甾醇及其衍生物的质谱学规律（Ⅰ）．△^（5，22）—、△^（5，24（25））—、△^（5，24（28））—甾醇乙酸酯的质谱特征

The Regular Patterns of Mass Spectrometry of Sterols and Related Derivatives(I). Mass Spectrometric Fragmentation Typicality of 5, 22-Dien-; 5, 24(25)-Dien-and 5, 24(28)-Dien -Steryl Acetates Steryl Acetates

质谱学在新的甾醇特别是海洋甾醇的结构鉴定中起到了至关重要的作用。对质谱的确切解释需要对甾醇的关键裂解规律有足够的了解。本文总结了如下三类甾醇乙酸酯中最重要碎片峰的裂解机理的解释：（１）△５，２２—甾醇乙酸酯；（２）△５，２４（２５）—甾醇乙酸酯；（３）△５，２４（２８）—甾醇乙酸酯。我们将此规律应用于南海海绵甾醇的结构鉴定中。

Mass spectrometry plays a crucial role in the structure elucidation on new sterols,notably those from marine organism. Secure interpretation of the mass spectra requires an adequate understanding of the mechanism of the key fragmentation processes of steroids and the present paper summarizes the elucidation of the fragmentation mechanism of the most important peaks of the following classes of steryl acetates: (1) 5, 22dien - ;(2) 5, 24 (25)-dien - ; and (3) 5, 24 (28)-dien-steryl acetates. Attention is drawn to the utility of such mass spectral decompositions in structure elucidation of the marine sterols isolated from the South China Sea sponges.