Sharma Venu, Kapoor Kamal K, Mukherjee Debaraj, Gupta Vivek K, Dhar Manoj K, Kaul Sanjana
a School of Biotechnology , University of Jammu , Jammu , India.
b Department of Chemistry , University of Jammu , Jammu , India.
Nat Prod Res. 2018 Aug;32(15):1751-1759. doi: 10.1080/14786419.2017.1402313. Epub 2017 Nov 16.
Phytochemical survey of the methanol extract of the dried aerial parts of Andrographis paniculata led to the isolation of major labdane diterpenes, namely 14-deoxy-11,12-didehydroandrographolide, andrographolide and neoandrographolide. Andrographolide was found to be the major phytoconstituent of the plant which was biologically active. For better physiochemical characteristics and bioefficacy, andrographolide is subjected to semi-synthetic modifications. However, presence of several free hydroxyl groups associated with this molecule make it quite polar and poorly soluble in many organic solvents and hence unsuitable for synthetic modifications. One way of resolving its solubility issue is to protect 1,3-diol quantitatively under mild reaction condition without effecting other functional groups. Reaction conditions were optimised using different solvent systems and catalysts towards this direction. X-ray structure of 3,19-isopropylidene-14-deoxy-11,12-didehydroandrographolide is being reported here for the first time. Isolated compounds and derivatives were confirmed by spectral analysis or X-ray data analysis.
对穿心莲干燥地上部分的甲醇提取物进行植物化学研究，从中分离出主要的半日花烷二萜类化合物，即14-脱氧-11,12-二脱氢穿心莲内酯、穿心莲内酯和新穿心莲内酯。发现穿心莲内酯是该植物具有生物活性的主要植物成分。为了获得更好的物理化学特性和生物功效，对穿心莲内酯进行了半合成修饰。然而，该分子上存在多个游离羟基，使其极性较大，在许多有机溶剂中溶解度较差，因此不适合进行合成修饰。解决其溶解性问题的一种方法是在温和的反应条件下对1,3-二醇进行定量保护，同时不影响其他官能团。朝着这个方向，使用不同的溶剂体系和催化剂对反应条件进行了优化。本文首次报道了3,19-亚异丙基-14-脱氧-11,12-二脱氢穿心莲内酯的X射线结构。通过光谱分析或X射线数据分析对分离得到的化合物和衍生物进行了确认。
