Three cyclohexenone derivatives, (4S,5S,6S)-5,6-epoxy-4-hydroxy-3-methoxy-5-methyl-cyclohex-2-en-1-one (1), (4R,5R)-4,5-dihydroxy-3-methoxy-5-methyl-cyclohex-2-en-1-one (2), and (4R,5S,6R)-4,5,6-trihydroxy-3-methoxy-5-methyl-cyclohex-2-en-1-one (3), were isolated from unpolished rice fermented with an xylariaceous endophytic fungus (strain YUA-026). The structures of three compounds were established on the basis of spectroscopic analyses and chemical conversion. The minimum inhibitory concentrations of 1 and 3 were 100 μg/ml and 400 μg/ml against Staphylococcus aureus, 100 μg/ml and 200 μg/ml against Pseudomonas aeruginosa, and 200 μg/ml and >400 μg/ml against Candida albicans, respectively. In addition, 1 and 3 exhibited phytotoxic activity against lettuce.
从用木霉菌内生真菌(YUA-026株)发酵的未抛光大米中分离出三种
环己烯酮衍
生物,即(4S,5S,6S)-5,6-环氧-
4-羟基-3-甲氧基-5-甲基-环己-2-烯-1-酮(1)、(4R,5R)-4,5-二羟基-3-甲氧基-5-甲基-环己-2-烯-1-酮(2)和(4R,5S,6R)-4,5,6-三羟基-3-甲氧基-5-甲基-环己-2-烯-1-酮(3)。根据光谱分析和
化学转化确定了三种化合物的结构。1和3对
金黄色葡萄球菌的最小抑制浓度分别为100 μg/ml和400 μg/ml,对
铜绿假单胞菌的最小抑制浓度分别为100 μg/ml和200 μg/ml,对白色念珠菌的最小抑制浓度分别为200 μg/ml和>400 μg/ml。此外,1和3对莴苣表现出植物毒性。