ES-242 derivatives and cycloheptapeptides from Cordyceps sp. strains BCC 16173 and BCC 16176

Five new ES-242 analogues ( 1- 5) were isolated together with nine known compounds ( 6- 14) from the insect pathogenic fungus Cordyceps sp. BCC 16173. A closely related strain, BCC 16176, provided cordyheptapeptide A ( 15) and small amount of its new analogue, cordyheptapeptide B ( 16), along with known ES-242s. Structures of the new bioxanthracenes, 1- 5, were determined to be 6'- O-desmethyl analogues of 6 (ES-242-4), 8, 9 (ES-242-2), 12, and 13, respectively, primarily by spectroscopic analyses. Cordyheptapeptide B ( 16) has an N-methyl- l-phenylalanine residue instead of the N-methyl- l-tyrosine in 15.

Depsidones from the endophytic fungus BCC 8616

Three new depsidones (1-3) have been isolated from the endophytic fungus BCC 8616 and their structures analyzed on the basis of spectroscopic data interpretation. Compound 1 exhibited weak cytotoxic activity against breast and epidermoid carcinoma cell lines.

Cytotoxic Prenylated Xanthones from the Young Fruit of Garcinia mangostana

Three new prenylated xanthones, mangostenones C (1), D (2), and E (3), together with 16 known xanthones 4-19, were isolated from the young fruit (7-week maturity stage) of Garcinia mangostana. The structural elucidation of the new compounds was mainly established on the basis of 1D and 2D NMR and HR-MS spectroscopic analysis. Compound 1 showed cytotoxic properties against three human cancer cell lines, epidermoid carcinoma of the mouth (KB), breast cancer (BC-1), and small cell lung cancer (NCI-H187), with IC50 values of 2.8, 3.53, and 3.72 microg/ml, respectively. Among the isolates, alpha-mangostin (12), the major metabolite, exhibited the most potent effects against the BC-1 cells with an IC50 value of 0.92 microg/ml, an activity greater than that of the standard drug ellipticine (IC50 = 1.46 microg/ml). Compound 12 also showed the highest activity against KB cells, while gartanin (10) displayed the strongest activity against the NCI-H187 cells at the respective IC50 values of 2.08 microg/ml and 1.08 microg/ml.

Azaphilone pigments from a yellow mutant of the fungus Monascus kaoliang

Azaphilone pigments, monascusones A (1) and B (2), together with two known azaphilones, monascin (3) and FK17-P2b2 (4), were isolated from the CH2Cl2 extract of a yellow mutant of the fungus M. kaoliang grown on rice. Structures of the isolated compounds were elucidated by analyses of spectroscopic data. Monascusone A (1), the major metabolite of M. kaoliang, showed no antimalarial (against Plasmodium falciparum), antitubercular (against Mycobacterium tuberculosis H37Ra), and antifungal (toward Candida albicans) activities. Compound 1 exhibited no cytotoxicity against BC (breast cancer) and KB (human epidermoid carcinoma of cavity) cell lines.