Control Efficacy of Entomopathogenic Fungus Purpureocillium lilacinum against Chili Thrips (Scirtothrips dorsalis) on Chili Plant.

In a laboratory assay, it was shown that B. bassiana BCC48145, BCC2660, and P. lilacinum TBRC10638 were the three strains that exhibited the highest insecticidal activity against chili thrips, causing 92.5% and 91.86% and 92.3% corrected mortality, respectively. The fungi B. bassiana BCC48145 and P. lilacinum TBRC10638 were selected for greenhouse spraying. Cytotoxicity test of the extracts from both fungi evaluated against 4 animal cell lines: KB; human oral cavity carcinoma, MCF7; human breast adenocarcinoma, NCI-H187; human small cell lung carcinoma and GFP-expressing Vero cells, showed none-cytotoxic to all cell lines. An efficacy validation in the greenhouse showed that P. lilacinum TBRC 10638 was more effective than B. bassiana BCC48145 and could control the thrips up to 80% when using the fungus at 108 spores/mL. The LC50 values of P. lilacinum TBRC 10638 against chili thrips based on total thrips count from two experiments were 1.42 × 108 and 1.12 × 107 spores/mL when the fungal spores were sprayed once a week. The optimal concentration of P. lilacinum TBRC 10638 spores for effective control of chili thrips was determined at 1.41 × 109 spores/mL. The average efficacy of P. lilacinum TBRC 10638 for thrips control from 3 field trials was 30.08%, 14.39%, and 29.92%. This result was not significantly different from that of the chemical insecticide treatment group, which showed efficacy at 19.27%, 14.92%, and 19.97%. Furthermore, there was no difference in productivity among the different treatment groups. Our results demonstrated that P. lilacinum TBRC 10638 is a promising biocontrol agent that could be used as an alternative to chemical insecticide for controlling chili thrips.

Antimicrobial drimane - phthalide derivatives from Hypoxylon fendleri BCC32408.

Fourteen new compounds including thirteen drimane - phthalide derivatives (fendlerals A - C, fendlerins A - D, fendlerols A - B, fendleric acids A - C, fendlerinine G) and one terphenyl derivative (fendleryl E) along with eight known compounds, fendlerinine A, rickenyls C - D, fendleryls C - D, atromentin, tetramethyl atromentin, and (±)-microsphaerophthalide F, were isolated from the wood fungus Hypoxylon fendleri BCC32408. Compared with the prior work, the results indicated the agitation effect on the production of bioactive drimane - phthalides. The chemical structures were determined based upon spectroscopic analyses and the absolute configurations were verified by comparison of the ECD spectral data with the calculated ECD spectra of the related compounds. Compounds 1-3 exhibited antimicrobial activity against Plasmodium falciparum (IC50 4.15-4.39 µM), Colletotrichum capsici (MIC 6.25-12.5 µg/mL), and Bacillus cereus (MIC 1.56-3.13 µg/mL). All tested compounds displayed broad cytotoxicity against cancerous (MCF-7, KB, and NCI-H187) and non-cancerous (Vero) cells.

Antimicrobial activity and cytotoxicity of xanthoquinodin analogs from the fungus Cytospora eugeniae BCC42696.

Eleven previously undescribed compounds, including cytosporanthraxanthone, xanthoquinodins A7-A10, ketoxanthoquinodin A6, xanthoquinodins B6-B8, and spiroxanthoquinodins A and B, and one synthetically known compound, 2-methoxy pinselin, as well as ten known compounds, including xanthoquinodins A4-A6, B4, and B5, chrysophanol, physcion, (4S)-5-hydroxy-4-methoxy-α-tetralone, (4S)-4,8-dihydroxy-α-tetralone (or isosclerone), and gonytolide C were isolated from the fungus Cytospora eugeniae BCC42696. Their chemical structures were determined based on the analysis of NMR spectroscopic and mass spectrometric data. Moreover, the absolute configurations of the unknown compounds were established by using NOESY and NOEDIFF NMR experiments along with CD spectroscopic data. The isolated xanthoquinodins exhibited a broad range of antimalarial, antibacterial, and fungicidal activities as well as cytotoxicity. Xanthoquinodins A6, B4, and B5 showed strong activity to Plasmodium falciparum, K1 strain (IC50 0.52-0.92 µM) and displayed anti-Bacillus cereus (MIC 1.56 µg/mL). Xanthoquinodin A6 also showed anti-Curvularia lunata (MIC 3.13 µg/mL). In addition, xanthoquinodins A4, A6, B4, and B5 and ketoxanthoquinodin A6 showed cytotoxicity against both cancerous (MCF-7, KB, NCI-H187) and non-cancerous (Vero) cells.

Phenalenone derivatives and the unusual tricyclic sesterterpene acid from the marine fungus Lophiostoma bipolare BCC25910.

Ten compounds including nine phenalenone derivatives (five bipolarides and four bipolarols) and a sesterterpene acid (bipolarenic acid), were isolated from a marine isolated of the fungus Lophiostoma bipolare (BCC25910), along with the known compounds, (-)-scleroderolide, (-)-sclerodin, and oxasetin. Chemical structures were elucidated based on NMR spectroscopic data and HRESIMS analysis. In addition, the absolute configurations of the phenalenones were resolved using specific rotations and chemical means, while the relative configuration of bipolarenic acid was confirmed by X-ray crystallographic analysis. The compounds were evaluated for biological activity against the Plasmodium falciparum K-1 strain, Candida albicans, and Bacillus cereus, and for cytotoxicity against both cancerous and non-cancerous cells.

Bioactive anthraquinone dimers from the leafhopper pathogenic fungus Torrubiella sp. BCC 28517.

Torrubiellins A (1) and B (2), two new dimeric anthraquinones were isolated from the leafhopper pathogenic fungus Torrubiella sp. BCC 28517. The structures of the new compounds were elucidated by analyses of the NMR spectroscopic and mass spectrometry data. Torrubiellin B (2) exhibited broad range of biological activities.

Eremophilane-type sesquiterpenes from the fungus Xylaria sp. BCC 21097.

Seven new eremophilane-type sesquiterpenoids (1-5, 7, and 8) and the known mairetolide F (6) were isolated from the endophytic Xylaria sp. BCC 21097. A new furofurandione (9) was also isolated from the fungal extract. The structures of the new compounds were elucidated by analyses of NMR spectroscopic and mass spectrometry data in combination with chemical reaction studies. Eremophilanolides possessing an alpha-methylene-gamma-lactone (1-3) exhibited moderate cytotoxic activities, while related analogues bearing an endo double bond (6 and 7) were inactive.

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.