Achaetolide-II isolated from Helminthosporium velutinum TS28

Natural ten-membered lactones: sources, structural diversity, biological activity, and intriguing future

“…The endophytic fungus Cytospora sp. is a producer of a large family of TMLs called cytospolides A-P (34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49). This family has one chemical feature that is unique for fungal TMLsthe presence of a methyl group at C-2.…”

“…This tendency may seem common, but nevertheless for some natural compounds trivial names for similar structures continue to be assigned by the following letters of the alphabet, despite the fact that the root of a trivial name is no longer associated with new producers. For example, a new natural product isolated by Arayama et al (2015) 38 from Helminthosporium velutinum TS28 was discovered to be an acylated analogue of achaetolide, a secondary metabolite of Achaetomium sp. 79 This new TML has been named achaetolide-II despite being isolated from a new producer.…”

“…3 In contrast, there are practically no targeted studies on SAR analysis for other types of activity. For example, Lu et al (2011) 26,27 discussed the possible SAR of cytospolides (34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49) and stated that the conguration of C-2 is important for cytotoxic activity. Among the family of bellidisins (27,28,50) and co-isolated compounds from Phoma bellidis, the 4S,5S-4,5-epoxyhexenoyl group in the ester moiety of bellidisin D ( 28) is probably the key pharmacophore for its cytotoxicity.…”

“…In a phytotoxicity assay, compound 58 inhibited root growth of Lactuca sativa at 500 μg mL −1 . 38 TML 59 originated from the sponge-associated fungus, Xylaria feejeensis . An in vitro assay revealed the significant down-regulating activity of 59 on osteoclast cell differentiation at 0.5 and 1 μM.…”