Crystal and molecular structure and absolute configuration of Withaperuvin E:: a C28 steroidal lactone
Crystal and molecular structure and absolute configuration of Withaperuvin E:: a C28 steroidal lactone
复制标题
DOI：
10.1023/a:1023204408338
复制
发表时间：
1998-07-01
影响因子：
0.8
通讯作者：
Palmer, RA
中科院分区：
文献类型：
--
作者：
Bhattacharyya, K;Mazumdar, SK;Palmer, RA
从秘鲁Physalis peruviana的风干根中分离得到Withaperuvin E (C28H36O8)，并采用硅胶色谱法进行纯化。该化合物具有显著的抗塑料活性。从甲醇/丙酮溶液中得到棱柱状的淡黄色晶体。该化合物与部分占据的[40(1)%]醋酸分子在P2(1)2(1)2(1)空间群中结晶，Z = 4, D-c = 1.242 g cm(-3)，单元参数a = 11.431(3), b = 14.104(1), c = 17.387(5)埃，V = 2803.2（11）埃(3),mu(CuK α) = 0.072mm（-1）。通过x射线分析发现该分子由甾体骨架组成，b环上有β取向的氧桥原子C(5)和C(6)。B沙发;C椅子;D中间半椅/沙发；内酯环E具有沙发构象。类固醇骨架的所有环都是反式连接的。Withaperuvin E骨架的绝对构型与天然存在的类固醇相对应，C（18）和C（19）都是β取向的。部分占据的乙酸分子与类固醇分子形成氢键。氢键也发生在羟基（14）和对称相关的氧O（20）之间。
The withanolide Withaperuvin E, C28H36O8, has been obtained from the air dried roots of Physalis peruviana and purified by silica gel chromatography. This compound exhibits significant antineo plastic activity. Prismatic pale yellow crystals were obtained from a methanol/acetone solution. The compound crystallizes together with a partially occupied [40(1)%] acetic acid molecule, in space group P2(1)2(1)2(1), Z = 4, D-c = 1.242 g cm(-3), with unit, cell parameters a = 11.431(3), b = 14.104(1), c = 17.387(5) Angstrom, V = 2803.2(11)Angstrom(3), and mu(CuK alpha) = 0.072mm(-1). Through the X-ray analysis the molecule was found to be comprised of a steroidal skeleton with a beta-oriented oxygen bridging atoms C(5) and C(6) in ring B. Steroid ring conformations are: A sofa; B sofa; C chair; D intermediate half-chair/sofa; the lactone ring E has a sofa conformation. All rings of the steroid skeleton are trans connected. The absolute configuration of the Withaperuvin E skeleton corresponds to that of naturally occurring steroids, C(18) and C(19) both being beta-oriented. The partially occupied acetic acid molecule forms a hydrogen bond to the steroid molecule. Hydrogen bonding also occurs between OH(14) and a symmetry related oxygen O(20) of the steroid.