Cytotoxic cytochalasans from cultures of the fungus Metarhizium brunneum TBRC-BCC 79240.

Fourteen new cytochalasans, brunnesins A-N (1-14), along with eleven known compounds, were isolated from the culture extracts of the insect pathogenic fungus Metarhizium brunneum strain TBRC-BCC 79240. The compound structures were established by spectroscopy, X-ray diffraction analysis, and electronic circular dichroism. Compound 4 exhibited antiproliferative activity against all cell lines tested (mammalian), with 50% inhibition concentration (IC50) values ranging from 2.09 to 16.8 µg mL-1. Compounds 6 and 16 were shown to be bioactive only against non-cancerous Vero cells (IC50 4.03 and 0.637 µg mL-1, respectively) whereas compounds 9 and 12 were bioactive only against NCI-H187 small-cell lung cancer cells (IC50 18.59 and 18.54 µg mL-1, respectively). Compounds 7, 13, and 14 showed cytotoxicity against NCI-H187 and Vero cell lines with IC50 values ranging from 3.98-44.81 µg mL-1.

Antimicrobial and Cytotoxic Angucyclic Quinones from Actinomadura miaoliensis.

Eight new angucyclic quinones, miaosporones A to H (1-8), along with the previously described metabolites 8-hydroxy-3-methylbenz[a]anthraquinone (9), tetrangulol (10), 5,6-dihydro-1,8-dihydroxy-3-methybenz[a]anthracene-7,12-quinone (11), and SF2315A (12), were isolated from the terrestrial actinomycete Actinomadura miaoliensis TBRC 5172 obtained from sediment collected from the Huai Yang reservoir, Prachuap Khiri Khan Province, Thailand. The relative and absolute configurations of the new compounds were determined from analysis of NMR spectroscopic and X-ray crystallographic data. Miaosporone A exhibited antimalarial activity against Plasmodium falciparum K1 and antibacterial activity against Mycobacterium tuberculosis with respective IC50 values of 2.5 and 2.4 µM and displayed cytotoxic activities against both cancerous (MCF-7 and NCI-H187) and nonmalignant (Vero) cells.

Secondary metabolites from cultures of the ant pathogenic fungus Ophiocordyceps irangiensis BCC 2728.

Five new compounds, iranginins A-E (1-5), together with sixteen known compounds were isolated from the insect pathogenic fungus Ophiocordyceps irangiensis BCC 2728. The structures and the absolute configurations of the new compounds were established by spectroscopic analyses, the application of modified Mosher's method (for 2), ECD calculation (for 5), and X-ray crystallographic analysis (for 4). LL-Z1640-5 and mucorisocoumarin C were active against Mycobacterium tuberculosis (MIC 41.7 and 85.0 µM, respectively), while peyroisocoumarin D exhibited cytotoxic activity (IC50 65.6 µM).

Antimalarial 9-Methoxystrobilurins, Oudemansins, and Related Polyketides from Cultures of Basidiomycete Favolaschia Species.

Fourteen new compounds, oudemansins 1-4, oudemansinols 5-7, favolasins 8-10, favolasinin (12), polyketides 13-15, and (R,E)-2,4-dimethyl-5-phenyl-4-pentene-2,3-diol (16), together with nine known compounds were isolated from the basidiomycete fungus Favolaschia sp. BCC 18686. Two new compounds, favolasin E (11) and 9-oxostrobilurin E (17), were isolated from the closely related organism Favolaschia calocera BCC 36684 along with nine ß-methoxyacrylate-type derivatives. Compounds in the class of oudemansins and strobilurins exhibited moderate to strong antimalarial activity with relatively low cytotoxicity against Vero cells (African green monkey kidney fibroblasts). Potent antimalarial activity was demonstrated for 9-methoxystrobilurins G, K, and E (IC50 values 0.061, 0.089, and 0.14 µM, respectively). The structure-activity relationships (SAR) for antimalarial activity is proposed on the basis of the activity of the new and several known ß-methoxyacrylate derivatives in combination with the data from previously isolated compounds. Furthermore, several compounds showed specific cytotoxicity against NCI-187 cells (human small-cell lung cancer), although the SAR was different from that for antimalarial activity.

Antimicrobial anthraquinones from cultures of the ant pathogenic fungus Cordyceps morakotii BCC 56811.

Five new anthraquinones, morakotins A-E (1-5), together with seven known compounds, lunatin (6), rheoemodin (7), YM187781 (8), bislunatin (9), 6-(1-hydroxypentyl)-4-methoxypyran-2-one, 9,11-dehydoergrosterol peroxide, and cerevisterol, were isolated from the insect pathogenic fungus Cordyceps morakotii BCC 56811. The morakotin structures were elucidated from NMR spectroscopic and mass spectrometric data. The absolute configurations of bianthraquinone compounds, morakotins C-E (3-5), were determined by application of the exciton chirality method. Compounds 3, 7, 8, and 9 showed weak to moderate antimycobacterial and antifungal activities. Compounds 4 and 8 exhibited antibacterial activity against both Bacillus cereus and Staphylococcus aureus (MIC 3.13-25 µg ml-1), whereas compounds 3 and 9 were active against B. cereus (MIC 12.5 and 3.13 µg ml-1, respectively), and compound 7 was active against Acinetobacter baumannii (MIC 12.5 µg ml-1).

F-THENA: a chiral derivatizing agent for the determination of the absolute configuration of secondary aromatic alcohols with a self-validating system.

F-THENA is designed as an alternative fluorine-containing chiral derivatizing agent (CDA). The fluorine atom functions exclusively as a reporter which can directly sense an anisotropic effect from an aromatic substituent of a chiral alcohol. In combination with chemical shift differences from both 19F NMR and 1H NMR, the F-THENA method can successfully be used for determining the absolute configuration of chiral secondary aromatic alcohols with a self-validating system.

Bioactive metabolites from cultures of basidiomycete Favolaschia tonkinensis.

Two strobilurins, 9-methoxystrobilurin B (1) and 9-methoxystrobilurin G (2), two monochlorinated 2,3-dihydro-1-benzoxepin derivatives, 3 and 4a, and butenolide 5, together with four known compounds, strobilurin B, 9-methoxystrobilurin A, and oudemansins A and B, were isolated from culture BCC 18689 of the fungus Favolaschia tonkinensis. 9-Methoxystrobilurins A, B (1), and G (2) and oudemansins A and B exhibited antimalarial, antifungal, and cytotoxic activities, while compounds 3, 4a, and 5 displayed only cytotoxic activity.

Isocoumarin glucosides from the scale insect fungus Torrubiella tenuis BCC 12732.

Three new isocoumarin glucosides (1, 3, and 4), 6,8-dihydroxy-3-methylisocoumarin (2), and 6,8-dihydroxy-3-hydroxymethylisocoumarin (5) were isolated from the scale insect pathogenic fungus Torrubiella tenuis BCC 12732. Structures of these compounds were elucidated using NMR spectroscopic and MS spectrometric analyses. Compound 5 exhibited moderate anti-HSV-1 and antimycobacterial activities with IC(50) and MIC values of 50 and 25 microg/mL, respectively.

Dichapetalin-type triterpenoids and lignans from the aerial parts of Phyllanthus acutissima.

Chemical investigation of the aerial parts of Phyllanthus acutissima resulted in the isolation of five new dichapetalin-type triterpenoids, acutissimatriterpenes A-E ( 1- 5), and two new lignans, acutissimalignans A ( 6) and B ( 7), along with two known lignans and three known ellagic acid derivatives. The structures of 1- 7 were determined mainly on the basis of spectroscopic methods. The compounds obtained were evaluated for cytotoxic and anti-HIV-1 activities.