Guaiane sesquiterpenes from the gorgonian Echinogorgia flora collected in the South China Sea

Abstract

Echinoflorine (1), a new dimethylamino-substituted guaipyridine alkaloid with a novel γ-lactone-cyclohepta[c]pyridine fused skeleton, and three new guaiane sesquiterpene lactones, echinofloranolides A–C (2–4), together with eight known guaiane sesquiterpenes were isolated from the gorgonian Echinogorgia flora collected in the South China Sea.

Synthesis of Guaipyridine Alkaloids Rupestine M and L by Cycloaddition/Cycloreversion of an Intermediate 1,4-Oxazinone

“…3 [] D 20 -38 (c 0.05, MeOH)]. We saw agreement between our 1 H and 13 C NMR data for the synthetic sample of 7 with the literature. 3 We anticipated that the optical rotation of synthetic material would be opposite to that reported by the isolation group; however, our synthetic material 7 showed similar sign and magnitude [synthetic [] D 23 -32.2 (c 0.4, MeOH); Lit.…”

“…1 H NMR spectra were recorded on a Varian Mercury 400 (400 MHz) spectrometer and are reported in ppm using solvent (CDCl 3 at 7.26 ppm) or tetramethylsilane (0.00 ppm) as an internal standard. Proton-decoupled 13 C NMR spectra are reported using solvent as an internal standard (CDCl 3 at 77.00 ppm). All compounds were judged to be homogeneous (>95% purity) by 1 H and 13 C NMR spectroscopy unless otherwise noted.…”

“…Proton-decoupled 13 C NMR spectra are reported using solvent as an internal standard (CDCl 3 at 77.00 ppm). All compounds were judged to be homogeneous (>95% purity) by 1 H and 13 C NMR spectroscopy unless otherwise noted. Mass spectra data analyses were obtained through positive electrospray ionization (with NaCl) on a Bruker 12 Tesla APEX-Qe FTICR-MS with an Apollo II ion source using an ICR ion trap mass analyzer.…”

Hot off the Press

“…Ecinoorine A 11, from the gorgonian Echinogorgia ora, is a guaiane-derived alkaloid with an undescribed skeleton containing a fused pyridine ring. 7 The structure claimed for plantarone 12, a metabolite of Lactobacillus plantarum, is impossibly strained and requires revision. 8 Racemic trichodermatrione A 13, a metabolite of endophytic Trichoderma sp.…”

“…Ecinoflorine A 11 , from the gorgonian Echinogorgia flora , is a guaiane-derived alkaloid with an undescribed skeleton containing a fused pyridine ring. 7 …”