Trichilianones A-D, Novel Cyclopropane-Type Limonoids from Trichilia adolfi

Abstract

The fractionation of an ethanol extract of the bark of Trichilia adolfi yielded four novel limonoids (trichilinones A-D, 1-4), with five fused rings and related to the hortiolide-type limonoids. Starting with an ε-lactone, which is α,β-unsaturated in trichilinones A and D (1 and 4), attached to a tetrahydrofuran ring that is connected to an unusual bicyclo [5.1.0] hexane system, joined with a cyclopentanone with a 3-furanyl substituent [(2-oxo)-furan-(5H)-3-yl in trichilinone D (4)], the four compounds isolated display a new 7/5/3/5/5 limonoid ring system. Their structures were established based on extensive analysis of NMR spectroscopic data. As the crude extract possessed anti-leishmanial properties, the compounds were assayed for cytotoxic and anti-parasitic activities in vitro in murine macrophages cells (Raw 264.7) and leishmania promastigotes (L. amazoniensis and L. braziliensis), respectively. The compounds showed moderate cytotoxicity (approximately 70 μg/mL), but are not responsible for the leishmanicidal effect of the extract.

Aglatestine A, a Rearranged Limonoid with a 3/6/6 Tricarbocyclic Framework from the Fruits of Aglaia edulis

“…This information suggested the existence of a ternary ring among C-1/5/10 in 1 . The key HMBC correlations (Figure ) from H-1 (δ H 1.24) to C-5, C-10, and keto-carbon (C-6, δc 203.0), from Me-19 (δ H 1.40) to C-1, C-5, and C-10, and from H-7 (δ H 5.19) to C-5 and C-6, still lacking one degree of unsaturation, suggested that a novel ternary carbon ring was formed , by the C-1-C-5 carbon–carbon bond. The perfect 1 J CH -resolved HSQC spectrum (Figure S1) of 1 showed that the one-bond proton-carbon coupling constant of H-1 ( 1 J CH 167.4 Hz) was obviously different from that of H-9 ( 1 J CH 117.1 Hz) of cyclohexane, while it was similar to the reported proton of cyclopropane ( 1 J CH 161.0 Hz), , which confirmed the existence of the cyclopropane ring in 1 .…”

Trichilones A–E: New Limonoids from Trichilia adolfi

“…In addition, the 1D NMR data indicate the presence of one methoxy group, five oxygenated but saturated carbons, four non-protonated but saturated carbons, eight saturated CH-groups (of which three are oxygenated), three saturated methylene groups and nine methyl groups. The atom numbering used in this study (see Figure 2 ) follows the same system as in our previous work [ 21 ], which is based on an earlier study of hortiolide-type limonoids isolated from Hortia colombiana [ 22 ].…”

“…14-H and 16-H 2 give HMBC correlations to the keto function, while 14-H in addition gives correlations to C-8, C-12, C-13, C-17 and C-18, which show the position and nature of C-15 and close the second ring. The missing substituent on C-17 is a 3-furanyl group, and this partial structure was determined in the same way as with the trichilianones [ 21 ] by COSY, HMBC and 1 J (C,H) couplings constants. This forms the third ring accounting by itself for three unsaturations, and the NMR data are quite similar to those reported for other limonoids containing a 3-furanyl substituent [ 23 ].…”

“…In a recent study by us, the four novel limonoids trichilianone A–D were isolated from the bark of Trichilia adolfi [ 21 ]. The structures of the trichilianones appear related to the hortiolide-type limonoids, with five fused rings.…”

“…Continuing our investigation constituents of T. adolfi, with the aim to characterize its antiparasitic metabol present study is focused on the characterization of new metabolites present in t The structures of the isolated metabolites were elucidated by spectroscopic a HR-MS, and 1D and 2D NMR experiments (COSY, HMBC and NOESY correlat summarized in Figures 3-5). The cytotoxicity of pure metabolites was evaluat vitro cell cultures of murine macrophages (Raw 264.7 cells), while the leishm properties were evaluated in the Leishmania amazoniensis and L. braziliensis proma In a recent study by us, the four novel limonoids trichilianone A-D were isolated from the bark of Trichilia adolfi [21]. The structures of the trichilianones appear related to the hortiolide-type limonoids, with five fused rings.…”