Terpenoids antimicrobial activity

Abstract Recent chemical studies on the marine soft corals and terrestrial plants have lesnlted in the isolation of several novel componnds. The soft corals, Pseudopterogorgia elisabethae and Cladiella species yielded several novel terpenoids, exhibiting antimicrobial activities. New steroids were isolated from terrestrial fungi, Mucor plumbeus and Coprims micaceus. Phytochemical studies on the Buxus hyrcana, collected from Iran, have yielded steroidal bases. This revdew describes the new natiual products exhibiting different bioactivities from the aforementioned sources. 

Secondary metabolites include essential oils, used in the flavour and fragrance industries. Essential oils are found in over 50 plant families and represent terpenoids and other aromatic compounds accumulating typically at relatively low concentrations (usually <1% of fresh weight, but can be up to 20%), but which have useful antimicrobial activity (Biavati el a/., 2003). Production of essential oils by plants is affected by many factors influencing plant growth. 

GRIFFIN, S.G., WYLLIE, S.G., MARKHAM, J.L., LEACH, D.N., The role of structure and molecular properties of terpenoids in determining their antimicrobial activity, Flavour and Frangrance J., 1999,14,322-332. 

Volatile or essential oils, as their name implies, are volatile in steam and are generally complex mixtures of hydrocarbons and oxygenated compounds derived from these hydrocarbons. The odour and taste of volatile oils is mainly determined by these oxygenated constituents. In chemical structure, most essential oils are terpenoids in origin. Testing and evaluation of the antimicrobial activity of essential oils is difficult because of their volatility, their water insolubility and their complexity. However, in recent years a large number of studies have been conducted on the antimicrobial activity of essential oils from the Anthemideae tribe. These reports concerned mainly the genera Achillea and Artemisia. 

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. 

Pisiferic acid (196), an abietane type diterpene acid was isolated [76] from the leaves and twigs of Chamaceyparis pisifera. This diterpene shows antimicrobial activity specially against all grampositive bacteria tested. The first total synthesis [77] of ( )-pisiferic acid (196) was reported by Matsumoto and Usui. In connection with research towards the synthesis of terpenoid compounds and in view of the antimicrobial activity of pisiferic acid (196), an alternative synthesis [78] was developed which is described in "Fig (16)". 

These compounds are also important constituents of the aroma of tomatoes, tea, strawberry, oUve oil, grape, apples, and pear. Moreover, plant essential oils, composed mainly by terpenoids, were extensively studied for their antimicrobial activity against many microorganisms including several pathogens. In particular, the activity of oils from Labiatae and citrus fruits were investigated. 

Rosemary is composed of various phenolics such as rosmarinic acid, the flavonoid hesperidin, and the terpenoids camosic acid, camasol, and rosmanol (Al-Sereiti et al. 1999). Rosemary is well known for antioxidant and antimicrobial activity (Naghibi et al. 2005). Multiple extracts and bioactive constituents of rosemary were evaluated for in vitro effect on human cancer cells (Yesil-Celiktas etal. 2010). These included human small cell lung, prostate, liver, breast, and myeloid leukemia, all rosemary extracts and finctionated compounds were toxic to the cell lines at low doses but camosic acid was most effective (Yesil-Celiktas et al. 2010). Bakirel etal. reported in 2007 that ethanol extracts of rosemary reduced blood glucose, and increased insulin levels of rabbits with induced diabetes. They also noted increased levels of the antioxidants SOD and CAT in these animals. 

Xenia macrospiculata Terpenoids (diterpenes) Crude extract and desoxyhavannahine Antimicrobial activity against Arthrobacter sp. [76]... 

About 120 chemical constituents have been identified in chamomile as secondary metabolites, including 28 terpenoids, 36 flavonoids and 52 additional compounds [4]. A substantial part of drag effects are determined by the essential oil content. Oil is collected from flower heads, either by steam distillation or solvent extraction, for yields of 0.24-1.90% of fresh or dry plant tissue. Among the essential oil constituents the most active are /-/-a-bisabolol and chamazulene. /-/-a-bisabolol has demonstrated anti-inflammatory, antispasmodic, antimicrobial, antiulcer, sedative and CNS activity. Chamazulene is also anti-inflammatory. Topical applications of chamomile preparation have shown benefit in the treatment of eczema, dermatitis and ulceration [5]. 

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]... 

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