1. Metabolites of Streptomyces sp., an endophytic actinomycete from Alpinia oxyphylla
Hao Zhou, Yabin Yang, Tianfeng Peng, Wei Li, Lixing Zhao, Lihua Xu, Zhongtao Ding Nat Prod Res. 2014;28(4):265-7. doi: 10.1080/14786419.2013.830219. Epub 2013 Aug 25.
Four known compounds had been isolated from the Streptomyces sp. YIM66017, and their structures were elucidated by spectral analysis as 2,6-dimethoxy terephthalic acid (1), yangjinhualine A (2), α-hydroxyacetovanillone (3) and cyclo(Gly-Trp) (4). Compound 1 was isolated from natural resources for the first time, and compounds 2-4 were isolated from streptomycetes for the first time. The 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity assays showed that 1 showed higher activity than rutin with IC50 of 4.61 μg/mL and 2 showed the activity with IC50 of 57.12 μg/mL.
2. Isolation of talathermophilins from the thermophilic fungus Talaromyces thermophilus YM3-4
Ji-Peng Guo, Jian-Lin Tan, Yan-Li Wang, Hong-Yang Wu, Chuan-Ping Zhang, Xue-Mei Niu, Wen-Zheng Pan, Xiao-Wei Huang, Ke-Qin Zhang J Nat Prod. 2011 Oct 28;74(10):2278-81. doi: 10.1021/np200365z. Epub 2011 Oct 3.
Six indole alkaloids with various levels of prenylation were isolated from the thermophilic fungus Talaromyces thermophilus strain YM3-4. Their structures were identified by NMR and MS spectroscopic analyses. Compounds 1 and 2 are new analogues of the key versatile precursor notoamide E. Compound 3 is a novel analogue of preechinulin, and compound 4 was reported as a natural occurring cyclo(glycyltryptophyl) for the first time. The metabolite profile of this thermophilic organism displayed a biosynthetic pathway for talathermophilins.
3. Metabolites from carnivorous fungus Arthrobotrys entomopaga and their functional roles in fungal predatory ability
De-Kai Wu, Chuan-Ping Zhang, Chun-Yan Zhu, Yan-Li Wang, Li-Lei Guo, Ke-Qin Zhang, Xue-Mei Niu J Agric Food Chem. 2013 May 1;61(17):4108-13. doi: 10.1021/jf400615h. Epub 2013 Apr 17.
The carnivorous fungus Arthrobotrys entomopaga (Drechsler) can develop adhesive knobs to capture nematodes. Chemical study on the culture medium of A. entomopaga producing adhesive knobs led to isolation of six trace amounts of metabolites, including two new metabolites, paganins A and B (1 and 2), blumenol A (3), talathermophilins A and B (4 and 5), and cyclo(glycyltryptophyl) (6). Compounds 3-6 were reported for the first time from carnivorous fungi. Compounds 1 and 2 promoted the formation of the predatory adhesive knobs with an increasing rate up to 118% at a concentration of 50 μM but showed moderate inhibitory activity at a concentration of 5 μM. Moreover, compounds 1 and 2 displayed strong inhibitory activities toward the formation of A. entomopaga conidiophores with inhibitory rates of 40-75%. Growth experiments suggested that compounds 1 and 2 could be involved in the regulation of the fungal predatory and reproductive abilities. Nematode chemotaxis bioassay indicated that compounds 1 and 3 displayed strong nematode-attracting abilities. These findings provided a new type of regulatory metabolite and support for the hypothesis that predators often evolve to respond to their metazoan prey.
