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本文报道从变色马兜铃(Aristolochia versicolar)的块根中提取的一种新倍半萜内酯一银袋内酯乙的乙酰化物的晶体结构和分子结构.分子式为C_(17)H_(22)O_4,分子量290.4,晶体属单斜晶系,空间群为P2_1,α=0.9594(5),b=0.6626(6),c=1.2924(12)12m,β=94.48(6)°,V=0.819(1)nm~3,Z=2,D_x=1.18g·cm~(-3),F(000)268e,μ=0.77cm~(-1)(Mo Kα).结构用直接法解出,经最小二乘法修正后1280个衍射点的偏离因子为R=5.5％,R_W=5.2％.分子由椅型·椅型的1,5二烯十员环([2323]矩形)和共用两个相邻Dunitz III型碳C(4),C(5),一个Dunitz II型碳C(6)的五员内酯环组成.十员环与五员内酯环之间夹角为99°.该分子骨架拓扑在迄今已知的倍半萜内酯中只与银袋内酯丙相似.所有非氢原子间的键长和键角均在实验误差范围内接近理论值。
In this paper, we report the crystal structure and molecular structure of a new sesquiolactone-acetolactone-B acetylate extracted from the roots of Aristolochia versicolar. The molecular formula is C_ (17) H_ (22) O_4 and molecular weight 290.4. The crystal is monoclinic with space group P2_1, α = 0.9594 (5), b = 0.6626 (6), c = 1.2924 (12) 12m, β = 94.48 (1) nm ~ 3, Z = 2, D_x = 1.18g · cm -3, F (000) 268e, μ = 0.77cm -1 Mo Mo α. The structure was solved by the direct method, The deviation factor of the 1280 diffraction points corrected by the least square method is R = 5.5% and R_W = 5.2%. The molecule is composed of a 1, 5-diene ten-membered ring ([2323] Adjacent Dunitz III carbon C (4), C (5), a Dunitz II type carbon C (6) five member lactone ring composition angle between the ten member ring and pentanolactone ring of 99 °. The molecular framework topology is only similar to soya lactone C in so far known sesquiterpene lactones, and all the bond lengths and bond angles between non-hydrogen atoms are close to the theoretical values within the experimental error range.