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Cordyanhydrides A and B, two new alkenoic acids bearing two and three maleic anhydride moieties in the linear acid chain, were isolated and identified from a culture broth of the insect pathogenic fungus Cordyceps pseudomilitaris BCC 1620.

Three known compounds, 2-hexylidene-3-methylsuccinic acid (1), cytochalasin Q (2), and 5-carboxymellein (3), together with two new derivatives, 2-hexylidene-3-methylsuccinic acid 4-methyl ester (4) and an ophiobolane sesterterpene named halorosellinic acid (5), were isolated from culture broth of the marine fungus Halorosellinia oceanica BCC 5149. Compounds 1-3 exhibited moderate cytotoxicity against KB and BC-1 cell lines with IC(50) values of 1-13 microg/mL, while compounds 2, 3, 5, and 6 showed antimalarial activity with respective IC(50) values of 17, 4, 13, and 19 microg/mL. Halorosellinic acid (5) possessed only weak antimycobacterial activity with the minimum inhibitory concentration of 200 microg/mL.

Bioassay-guided fractionation of the extracts from the insect pathogenic fungus Cordyceps nipponica BCC 1389 led to the isolation of N-hydroxy- and N-methoxy-2-pyridones, cordypyridones A-D (1-4). Structures of these compounds, including absolute configuration, were determined by spectroscopic methods, chemical conversions and single-crystal X-ray diffraction analyses. Codypyridones A and B, atropisomers of each other, exhibited potent in vitro antimalarial activity with IC(50) values of 0.066 and 0.037 microg/mL, respectively, while their cytotoxicity was much weaker.

The first naturally occurring atropisomeric flavans, myristinins B (2), C (2a), E (4), and F (4a), together with their corresponding trans-isomers, myristinins A (1) and D (3), were isolated from the CH2Cl2 extract of Myristica cinnamomea fruits. Compounds 1, the mixture of 2 and 2a, and the mixture of 4 and 4a, exhibited antifungal activity against Candida albicans with IC50 values ranging from 5.9 to 8.8 μg/mL, and they selectively inhibited the enzyme cyclooxygenase-2 (COX-2).

Optimal fermentation conditions for enniatin production using the entomopathogenic fungus Verticillium hemipterigenum BCC 1449 have been investigated. Among various liquid media tested, highest efficiency of enniatin production was achieved by fermentation in yeast extract sucrose. Application of this condition to large-scale fermentation resulted in the isolation of three new analogs, O1, O2 and O3, which are closely related isomers that were characterized as an inseparable mixture, along with seven known enniatins.

Structurally unique isocoumarin glucosides, named halorosellins A (1) and B (2), were isolated from the EtOAc extract of a broth of the marine fungus Halorosellinia oceanica. Other new minor metabolites including 4,8-dihydroxy-6-methoxy-4,5-dimethyl-3-methyleneisochroman-1-one (3), 3-acetyl-7-hydroxy-5-methoxy-3,4-dimethyl-3H-isobenzofuran-1-one (4) and an ophiobolane sesterterpene, 17-dehydroxyhalorosellinic acid (5), were also isolated. Structures of these compounds were elucidated by analyses of spectroscopic data. Compound 4 exhibited mild antimycobacterial activity (MIC value of 200 µg mL−1).

Racemosol and demethylracemosol, together with their possible biogenetic precursors, preracemosol A and preracemosol B, were isolated from the roots of Bauhinia malabarica Roxb. While only racemosol and demethylracemosol exhibited cytotoxicity against KB and BC cell lines, all four compounds exhibited moderate antimalarial activity.

Department of Chemistry, Faculty of Science,Mahidol University, Bangkok 10400, Thailand;and National Center for Genetic Engineering andBiotechnology (BIOTEC), National Science andTechnology Development Agency (NSTDA), 73/1,Rama VI Rd., Rajdhevee, Bangkok 10400, Thailandprasat@biotec.or.th.Received March 23, 2000

Antimalarial activity-guided study of the aerial parts of Artocarpus integer led to the isolation of the prenylated stilbene, trans-4-(3-methyl-E-but-1-enyl)-3,5,2',4'-tetrahydroxystilbene with an EC50 of 1.7 micrograms/ml against Plasmodium falciparum in culture. The known stilbenes, trans-4-isopentenyl-3,5,2',4'-tetrahydroxystilbene and 4-methoxy-2,2-dimethyl-6-(2-(2,4-dihydroxy)phenyl-trans-ethenyl)chromene , were also isolated. Structures of these compounds were deduced on the basis of their spectral data.