Walailak Frontier 20, September 2019
Soil fungi are efficient producers of various secondary metabolites. They have drawn attention from many researchers to search for novel metabolites with effective antimicrobial activities. Asst.Prof.Dr.Jariya Sakayaroj (Walailak University) in collaboration with Asst.Prof.Dr.Saranyoo Klaiklay, Prof.Dr.Vatcharin Rukachaisirikul, Dr.Saowanit Saithong and Prof.Dr.Souwalak Phongpaichit (Prince of Songkla University) investigated secondary metabolites from a fungus (PSU-RSPG27) isolated from soil sample from Suratthani Province. This fungus was then identified based on morphological features and the ribosomal DNA analysis, and it was successfully identified as Trichoderma brevicompactum.
In this study, a focus was placed on the investigation of secondary metabolites. Six new (1–6), together with seven known (7–13), trichothecenes were isolated from a soil-derived Trichoderma brevicompactum PSU-RSPG27.
Their structures were established using spectroscopic data. The structure of 1 was confirmed by X-ray data. Trichodermin (7) exhibited the most potent activity against Plasmodium falciparum (K1 strain) with an IC50 value of 0.1 μM, while other trichothecenes (1, 8, 9, and 12) were much less active, with IC50 values in the range of 7.1–9.6 μM. Compound 7 displayed activity against noncancerous Vero cells with an IC50 value of 0.4 μM. The remaining compounds showed moderate to weak activity, with IC50 values in the range of 6.9–15.3 μM. Compounds 7 and 12 were active against human oral carcinoma (KB) cells with IC50 values of 2.4 and 3.7 μM, respectively. Additionally, compounds 7 and 12 displayed antifungal activity against Candida albicans with the respective MIC values of 1 and 2 μg/mL and were active against Cryptococcus neoformans with equal MIC values of 4 μg/mL.
Klaiklay, S., Rukachaisirikul, V., Saithong, S., Phongpaichit, S. and Sakayaroj, J. 2019. Trichothecenes from a Soil-Derived Trichoderma brevicompactum, J. Nat. Prod. 82: (4): 687-693