Bednarczyk-Cwynar Barbara, Zaprutko Lucjusz
Department of Organic Chemistry, Faculty of Pharmacy, Poznan University of Medical Sciences, Grunwaldzka Str. No. 6, 60-780 Poznan, Poland.
Phytochem Rev. 2015;14(2):203-231. doi: 10.1007/s11101-014-9353-5. Epub 2014 Apr 11.
During the last few decades more and more attention has been paid to triterpenes-a group of compounds with five- or four-ring skeleton and carboxyl, hydroxyl or oxo groups. Triterpenes with unsubstituted C-3 hydroxyl group can be easily transformed into appropriate ketones and then into oximes. The carbonyl group can be created not only from the hydroxyl group at C-3 position, but also at C-2, C-12 or C-28 positions. Several methods of creation of two = NOH groups within one molecule of triterpene are known. There are also known triterpenes with two carbonyl groups, e.g. at C-3 and C-11 positions, which differ in reactivity: among them only C-3 group can be transformed into oxime. A reactive hydroxyimine group can undergo the action of acylating agents, such as carboxylic acids or their derivatives, also the ones with significant pharmacological activity. Acyl derivatives of triterpenic oximes exhibit important pharmacological activity. The biological tests performed with the use of cell cultures inoculated with viruses showed inhibitory activity of some triterpenic acyloximes against type 1 HSV (H7N1), ECHO-6 and HIV-1 viruses. Another acylated oximes derived from triterpenes shown cytotoxic or antiproliferative activity against many lines of cancer cells. In many cases the pharmacological effects of the tested acyloxyiminotriterpenes were comparable to those of appropriate standard drugs. One of the newest application of acyl derivatives of triterpenic oximes is their ability to form organogels.
在过去几十年里，人们越来越关注三萜类化合物——一类具有五环或四环骨架以及羧基、羟基或氧代基团的化合物。具有未取代C-3羟基的三萜类化合物可轻松转化为相应的酮，进而转化为肟。羰基不仅可以由C-3位的羟基形成，也可以在C-2、C-12或C-28位形成。已知有几种在三萜分子内生成两个=N—OH基团的方法。也有已知的具有两个羰基的三萜类化合物，例如在C-3和C-11位，它们的反应性不同：其中只有C-3基团可以转化为肟。一个具有反应活性的羟基亚氨基团可以受到酰化剂的作用，如羧酸或其衍生物，也包括具有显著药理活性的酰化剂。三萜肟的酰基衍生物具有重要的药理活性。使用接种病毒的细胞培养物进行的生物学测试表明，一些三萜酰氧基肟对1型单纯疱疹病毒（H7N1）、埃可病毒6型和HIV-1病毒具有抑制活性。另一些源自三萜的酰化肟对许多癌细胞系表现出细胞毒性或抗增殖活性。在许多情况下，测试的酰氧基亚氨基三萜的药理作用与相应的标准药物相当。三萜肟的酰基衍生物的最新应用之一是它们形成有机凝胶的能力。
