Antimicrobial sesquiterpenes

F. S. El-Feraly, T. McPhail and K. D. Onan, X-ray crystal structure of canellal, a novel antimicrobial sesquiterpene from Canella winterana, J. Chem. Soc., Chem. Commun., (1978) 75-76. 

Examples of other antimicrobial sesquiterpenes from the Anthemideae tribe also included new sesquiterpenes from the hexane extract of aerial parts of Santolina rosmarinifolia subsp. canescens (Lagasca) Nyman [175], and the guaiane sesquiterpenes rupicolin A, Fig. (13) and B, 1-deoxy-la-peroxy-rupicolin A and B isolated from Achillea clavennae [25]. 

Examples of other antimicrobial sesquiterpene lactones from the Anthemideae tribe also included those isolated from Anaphalis margaritacea (L.) Benth Hook., Fig. (24) [196], two new antibacterial melampolide-type sesquiterpene lactones from Smallanthus sanchifolius (Poepp. and Endl.) H. Robinson, which exhibited potent antimicrobial activity against Bacillus subtilis and Pyricularin oryzae [197], and six... 

Komaraiah P, Reddy GV, Reddy PS, Raghavendra AS, Ramakrishna S V, Reddanna P (2003) Enhanced production of antimicrobial sesquiterpenes and lipoxygenases metabolites in eUcitor-treated hairy root cultures of Solarium tuberosum. Biotechnol Lett 25 593-597... 

The capsules contained a mean of 82 mg feverfew and thus the level of activity calculated as parthenolide can be estimated as 0.67%. Other studies quote 0.87% sesquiterpene lactones calculated as parthenolide [27] and 0.25-0.30% of active (antimicrobial) material [33]. Bohlmann s extraction of individual components from the dried plant yielded 116 mg sesquiterpene lactones/kg dried feverfew which amounts to less than 0.01 % [17]. Another extraction yielded 330 mg endoperoxides/kg and 56 mg canin/kg alone [19] which would amount to a level of sesquiterpene lactones of at least 0.04%. Thus, the level of sesquiterpene lactones appears to vary with different sources of the plant and this could have been due to a number of factors including the conditions in which feverfew was grown, the season in which it was picked and the way in which it was stored. Another important determinant of the parthenolide content of feverfew appears to be the geographical location. A recent survey of commercial preparations found that all the North American commercial products tested contained less that 0.1% parthenolide, wheras much higher values were obtained for British products. A minimum level of 0.2% parthenolide in commercial products has been proposed by the Health Protection Branch of Health and Welfare Canada [71]. 

Aljancic, I. et al., Flavones and sesquiterpenes from Achillea atrata subsp. multifida antimicrobial activity, J. Nat. Prod., 62, 909, 1999. 

A wide variety of EOs are known to possess antimicrobial properties and in many cases this activity is due to the presence of active constituents, mainly attributable to isoprenes such as monoterpenes, sesquiterpenes and related alcohols, other hydrocarbons and phenols [8, 9]. 

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... 

Jawad, A L.M., Dhahir, A.B.J., Hussain, A.M., Ali, K.F. and Saleh, H.M. (1985) Antimicrobial activity of sesquiterpene lactones extracted from Iraqi plants. Part II. Journal of Biological Sciences Research 16(2), 17-22. 

The first Mexican substance searched for, found, and isolated based on old traditions, was the sesquiterpene hemandulcin from Lippia dulcis Trev. It was determined by a human taste panel to be more than 1000 times sweeter than sucrose. The structure of this sesquiterpene was determined and confirmed by chemical synthesis. It was nontoxic when administered orally to mice, and did not induce bacterial mutation.5 Further work has been carried out with some of the plants more frequently used (Table 12.3). The sesquiterpene alkaloids hippocrateine I, hippocrateine II, and emarginatine were identified in Hippocratea excelsa used in Mexican traditional medicine, and antimicrobial abietane type diterpenes were isolated from Salvia albocaerulea.6 7... 

Eudesmanolide sesquiterpene lactones (G6 G6 C40L) include a variety of variously cytotoxic compounds. The antifeedants alantolactone and isoalantolactone (helenin being a mixture of the two) (C6 ] C5 C40L=CH2) are antimicrobial. The pro-apoptotic activity of these compounds may derive from the reactivity of the a-methylene-y-butyrolactone ring... 

Direct-defense compounds can be either constitutively present in (specific parts of) the plant or be produced after induction by pathogens or herbivores. The latter compound will be less costly for the plant. For example, elicitor-induced accumulation of the antimicrobial sesquiterpenoid capsidiol correlated with the induction of 5-ept-aristolochene synthase, which is a branch-point sesquiterpene cyclase involved in the synthesis of sesquiterpene phytoalexins (8). In rice Oryza saliva L.), 14 diterpenoid phytoalexins have been identified. All these compounds are accumulated in rice leaves after inoculation with the... 

Floral volatiles could play many roles instead of or in addition to pollinator attraction. For example, many terpenes, including P-myrcene, ( )-P-ocimene, linalool, and ( )-P-caryophyllene, react readily with ozone and other reactive oxygen species (27). Thus, floral volatiles could function to protect the reproductive organs from oxidative damage. A variety of monoterpenes and sesquiterpenes is reported to have antimicrobial activity (28). Hence, floral terpenes could help defend floral organs, like the moist stigma, from bacterial or fungal infection. 

Parthenolide located on the surface of the leaves and seeds was found to have antimicrobial properties. This compound was annoimced to be able to inhibit the growth of Gram positive bacteria, yeast and filamentous fimgi [203,204]. T. indicum var. tuneful is also contain sesquiterpene lactones with antimicrobial activity [205]. 

The volatile constituents of Conyza dioscorides L. (Desf.) growing in Egypt showed promising antimicrobial activities against some tested microorganisms [153]. The volatile constituents consisted mainly of sesquiterpene hydrocarbons and oxygenated sesquiterpenes. The major sesquiterpene hydrocarbons are (3-maaliene and a-elemene, while the major oxygenated sesquiterpene compounds are a-cadinol, muurolol, caryophyllene oxide isomers and a sesquiterpene alcohol. 

During the last years, a large number of studies have been performed coneeming the antimierobial activity of terpenoids from the Anthemideae tribe. These reports concerned mainly sesquiterpenes and sesquiterpene laetones. Some of these compounds were isolated by bioassay-guided fractionation, after previously detecting antimicrobial activity on the part of the plant. 

A1 Dabbas et al. [163] reported the antibacterial activity of the ethyl acetate extract of the whole aerial part of Varthemia iphinoides L. The bioassay-guided fractionation led to the isolation and identification of an antibacterial eudesmane sesquiterpene, selina-4,ll(13)-dien-3-on-12 oic acid. Fig. (10). This compound exhibited potent antimicrobial activity against 6 bacterial species Staphylococcus aureus, Bacillus subtilis. Micrococcus luteus, Escherichia coli. Bacillus cereus and Salmonella enter Hides ). The MIC values of this sesquiterpene, which was determined by the agar dilution method, ranged between 250 and 500 ig/ml. 

The methanol extract of the campsite plant Xanthium strumarium (Cocklebur) displayed antimicrobial activity against Proteus vulgaris. Staphylococcus aureus. Bacillus subtilis, Candida albicans and Candida pseudotropicalis [170]. This activity was attributable to the presence of the sesquiterpene xanthanol. 

Antimicrobial substances from the rhizomes of chicory Cichorium intybus) were studied, in connection with a proposed defensive mechanism [174]. A new antimicrobial sesquiterpenoid, 8a-angeloyloxycichoralexin, in addition to guaianolides such as cichoralexin and 1 Oa-hydroxyciclopumilide was isolated. These sesquiterpenes exhibited antifungal activities against Pericularia oryzae, Pellicularia sasakii and Alternaria kikuchiana. 

Bioassay-guided fractionation of the antimicrobial dichloromethane extract from Xanthium spinosum L. yielded xanthatin, Fig. (22) [194]. This compound was active against Colletotrichum gloesporoides, Trichotecium roseum. Bacillus cereus and Staphylococcus aureus. These compounds together with another sesquiterpene lactone xanthinin, Fig. (23) were also isolated from Xanthium italicum Moretti [195]. 

Mentha piperita subsp. citrata Briq. -horteia Tranquilizer Branch (infusion, ingested) Caboclos [57] Essential oils [138,139] flavonoid glycosides [140,141] menthol [142] menthofurolactone [143,144] pyridine-derivatives [145] mintlactone [146] flavones [147] triterpenes [148] terpenoids [149] sesquiterpenic hydrocarbons [150] menthofuran [151,152], Antimicrobial and antioxidant activities [138,265] antiallergic effect [140] anti-nociceptive and anti-inflammatory effects [266]... 

The total synthesis of the antimicrobial drimane-type sesquiterpene (-)-pereniporin A was achieved by the research team of K. Mori. The advanced intermediate bicyclic primary alcohol was first oxidized to the corresponding aldehyde using the Moffatt oxidation. Interestingly, the sensitive a-hydroxy aldehyde moiety in the product remained unchanged. The final step was a global deprotection followed by a spontaneous lactol formation. 

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