Terpenoid constituents from leaves of Guarea kunthiana

Abstract

sesquiterpenos (alismol, alismóxido, espatulenol e 4β,10α-aromadendranodiol), poliprenol-12 e α-e δ-tocoferóis. Kolavenal está sendo relatado pela primeira vez como produto natural, assim como a ocorrência de diterpenos do tipo cembrano e ent-caurano na família Meliaceae.From leaves of Guarea kunthiana one new kaurene diterpene (ent-kaur-16-en-2-one) was isolated along with eight known diterpenes (ent-kaur-16-ene, ent-3α-and 3β-hydroxykaur-16-ene, kolavelool, kolavenol, kolavenal, ent-13-epi-manoyloxide and (-)-nephthenol), four sesquiterpenes (alismol, alismoxide, spathulenol and 4β,10α-aromadendranediol), polyprenol-12 and α-and δ-tocopherols. Kolavenal is reported for the first time as a natural product, as well as the occurrence of cembrane-and ent-kaurane-type diterpenes in the Meliaceae.

Chemical composition, antimicrobial and antioxidant potential of the essential oil of Guarea kunthiana A. Juss

“…Studies conducted on extracts from the roots of this plant have reported antiparasitic (Lima, 2006;Mesquita et al, 2005) and insecticidal (Coelho, 2006) activities. Phytochemical studies have indicated the occurrence of diterpenes and sesquiterpenes in ethanolic extract obtained from the leaves of G. kunthiana (Garcez et al, 2004) and a limonoid ecuadorin isolated from the dichloromethane extract of the leaves (Mootoo et al, 1992). However, the antimicrobial and antioxidant potential and the chemical composition of the essential oil of G. kunthiana have not been reported in the literature.…”

Laevigatbenzoate from Croton laevigatus Vahl.

“…Thus, clerodanes and cembranoids are biosynthetically related, and were reported to coexist in the same plant material, such as Echinodorus macrophyllus [14,15], and Guarea kunthiana [16]. However, to the best of our knowledge, Croton oblongifolius [17,18] was the only species from genus Croton that was reported to produce clerodanes together with cembranoids.…”

Flexibilins A–C, New Cembrane-Type Diterpenoids from the Formosan Soft Coral, Sinularia flexibilis

“…Our studies of S. flexibilis have led to the isolation of three new cembranes, flexibilins A–C ( 1 – 3 ), along with a known metabolite, (−)-sandensolide ( 4 ), and flexibilin B ( 2 ) displayed a moderate inhibitory effect on the release of elastase by human neutrophils. In addition to marine organisms, cembrane-type diterpenoids are also found in higher plants and bryophytes [34,35,36,37,38,39,40,41,42,43]. However, the carboxylic acid moieties exhibited in cembranes 1 and 2 are rarely found [35,44].…”