Artemisia santolina

Above right) Drought-tolerant herbs Rosemary and lavender (pictured) are perfect companions in a dry, sunny spot. Other drought-tolerant herbs include sage, thyme, curry plant, cotton lavender (santolina), and artemisia. 

In the laboratory, however, the route from prenyl ethers or thioethers to artemisia compounds and thence to the santolina skeleton is possible, and an interesting conversion to the lavandulyl skeleton of prenyl compounds has been described. A mixture of 3-methylbut-2-enyl acetate (44) (or chloride) and 3-methylbut-2-enylthiol acetate (45) is treated with aluminium chloride or zinc chloride, when, in addition to the thioether (46), 19% of the lavandulylthiol acetate (47) and 6% of the corresponding isolavandulyl compound (48) are formed. An ingenious two-step synthesis of trans-chrysanthemyl alcohol (49) has also been achieved from prenyl alcohol (50) and 3-methylbut-l-yn-3-yl... 

Karamenderes et al. [67] reported the composition and antimicrobial activity of the essential oils obtained from Achillea millefolium L. subsp. pannonica (Scheele) Hayek, Achillea millefolium subsp. millefolium, Achillea arithmifolia Waldst Kitt and Achillea kotschyi Boiss. subsp. kotschyi, four Achillea species from Turkey. 1,8-cineole, Fig. (2), artemisia alcohol and ascaridole were identified as major components. The essential oils showed antibacterial and antifungal effects even with low concentrations. The essential oil of the flowering tops of another Achillea species, Achillea fragantissimum (Forsk.) Sch. Bip growing in Sinai, was analyzed [68]. Santolina alcohol, a- and P-thujone, Fig. (5) and artemisia ketone account for approximately 80% of the oil. The oil showed marked antimicrobial activities against Escherichia coli. Bacillus subtilis and Staphylococcus aureus. 

Artemisia species are rich sources of irregular monoterpenes. Thus Artemisia vulgaris contains a number of lyratol (195) esters, santolina alcohol (196) acetate, and the more oxygenated santolina compounds 197 and the two alcohols 198. The (Z)-isomer of lyratol acetate was also found. Lyratol (195) and its acetate... 

Occurrence Usually a mixture of A. and iso-A. is isolated Artemisia oil, obtained from the annual mugwort. (Artemisia annua, Asteraceae) in the flowering season contains a ca. 30% mixture of A. and iso-A. 65% mixtures occur in the essential oil of lavender cotton (Santolina chamaecyparissus, Asteraceae). 

Artemisia ketone (94), derived from IPP and DMAPP in Santolina chamaecyparissus, is asymmetrically labeled that is, the label from IPP is incorporated at much greater levels than that from DMAPP (Allen et al., 1977). A dehydrogenase system rather than a mixed-function oxidase (MFO) system based on cytochrome P-450 appears to be involved in formation of artemisia ketone. 

In cell-free extracts of Artemisia annua and Santolina chamaecyparissus, chrysanthemyl alcohol and its pyrophosphate are incorporated into artemisia ketone and alcohol. Artemisia alcohol (95) is converted into artemisia ketone (94) and tranj-chrysanthemic acid in the preparation from S. chamaecyparissus (Banthorpe et al., 1977a). IPP and DMAPP are incorporated into irregular monoterpenes whereas geranyl and neryl-OPP are not. An enzymatic sulf-hydryl group is involved. 

In the buffered hydrolysis of N-methyl-4-(chrysanthemyloxy)-pyri-dinium iodide (16-OPy-hI ), a leaving group which is expected to minimize internal return, the naturally occurring allylic isomers, artemisia and yomogi alcohols (18 and 19) are the major products, but a small amount (0.5%) of santolina alcohol (17) is present (66, 67). Similar results have been reported for amine deamination (69) and dinitro-benzoate solvolysis (66, 67, 70). The absolute configuration of natural santolina alcohol corresponds to that of chrysanthemic acid, as predicted by the Bates and Paknikar biogenesis (73). 

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