Investigation of Indian Diospyros Species for Antiplasmodial Properties

Despite decades of intense research, malaria remains a deadly disease worldwide and new antimalarials are urgently needed due to increasing drug resistance of Plasmodium falciparum to existing drugs. This article reports the evaluation of four Indian Diospyros species viz., Diospyros melanoxylon, D. peregrina, D. sylvatica, D. tomentosa for antiplasmodial activities against chloroquine-sensitive (3D7) and chloroquine-resistant (K1) strains of P. falciparum. Six of eight methanolic extracts were found to have significant activity, (IC50 = 16.5–92.9 µg ml−1), against strain 3D7 and five of these showed similar activities against strain K1 (IC50 = 20.5–121.6 µg ml−1). Diospyros sylvatica was found to be the most active species (IC50 = 16.5–29.4 µg ml−1) and is worthy of further investigation

DESIGN AND SYNTHESIS OF NOVEL IMIDAZO[1,2-A]PYRIDINE DERIVATIVES AND THEIR ANTI-BACTERIAL ACTIVITY

Objective: The present study aims to synthesize a novel derivatives of Imidazo[1,2-a]pyridines and the compounds were evaluated for their antibacterial activity.Methods: A series of newly synthesized compounds were characterized by 1H-nuclear magnetic resonance (NMR), 13C-NMR, Fourier transform infrared, mass spectral analysis, and screened for their antibacterial activity by disc diffusion method. Molecular docking studies were performed with a bacterial beta subunit of DNA gyrase using Auto Dock 4.2.6, and the docked conformations were analyzed using visual molecular dynamics.Results: The structural activity relationship of the synthesized imidazo[1,2-a]pyridine derivatives was studied against Gram-positive and Gram-negative bacteria. Among the synthesized compounds N-benzyl-4-((2-(6-methyl-2-(p-tolyl)imidazo[1,2-a]pyridin-3-yl) acetamido)methyl) benzamide (9a) are possessing high activity against Bacillus subtilis. The zone of inhibition produced by the compound 9a is wider than that of remaining compounds used in this study.Conclusion: The synthesized compounds exhibited good antibacterial activity in comparison with standard drug streptomycin. This suggests that the compound 9a and its analogs are exerting their activity by probably inhibiting bacterial beta subunit of DNA gyrase

Evaluation of Indian medicinal plants used traditionally for the treatment of Malaria. Phytochemical investigation of Alangium lamarkii and Tarenna zeylanica for antiplasmodial and cytotoxic properties.

Association of Commonwealth Universities. Commonwealth Scholarship Commission. United Kingdom

Complete NMR assignments of tubulosine

NoThis article reports the structural elucidation of the Alangium alkaloid, tubulosine (1) on the basis of systematic 2D-NMR analyses (DEPT, COSY, TOCSY, NOESY, ROESY, HMQC and HMBC). The data obtained allowed the unambiguous assignment of all proton and carbon signals in 1 for the first time

Screening Indian plant species for antiplasmodial properties – ethnopharmacological compared to random selection.

noIn the search for biologically active plant species, many studies have shown that an ethnopharmacological approach is more effective than a random collection. In order to determine whether this is true in the case of plant species used for the treatment of malaria in Orissa, India, the antiplasmodial activities of extracts prepared from 25 traditionally used species were compared with those of 25 species collected randomly. As expected, plant species used traditionally for the treatment of malaria were more likely to exhibit antiplasmodial activity (21 species (84%) active against Plasmodium falciparum strain 3D7) than plant species collected randomly (9 species (32%)). However, of the nine active randomly collected species, eight had not previously been reported to possess antiplasmodial activity while one inactive species had been reported to be active in another study. Of the 21 active species of traditional antimalarial treatments, only six had been reported previously. This study suggests that while the selection of traditional medicinal plants is more predictive of antiplasmodial study, random collections may still be of value for the identification of new antiplasmodial species

A new embelin from the mangrove Aegiceras corniculatum.

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Evaluation of Alangium lamarckii bark for antiplasmodial and cytotoxic constituents and isolation of a novel tubulosine analogue

NoAlangium lamarkii is traditionally used in India for the treatment of malaria. Partial activity guided-fractionation of the basic chloroform fraction of the methanolic extract of the bark led to the isolation of a novel tubulosine analogue, 10-demethyl-9ˊ-N-methyltubulosine (1), for which the trivial name tubulosatine is suggested. In addition, the known A. lamarkii constituents, tubulosine (2), cephaeline and emetine were isolated as potent antiplasmodial and cytotoxic constituents, but 1 was up to 1000-fold less potent than the former alkaloids against both malaria parasites and human cancer cell lines. The compounds were active against both chloroquine-sensitive and chloroquine-resistant malaria parasites, but no selective toxicity was observed towards malaria parasites compared with cancer cells with any of the alkaloids. Further work to explore the basis for the relatively weak biological activities of 1 would be worthwhile. Betulinic acid, stigmasterol and its 3-O-glucoside were isolated from the neutral chloroform fraction of the methanolic extract.ACU, UK (Commonwealth Scholarship, Ref. No.: INCS-2004-144)