Three New Sesquiterpenes from Laggera pterodonta

A new eremophilane sesquiterpene, (2β)‐2‐deoxo‐2‐methoxytessaric acid ( 1 ), and two new eudesmane sesquiterpenes, (3β,10α)‐3‐methoxyleudesma‐4,11(13)‐dien‐12‐oic acid ( 2 ) and (3α,4β,8α)‐4‐(acetyloxy)‐3‐(2,3‐dihydroxy)‐2‐methyl‐1‐oxobutoxy‐8‐hydroxyeudesm‐7(11)‐eno‐12,8‐lactone ( 3 ), along with the ten known compounds 4 – 13 were isolated from the aerial parts of Laggera pterodonta. The structures of the new compounds were elucidated by spectroscopic analyses, including 2D‐NMR data.     

New Sesquiterpenes from Ligulariopsis Shichuana

A thorough investigation of Ligulariopsis shichuana afforded five new sesquiterpenes, including 1β,10β‐epoxy‐3α‐angeloyloxy‐9β‐acetoxy‐8α,11β‐dihydroxybakkenolide ( 1 ), 1β,7‐dihydroxy‐3β‐acetoxy‐noreremophil‐6(7),9(10)‐dien‐8‐one ( 2 ), 8α‐hydroxy‐3‐oxoeremophil‐1(2),7(11),9(10)‐trien‐8β(12)‐olide ( 3 ), 1β,10β‐dihydroxy‐3β‐acetoxyeremophil‐7(11),8(9)‐dien‐8(12)‐olide ( 4 ) and 1β,10β‐epoxy‐8,12‐dihydroxy‐3β‐acetoxy‐9β‐angeloyloxyeremophil‐7(11)‐en‐8,12‐disemiketal ( 5 ). Their structures were established by spectroscopic methods and 2D NMR techniques. In addition, bakkenolide ( 1 ) and eremophilenolides ( 5 ) showed antibacterial and cytotoxic activities.     

Novel Sesquiterpenoids from Siegesbeckia orientalis

Five new sesquiterpenoids, namely, 8β‐(angeloyloxy)‐4β,6α,15‐trihydroxy‐14‐oxoguaia‐9,11(13)‐dien‐12‐oic acid 12,6‐lactone ( 1 ), 4β,6α,15‐trihydroxy‐8β‐(isobutyryloxy)‐14‐oxoguaia‐9,11(13)‐dien‐12‐oic acid 12,6‐lactone ( 2 ), 11,12,13‐trinorguai‐6‐ene‐4β,10β‐diol ( 3 ), (1(10)E,4E,8Z)‐8‐(angeloyloxy)‐6α,15‐dihydroxy‐14‐oxogermacra‐(1(10),4,8,11(13)‐tetraen‐12‐oic acid 12,6‐lactone ( 9 ), and (1(10)E,4β)‐8β‐(angeloyloxy)‐6α,14,15‐trihydroxygermacra‐1(10),11(13)‐dien‐12‐oic acid 12,6‐lactone ( 11 ), and three new artifacts, (1(10)E,4Z)‐8β‐(angeloyloxy)‐9α‐ethoxy‐6α,15‐dihydroxy‐14‐oxogermacra‐1(10),4,11(13)‐trien‐12‐oic acid 12,6‐lactone ( 6 ), (1(10)E,4Z)‐8β‐(angeloyloxy)‐9α,13‐diethoxy‐6α,15‐dihydroxy‐14‐oxogermacra‐1(10),4‐dien‐12‐oic acid 12,6‐lactone ( 7 ), and (1(10)E,4Z)‐8β‐(angeloyloxy)‐9α‐ethoxy‐6α,15‐dihydroxy‐13‐methoxy‐14‐oxogermacra‐1(10),4‐dien‐12‐oic acid 12,6‐lactone ( 8 ), together with the three known sesquiterpenoids 4, 5 , and 10 , were isolated from the aerial parts of Siegesbeckia orientalis L. Their structures were established by spectral methods, especially 1D‐ and 2D‐NMR spectral methods.     

Five New Sesquiterpenoids from Parasenecio petasitoides

From the whole plants of Parasenecio petasitoides, five new sesquiterpenoids were isolated, (E,E)‐3α,9β‐dihydroxy‐6βH,11βH‐13‐norgermacra‐1(10),4‐dien‐11,6‐carbolactone ( 2 ), (E,E)‐2α,9β‐dihydroxy‐6βH,11βH‐13‐norgermacra‐1(10),4‐dien‐11,6‐carbolactone ( 3 ), (E,E)‐2α,9β‐dihydroxy‐6βH,11αH‐13‐norgermacra‐1(10),4‐dien‐11,6‐carbolactone ( 4 ), (E)‐15‐hydroxy‐2‐oxo‐6βH,11αH‐13‐norguaia‐3‐ene‐11,6‐carbolactone ( 7 ), and (E)‐11β,15‐dihydroxy‐2‐oxo‐6βH‐13‐norguaia‐3‐ene‐11,6‐carbolactone ( 8 ), together with three known compounds, deacetyl herbolide A ( 1 ), jacquilenin ( 5 ), and (E)‐15‐hydroxy‐2‐oxo‐6βH,11βH‐13‐norguaia‐3‐ene‐11,6‐carbolactone ( 6 ). The structures of these natural products were elucidated spectroscopically, especially by 1D‐ and 2D‐NMR techniques, in combination with high‐resolution mass spectroscopy.     

New Eremophilenolactones from Senecio nemorensis

Three new eremophilane sesquiterpenes were isolated from the MeOH extract of the roots of Senecio nemorensis. Their structures were identified as 8α‐hydroxy‐6β‐(isobutanoyloxy)‐1‐oxoeremophila‐7(11),9‐dieno‐12,8β‐lactone ( 1 ), 6β,8β‐dimethoxy‐1‐oxoeremophila‐7(11),9‐dieno‐12,8α‐lactone ( 2 ), and 10α‐hydroxy‐6β‐(isobutanoyloxy)‐1‐oxoeremophila‐7(11),8‐dieno‐12,8‐lactone ( 3 ), respectively, based on spectroscopic data, including IR, EI‐MS, HR‐ESI‐MS, and 1D‐ and 2D‐NMR data.     

Diversity of Sesquiterpenoids from Carpesium cernuum

Two new sesquiterpene lactones, 6β‐hydroxy‐8α‐ethoxyeremophil‐7(11)‐en‐12,8β‐olide ( 1 ) and 4β,10β‐dihydroxy‐1αH,5αH,11αH‐guaian‐12,8β‐olide ( 2 ), together with 22 known sesquiterpenoids with various structural types, were isolated from Carpesium cernuum (Compositae). Their structures and configurations were elucidated by extensive 1D‐ and 2D‐NMR spectroscopic analysis in combination with MS experiments, and comparison with literature data of related compounds.     

Sesquiterpenoids from Chloranthus spicatus （Thunb.） Makino

Two new sesquiterpenoids, namely 1β,4β-dihydroxy-5 α,8β（H）-eudesm-7（11）Z-en-8,12-olide （1） and 1β,4α-dihydroxy-5α,8β（H）-eudesm-7（11）Z-en-8,12-olide （2）, along with six known ones, homalomenol A （3）, oplodiol （4）, 5α,7α（H）-6,8-cycloeudesma-1β,4β-diol （5）, oplopanone （6）, 4β,10α-dihydroxyaromadendrane （7） and spathulenol （8）, were isolated from the aerial part of Chloranthus spicatus （Thunb.） Makino, and their structures were established by spectroscopic methods.     

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.     

Baimantuoluosides A – C,Three New Withanolide Glucosides from the Flower of Datura metel L.

In search for bioactive compounds from the flower of Datura metel L., three new withanolide glucosides, namely baimantuoluosides A, B, and C ( 1 – 3 , resp.) were isolated. Enzymatic hydrolysis of 1 – 3 afforded the corresponding aglycones 1a, 2a , and 3a , respectively. The structures of the new compounds were elucidated as (5α,6α,7α,12β,22R)‐5,12‐dihydroxy‐1,26‐dioxo‐6,7 : 22,26‐diepoxyergosta‐2,24‐dien‐27‐yl β‐D ‐glucopyranoside ( 1 ), (5α,6α,7α,12α,22R)‐5,12‐dihydroxy‐1,26‐dioxo‐6,7 : 22,26‐diepoxyergosta‐2,24‐dien‐27‐yl β‐D ‐glucopyranoside ( 2 ), (5α,6α,7α,22R)‐5‐hydroxy‐1,26‐dioxo‐6,7 : 22,26‐diepoxyergosta‐2,24‐dien‐27‐yl β‐D ‐glucopyranoside ( 3 ) on the basis of chemical and physicochemical evidence, and are further confirmed by the structure determination by X‐ray diffraction of withanolide aglycone 1a .     

Terpenoids from the Roots of Ligularia muliensis

Three new eremophilane‐type sesquiterpenes, (6β,8α)‐6‐(acetyloxy)‐8‐hydroxyeremophil‐7(11)‐en‐12,8‐olide ( 1 ), (6α,8α)‐6‐hydroxyeremophil‐7(11)‐en‐12,8‐olide ( 2 ), and (6α,8α)‐6‐(acetyloxy)eremophil‐7(11)‐en‐12,8‐olide ( 3 ) ((8α)‐eremophil‐7(11)‐en‐12,8‐olide = (4aR,5S,8aR,9aS)‐4a,5,6,7,8,8a,9,9a‐octahydro‐3,4a,5‐trimethylnaphtho[2,3‐b]furan‐2(4H)‐one), besides the recently elucidated eremoligularin ( 4 ) and bieremoligularolide ( 5 ), as well as a new highly oxygenated monoterpene, rel‐(1R,2R,3R,4S,5S)‐p‐menthane‐1,2,3,5‐tetrol ( 12 ), together with six known constituents, i.e., the sesquiterpenes 6 and 7 , the norsesquiterpenes 8 – 10 , and the monoterpene 13 , were isolated from the roots of Ligularia muliensis. In addition, an attempt to dimerize 1 to a bieremophilenolide (Scheme) resulted in the generation of the new derivative (6β,8β)‐6‐(acetyloxy)‐8‐chloroeremophil‐7(11)‐en‐12,8‐olide ( 11 ). The new structures were established by means of detailed spectroscopic analysis (IR, FAB‐, EI‐, or HR‐ESI‐MS as well as 1D‐ and 2D‐NMR experiments). Compounds 4 and 5 were evaluated for their antitumor effects in vitro (Table 3).     

Sesquiterpenoids from Ligularia dentata

Five new compounds were isolated from the roots of Ligularia dentata, including four bisabolane‐type sesquiterpenoids, 1 – 4 , as well a new eudesmane, 5 . The previously isolated 3α,6α,9‐tris(angeloyloxy)‐2α,4β‐dihydroxy‐7,11‐epoxybisabol‐10(15)‐en‐5‐one ( 6 ), when left as an oil in a refrigerator over nine months, gave rise to a mixture of two positional isomers, 7 and 8 . Their formation is rationalized by means of epoxide ring opening and shift of an angeloyl (Ang) group. The structures of compounds 1 – 5, 7 , and 8 were established by in‐depth spectroscopic (UV, CD, IR, 1D‐ and 2D‐NMR) as well as mass‐spectrometric methods.     

Two New Sesquiterpenes from the Roots of Valeriana fauriei Briq.

A phytochemical investigation of the MeOH extract of Valeriana fauriei Briq . roots resulted in the isolation of two new sesquiterpenes, isovalerianin A (=(1β,4Z,6β,8α)‐8‐(acetyloxy)‐1,10‐dihydroxy‐6,11‐cyclogermacr‐4‐en‐15‐al=rel‐(1R,2Z,6S,7R,9R,10S)‐9‐(acetyloxy)‐6,7‐dihydroxy‐7,11,11‐trimethylbicyclo[8.1.0]undec‐2‐ene‐3‐carboxaldehyde; 1 ) and valerianin C (=(2α,3α,6α,8α)‐3‐(acetyloxy)‐2,4,8‐trihydroxyguai‐1(10)‐ene‐12,6‐lactone=rel‐(3R,3aS,4R,7S,8S,9R,9aR,9bR)‐8‐(acetyloxy)‐3a,4,5,7,8,9,9a,9b‐ octahydro‐4,7,9‐trihydroxy‐3,6,9‐trimethylazuleno[4,5‐b]furan‐2(3H)‐one; 2 ), together with six known compounds, i.e., camphor, methyl 4‐hydroxybenzoate, 2‐methoxybenzoic acid, benzoic acid, quercetin, and kaempferol. The structures of the compounds were established by detailed spectral analysis and comparison with previously reported data.     

Chemical Constituents from Myrsine africana L.

Three new compounds, myrsinoside A (=2,4‐dihydroxy‐6‐methylphenyl β‐D ‐(6′‐galloyl)glucopyranoside; 1 ), myrsinoside B (2,4‐dihydroxy‐6‐methylphenyl β‐D ‐glucopyranoside; 2 ), and (3β,16α,20α)‐3,16,28‐trihydroxyolean‐12‐en‐29‐oic acid 3‐{O‐β‐D ‐glucopyranosyl‐(1→2)‐O‐[β‐D ‐glucopyranosyl‐(1→4)]‐α‐L ‐arabinopyranoside} ( 3 ), along with four known compounds, were isolated from the stems of Myrsine africana L. The structures of these new compounds were elucidated on the basis of spectroscopic analysis, including 1D‐ and 2D‐NMR and ESI‐MS techniques, and chemical methods.     

Sesquiterpenoids and Lactone Derivatives from Ligularia dentata

Seven new compounds were isolated from the roots of Ligularia dentata, including five bisabolane‐type sesquiterpenoids (bisabolane=1‐(1,5‐dimethylhexyl)‐4‐methylcyclohexane), namely (8β,10α)‐8‐(angeloyloxy)‐5,10‐epoxybisabola‐1,3,5,7(14)‐tetraene‐2,4,11‐triol ( 1 ), (8β,10α)‐8‐(angeloyloxy)‐5,10‐epoxythiazolo[5,4‐a]bisabola‐1,3,5,7(14)‐tetraene‐4,11‐diol ( 2 ), (1α,2α,3β,5α,6β)‐1,5,8‐tris(angeloyloxy)‐10,11‐epoxy‐2,3‐dihydroxybisabol‐7(14)‐en‐4‐one ( 3 ), (1α,2α,3β,5α,6β)‐2,5,8‐tris(angeloyloxy)‐10,11‐epoxy‐1,3‐dihydroxybisabol‐7(14)‐en‐4‐one ( 4 ), and (1α,2β,3β,5α,6β)‐1,8‐bis(angeloyloxy)‐2,3‐epoxy‐5,10‐dihydroxy‐11‐methoxybisabol‐7(14)‐en‐4‐one ( 5 ) (angeloyloxy=[(2Z)‐2‐methyl‐1‐oxobut‐2‐enyl]oxy), and two lactone derivatives, (2α,3β,5α)‐2‐(acetyloxy)‐9‐methoxy‐5‐(methoxycarbonyl)‐2,3‐dimethylheptano‐5‐lactone ( 6 ), and (2β,4β)‐2‐ethyl‐5‐hydroxy‐5‐(methoxycarbonyl)‐4,5‐dimethylpentano‐4‐lactone ( 7 ) (α/β denote relative configurations), together with (2E,4R,5S)‐2‐ethylidene‐5‐(methoxycarbonyl)‐4‐methylhexano‐5‐lactone ( 8 ), a known synthetic compound. Compound 2 is the first sesquiterpenoid derivative containing the uncommon benzothiazole moiety. The structures of 1 – 8 were established by spectroscopic methods, especially 2D‐NMR and MS analyses.     

Tri‐ and Bicyclic Taxoids from the Taiwanese Yew Taxus sumatrana

Five new taxoids, including a new 2(3→20)‐abeo‐taxane with a 6/10/6‐membered ring system and four 3,8‐seco‐taxanes having a 6/12‐membered ring system, were isolated from an acetone extract of the leaves and twigs of the Taiwanese yew (Taxus sumatrana, Taxaceae). The structures were established as 2α,7β,10α‐triacetoxy‐5α‐hydroxy‐2(3→20)‐abeo‐taxa‐4(20),11‐dien‐9,13‐dione ( 1 ), (3E,8E)‐2α,9,10β, 13α,20‐pentaacetoxy‐7β‐hydroxy‐3,8‐secotaxa‐3,8,11‐trien‐5‐one ( 2 ), (3E,8E)‐2α,9,10β,13α,20‐pentaacetoxy‐5α,7β‐dihydroxy‐3,8‐secotaxa‐3,8,11‐triene ( 3 ), (3E,8E)‐9,10β,13α‐triacetoxy‐2α,7β,20‐trihydroxy‐5α‐[(2E)‐cinnamoyloxy]‐3,8‐secotaxa‐3,8,11‐triene ( 4 ), and (3E,8E)‐2α,5α,7β,9,10β,13α‐hexaacetoxy‐20‐hydroxy‐3,8‐secotaxa‐3,8,11‐triene ( 5 ), respectively, on the basis 1D‐ and 2D‐NMR spectral analyses. The in vitro cytotoxic activity of compounds 1 – 5 against four human tumor cell lines, including HeLa (cervical epitheloid), WiDr (colon), Daoy (medulloblastoma), and Hep2 (liver carcinoma) tumor cells was evaluated. Whereas compounds 1 – 3 were inactive, the novel taxanes 4 and 5 showed significant cytotoxicity.     

New Cadinane‐Type Sesquiterpenes from the Roots of Taiwania cryptomerioides Hayata

Six new cadinane‐type sesquiterpenes, (1β,4β,5α,10α)‐1,4‐epoxymuurolan‐5‐ol ( 1 ), (4α,10β)‐4,10‐dihydroxycadin‐1(6)‐en‐5‐one ( 2 ), (2β,3α,4β,6β)‐2,3‐dihydroxycadin‐1(10)‐en‐5‐one ( 3 ), (2β,3α)‐α‐corocalene‐2,3‐diol ( 4 ), (7S)‐α‐calacoren‐14‐ol ( 5 ), and (8β,9β,10β)‐8,9‐epoxycalamenene‐3,10‐diol ( 6 ) together with one known compound, (8β,9β,10β)‐8,9‐epoxycalamenen‐10‐ol ( 7 ), were isolated from the roots of Taiwania cryptomerioides. The structures of the new constituents were essentially elucidated by spectral evidence.     

Two New Highly Oxidized Humulane Sesquiterpenes from the Basidiomycete Lactarius mitissimus

Two new highly oxidized humulane sesquiterpenes, mitissimols F ( 1 ) and G ( 2 ), were isolated from the fruiting bodies of Lactarius mitissimus. Their structures were elucidated by using extensive spectroscopic techniques including 1D‐ and 2D‐NMR experiments. The absolute configuration of mitissimol F ( 1 ) was determined by ¹H‐NMR resolution of its diastereoisomeric α‐methoxy‐α‐(trifluoromethyl)benzeneacetates (MTPA). It was shown to be (1S,3E,6S,8R,9R,10S,11R)‐8,9 : 10,11‐diepoxy‐1,6‐dihydroxyhumul‐3‐en‐5‐one (=(1S,2R,4R,6S,8E,11S,12R)‐6,11‐dihydroxy‐1,6,10,10‐tetramethyl‐3,13‐dioxatricyclo[10.1.0.0^2,4]tridec‐8‐en‐7‐one).     

Three New Sesquiterpenoids from Echinops ritro L.

From the whole plants of E. ritro L., the three new sesquiterpenoids (3α,4α,6α)‐3,13‐dihydroxyguaia‐7(11),10(14)‐dieno‐12,6‐lactone ( 1 ), (3α,4α,6α,11β)‐3‐hydroxyguai‐1(10)‐eno‐12,6‐lactone ( 2 ), and (11α)‐11,13‐dihydroarglanilic acid methyl ester (=(4β,6α,11α)‐4,6‐dihydroxy‐1‐oxoeudesm‐2‐en‐12‐oic acid methyl ester; 3 ), together with eight known sesquiterpenoids, were isolated. Their structures were elucidated through analysis of spectroscopic data including extensive 2D‐NMR.     

Triterpenoid Saponins from the Spikes of Prunella vulgaris

Three new oleanane‐skeleton triterpenoid saponins, 3β,4β,16α‐17‐carboxy‐16,24‐dihydroxy‐28‐norolean‐12‐en‐3‐yl 4‐O‐β‐D ‐xylopyranosyl‐β‐D ‐glucopyranosiduronic acid ( 1 ), (3β,4β,16α)‐17‐carboxy‐16,24‐dihydroxy‐28‐norolean‐12‐en‐3‐yl β‐D ‐glucopyranosiduronic acid methyl ester ( 2 ), and (3β,4β)‐24‐hydroxy‐16‐oxo‐28‐norolean‐12‐en‐3‐yl 4‐O‐β‐D ‐xylopyranosyl‐β‐D ‐glucopyranosiduronic acid ( 3 ), together with eight known constituents, i.e., the oleanane‐type triterpenoids 4 – 6 , and the ursane‐type triterpenoids 7 – 11 , were isolated from the spikes of Prunella vulgaris. The new structures were established by means of detailed spectroscopic analysis (IR, HR‐ESI‐MS, 1D‐ and 2D‐NMR experiments). Compounds 1 – 3 were tested for their inhibition activity against the growth of tumor cell lines; only compound 3 displayed marginal inhibition activity.     

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 ).