Three New Bisabolane Sesquiterpenes from Ligularia songarica

Abstract

Three new bisabolane sesquiterpenes, songaricalarins F–H (1–3, resp.), and five known analogs, 4–8, were isolated from roots and rhizomes of Ligularia songarica. The structures were elucidated by spectroscopic methods, including 2D‐NMR techniques. The isolated compounds were also evaluated for their cytotoxic activities, against human lung carcinoma (A‐549) and human breast adenocarcinoma (MCF‐7) cell lines, and three compounds were found to show moderate cytotoxicities.

Antiproliferative Sesquiterpenoids from Ligularia rumicifolia with Diverse Skeletons

“…Compound 23 has the molecular formula of C 23 H 34 O 7 , as established via the 13 C NMR and (+)-HRESIMS data. Its NMR data were highly similar to those of fararone A (25) 19 except for the replacement of the 2-chloro and 3-hydroxy groups in 25 by a hydroxy and a methoxy (δ C 52.4) group in 23, respectively. Therefore, the structure of rumicifoline N (23) was assigned as shown.…”

“…b1 H NMR data recorded at 400 Hz and 13 C NMR data recorded at 400 Hz. 14)-oplopen-3-one (12), 11 petasin (17), 12 3α-tigloyloxyeremophila-9,11-dien-8-one (18), 13 19, 14 petasol (20), 15 (1R,2R,3S,5S,6R)-5-acetoxy-2,8-diangeloyloxy-1,3-dihydroxybisabola-7(14),10-den-4-one (21), 16 fararone A (25), 17 (1R,3R,4R,5S,6S)-1-acetoxy-8-angeloyloxy-3,4-epoxy-5-hydroxybisabola-7( 14),10-dien-2-one (30), 18 songaricalarin F (31), 19 (4R,6E)-2-acetoxy-8-angeloyloxy-4-hydroxybisabola-2,6,10trien-1-one (32), 20 tussfararin F (33), 21 altaicalarin B (34), 7 ligudentatol (35), 22 7α-H-3α-angeloyloxy-9(10)-en-11,12epoxy-8-oxoeremophilane (36), 23 and 7β-H-3α-angeloyloxy-9(10)-en-11,12-epoxy-8-oxoeremophilane (37) 23 by comparing their observed and reported spectroscopic data.…”

“…The MeOH extract of the air-dried whole plant of L. rumicifolia was applied to purification using RP-18 silica gel CC, silica gel CC, semipreparative HPLC, and Sephadex LH-20 to afford a new nor -eudesmane-type, 10 new oplopane-type, four new eremophilane-type, and seven new bisabolane-type sesquiterpenoids, as well as 15 known analogues (Chart ). These known compounds were identified as (1 R ,2 S ,4 Z ,6 R ,7 S ,8 R ,9 S ,11 S ,2″ S ,2‴ E ,2⁗ S )-11,12-epoxy-2,8-di­(2-methylbutanoyloxy)-9-(3‴-methyl-2‴-pentenoyloxy)-10­(14)-oplopen-3-one ( 12 ), petasin ( 17 ), 3α-tigloyloxyeremophila-9,11-dien-8-one ( 18 ), 19 , petasol ( 20 ), (1 R ,2 R ,3 S ,5 S ,6 R )-5-acetoxy-2,8-diangeloyloxy-1,3-dihydroxybisabola-7­(14),10-den-4-one ( 21 ), fararone A ( 25 ), (1 R ,3 R ,4 R ,5 S ,6 S )-1-acetoxy-8-angeloyloxy-3,4-epoxy-5-hydroxybisabola-7­(14),10-dien-2-one ( 30 ), songaricalarin F ( 31 ), (4 R ,6 E )-2-acetoxy-8-angeloyloxy-4-hydroxybisabola-2,6,10-trien-1-one ( 32 ), tussfararin F ( 33 ), altaicalarin B ( 34 ), ligudentatol ( 35 ), 7α-H-3α-angeloyloxy-9(10)-en-11,12-epoxy-8-oxoeremophilane ( 36 ), and 7β-H-3α-angeloyloxy-9(10)-en-11,12-epoxy-8-oxoeremophilane ( 37 ) by comparing their observed and reported spectroscopic data.…”