A NOVEL METHOD FOR CONSTRUCTION OF SIDE CHAIN OF BRASSINOSTEROIDS

Construction of the side chain of brassrnolide and its related compounds by the aldolreaction of lithofuran with 22-steroidal aldehyde obtained from hyodeoxycholic acid isdescribed. A key intermediate, 22R, 23R-γ-hydroxy-α, β-unsaturated lactone (16) wassynthesized.     

I_2-KIO_3-AcOH-H_2O体系氧化3,5-环-24S-乙基-胆甾-22烯-6-酮反应的研究

油莱甾醇内酯(Brassinolide)(1)是一种高效的植物生长激素,其生理活性与侧链中C_(22)、C_(23)的构型密切相关。当C_(22)、C_(23)为S、S构型时,其活性仅为1的十分之一。在1的     

25,26,27-三失碳-B-高-7-氧-6-酮-5α-胆甾-3α,24-二醇的合成

本文报道以3α-羟基-6-羰基-5α-胆烷酸甲酯(3)为原料经六步反应合成了油菜甾醇类似物25,26,27-三失碳-B-高-7-氧-6-酮-5α-胆甾-3α,24-二醇(9a).总产率14%.9a的促进植物生长作用是24-表油菜甾醇内酯的60%.     

Studies on the Model Synthesis of the Brassinolide and Dolicholide‘s Side Chains

A highly stereoselective synthesis of the side Chain enantiomers of brassinolide and dolicholide through an aldol reaction of 2-(4-methoxy benzyloxyl) proplonylaldehyde (5) with the anion of 1- ( tert -butyldimethylsiloxy )-3-methyl-2-butanone ( 6 ) is described.     

Manifestation of structure and intermolecular interactions of biologically active brassinosteroids in infrared spectra

We have analyzed the IR spectra obtained for steroidal phytohormones 24-epibrassinolide, 24-epicastasterone, 28-homobrassinolide, and 28-homocastasterone. The characteristic frequencies of the stretching vibrations of the hydrocarbon groups CH₃, CH₂, and CH and also the C=O groups in the spectra of brassinolides are higher than in the spectra of castasterones, which makes it possible to identify them from the IR spectra. Study of the spectra of these brassinosteroids in different media (pressed samples in KBr, films, solutions in CHCl₃ and CDCl₃) allowed us to establish the presence of intermolecular interactions in which C=O and OH groups, OH-OH groups participate, and also the possible formation of intramolecular hydrogen bonds between the OH groups of the molecules. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 5, pp. 610–616, September–October, 2007.     

高效液相色谱法测定22S，23S，24R表高油菜素内酯

The sample was dissolved in ethyl acetate and reactcd with pbenylboronic acid at 80°for 3Omin.Then itwas detemined by HPLC using UV detector at 222nm. The linear relations between the amounts and thepeak areas in the range of 0. 02mg/mL to 0.12mg/mL were staisfactory(γ=0. 9999,n=6). Average recovery was 99.27%～101.5%.     

油菜甾醇内酯及其类似物的侧链部分合成新方法

以豆甾醇为原料，合成了油菜甾醇内酯及其类似物的侧链部分；并为这一类化 合物的侧链部分的合成提供了一条简便、经济、高效的合成方法。其关键步骤为醛 5及酮6之间的不对称Aldol反应，以及羰基α位的差向异构化反应。     

新型绿色植物生长调节剂——芸苔素内酯的研究进展*

芸苔素内酯是一种新型绿色环保植物生长调节剂,具有促进植物生长、提高植物抗逆抗病能力、改善植物生长品质等多方面功能,被视为第六类植物生长激素。概述了芸苔素内酯的研究进展,介绍了芸苔素内酯在农业生产中的应用,为推动芸苔素内酯的广泛使用提供参考。