Plant-derived juvenile hormone III analogues and other sesquiterpenes from the stem bark of Cananga latifolia

Abstract

Juvenile hormone III (JH III) is a larval metamorphosis-regulating hormone present in most insect species. JH III was first isolated from the plant, Cyperus iria L., but the presence of JH III has not been reported in other plant species. In the present study, proof of the existence of JH III and its analogues from Cananga latifolia was established. From an aqueous MeOH extract of C. latifolia stem bark, six compounds were isolated along with nine known compounds. These were identified by using spectroscopic analyses as: (2E,6E,10R)-11-butoxy-10-hydroxy-3,7,11-trimethyldodeca-2,6-dienoic acid methyl ester, (2E,6E)-3,7,11-trimethyl-10-oxododeca-2,6-dienoic acid methyl ester, (2E)-3-methyl-5-[(1S,2R,6R)-1,2,6-trimethyl-3-oxocyclohexyl]-pent-2-enoic acid methyl ester, 1β-hydroxy-3-oxo-4β, 5α,7α-H-eudesmane 11-O-α-l-rhamnopyranoside, 4-epi-aubergenone 11-O-2',3'-di-O-acetyl-α-l-rhamnopyranoside and 4-epi-aubergenone 11-O-2',4'-di-O-acetyl-α-l-rhamnopyranoside. Three of the previously known compounds, (2E,6E,10R)-10-hydroxy-3,7,11-trimethyldodeca-2,6,11-trienoaic acid methyl ester, (2E,6E,10R)-10,11-dihydroxy-3,7,11-trimethyldodeca-2,6-dienoic acid and (2E,6S)-3-methyl-6-hydroxy-6-[(2R,5R)-5-(2-hydroxypropan-2-yl)-2-methyltetrahydrofuran-2-yl]-hex-2-enoaic acid methyl ester have now been found in a plant species. Ultra performance liquid chromatography-quadruple time-of-flight mass spectroscopy (UPLC-QTOF/MS) analysis of the chemical constituents of C. latifolia showed that several were predominant in the sub-fractions of a C. latifolia stem bark extract.