Progress in Essential Oils

By: Brian M. Lawrence

Posted: August 23, 2006, from the September 2006 issue of P&F magazine.

Tagetes Oil

Garg and Mehta (1998) characterized three new acyclic monoterpene ketones in a steam-distilled oil of Tagetes minuta. They were 3,7-dimethyl-1-octen-6-one, 3,7-dimethyl-5-hydroxy-1-octen-6-one and 3,7-dimethyl-1,7-dien-6-one. The main constituents of this oil were found to be:

(Z)-beta-ocimene (38.72 percent)

dihydrotagentone (9.07 percent)

(Z)-tagetone (7.00 percent)

(Z)-tagetenone (7.00 percent)

(E)-tagetenone (13.00 percent)

Larrán et al. (2001) screened a number of oils against the causal fungus of the chalkbrood disease of honeybees. One of the oils screened was T. minuta, produced from plants cultivated in Argentina. The main constituents of this oil were found to be:

limonene (3.2 percent)

(Z)-beta-ocimene (44.3 percent)

dihydrotagetone (7.2 percent)

(E)-tagetone (5.3 percent)

(Z)-tagetone (0.7 percent)

(Z)-tagetenone (12.2 percent)

(E)-tagetenone (7.7 percent)

The main constituents of T. minuta oil, produced from plants grown in Kumaon, Uttaranchal (India), were the subject of analysis by Chowdhury (2001). He characterized the following constituents in this oil:

alpha-pinene (2.18 percent)

myrcene (5.94 percent)

isolimonene† (4.63 percent)

p-cymene (2.10 percent)

beta-ocimene* (0.50 percent)

1-penten-3-ol† (5.10 percent)

dihydrotagetone (3.50 percent)

linalool (1.68 percent)

linalyl acetate (2.24 percent)

carvotanacetone† (1.37 percent)

2-nonanone† (2.68 percent)

beta-cubebene† (3.75 percent)

menthol† (1.84 percent)

tagetone* (17.40 percent)

beta-ionone* (3.06 percent)

alpha-terpineol (1.35 percent)

gamma-terpineol‡ (1.20 percent)

neral + geranial† (2.27 percent)

phenylacetaldehyde† (1.72 percent)

tagetenone* (1.10 percent)

beta-caryophyllene (11.07 percent)

beta-bisabolene (2.45 percent)

nerolidol* (0.93 percent)

spathulenol (2.88 percent)

carvacrol† (3.72 percent)

isoeugenol*† (2.69 percent)

†questionable identity; *correct isomer not identified; ‡natural occurrence of this compound has never been unequivocally proven

This is only an excerpt of the full article that appeared in P&F Magazine, but you can purchase the full-text version.