Showing papers by "Alexander I. Gray published in 2021"
TL;DR: In this paper, the authors investigated the antitrypanosomal and antileishmanial activity of chalcones and flavanones from polygonum salicifolium, which grows in the wetlands of Iraq.
Abstract: Trypanosomiasis and leishmaniasis are a group of neglected parasitic diseases caused by several species of parasites belonging to the family Trypansomatida The present study investigated the antitrypanosomal and antileishmanial activity of chalcones and flavanones from Polygonum salicifolium, which grows in the wetlands of Iraq The phytochemical evaluation of the plant yielded two chalcones, 2′,4′-dimethoxy-6′-hydroxychalcone and 2′,5′-dimethoxy-4′,6′-dihydroxychalcone, and two flavanones, 5,7-dimethoxyflavanone and 5,8-dimethoxy-7-hydroxyflavanone The chalcones showed a good antitrypanosomal and antileishmanial activity while the flavanones were inactive The EC50 values for 2′,4′-dimethoxy-6′-hydroxychalcone against Trypanosoma brucei brucei (05 μg/mL), T congolense (25 μg/mL), and Leishmania mexicana (52 μg/mL) indicated it was the most active of the compounds None of the compounds displayed any toxicity against a human cell line, even at 100 µg/mL, or cross-resistance with first line clinical trypanocides, such as diamidines and melaminophenyl arsenicals Taken together, our study provides significant data in relation to the activity of chalcones and flavanones from P salicifolium against both parasites in vitro Further future research is suggested in order to investigate the mode of action of the extracted chalcones against the parasites
13 citations
TL;DR: The powder roots of the medicinal plant Acacia nilotica were extracted with hexane and ethyl acetate and the extracts subjected to column chromatography for the isolation of potentially bioactive compounds and their screening against kinetoplastid pathogens.
Abstract: The powdered roots of the medicinal plant Acacia nilotica were extracted with hexane and ethyl acetate and the extracts subjected to column chromatography for the isolation of potentially bioactive compounds and their screening against kinetoplastid pathogens. NMR and HREI mass-spectrometric analyses identified two new diterpenes, characterized as 16, 19-dihydroxycassa-12-en-15-one (Sandynone, 1) and (5S, 7R, 8R, 9R, 10S, 13Z, 17S)-7,8:7,17:16,17-triepoxy-7,8-seco-cassa-13-ene (Niloticane B, 2). Also isolated were the previously reported (5S,7R,8R,9R,10S) -(-)-7,8-seco-7, 8-oxacassa-13,15-diene-7,17-diol (3), (5S,7R,8R,9R,10S) -(-)-7,8-seco-7, 8-oxacassa-13,15-dien-7-ol-17-al (4) and (5S,7R,8R,9R,10S) -(-)-7,8-seco-7, 8-oxacassa-13,15-dien-7-ol (5). A mixture of stigmasterol (6a) and sitosterol (6b), as well as lupeol (7) were also isolated. Several column fractions displayed significant activity against a panel of Trypanosoma and Leishmania spp and from the most active fraction, compound 4 was isolated to high purity. The compound displayed high activity, particularly against T. brucei, T. evansi and L. mexicana (0.88 - 11.7 µM) but only a modest effect against Human Embryonic Kidney cells, and no cross-resistance with the commonly used melaminophenyl arsenical and diamidine classes of trypanocides. The effect of compound 4 against L. mexicana promastigotes was irreversible after a 5-h exposure, leading to the sterilization of the culture between 24 and 48 h.
5 citations
TL;DR: The stem bark of Cassia sieberiana was extracted with methanol and the meethanol extract partitioned with chloroform yielded a novel benzofurochromene, which was determined by Nuclear Magnetic resonance and mass spectrometry.
3 citations
TL;DR: A new eusdesmane sesquiterpenoid, characterised as 5-acetoxy-9aβ-hydroxy-4aαH-3,5α, 8αβ-trimethyl-4, 4a, 6, 7, 8a, 9hexahydronaphtho-2, 3b]-dihydrofuran-2-one)-8-one or phaeusmane F acetate (1) has been isolated from the rhizomes of the South African variety of wild ginger (
2 citations