Sesquiterpenes biological activities

Biosynthesis of ( , )-Famesyl Pyrophosphate Interconversion of 2-E-6-E- and 2-Z-6- -Famesyl Pyrophosphate Acyclic Sesquiterpenes Cyclization of Acyclic Precursors The Origin of Major Groups of Cyclic Sesquiterpenes Biological Activity Allelopathy Medicinal Properties... 

Chemistry and biological activity of artemisinin (sesquiterpene y-lactone with oxepane fragment and transannular peroxide bridge) and related antimalari-als 99H(51)1681. 

Composites -have been reported (8) to contain a wide variety of sesquiterpene lactones and lactones of this type have been previously found in both Russian knapweed and yellow starthistle (9,10,11,12). The wide range of biological activity associated with sesquiterpene lactones, e.g., cytotoxicity, phytotoxicity, antineoplasticity, etc. (8) suggested the possibility that these compounds may play a role in the allelopathy of both Russian knapweed and yellow starthistle. 

One final comment on the biological activity of the sesquiterpene lactones in relation to ENE disease in horses. Unfortunately, horses are the only animal which contract this disease. Consequently, acquiring sufficient pure material to be fed to horses becomes a formidable task. At the present time, trial studies are being initiated with solstltlalln-A to observe its effect on horses. Insufficient material is available to permit the testing of the other sesquiterpene lactones. 

Effects of Sesquiterpene Lactones on Seed Germination. Sesquiterpene lactones are common constituents of the Asteraceae but are also found in other angiosperm families and in certain liverworts (31,32). These highly bitter substances exhibit a wide spectrum of biological activities (J 3) which include cytotoxicity, anti-tumor, anti-microbial, insecticidal (34) and molluscicidal (35) properties. Furthermore, they are known causes for livestock poisoning and contact dermatitis in humans (33). Structure-activity relationship studies on sesquiterpene lactones have demonstrated that biological activity frequently depend on the presence of the cr... 

Farnesylamine (123) (Fig. 20), a sesquiterpene alkaloid, was recently detected in whole extracts of Monomorium fieldi [129]. This compound had already be prepared by synthesis and found to display a whole range of biological activities. Among others, it inhibits arthropod molting, squalene synthesis, and the growth of malignant tumor cells, modulates human T cells and has anti-osteo-porosis activity [129]. 

There have been no reports on the chemical synthesis of parthenolide or indeed on the modification of the biological activity (see below) of parthenolide or the sesquiterpene lactones in general. However, routes for the synthesis of constunolide have been reported [23-25]. 

One of the first biological activities for which sesquiterpene lactones were screened was their possible anti-tumour activity. Studies have shown that... 

A different cychzation reaction of 460, by treatment with iodine and silver oxide, gave l,6-dioxaspiro[3.4]octanes 469 (Scheme 130). This heterocychc core present in a series of sesquiterpenic lactones has interesting biological activity and is isolated as secondary metabolites from species of the Compositae family . 

Terpenoids are a diverse group of conqiounds showing a wide spectrum of biological activities. Among the most biologically active terpenoids are the sesquiterpene lactones. Their biological activity has been reviewed (56, 57, 58). 

The biological activity and toxicity of terpenoids to herbivores has been discussed (56,84) and representatives of each major type of terpene are known to be active. Well known examples are sesquiterpene lactones, pyrethrins, and several classes of diter-penes and triterpenes. 

A number of sesquiterpenes have been demonstrated to have pronounced biological activity ( ) among the non-volatile compounds the sesquiterpene lactones are best known (M) but other oxygenated sesquiterpenes are also known to be active. For example, the role of gossypol, a dimeric sesquiterpene and structurally related compounds has been investigated (21,22). The oxygenated sesquiterpenes, shiromodiol monoacetate and diacetate, from Parabenzoin trilobum (=Lindera triloba Blume) possess potent anti feeding activity toward Spodoptera litura larvae (85). 

Biendl, M., Hauptmann, H. and Sass, H. (1989). Periplanone Di and periplanone D2 two new biologically active germacranoid sesquiterpenes from Periplaneta americana. Tetrahedron Letters 30 2367-2368. 

Puupehenone (63) is a member of a distinctive family of sponge metabolites — a sesquiterpene joined to a C6-shikimate moiety — first exemplified by the quinol-quinone pair of avarol and avarone. Among the varied activities that have been reported for this diverse class of compounds is the property of ilimaquinone to inhibit replication of the HIV virus.78 Preliminary screening of puupehenone against Mycobacterium tuberculosis showed 99% inhibition of the organism. A series of chemical modifications have been conducted on puupehenone to study the effect on its biological activity. 

From another Dysidea sponge species, Dysidea avara, the sesquiterpenes avarol, Fig. (9) and avarone, Fig. (10), which show a wide variety of biological activities, were first isolated. Both compounds are potent antileukemic agents in vitro and in vivo. They were determined to be neither direct mutagens nor premutagens, and they displayed antimutagenic activity... 

The sesquiterpene quinones and hydroquinones display a wide range of biological activities.4 Some of the compounds are cytu-toxic, whereas others show antimicrobial characteristics. Avarol (2) has been the subject of investigation as a consequence of its ability to inhibit reverse transcriptase, but no clinical value (as an anti-AIDS agent, for example) has yet been established.3... 

Pieman, A.K. Biological activities of sesquiterpene lactones. Biochem Syst Ecol 1986 4 255-281. 

Sesquiterpene lactones (SL) constitute a numerous group of compounds with several biological activities reported, usually related to the presence of an a, 3-unsaturated carbonyl system in the lactone ring.42 This is a very common chemical feature in these compounds, and their alkylating properties through Michael addition reactions are considered as responsible for such activity.16... 

The nucleophilic properties of groups such as -NHR and -SH have been reported in natural Michael acceptor systems present in many natural products. Typical examples are the addition of the sulfhydryl groups of glutathione to the exocyclic methylene of sesquiterpene lactones (Fig. 6.7).14,41 Such interactions have been considered as responsible for the biological activity observed in many natural products, and this is again the case in Zwanenburg s hypothesis for strigolactones. 

Participation of Br in marine terpene biosynthesis (Section II.C) is reflected in the impressive number (several hundred) of halogenated terpenes, some with useful biological activities, that have been identified. For example, the poly halogenated sesquiterpenes isoobtusol (14) and isoobtusol acetate (15), isolated from the red alga Laurencia obtussa, showed potent activity against HeLa 229 human carcinoma cells1011. 

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