Twelve new compounds, variecolorins A-L ( 1- 12), together with eleven known analogues ( 13- 23) were isolated from the broth of a halotolerant fungus, Aspergillus variecolor. The structures of compounds 1- 12 were determined by chemical and spectroscopic methods. Compounds 1- 11, 13- 15, and 20- 23 exhibited weak radical scavenging activity against DPPH, with IC 50 values from 43 to 103 microM. The new compounds 1- 12 all were essentially nontoxic against the P388, HL-60, BEL-7402, and A-549 cell lines with IC 50 values from 70 to 260 microM.

An aciduric fungal strain, Penicillium camemberti OUCMDZ-1492, was isolated from an acidic marine niche, mangrove soil and mud, around the roots of Rhizophora apiculata. Six new indole-diterpenoids (1-6), along with five known analogues, emindole SB (7), 21-isopentenylpaxilline (8), paspaline (9), paxilline (10), and dehydroxypaxilline (11), were isolated from the fermentation broth of P. camemberti OUCMDZ-1492 grown at pH 5.0. On the basis of spectroscopic analyses, CD spectra, quantum ECD calculations, and chemical methods, new structures 1-6 were established as 3-deoxo-4b-deoxypaxilline, 4a-demethylpaspaline-4a-carboxylic acid, 4a-demethylpaspaline-3,4,4a-triol, 2'-hydroxypaxilline, 9,10-diisopentenylpaxilline, and (6S,7R,10E,14E)-16-(1H-indol-3-yl)-2,6,10,14-tetramethylhexadeca-2,10,14-triene-6,7-diol, respectively. Compounds 1-3 and 5-10 exhibited significant activity against the H1N1 virus with IC50 values of 28.3, 38.9, 32.2, 73.3, 34.1, 26.2, 6.6, 77.9, and 17.7 μM, respectively. The results showed that 3-oxo, 4b-hydroxy, and 9-isopentenyl substitutions tend to increase the anti-H1N1 activity of hexacyclic indole-diterpenoids.

Three new diketopiperazine alkaloids, 6-methoxyspirotryprostatin B (1), 18-oxotryprostatin A (2), and 14-hydroxyterezine D (3), with an oxaspiro[4.4]lactam moiety, 14-norpseurotin A (4), and the 29-nordammarane triterpenoid 6beta,16beta-diacetoxy-25-hydroxy-3,7-dioxy-29-nordammara-1,17(20)-dien-21-oic acid (5), as well as 12 known compounds (6- 17), were isolated from the ethyl acetate extract of a marine-derived fungal strain, Aspergillus sydowi PFW1-13. The structures of compounds 1- 5 were elucidated by comprehensive spectroscopic analysis. Compounds 1- 3 exhibit weak cytotoxicity against A-549 cells, with IC 50 values of 8.29, 1.28, and 7.31 microM, respectively. Compound 1 also shows slight cytotoxicity against HL-60 cells, with an IC 50 value of 9.71 microM. Compounds 4 and 5 display significant antimicrobial activities against Escherichia coli, Bacillus subtilis, and Micrococcus lysoleikticus with MICs of 3.74, 14.97, and 7.49 microM and 10.65, 5.33, and 10.65 microM, respectively.

No abstract

Eight new aromatic polyketides (2, 4-6, 8, 14, 16, and 17) together with eight known analogues (3, 7, 9-13, and 15) were isolated from the marine-derived fungus Aspergillus glaucus. The structures and stereochemistry of the new compounds were elucidated by spectroscopic and chemical methods, and their cytotoxicities were evaluated against the HL-60 and A-549 cell lines.

Eight drimane sesquiterpenes (1-8), six isochromane derivatives (9-14), and three known compounds, daldinin B (15), 9alpha-hydroxy-6beta-[(2E,4E,6E)-octa-2,4,6-trienoyloxy]-5alpha-drim-7-en-11,12-olide (16), and pergillin (17), were isolated from the EtOAc extract of the marine-derived fungus Aspergillus ustus 094102. The structures of the new compounds were elucidated on the basis of spectroscopic analysis. The cytotoxic effects on A549 and HL-60 cell lines were evaluated by SRB and MTT methods. Ustusorane E (13) showed significant cytotoxicity against HL-60 cells with an IC50 value of 0.13 microM. Ustusolates C (6) and E (8) exhibited moderate cytotoxicity against A549 and HL-60 cells with IC50 values of 10.5 and 9.0 microM, respectively, and ustusolate A (4) showed weak cytotoxicity against HL-60 and A549 cells with IC50 values of 20.6 and 30.0 microM, respectively.

Two novel cyclic hexapeptides containing both anthranilic acid and dehydroamino acid units, sclerotides A (1) and B (2), were isolated from the marine-derived halotolerant Aspergillus sclerotiorum PT06-1 in a nutrient-limited hypersaline medium. Both 1 and 2 are photointerconvertible and could be interconverted via a radical reaction initiated by direct photoisomerization. Both compounds showed moderate antifungal activity. Compound 2 also showed weak cytotoxicity and antibacterial activity.

Eleven new unusual C25 steroid isomers with bicyclo[4.4.1]A/B rings, 24- epi-cyclocitrinol (1), 20-O-methyl-24-epi-cyclocitrinol (3), 20-O-methylcyclocitrinol (4), 24-oxocyclocitrinol (7), 12 R-hydroxycyclocitrinol (8), neocyclocitrinols B (10) and D (12), erythro-23-O-methylneocyclocitrinol (13), threo-23-O-methylneocyclocitrinol (14), isocyclocitrinol B (15), and precyclocitrinol B (18), and five known steroids, cyclocitrinol (2), neocyclocitrinols A (9) and C (11), isocyclocitrinol A (16), and 22-O-acetylisocyclocitrinol A (17), were characterized from cultures of the volcanic ash-derived fungus Penicillium citrinum HGY1-5. Their structures and absolute configurations were established by spectroscopic and chemical methods together with X-ray diffraction analysis. Compounds 3, 4, and 10- 14 were determined to be artifacts on the basis of acidic transformation of 1- 4. The biosynthetic origin of these steroids derived from ergosterol was investigated by feeding (13)C-labeled acetates to the growing cultures of P. citrinum HGY1-5. The biological activities of all 16 steroids were tested using the cAMP assay on GPR12-CHO and WT-CHO cells. The results showed that compounds 1, 2, 10, 11, and 14 could induce the production of cAMP in GPR12-transfected CHO cells.