Antiprotozoal and Antimicrobial Compounds from the Plant Pathogen Septoria pistaciarum

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• 作者：Mallika Kumarihamy ; Shabana I. Khan ; Melissa Jacob ; Babu L. Tekwani ; Stephen O. Duke ; Daneel Ferreira ; N. P. Dhammika Nanayakkara
• 刊名：Journal of Natural Products
• 出版年：2012
• 出版时间：May 25, 2012
• 年：2012
• 卷：75
• 期：5
• 页码：883-889
• 全文大小：312K
• 年卷期：v.75,no.5(May 25, 2012)
• ISSN：1520-6025

文摘

Four new 1,4-dihydroxy-5-phenyl-2-pyridinone alkaloids, 17-hydroxy-N-(O-methyl)septoriamycin A (1), 17-acetoxy-N-(O-methyl)septoriamycin A (2), 13-(S)-hydroxy-N-(O-methyl)septoriamycin A (3), and 13-(R)-hydroxy-N-(O-methyl)septoriamycin A (4), together with the known compounds (+)-cercosporin (5), (+)-14-O-acetylcercosporin (6), (+)-di-O-acetylcercosporin (7), lumichrome, and brassicasterol, were isolated from an ethyl acetate extract of a culture medium of Septoria pistaciarum. Methylation of septoriamycin A (8) with diazomethane yielded three di-O-methyl analogues, two of which existed as mixtures of rotamers. We previously reported antimalarial activity of septoriamycin A. This compound also exhibited significant activity against Leishmania donovani promastigotes. Compounds 5鈥?b>7 showed moderate in vitro activity against L. donovani promastigotes and chloroquine-sensitive (D6) and -resistant (W2) strains of Plasmodium falciparum, whereas compound 5 was fairly active against methicillin-sensitive and methicillin-resistant strains of Staphylococcus aureus. Compounds 5鈥?b>7 also displayed moderate phytotoxic activity against both a dicot (lettuce, Lactuca sativa) and a monocot (bentgrass, Agrostis stolonifera) and cytotoxicity against a panel of cell lines.