Alantolactone

Other interesting synthetic applications of the ketone-derived enamine alkylation are found in the monomethylation of steroid enamines (249), extension of the benzylation reaction (250) to a ferrocene derivative (251), the use of a-bromoesters (252) and ketones (252) or their vinylogues (25J), in the syntheses of alantolactone (254-256), isoalantolactone (257), and with a bridged bis-enamine (258). The use of bifunctional alkylating agents is also seen in the introduction of an acetylenic substituent in the synthesis of the characteristic fragrant constituent of jasmine (259), the synthesis of macrocyclic ketolactones (260), the use of butyrolactone (261), and the intermolecular or intramolecular double alkylations of enamines with dihalides (262). 

Alantolactone, CjjH oOj, also known as helenin, is a constituent of the essential oil of Imda hdenium. It is a crystalline compound, melting at... 

Alantolactone forms a hydrochloride melting at 117°, a hydrobromide melting at 106°, a dihydrochloride melting at 127° to 134°, and a dihydrobromide melting at 117°. 

Helenin Hesperidene Heterob ryof lavone Alantolactone (+)-Omonene... 

Elecampane is stated to possess expectorant, antitussive, diaphoretic, and bactericidal properties. Traditionally, it is used in the treatment of bronchial and tracheal catarrh, cough associated with pulmonary tuberculosis, and dry irritating cough in children. Alantolactone is used as an anthelmintic in the treatment of roundworm, threadworm, and whipworm infection. 

Eudesmanolide sesquiterpene lactones (G6 G6 C40L) include a variety of variously cytotoxic compounds. The antifeedants alantolactone and isoalantolactone (helenin being a mixture of the two) (C6 ] C5 C40L=CH2) are antimicrobial. The pro-apoptotic activity of these compounds may derive from the reactivity of the a-methylene-y-butyrolactone ring... 

Alantolactone (eudesmanolide sesquiterpene lactone) Inula helenium I. spp. (Asteraceae) Insect antifeedant... 

Epi-alantolactone (477) has been synthesized from the known lactone (475) and in a subsequent study the intermediate bromo-lactone (476) has been converted into the rare 7a,8a-lactone, dihydrocallitrasin (478) (Scheme 60). ° Another synthesis of frullanolide (479) has been recorded (Scheme 61). ... 

Following the successful conversion of both alantolactone (262) and iso-alantolactone (263) into artemisin (264) via the keto-ester (265), Nakazaki and Naemura synthesised this (-l-)-keto-ester by elaboration of the racemic hydroxy-enone (266) and subsequent resolution, so effecting the total synthesis of (264). 

Alantolactone. [3aR-(3a5p.8aft.9a[Pg.35]

The compound alantolactone demonstrated sensitizing activity in an epicutaneous test in mice. No sensitizing activity of isoalantolactone was observed (Alanso Blasi et al. 1992). 

Stampf, J.L., C. Benezra, G. Klecak, et aL 1982. The sensitizing capacity of helenin and of 2 of its main constituents, the sesquiterpene lactones alantolactone and iso-alantolactone A comparison of epicutaneous and intradermal sensitizing methods in different strains of guinea-pig. Contact Dermat. 8(l) 16-24. 

In sensitization tests in guinea pigs, the compound iso-alantolactone showed sensitizing activity after intradermal injection (Stampf et al. 1982). 

Phytochemistry The aboveground parts contain flavonoids, essential oil, tannins, ergolide, britanin, and other sesquiterpene lactones. The underground parts contain essential oil (with alantolactone and isoalantolactone), alkaloids, and inuUn. The leaves contain vitamin C (Khalmatov et al. 1984 Zhou et al. 1993 Han et al. 2001 Kim et al. 2002). 

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