Cinnafragrins A−C, Dimeric and Trimeric Drimane Sesquiterpenoids from Cinnamosma fragrans, and Structure Revision of Capsicodendrin

Abstract

Two new dimeric sesquiterpenoids and a new trimeric drimane sesquiterpenoid named cinnafragrins A-C (1-3), together with cinnamodial (4), D-mannitol, capsicodendrin (5), and a vitamin E analogue, delta-tocotrienol, were isolated from Cinnamosma fragrans, a Malagasy medicinal plant. The structures of the new compounds were determined on the basis of physical, chemical, and spectroscopic evidence. Capsicodendrin, previously isolated from Capsicodendron dinisii and tentatively suggested to be a tetramer of cinnamodial, was revised structurally as a mixture of C-12'-epimers of 12'-hydroxycinnafragrin B by extensive 2D NMR analysis and X-ray crystallography of the lactone derivative, cinnafragrolide (6). The chemosystematics of the family Canellaceae are discussed.

Natural sesquiterpenoids

“…48 The dimeric and trimeric drimane sesquiterpenes cinnafragrins A-C 52-54 have been found in an extract from the medicinal plant Cinnamosma fragrans. 49 In this work, the structure of capsicodendrin has been revised to a mixture of the C-12 epimers 55.…”

ChemInform Abstract: Naturally Occurring Dimers from Chemical Perspective

“…are three acetals isolated from Cinnamosma fragrans Baillon collected in Madagascar [83] (Scheme 12). To establish the absolute configuration, 140 was dissolved in pyridine and allowed to stand overnight to be converted into its monomer, which was identified as 143 from its spectroscopic data (including X-ray crystallography) and its optical rotation value [83]. The structure of capsicodendrin (142) was revised as a mixture of two C(12')-epimers of 12'-hydroxycinnafragrin B [83].…”

“…To establish the absolute configuration, 140 was dissolved in pyridine and allowed to stand overnight to be converted into its monomer, which was identified as 143 from its spectroscopic data (including X-ray crystallography) and its optical rotation value [83]. The structure of capsicodendrin (142) was revised as a mixture of two C(12')-epimers of 12'-hydroxycinnafragrin B [83]. Korolkoside (144) from Lonicera korolkovii is a bis-iridoid glucoside consisting two secologanin moieties connected by an acetal linkage [84].…”

Recent Advances of Biologically Active Substances from the Marchantiophyta

“…Jungermannia obovata contains a trisnormonoterpene ketone, 4-hydroxy-4-methyl cyclohex-2-en-1-one (31), which possesses an intense carrot-like odor [23,24]. The strong and distinct mossy odor of Lophocolea heterophylla and L. bidentata is due to a mixture of (-)-2-methylisoborneol [25] and geosmin (32) [26]. Geosmin, possessing a strong earthy-musty odor, has also been found in in vitro cultured Symphyogyna brongniartii [27].…”