四种未描述的麦角烷型类固醇,(22E,24R)-4α,5α-环氧麦角-9α,14β-二羟基-7,22-二烯-3,6-二酮,(22E,24R)-4α,5α-环氧麦角-9α,14α-二羟基-7,22-二烯-3,6-二酮,12α-羟基麦角塔-7,22,24(28)-三烯-3-酮,和3β,12α-二羟基麦角-7,24(28)-二烯,以及一个已知的同源物(22E,24R)-9α,14β-二羟基麦角草-4,7,22-三烯-3,6-二酮,从真菌Lasiodiplodia假细菌中分离出来。它们的结构用核磁共振来阐明,HRESIMS,ECD计算,和X射线衍射分析。(22E,24R)-4α,5α-环氧麦角-9α,14β-二羟基-7,22-二烯-3,6-二酮和(22E,24R)-4α,5α-环氧麦角-9α,14α-二羟基-7,22-二烯-3,6-二酮是一对C-14差向异构体,在C-4和C-5之间具有不寻常的环氧基,使用单晶X射线衍射分析证明了这一点。12α-羟基麦角塔-7,22,24(28)-三烯-3-酮和3β,通过ECD计算确定12α-二羟基麦角-7,24(28)-二烯。此外,3β,12α-二羟基麦角-7,24(28)-二烯在谷氨酸处理的SH-SY5Y细胞系中具有体外神经保护活性。
Four undescribed ergostane-type steroids, (22E,24R)-4α,5α-epoxyergosta-9α,14β-dihydroxy-7,22-diene-3,6-dione, (22E,24R)-4α,5α-epoxyergosta-9α,14α-dihydroxy-7,22-diene-3,6-dione, 12α-hydroxyergosta-7,22,24(28)-triene-3-one, and 3β,12α-dihydroxyergosta-7,24(28)-diene, along with a known congener (22E,24R)-9α,14β-dihydroxyergosta-4,7,22-triene-3,6-dione, were isolated from the fungus Lasiodiplodia pseudotheobromae. Their structures were elucidated using NMR, HRESIMS, ECD calculation, and X-ray diffraction analyses. (22E,24R)-4α,5α-epoxyergosta-9α,14β-dihydroxy-7,22-diene-3,6-dione and (22E,24R)-4α,5α-epoxyergosta-9α,14α-dihydroxy-7,22-diene-3,6-dione are a pair of C-14 epimers possessing an unusual epoxy group between C-4 and C-5, which was demonstrated using single-crystal X-ray diffraction analyses. The absolute configurations of 12α-hydroxyergosta-7,22,24(28)-triene-3-one and 3β,12α-dihydroxyergosta-7,24(28)-diene were determined by ECD calculations. Moreover, 3β,12α-dihydroxyergosta-7,24(28)-diene exhibited neuroprotective activity in vitro in glutamate-treated SH-SY5Y cell lines.