Plants non-nutritiously ingested by wild chimpanzee, and their bioactive constituents

野生黑猩猩食用的非营养性非洲植物作为发现具有生物活性的天然产物的新途径，一直受到人们的关注。收集到的几种植物具有显著的生物活性，如细胞毒性、酶活性抑制、免疫抑制和抗菌活性。苦杏仁的生物活性特别广泛和有效。在坦桑尼亚的马哈尔山国家公园，实地调查人员（M.Huffman）观察到生病的黑猩猩将这种极苦的植物用作药物。从该植物中分离得到倍半萜内酯和甾体相关成分。苦倍半萜内酯具有较强的细胞毒性和抗菌活性。所有类固醇相关成分都是新的，并且一些分离的糖苷尝起来也很苦。使用这种植物的黑猩猩曾被认为患有与寄生虫有关的疾病。马鞭草苷、马鞭草苷B_1及其天然苷元等倍半萜内酯具有显著的体外抗寄生虫活性。主要的倍半萜内酯弗诺达林对感染尾蚴的小鼠具有高毒性。髓的使用似乎是马哈尔黑猩猩使用的常见部位。内酯在叶子中大量存在，在树皮中少量存在。然而，它在髓中被检测到是微不足道的。另一方面，马尾草苷B_1及其苷元在各部位的含量均较高。在此基础上，研究人员假设马哈尔的黑猩猩通过摄入含有类固醇相关成分的植物的髓来控制与寄生虫有关的疾病。

As a new approach to discovering bioactive natural products, African plants non-nutritiously ingested by wild chimpanzees have been focused on. Several plants collected possessed significant bioactivities such as cytotoxicity, enzyme-activity inhibition, immuno-suppression, and antiparacitic activities. Bioactivities of Vernonia amygdalina were particularly broad and potent. Medicinal use of this highly bitter plant by sick chimpanzees had been observed by the field survey (M.Huffman) at the Mahale Mountains National Park, Tanzania. From this plant, sesquiterpene lactones and steroid related constituents were isolated. The bitter sesquiterpene lactones showed potent cytotoxic and also antibacterial activities. All of the steroid related constituents were new, and some of the isolated glucosides also tasted bitter. Chimpanzee used this plant had been thought to suffer from parasite-related diseases. The sesquiterpene lactones including vernodalin and major steroid related constituents, vernonioside B_1 and its natural aglycone showed significant antiparasitic activities in vitro. The major sesquiterpene lactone, vernodalin, was highly toxic to cercaria-infected mouse. The use of the pith seems to be the common part used by chimpanzees at Mahale. The lactone was shown to occur abundantly in the leaves, and slightly in the bark. While, it was negligibly detected in the pith. On the other hand, the levels of vernonioside B_1 and its aglycone were comparably high in all of the plant parts. Based on these, chimpanzees at Mahale were hypothesized to control parasite-related diseases by ingesting the pith of the plant containing steroid-related constituents.