Sesquiterpenoids and Lignans from Ligularia virgaurea spp. oligocephala

From the BuOH extract of the whole plant of Ligularia virgaurea spp. oligocephala, a series of sesquiterpenes, sesquiterpene glycosides, and lignan glycosides were isolated, including the three new compounds (1α)‐1‐hydroxy‐8‐oxo‐eremophila‐6,9‐dien‐12‐oic acid ( 1 ), 8‐[(β‐D ‐glucopyranosyl)oxy]eremophila‐1(10),8,11‐trien‐2‐one ( 2 ), and 4‐[(β‐D ‐glucopyranosyl)oxy]pinoresinol ( 4 ). Their structures were elucidated by 1D‐ and 2D‐NMR as well as HR‐ESI‐MS analyses, and by comparison of the spectroscopic data with those reported for structurally related compounds.     

Novel Sesquiterpenes from Ligularia virgaurea spp. oligocephala

Two novel sesquiterpene dimers, ligularin A ( 1 ) and ligulolide D ( 2 ), and one new sesquiterpenoid, 1β,10α‐dihydroxy‐6β‐[(2‐methylpropyl)oxy]furanoeremophil‐9‐one ( 3 ), as well as two known sesquiterpenoids, 6β‐[(2‐methylpropyl)oxy]‐furanoeremophil‐1(10)‐en‐9‐one ( 4 ) and 1‐hydroxy‐3,7‐dimethyl‐2‐(pent‐3‐enyl)benzofuran ( 5 ), were isolated from the petroleum‐ether fraction from an alcoholic extract of the whole plant of Ligularia virgaurea spp. oligocephala. Their structures were elucidated by 1D and 2D‐NMR spectroscopy together with HR‐ESI‐MS analysis, and comparison of the spectroscopic data with those reported for structurally related compounds. In addition, the cytotoxicities against human gastric cancer SGC‐7910 cell were measured in vitro, the results demonstrated that these sesquiterpenes have no cytotoxicity against the selected tumor cell (all IC₅₀ values >200 μM ).     

A Novel Dimeric Eremophilane from Ligularia virgaurea spp. oligocephala

A novel dimeric eremophilane, ligulolide B, was isolated from the alcoholic extract of the whole plant of Ligularia virgaurea spp. oligocephala. The structure was elucidated by various spectroscopic methods including intensive 2D NMR techniques （^1H-^1H COSY, gHMQC, gHMBC and ^1H-^1H NOESY） and HR-ESI-MS.     

A new eremophilane-type sesquiterpene from Ligularia virgaurea

A new eremophilane-type sesquiterpene,1α,8β,10β-trihydroxy-6β-(2-methylacryloyl)oxyeremophil-7(11)-en-8α,12-olide, was isolated from the roots of Ligularia virgaurea.Its structure was established on the basis of various spectroscopic analyses, including the 1D,2D NMR techniques and HR-ESI-MS.     

Two New Eremophilane Sesquiterpene Lactones from Ligularia myriocephala Ling

Two new eremophilane sesquiterpene lactones, 1β-angeloyloxy-6β, 10β-dihydroxy-8β- methoxyeremophila-7（ll）en-8α,12-olide and 1β-angeloyloxy-6β,10α-dihydroxy-8α-methoxyeremo- phila-7（ 11）en-8β, 12-olide were isolated from the extract of the whole plant of Ligularia myriocephala Ling. Their structures and stereochemistry were elucidated by various spectroscopic methods including intensive 2D-NMR techniques （COSY, gHMQC, gHMBC and ^1H-^1H NOESY） and HR-ESIMS.     

Unusual sesquiterpene lactones from Ligularia virgaurea spp. oligocephala

[structure: see text] [structure: see text] Sesquiterpene lactones, ligulolide A (1) and 6beta,8alpha-dihydroxy-1-oxoeremophila-7(11),9(10)-diene-12,8-olide (2), were isolated from Ligularia virgaurea spp. oligocephala. Their structures were established by analysis of one- and two-dimensional NMR data. The relative stereostructures were determined on the basis of NOESY and single-crystal X-ray experiments. 1 represents a novel sesquiterpene carbon framework, and a possible biosynthetic process is proposed. 2 is a novel eremophilane-type sesquiterpene.     

Two New Eremophilenolides from Ligularia sagitta

Chemical investigation of L.sagitta afforded two new eremophilenolides, which were identified as 6β-angeloyloxy-10β-hydroxy-8 β-methoxy-eremophil-7(11)-en-12, 8α-olide (1) and 6β, 8β-dimethoxy-10β-hydroxy-eremophil-7(11)-en-12, 8α-olide (2). Their structures were estab- lished by spectroscopic methods including 2D NMR experiments.     

Two New Eremophilenolides from Ligularia tongolensis

Chemical investigation of L. tongolensis afforded two new eremophilenolides, which were identified as 3β-（2＇-methylbutanoyloxy）-8βH-eremophil-7（11）-en-12, 8α（14, 6α）-diolide （1）and 8βH-eremophil-3, 7（11）-dien-12, 8α （14, 6α）-diolide （2）. Their structures were established by spectroscopic methods including 2D NMR experiments.     

Eremophilane‐Type Sesquiterpenes from the Roots of Ligularia virgaurea

From the roots of Ligularia virgaurea, five new eremophilane‐type sesquiterpenes were isolated, including three new eremophilenolides, 6β‐(angeloyloxy)‐1α,8β,10β‐trihydroxyeremophil‐7(11)‐en‐12,8α‐olide ( 1 ), 6β‐(angeloyloxy)‐1β,10β‐epoxy‐8β‐ethoxyeremophil‐7(11)‐en‐12,8α‐olide ( 2 ), and 1β,10β‐epoxy‐8β‐ethoxy‐6β‐[(2‐methylacryloyl)oxy]eremophil‐7(11)‐en‐12,8α‐olide ( 3 ), two new noreremophilanes, 3β‐[(2‐methylacryloyl)oxy]‐8‐oxo‐12‐noreremophil‐6‐en‐11‐one ( 9 ), and 9β‐hydroxy‐8‐oxo‐12‐noreremophil‐6‐en‐11‐one ( 10 ), and six known eremophilanes, namely 4 – 8 , and 11 . Their structures were elucidated by means of spectral methods, such as IR, HR‐ESI‐MS, and 1D‐ and 2D‐NMR, and by comparison of the spectral data with those reported for structurally related compounds.     

Sesquiterpenoids from the Rhizome of Ligularia virgaurea

Two novel sesquiterpene dimers, compounds 1 and 2 , were isolated from the rhizome of Ligularia virgaurea, together with the six known sesquiterpenoids 3 – 8 . Their structures were established by physico‐chemical and spectroscopic methods, especially by means of 1D‐ and 2D‐NMR as well as HR‐MS analyses. A mechanism based on a classical Diels–Alder cyclization is proposed for the formation of the dimer 1 from the precursors 8 and the quinone form of 6 (Scheme).     

Two New Sesquiterpenes from Ligularia macrophylla

Two new eremophilane sesquiterpenes, 15β-formic ether-6-oxo-furanoeremophilane （1） and 6α, 15β-epoxy eremophila-7（11）-en-8α, 12-olide （2） were isolation from the roots of Ligularia macrophylla. Their structures were deduced from spectroscopic methods and 2D NMR experiments.     

Eremophilane,bakkane, secoeremophilane,and secobakkane sesquiterpenoids from Ligularia virgaurea collected in China

Secobakkane B (C-6/C-7 cleaved secobakkane type aldehyde), secovirgaurenols B and C (C-8/C-9 cleaved secoeremophilane type), a 1β,10β-epoxyfuranoeremophilane, two 1β,10β-epoxyeremophilanolides, and fukinospirolide C (bakkane-type lactone), as well as 33 known compounds were isolated from three samples of Ligularia virgaurea collected in China. Two of the three analyzed samples were grouped in the neoadenostylone (N) type, and the rest, a mixture of the 6-hydroxyeuryopsyn (H) and cacalol (C) types, out of five chemotypes found in this species.     

Two New Sesquiterpenes from Ligularia veitchiana

A new furanoeremophilane and a new eudesmane were isolated from the roots of Ligularia veitchiana .Their structures were elucidated as 1 β,10β-epoxy-6β-isobutyryloxy-9-oxo-furanoeremophilane and 8α-hydroxy-4(15),11-eudesmadiene by spectroscopic methods.     

A New Bisesquiterpene from Ligularia macrophylla

From the roots of Ligularia macrophylla, a bisesquiterpene,ligumacrophyllal was isolated and its structure was elucidated on the basis of spectroscopic methods.     

Benzofuran Derivatives from Ligularia Stenocephala

Four new benzofuran derivatives were isolated from the roots of Ligularia stenocephala; they were named as ligustenin A ( 1 ), B ( 2 ), C ( 3 ) and D ( 4 ), and the structures were established by spectroscopic methods including 2D NMR techniques. Ligustenin A (1) was found to exhibit potent anti‐tumor activity against HL‐60 (human leukemia cells), Bel‐7402 (human hepatoma cells) and HO‐8910 (human ovarian neoplasm cells) with IC₅₀ values of 18.6, 27.6 and 57.5 μM, respectively.     

A New Isopropenyl Benzofuran-type Tetramer from Ligularia stenocephala

A new isopropenyl benzofuran-type tetramer was isolated from the roots of ligularia stenocephala and its structure was established by spectroscopic methods.     

Two New Eremophilenolides from Ligularia fischeri

Ligulariajischerihasl0ngbeenusedastraditi0naImedicinet0relievec0ugh,invig0ratethecircuIation0fbIo0dandst0ppain'.FromtheplantgrowinginShengnonaiia,Hubei-Chlna,t\v0neweremophiIen0lideshavebeenisolated.Comp0undlwasneedlecrystalsfrompetr0lether(60-9O'C),m.p.=148-l50'C.ItsformulawasdeterminedasC,,H,'O'by"C-NMRandDEPTspectrainaccordancewiththem0lecularionpeakm/z=280inEIMS.Thetypeofcarbonsignals(5xC,3xCH,4xCH,,4xCH,)(Table2)sh0wedithadabicyclicsesquiterpeneskeletonbearingameth0xy.ahemi-…     

Two New Oplopanol Esters from Ligularia narynensis

Mainly species of Ligularia have long been used for treatment of fever, inflammation, detoxication, invigorating the circulation of blood and smoothing pain1. So far the opl- opane derivatives were not found in the genus Ligularia. Here we report the stru…     

Bisabolane Sesquiterpenes from Ligularia thyrsoidea

Phytochemistry investigation of the whole plants of Ligularia thyrsoidea, has led to the isolation of five new bisabolane sesquiterpenes along with three known compounds. The structures of these new compounds were elucidated by spectroscopic methods and 2D NMR techniques.