activity of Ethanolic extract of Cassia spectabilis DC leaf and its inhibition effect in Heme detoxification.

BACKGROUND: In previous studies, Cassia spectabilis DC leaf has shown a good antiplasmodial activity. Therefore, this study is a follow-up study of the extract of leaf of C. spectabilis DC on its in vitro and in vivo antiplasmodial activity and mechanism as an antimalarial. METHODS: The extract was fractionated, sub-fractionated and isolated to obtain the purified compound. In vitro antiplasmodial activity test against Plasmodium falciparum to find out the active compound. In vivo test against P. berghei ANKA-infected mice was conducted to determine prophylactic activity and antiplasmodial activity either alone or in combination with artesunate. The inhibition of heme detoxification test as one of the antimalarial mechanisms was carried out using the Basilico method. RESULTS: The results showed that active antimalarial compound isolated from C. spectabilis DC leaf had a structural pattern that was identical to (-)-7-hydroxycassine. Prophylactic test of 90% ethanolic extract of C. spectabilis DC leaf alone against P. berghei ANKA-infected mice obtained the highest percentage inhibition was 68.61%, while positive control (doxycycline 13 mg/kg) was 73.54%. In combination with artesunate, 150 mg/kg three times a day of C. spectabilis DC (D0-D2) + artesunate (D2) was better than the standard combination of amodiaquine + artesunate where the inhibition percentages were 99.18 and 92.88%, respectively. The IC50 of the extract for the inhibitory activity of heme detoxification was 0.375 mg/ml which was better than chloroquine diphosphate (0.682 mg/ml). CONCLUSION: C. spectabilis DC leaf possessed potent antiplasmodial activity and may offer a potential agent for effective and affordable antimalarial phytomedicine.

Determination of Cassiarin A Level of Cassia siamea Leaf Obtained from Various Regions in Indonesia Using the TLC-Densitometry Method.

Cassia siamea leaf has been proven in vitro and in vivo to have a strong antimalarial activity with Cassiarin A as its active compound. To obtain a source of C. siamea medicinal plant with high level of active antimalarial compound (Cassiarin A), a valid method for determining Cassiarin A level is needed. For this reason, this research conducts the validation of the Cassiarin A content with determination method using thin-layer chromatography (TLC) densitometry which includes the determination of selectivity (Rs), linearity (r), accuracy, precision, limit of detection (LOD), and limit of quantification (LOQ). Cassiarin A was chromatographed on silica gel 60 F254 TLC plate using chloroform : ethanol (85 : 15 v/v) as a mobile phase. Cassiarin A was quantified by densitometric analysis at 368 nm. The linear regression analysis data for the calibration plots showed good linear relationship with r = 0.9995. The method was validated for precision, recovery, repeatability. The minimum detectable amount was found to be 0.0027 µg/spot, whereas the limit of quantitation was found to be 0.008 µg/spot. The results of this validation are then used to determine the Cassiarin A level of C. siamea leaf from various regions in Indonesia. Based on the results of the study, it can be concluded that the TLC-densitometry method can be used to determine level of the Cassiarin A compound with the advantages of being fast, easy, accurate, and inexpensive. In addition, it showed that C. siamea leaves from Pacitan have the highest level of Cassiarin A compared to other areas studied.

CALLUS INDUCTION OF Sonchus arvensis L. AND ITS ANTIPLASMODIAL ACTIVITY.

BACKGROUND: Malaria is a global health problem that requires urgent need for new drugs. Tempuyung (Sonchus arvensis L.) possesses many potential medicinal compounds. As the plant is originally found wild, it is important to reproduce its secondary metabolites by tissue culture. The objectives of this study were to look for effective methods to induce callus from leaf explants of Sonchus arvensis L. and to test its in vitro antiplasmodial activity. MATERIALS AND METHODS: The leaves and petioles of the plant were cultured on Murashige and Skoog (MS) solid medium supplemented with indole acetic-3-acid (IAA), indole-3-butyric acid (IBA), naphthalene acetic acid (NAA), 2,4-dichlorophenoxyacetic acid (2,4-D) and benzyl amino purine (BAP), in light and dark incubations. The best results obtained from callus induction were then treated by with several concentrations of sucrose (1- 5%). The best results from callus induction were then extracted with methanol for antiplasmodial test by Trager and Jensen's method. It was also tested against 3D7 strain of Plasmodium falciparum. RESULTS: The combination of 1mg/L 2,4-D and 0.5 mg/L BAP in dark incubation was the best treatment for callus induction of tempuyung. It produced the best quality of callus and the shortest period for callusing. Sucrose treatment had various effects on leaves callusing, but had no effect on petioles callusing, whereby 4% sucrose was the best treatment for leaves callusing in dark incubation. The methanol extract of the best callus had anti-plasmodial activity with IC50=0.343 µg/mL. CONCLUSION: Methanol extract of tempuyung callus shows potential as an antimalarial drug but more studies would be required.

IN VITRO ANTIMALARIAL ACTIVITY AND TOXICITY STUDIES OF JOHAR (CASSIA SIAMEA) LEAVES FROM THREE DIFFERENT LOCATIONS.

BACKGROUND: Antimalarial activity of Cassia siamea leaves has been proven by the active compound that has been found, i.e. Cassiarin A. It is known that the quantity of the content of a compound that has the potential as a raw material for medicine can be influenced by various factors including differences in plant origin. This study aims at comparing the antimalarial activity and toxicity of C.siamea leaves from three regions with different meters location values above sea level (asl), i.e Pariaman (1,000 m asl), Palu (60 m asl), and Surabaya (2 m asl). MATERIALS AND METHODS: The materials used in this study were Johar leaves from Pariaman, Surabaya, and Palu extracted with n-hexane, and 90% ethanol containing 1% tartaric acid. The antimalarial activity test was done with Plasmodium falciparum 3D7. The toxicity test applied MTT ELISA method. RESULTS: C.siamea leaf that had highest antimalarial activity came from Pariaman with IC50 value of 0.006µg/ml, then from Palu was 0.037µg/ml, and the lowest antimalarial activity was from Surabaya that was 0.09µg/ml . In testing the toxicity to get CC50, the highest toxicity came from Surabaya with CC50 value of 135.81µg/ml, Pariaman with CC50 value of 220.82 µg/ml, and the least toxic came from Palu with CC50 value of 235.52µg/ml . CONCLUSION: C.siamea leaf obtained from Pariaman had a selectivity index value that satisfies the requirements of a promising antimalarial effect.

Various Parts of Helianthus annuus Plants as New Sources of Antimalarial Drugs.

BACKGROUND: Each part of H. annuus plants is traditionally used as medicinal remedies for several diseases, including malaria. Antimalarial activity of the leaf and the seed has already been observed; however, there is no report about antimalarial activity of the other parts of H. annuus plants. In this study, we assess in vitro and in vivo antimalarial activity of each part of the plants and its mechanism as antimalarial agent against inhibition of heme detoxification. OBJECTIVE: To investigate the antimalarial activity of various parts of H. annuus. METHODS: Various parts of the H. annuus plant were tested for in vitro antimalarial activity against Plasmodium falciparum 3D7 strain (chloroquine-sensitive), in vivo antimalarial activity against P. berghei using Peters' 4-day suppressive test in BALB/c mice, curative and prophylaxis assay, and inhibition of heme detoxification by evaluating ß-hematin level. RESULTS: Ethanol extract of the roots showed the highest antimalarial activity, followed by ethanol extract of leaves, with IC50 values of 2.3 ± 1.4 and 4.3 ± 2.2 µg/mL, respectively and the percentage inhibition of P. berghei of 63.6 ± 8.0 and 59.3 ± 13.2 at a dose of 100 mg/kg, respectively. Ethanol extract of roots produced an ED50 value of 10.6 ± 0.2 mg/kg in the curative test and showed an inhibition of 79.2% at a dose of 400 mg/kg in the prophylactic assay. In inhibition of heme detoxification assay, root and leaf ethanol extracts yielded a lower IC50 value than positive (chloroquine) control with a value of 0.4 ± 0.0 and 0.5 ± 0.0 mg/mL, respectively. CONCLUSION: There were promising results of the ethanol extracts of root of H. annuus as a new source for the development of a new plant-based antimalarial agent.

DETERMINATION OF EFFECTIVE DOSE OF ANTIMALARIAL FROM CASSIA SPECTABILIS LEAF ETHANOL EXTRACT IN PLASMODIUM BERGHEI-INFECTED MICE.

BACKGROUND: The preliminary study on antimalarial activity of the ethanol extract of Cassia spectabilis leaves against Plasmodium berghei has been carried out by in vivo experiment. It was demonstrated that ethanol extract of C. spectabilis leaves could inhibit growth of rodent malaria parasite P. berghei by 59.29 % (at a dose of 100 mg/kg bodyweight). However, further investigation is required to determine an effective dose of the administered extract for a higher inhibitory effect and increasing effectiveness of the extract. MATERIAL AND METHODS: To determine the effective dose of ethanol extract of C. spectabilis leaves, a "4-day suppressive test" of Peter was performed with some modifications. The extract was administered orally to P. berghei-infected mice in multiple doses (twice and thrice daily) and single dose (once daily) with dose ranging from 50 - 250 mg/kg body weight. Antimalarial activities were determined by analyzing suppression of parasitaemia of treated mice. RESULTS: The results showed that oral administration of the ethanol extract of C. spectabilis leaves at dose of 150mg/kg bodyweight thrice daily possessed higher inhibition (62.42%) compared to those twice daily (52.58%) and once daily (46.25%). CONCLUSION: These results suggested that ethanol extract of C. spectabilis is promising candidate for development of antimalarial drugs. The effective dose of the ethanol extract is 150 mg/kg bodyweight with thrice administration daily.

New tricyclic alkaloids, cassiarins G, H, J, and K from leaves of Cassia siamea.

Four new alkaloids, cassiarins G, H, J, and K (1-4) which showed moderate antiplasmodial activity against Plasmodium falciparum 3D7, were isolated from the leaves of Cassia siamea (Leguminosae) and the structures of 1-4 were elucidated by 1D- and 2D-NMR analysis and X-ray crystallographic analysis.

Antiplasmodial decarboxyportentol acetate and 3,4-dehydrotheaspirone from Laumoniera bruceadelpha.

A new spiro heterocycle, decarboxyportentol acetate (1) was isolated from the barks of Laumoniera bruceadelpha Nooteboom (Simaroubaceae), together with 3,4-dehydrotheaspirone (2), and their structures were elucidated by 2D NMR analysis. 3,4-Dehydrotheaspirone (2) showed potent antiplasmodial activity against Plasmodium falciparum 3D7.

Antiplasmodial indole alkaloids from Leuconotis griffithii.

A new indole alkaloid, leucoridine A N-oxide (1), consisting of two units of a strychnan type of skeleton, was isolated from the leaves of Leuconotis griffithii. Its structure was elucidated by various spectroscopic means such as NMR and MS, and also by chemical means. Antiplasmodial activity against Plasmodium falciparum 3D7 of indole alkaloids isolated from L. griffithii was investigated.

Total synthesis of a novel tetracyclic alkaloid, cassiarin F from the flowers of Cassia siamea.

A novel alkaloid, cassiarin F (1), which showed potent antiplasmodial activity against Plasmodium falciparum in vitro, was isolated from the flowers of Cassia siamea, and its structure was elucidated on the basis of 2D NMR analyses. A total synthesis of 1 was also achieved by employing the Suzuki coupling constructing biaryl unit, nucleophilic aromatic substitution, and Houben-Hoesch type ring construction as key steps.

New antiplasmodial indole alkaloids from Hunteria zeylanica.

Two new indole alkaloids, bisnicalaterine D (1), consisting of an eburnane and a corynanthe type of skeletons, and nicalaterine A (2) were isolated from the bark of Hunteria zeylanica. Their structures were elucidated by various spectroscopic data such as NMR and CD spectra. A series of bisnicalaterines and nicalaterine A showed potent antiplasmodial activity against Plasmodium falciparum 3D7.