萝卡辛; 吐楞宁 beta-D-吡喃葡萄糖甙 | 31282-07-2

• 物质功能分类: 天然产物 - 生物碱
• 分子结构分类: 有机化合物 - 生物碱及其衍生物 - 可吗灵-沙巴秦生物碱
• 中文名称: 萝卡辛; 吐楞宁 beta-D-吡喃葡萄糖甙
• 中文别名: 萝卡辛;吐楞宁beta-D-吡喃葡萄糖甙
• 英文名称: raucaffricine
• 英文别名: [(1R,10S,12R,13E,14R,16S,17S,18R)-13-ethylidene-14-[(2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-8,15-diazahexacyclo[14.2.1.01,9.02,7.010,15.012,17]nonadeca-2,4,6,8-tetraen-18-yl] acetate
• CAS: 31282-07-2
• 化学式: C₂₇H₃₂N₂O₈
• 分子量: 512.56
• InChiKey: OSJPGOJPRNTSHP-RACSMSOZSA-N

物化性质

• 密度：
  1.75±0.1 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  -0.2
• 重原子数：
  37
• 可旋转键数：
  5
• 环数：
  8.0
• sp3杂化的碳原子比例：
  0.63
• 拓扑面积：
  141
• 氢给体数：
  4
• 氢受体数：
  10

反应信息

• 作为反应物：
  描述：

  萝卡辛; 吐楞宁 beta-D-吡喃葡萄糖甙 在 His6-tagged Rauvolfia raucaffricine O-β-D-glucosidase 作用下， 生成 吐楞宁
  参考文献：
  名称：

  Structures of Alkaloid Biosynthetic Glucosidases Decode Substrate Specificity

  摘要：

  Two similar enzymes with different biosynthetic function in one species have evolved to catalyze two distinct reactions. X-ray structures of both enzymes help reveal their most important differences. The Rauvolfia alkaloid biosynthetic network harbors two O-glucosidases: raucaffricine glucosidase (RG), which hydrolyses raucaffricine to an intermediate downstream in the ajmaline pathway, and strictosidine glucosidase (SG), which operates upstream. RG converts strictosidine, the substrate of SG, but SG does not accept raucaffricine. Now elucidation of crystal structures of RG, inactive RG-E186Q mutant, and its complexes with ligands dihydro-raucaffricine and secologanin reveals that it is the "wider gate" of RG that allows strictosidine to enter the catalytic site, whereas the "slot-like" entrance of SG prohibits access by raucaffricine. Trp392 in RG and Trp388 in SG control the gate shape and acceptance of substrates. Ser390 directs the conformation of Trp392. 3D structures, supported by site-directed mutations and kinetic data of RG and SG, provide a structural and catalytic explanation of substrate specificity and deeper insights into O-glucosidase chemistry.

  DOI：

  10.1021/cb200267w

文献信息

• Purification, partial amino acid sequence and structure of the product of raucaffricine-O-β-d-glucosidase from plant cell cultures of Rauwolfia serpentina
  作者：Heribert Warzecha、Peter Obitz、Joachim Stöckigt

  DOI：10.1016/s0031-9422(98)00689-x

  日期：1999.4

  glycosylated. Structural investigation of the enzyme product, vomilenine, demonstrated that the alkaloid exists in aqueous solutions in an equilibrium of 21(R)- and 21(S)-vomilenine in a ratio of 3.4:1. Proteolysis of the pure enzyme with endoproteinase Lys C revealed six peptide fragments with 6-24 amino acids which were sequenced. The two largest fragments showed sequences, of which the motif Val-Thr-Glu-Asn-Gly

  Rauwolfia 的植物细胞悬浮培养物在 1 周内产生大约 250 nkat/l 的 raucaffricine-O-beta-D-葡萄糖苷酶。使用阴离子交换层析、羟基磷灰石层析、凝胶过滤和 Mono Q 和 Mono P 上的 FPLC 层析的五步程序以 0.9% 的产率交付，富含约 1200 倍的葡萄糖苷酶。使用 DEAE 琼脂糖凝胶、TSK 55 S 凝胶层析和 Mono Q 纯化的简短方案得到了 5% 的葡萄糖苷酶回收率，其浓缩了 340 倍。SDS-PAGE显示61kDa酶的Mr。该酶未糖基化。酶产物伏米林的结构研究表明，该生物碱以 3.4:1 的 21(R)- 和 21(S)-伏米林平衡存在于水溶液中。用内切蛋白酶 Lys C 对纯酶的蛋白水解揭示了 6 个已测序的具有 6-24 个氨基酸的肽片段。两个最大的片段显示了序列，其中的基序 Val-Thr-Glu-Asn-Gly 是