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.

Lanostane and hopane triterpenes from the entomopathogenic fungus Hypocrella sp. BCC 14524.

Seven new lanostane-type triterpenes, hypocrellols A-G (1-7), and six new hopane-type triterpenes, 7ß,15α-dihydroxy-22(29)-hopene (8), 3ß,7ß-dihydroxy-22(29)-hopene (9), 3ß-acetoxy-15α-hydroxy-22(29)-hopene (10), 3ß,7ß,15α,22-tetrahydroxyhopane (11), 3ß-acetoxy-7ß,15α,22-trihydroxyhopane (12), and 7ß,15α,22-trihydroxyhopane (13), were isolated from the scale insect pathogenic fungus Hypocrella sp. BCC 14524. The structures of the new compounds were elucidated by analyses of the NMR spectroscopic and mass spectrometry data. The structure of 1 was confirmed by X-ray crystallography.

Butyrolactones from the fungus Aspergillus terreus BCC 4651.

Two new butenolides, butyrolactones VI (1) and VII (2), were isolated together with six known compounds, butyrolactones I (3), II (4), IV (5), and V (6), aspernolide B (7), and bisdethiodi(methylthio)acetylaranotin (8) from the fungus Aspergillus terreus BCC 4651. Compound 8, exhibiting a minimum inhibitory concentration (MIC) value of 1.56 µg/ml against Mycobacterium tuberculosis H37Ra, proved to be the antimycobacterial principle from the culture of this fungus. On the other hand, butyrolactone V (6) showed antiplasmodial activity against Plasmodium falciparum K1 with an IC50 of 7.9 µg/ml.

Gamma-lactones and ent-eudesmane sesquiterpenes from the endophytic fungus Eutypella sp. BCC 13199.

Two new gamma-lactones, eutypellins A (1) and B (2), and two ent-eudesmane sesquiterpenes, ent-4(15)-eudesmen-11-ol-1-one (3) and ent-4(15)-eudesmen-1alpha,11-diol (4), together with three known pimarane diterpenes, diaporthein B, scopararane A, and libertellenone C, were isolated from the endophytic fungus Eutypella sp. BCC 13199. The structures of these compounds were elucidated by interpretation of spectroscopic data. The absolute configuration of 4 was confirmed by application of the modified Mosher's method. Eutypellin A (1) and sesquiterpene 3 exhibited weak cytotoxic activities.

Aurocitrin and related polyketide metabolites from the wood-decay fungus Hypocrea sp. BCC 14122.

The known gentisaldehyde antibiotic aurocitrin (1), its cis-olefinic isomer (2), a salicylaldehyde analogue (3), two new benzofuran derivatives (4 and 5), and a new dihydroisocoumarin (6) were isolated from the wood-decay fungus Hypocrea sp. BCC 14122. The structures were elucidated primarily by NMR and mass spectroscopic analyses.