Mentha spp

Ravid U, Putievsky E, Katzir I, Enantiomeric distribution ofpiperitone in essential oils of some Mentha spp., Calamintha incana (Sm.) Heldr. and Artemisia judaica L, Flavour Fragr J, 9 85-87, 1994. 

HAUDENSCHILD, C., SCHALK, M., KARP, F., CROTEAU, R. Functional expression of regiospecific cytochrome P450 limonene hydroxylases from mint (Mentha spp.) in Escherichia coli and Saccharomyces cerevisiae, Arch. Biochem. Biophys., 2000,379, 127-136. 

Piperitone Mentha spp. (Lamiaceae), Eucalyptus dives OD-R (camphor- ... 

Mentha spp., Hyssopus spp. (Lamiaceae), Citrus sinensis (orange), C. limon (lemon), Citrus spp., Poncirus trfoliata (Rutaceae) [leaf]... 

Menthol is a well-known terpenoid from the essential oil of mint Mentha spp.) (15), and is described here as a representative of the different acyclic and cyclic plant monoterpenoids. Because of its pleasant odor, taste, and anesthetic and antimicrobial effects, (-)-menthol is an industrially important terpenoid and is produced commercially in large scale both from the essential oils of Mentha spp. and by asymmetric synthesis. The essential oil is produced in glandular trichomes, which are secretory cells that number in the thousands on Mentha leaves. The presence of these specialized cells, which easily can be separated physically from other cell types, has greatly facilitated studying (-)-menthol biosynthesis. 

Some of the more interesting and attractive groups of native species include the skullcaps (Scutellaria spp.), physostegias (Physostegia spp.), hemp-nettles (Stachys spp.), sages (Salvia spp.), horse-mints or bergamots (Monarda spp.), bugle-weeds (Lycopus spp.), and tme mints (Mentha spp.). 

Time-course studies with 14COa showed that in a Thymus sp., y-terpinene was converted into p-cymene and thymol in sequence,916 and the appropriate y-terpinene synthetase (MW ca. 96 000) was partially purified. Tracer studies indicated that loss of a proton from C-5 of the a-terpinyl-like precursor to form the A4-un-saturation was accompanied, perhaps concertedly, by a 1,2-hydride shift from C-4 to C-8 to form y-terpinene.917 Neomenthyl-p-D-glucoside was a major metabolite of menthone in Mentha spp.,918 and a cell-free extract also acetylated menthol.919 Detailed in vivo and in vitro investigations revealed that in leaf discs the bulk of the neomenthol and menthol (produced from menthone) was converted into the gluco-... 

Tissue Cultures, Microbial Transformations.—Little success has rewarded the search for cell cultures that effectively biosynthesize monoterpenes de novo. The most impressive studies utilize cultures from a variety of Mentha spp. yields of oil were some 60 % (w/v) of those in the parent plants, but the monoterpene products were generally more oxidized (i.e. ketones extra C=C bonds predominated). In vitro, oxidation at C-3 of the menthane skeleton was also restricted, apparently owing to an inhibition of the enzymic reduction of the 4(8) double bond in the intermediates formed.925 926 Colchicine stimulated synthesis of essential oil by Mentha cultures.927 Iridoid glucosides have been produced by cultured cells of Gardenia spp.673 Menthone was biotransformed to neomenthol by Mentha suspension cultures,928 and Nicotiana lines oxidized linalool and its derivatives at C-10 to aldehydes and alcohols,929 and also foreign substrates such as a-terpineol (at C-6 and C-7) and /raw.s-/ -menthan-9-en-l-ol (at C-4 and C-10).930... 

Related studies record the change in monoterpene corporation during maturation of Sequoia spp.949 and the similar variations of menthol and its p-glucoside in Mentha.950 Hybridization experiments have shown that the occurrence of 60—90% pulegone in certain strains of Mentha spp. resulted from the lack of the genes necessary to reduce this ketone to menthone or to oxidize it to menthofuran.951 A detailed genetic analysis of menthone-isomenthone production in Mentha spp. has also been described.952... 

The most recent group of botanical products that have seen some commercial success as insecticides are the plant essential oils. Though some of these have traditional uses dating back decades, if not longer, commercialization has only taken place in the past 7-8 years. Plants producing essential oils that have been exploited for insect control include a number of herbs, most notably from the mint family (Lamiaceae), such as garden thyme Thymus vulgaris L.), rosemary Rosmarinus officinalis), and various species of mint Mentha spp.). ... 

Mint Mentha spp. menthol, pulegone Tetranychus urticae [14]... 

Synonyms Cyclohexanol, 2-isopropyl-5-methyl- Cyclohexanol, 5-methyl-2-(1-methylethyl)- Hexahydrothymol 2-lsopropyl-5-methylcyclohexanol 3-p-Menthanol p-Menthan-3-ol 5-Methyl-2-isopropylcyclohexanol 5-Methyl-2-isopropyl hexahydrophenol 5-Methyl-2-(1-methylethyl) cyclohexanol Peppermint camphor Racemic menthol Classification Diterpene alcohol Definition Alcohol obtained from diverse mint oils, Mentha spp. or prepared synthetically may be levorotatory (I-), from natural or syn. sources, or racemic (dl-)... 

These are almost universal in essential oils, acting also as precursors of the more complex, oxidised terpenes. Limonene, for example, is the precursor of the main constituents of the monoterpenes in mints, Mentha spp. (Lamiaceae), including carvone and menthol... 

The most important compounds are menthadienes, derived from p-menthane, which differ in the positions of the double bonds (8-5). A common hydrocarbon is limonene (p-mentha-1,8-diene), which typically occurs in many essential oils (such as essential oils of citruses, mints and conifers) and turpentine. For example, the (-1-)-limonene isomer is the major component (>90%) ofessentialoilsof citrus peels, (-)-Kmonene is a component of essential oils of different types of mint Mentha spp., Lamiaceae) and conifers. Racemate, which is trivially known as dipentene, occurs in many essential oils. Other important menthadienes include a-terpinene (p-mentha-1,3-diene), y-terpinene (p-mentha-1,4-diene), a-phellandrene... 

Analysis of individual forms is also important to determine the authenticity of foods or essential oils. The presence of certain forms, such as the geometrical (E)-isomers, is often evaluated as an off-flavour. For example, (-F)-(E)-Hmonene (8-5) is a natural component of citrus essential oils and has a citrus smell like oranges. The isomer (-)-(S)-limonene (8-5), which is the main component of essential oils of silver fir Abies alba, Pinaceae), other conifers and various types of mints Mentha spp.), has a smell reminiscent of turpentine. The alcohol (-)-(E)-Hnalool, also known as licareol (8-18) has a strong woody smeU like lavender, but (-F)-(S)-isomer, also known as coriandrol (8-18) has a sweet smell with lavender tones. Another alcohol (-)-(E)-oct-l-en-3-ol (8-16), has an intense smell of fresh mushrooms, but (-F)-(S)-isomer (8-16) has a smell resembling vegetables with faint mushroom notes. The ketone (-)-(E)-carvone (8-50) has a mint-like smell (and is the main component of spearmint essential oil), while its isomer (-F)-(S)-... 

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