选定日本75#高碳精钢，五环高硬度的弹簧作为坚强核心。
五环三萜类化合物抗人肺癌细胞侵袭和诱导细胞凋亡的研究
1988年的汉城奥运会犹如一只浴火的凤凰，令五环终于飘扬在亚洲的天空；
1·Aim: to search for novel modulators of glycogen metabolism through structural modifications of natural pentacyclic triterpenes.
目的：对天然五环三萜进行结构修饰，寻找新型糖原代谢调控药物。
2·This article is reviewing the structure-activity relationship of pentacyclic triterpenes.
笔者讨论了一些五环三萜类化合物的药理活性与结构的关系。
3·Ginsenoside, the main components of ginseng, is dammarane tetracyclic triterpenoids or hong resin alkyl type pentacyclic triterpene, which has not yet been synthesized artificially.
其主要功能成分是人参皂苷，即达玛烷型四环三萜类或香树脂烷型五环三萜类化合物，至今人参皂苷尚未能人工合成。
4·Ursolic acid, a pentacyclic triterpene compound, naturally occurs in a large variety of plants, has attracted considerable interest owing to its significant biological activities.
熊果酸属于五环三萜类化合物，广泛存在于天然植物中，具有多种显著的药理活性。
5·Pentacyclic triterpenes are among the most important bioactive compounds and biotransformation is a very useful tool to carry out the structural modification on these compounds.
五环三萜是一类重要的天然产物，研究发现生物转化能够对该类化合物进行多种类型的结构修饰。