Acaulins A and B, Trimeric Macrodiolides from Acaulium sp H-JQSF

Acaulin A (1) and its macrolactone ring-opened congener acaulin B (2) were characterized from the culture of Acaulium sp. H-JQSF (an isopod-associated fungus) as architecturally undescribed trimeric macrodiolides, with the former being antiosteoporotic at 0.4 mu M in the prednisolone-induced osteoporotic zebrafish. Identification of acaudiolic acid (3) as the monomeric macrodiolide precursor facilitated the proposal of the acaulin biosynthetic pathway.

从Acaulium属真菌H - JQSF（一种与等足类动物相关的真菌）的培养物中鉴定出无茎真菌素A（1）及其大环内酯开环同系物无茎真菌素B（2），它们是结构上未曾描述过的三聚大二醇酯，前者在泼尼松龙诱导的骨质疏松斑马鱼模型中，在0.4 μM浓度下具有抗骨质疏松作用。将无茎真菌酸（3）鉴定为单体大二醇酯前体，有助于提出无茎真菌素的生物合成途径。