Lignans and Triterpenoids from the Stems of Kadsura induta

Abstract

Two new lignans, kadsurindutins C and H (1 and 2, resp.), and a new 18(13 ! 12)-abeo-lanostane triterpenoid acid, kadindutic acid (3), were isolated from the stems of Kadsura induta, together with known lignans and triterpenoids. Their structures and configurations were elucidated by spectroscopic methods, including 2D-NMR techniques.

Lignans from the Australian Endemic PlantAustrobaileya scandens

“…The TDDFT ECD calculations for 1 and 2 resulted in a positive CE near 290 nm and a negative CE near 270 nm, in agreement with those reported by Ayres and Loike . However, the calculated ECD spectrum of kadsurindutin C ( 20 ), previously assigned the (7′ S ,8 R ,8′ S ) absolute configuration, showed a negative CE at 289 nm and a positive CE at 275 nm (Figure ), the opposite of the experimental data (Figure ). The absolute configuration of compound 20 was thus revised as (7′ R ,8 S ,8′ R ).…”

Triterpenoids from the Schisandraceae family: an update

“…From a biogenetic point of view, the cleavage of C-3/C-4 via a Baeyer-Villiger oxidation followed by the formation of a 3,4-lactone group are supposed to generate the structural feature of this group of compounds. This is seen in coccinilactones A (25) 12 and B (14) 19 and kadnanolactone C (31), 20 whose structures further lead to the formation of a hydroxyl group at C-2 (38 and 39). 21 The absolute conguration of schiglausin A (38) was determined by a combination of X-ray crystallography and experimental electronic circular dichroism (ECD) spectrum.…”