小花八角枝叶中的薄荷烷型单萜

Menthane-type monoterpenes from branches and leaves of Illicium micranthum

目的研究有毒药用植物小花八角Illicium micranthum枝叶的化学成分及其对韭菜迟眼蕈蚊幼虫的毒杀活性。方法利用硅胶柱色谱、Sephadex LH-20凝胶柱色谱等方法对小花八角枝叶的化学成分进行系统的分离，通过质谱、核磁共振谱等波谱方法，结合理化性质分析鉴定化合物结构；采用触杀胃毒联合毒力方法测定化合物2对韭菜迟眼蕈蚊幼虫的毒杀活性。结果从小花八角枝叶甲醇提取物的醋酸乙酯萃取部位分离得到5个薄荷烷型单萜化合物，分别鉴定为（-）-（1R^＊ 4S^＊）-1-羟甲基-2-烯基-4-异丙基-1，4-环己二醇（1）、（1R，2R，4R）．1-甲基-4-异丙基-1，2，4-环己三醇（2）、4．羟基胡椒酮（3）、乳香醇C（4）、α,α-二甲基．4．羟甲基苯甲醇（5）。其中化合物1为新化合物，命名为小花八角素A。结论化合物1为新化合物，化合物2～5为首次从该植物中分离得到。化合物2对韭菜迟眼蕈蚊幼虫的毒杀活性与浓度呈正相关，48h后的LD50值为30．4mg／L，72h后的LD50值为22．5mg／L。

Objective To study the chemical constituents from the branches and leaves oflllicium micranthum and insecticidal activitives on larvae of Bradysia odoriphaga. Methods The chemical constituents were isolated and purified by silica gel, and Sephadex LH-20 column chromatography. Their structures were elucidated by physicochemical properties and spectroscopic analyses. The standard contact and stomach bioassay method was used to assess the effects of median lethal dose （LDs0） of compound 2 on the demographic parameters of larvae of B. odoriphaga. Results Five monoterpenoids were isolated from the ethyl acetate layer of methanol extract from the branches and leaves of I. micranthum. Compound 1, （-）-（1R＊,4S＊）-l-（hydroxymethyl）-4-isopropylcyclohex-2-ene-l,4-diol, was a new monoterpenoid and named as illicmicrene A, and the other compounds were identified as （1R,2R,4R）-l-methyl-4-（1-methylethyl）- 1,2,4-cyclohexanetriol （2）, 4-hydroxypiperitone （3）, olibanumol C （4） and ct,ct-dimethyl-4-hydroxymethylbenzyl alcohol （5）, respectively. Conclusion Compound 1 is isolated as a new compound and compounds 2--5 are obtained from I. micranthum for the first time. Furthermore, compound 2 shows the insecticidal effects on larvae ofB. odoriphaga with LD50 values at 30.4 mg/L after 48 h, at 22.5 mg/L after 72 h.