Aroma jasmonate

Wang, D. M., K. Kubota and A. Kobayashi. Optical isomers of methyl jasmonate in tea aroma. Biosci Biotech Biochem 1996 60(3) 508-510. Kitagawa, I., S. Kobayashi, H. Sage-saka and T. Uemura. Extraction of saponins from tea leaves. Patent-Japan Kokai Tokkyo Koho-07 61,998 1995 9 pp. 

The methyl ester of jasmonic acid (methyl 3-oxo-2-(2 -pentenyl)-cyclopentaneacetate) is also known as both an active plant hormone and an important fragrance and flavor component with sweet-floral and jasmine-like aroma notes (13). Methyl jasmonate induces plant systems to provide defense from microbial infection, and is a secondary synthesis product of plants. Methyl jasmonate was also isolated from the Oriental fruit moth, Grapholitha molesta as a part of the male sex hormone (7,75). The authors demonstrated that the volatile form of jasmonic acid, methyl jasmonate, is a major signal molecule for inter- and intra species communications. Methyl jasmonate is expected to have... 

Apple flavor The sometimes marked differences between aromas of individual varieties of apples are mainly due to quantitative variations in the composition of apple flavor substances. Key components are ethyl (+)-2-methylbutanoate and other esters of 2-methylbutanoic acid, in addition to ethyl and hexyl bu-tanoates, hexyl acetate, (E)-2- and (2)-3-hexenyl acetates (see fruit esters) and j3-damascenone. ( )-2- Hexenal, ( )-2- hexen-l-ol, and hexanal (see alka-nals) play a special role in A. f. These are trace aroma substances in intact apples. When the fruit cells are destroyed, the concentration of the Cg units increase strongly due to enzymatic processes. They are the main aroma components of apple juice. Accordingly, the aromas of fresh apples and apple juice differ markedly. Apricot flavor The typical aroma is due to the combined effects of numerous components with flowery and fruity characters these include linalool, 1-ter-pinen-4-ol, a-terpineol (see p-menthenols), 2-phen-ylethanol, a- and )8- ionones, /5- damascenone, and (Z)-jasmone for the flowery part together with fruit esters and lactones, e. g., 4-octanolide, 4- and 5-deca-nolide, 4-dodecanolide (see alkanolides), hexyl acetate and hexyl butanoate for the fruity part, rounded off by benzaldehyde. 

Methyl (Z)-(-)-jasmonate has been identified as a component in the scent of Tunisian rosemary, in the stems and leaves of wormwood (Artemisia absinthium L.), and in the absoiue of tuberose and gardenia flowers. Methyl (Z)-(-)-(3H,7S -jasmonate has been discovered in the oil of lemon peel and in the pheromone of the oriental fruit moth (Grapholitha molesta B.,1 The culture filtrate of the fungus Lasiodiplodia fheobromae contains the free acid. In the oils from the blooms of osmanthus, gardenia and mimosa, (-)-jasmolactone has been found, which is also an important component of tea aroma. [75] On the other hand, the oil from tuberose flowers contains (+)-jasmolactone. 

While the majority of Ru-catalyzed hydrogenation reactions are carried out using preformed and isolated diphosphine complexes, in situ preparation of the active catalyst is in some cases the preferred option. A case in point is the enantioselective hydrogenation of jasmonates developed by Firmenich [96] to produce cis methyl dihydrojasmmiate, an aroma compound with a floral odor (Scheme 41) manufactured on a multi-l/year scale. Key to success was the development of special Ru precursor which is then reacted with the diphosphine of choice. 

Methyl jasmonate has been detected from leaves oi Artemisia absinthium and A. tridentata [102] as well as from the essential oil of rosemary and peppermint [103,104], Although it has been identified as an aroma component of semi-fermented teas [85], it is not clear if methyl jasmonate is present in fresh tea leaves or is produced during the fermentation process. 

The examples of the cis-trans-isomerizoXion are the photoreaction of a-ionone 1 and jasmone 2 as shown in Scheme 6. a-Ionone has a fresh violet-like odor and a warm-woody balsamic-floral odor of deep sweetness and moderate tenacity. It is used widely in all types of perfume compositions (Shibamoto and Mihara, 1983). cz5-a-Ionone is yielded from trans-a-ionone by photo irradiation (Buchi and Yang, 1955). Jasmone, which has a jasmine-like odor, is the principal aroma component in jasmine oil (Nofal et al. 1982 Toda et aL, 1983). On irradiation, jasmone gives the final products trans- and cis-2- 2 -ethylcyclopropyl)-3-methyl-2-cyclopenten-l-one (Tateba and Mihara, 1986). These two products are described as having a waxy, oily, and cz -jasmone-like odor for trans-form and a cz -jasmone-like odor with a mild, minty, and woody undertone for cz5--form. 

In addition to the 5-lactones of structure (41), other lactonic aroma components with a saturated ring are known, the structure of which, however, is somewhat different from that of the n-series represented by (41). These are 6-hydroxy-5-hexanolide (42), identified in tomato (557), and three cyclic compounds carrying an unsaturated chain in position 5, viz. (Z)-7-decen-5-olide (jasmine lactone) (44) 712), identified in the flavor of black tea (50) together with methyl jasmonate (779). (Z)-9-dodecen-5-olide (45) and (Z)-9-tetradecen-5-olide (46), the latter two lactones having been isolated from butter flavor (50, 725). On the other hand, lactone (43) was isolated from milk where it is present in a quantity of 10 pg/kg (0.001 ppb) (247) this quantity, however, is probably much lower than the threshold value. 

Dimethyl sulfide has been reported to be an important aroma compound of green tea, along with benzylaldehyde, benzyl alcohol, cyclohexanones, dihydroactinodiolide, cw-hexen-3-ol, hexenyl hexanoate, cis-jasmone, linalool, linalool oxides, nerolidol, and phenylethanol. ... 

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