Cucurbitane‐Type Triterpenoids from Momordica charantia

The six new cucurbitane‐type triterpenoids 1 – 6 , along with the ten known triterpenoids 7 – 16 , were isolated from the vines and leaves of Momordica charantia. The structures of the new compounds were elucidated as (3β,7β,15β,23E)‐3,7,15,25‐tetrahydroxycucurbita‐5,23‐dien‐19‐al ( 1 ), (3β,7β)‐3,7,22,23‐tetrahydroxycucurbita‐5,24‐dien‐19‐al ( 2 ), (3β,7β)‐3,7,23,24‐tetrahydroxycucurbita‐5,25‐dien‐19‐al ( 3 ), (3β,7β,23S)‐3,7,23‐trihydroxycucurbita‐5,24‐dien‐19‐al 7‐β‐D ‐glucopyranoside ( 4 ), (3β,7β,23E)‐cucurbita‐5,23‐diene‐3,7,19,25‐tetrol 7‐β‐D ‐glucopyranoside ( 5 ), and (3β,7β,23E)‐3,7‐dihydroxy‐25‐methoxy‐cucurbita‐5,23‐dien‐19‐al 3‐β‐D ‐allopyranoside ( 6 ), by extensive analyses of their spectral data, as well as by chemical methods.     

Triterpenoids from the Stems of Momordica charantia

Two new cucurbitane triterpenes, (23E)‐7β‐methoxycucurbita‐5,23,25‐trien‐3β‐ol ( 1 ) and 23,25‐dihydroxy‐5β,19‐epoxycucurbit‐6‐ene‐3,24‐dione ( 2 ), and a new D : C‐friedooleanane triterpene, 3α‐[(E)‐feruloyloxy]‐D : C‐friedooleana‐7,9(11)‐dien‐29‐oic acid ( 3 ), together with two known D : C‐friedooleanane triterpenes, 3β‐[(E)‐feruloyloxy]‐D : C‐friedooleana‐7,9(11)‐dien‐29‐oic acid ( 4 ) and 3‐oxo‐D : C‐friedooleana‐7,9(11)‐dien‐29‐oic acid ( 5 ), were isolated from the stems of Momordica charantia. The structures of the new compounds 1 – 3 were determined by spectroscopic methods.     

Cucurbitane‐type triterpene glycosides from the fruits of Momordica charantia

The chemical study of Momordica charantia fruits led to the isolation of three new cucurbitane triterpene glycosides, momordicosides U, V, and W (1–3). The structures of these compounds were determined to be (19R, 23R)‐5β, 19‐epoxy‐19‐methoxycucurbita‐6,24‐diene‐3β, 23‐diol 3‐O‐β‐D‐allopyranoside (1), (23R)‐5β, 19‐epoxycucurbita‐6,24‐diene‐3β, 23‐diol 3‐O‐β‐D‐allopyranoside (2), and (19R)‐5β, 19‐epoxy‐19,25‐dihydroxycucurbita‐6,23(E)‐diene‐3β‐ol 3‐O‐β‐D‐glucopyranoside (3), by chemical and spectroscopic methods. Copyright © 2010 John Wiley & Sons, Ltd.     

Two New Cucurbitane Triterpenoids from Immature Fruits of Momordica charantia

Two new cucurbitane triterpenoids, kuguacin X ( 1 ) and kuguaglycoside I ( 2 ), together with three known analogs, were isolated from immature fruits of Momordica charantia. By detailed analysis of IR, NMR, and MS data, acid hydrolysis, and comparison with spectroscopic data of known compounds, the new compounds were determined to be (23E)‐5β,19‐epoxycucurbita‐6,23‐diene‐3β,22ξ,25‐triol ( 1 ) and (23E)‐5β,19‐epoxycucurbita‐6,23‐dien‐19‐on‐3β,25‐diol 3‐O‐β‐D ‐allopyranoside ( 2 ).     

Two New Tetracyclic Triterpenoids and Other Constituents from Aster Ageratoides var. Oophyllus

Two new tetracyclic triterpenoids shiona‐19(E),21‐dien‐3β‐ol ( 1 ), and shiona‐22(29)‐en‐3β,21‐diol ( 2 ), together with four known compounds shiona‐21‐en‐3β‐ol ( 3 ), friedelinol ( 4 ), β‐sitosterol ( 5 ), and (24R)‐stigmast‐7,22(E)‐dien‐3a‐ol ( 6 ) were isolated from Aster ageratoides var. oophyllus. The structures of two new compounds were established on the basis of IR, MS, ¹H, ¹³C and 2D NMR spectroscopic methods.     

Sterols from the Stems of Momordica charantia

A new sterol, 5α,6α‐epoxy‐3β‐hydroxy‐(22E,24R)‐ergosta‐8,22‐dien‐7‐one ( 1 ), together with eight known sterols, 5α,6α‐epoxy‐(22E,24R)‐ergosta‐8,22‐diene‐3β,7α‐diol ( 2 ), 5α,6α‐epoxy‐(22E,24R)‐ergosta‐8,22‐diene‐3β,7β‐diol ( 3 ), 5α,6α‐epoxy‐(22E,24R)‐ergosta‐8(14),22‐diene‐3β,7α‐diol ( 4 ), 3β‐hydroxy‐(22E,24R)‐ergosta‐5,8,22‐trien‐7‐one ( 5 ), ergosterol peroxide ( 6 ), clerosterol ( 7 ), decortinol ( 8 ), and decortinone ( 9 ), were isolated from the stems of Momordica charantia. Their structures were elucidated by mean of extensive spectroscopic methods, including ¹H, ¹³C, 2D‐NMR and HR‐EI‐MS, as well as comparison with the literature data. Compounds 1 , 4 , 5 , 8 , and 91 were not cytotoxic against the SK‐Hep 1 cell line.     

Triterpenoids from the Mangrove Plant Hibiscus tiliaceus

Three new triterpenoids with the rarely occurring nigrum skeleton, namely (20E)‐22‐hydroxynigrum‐20‐en‐3‐one ( 1 ), 21β‐hydroxynigrum‐22(29)‐en‐3‐one ( 2 ), and 21α‐hydroxynigrum‐22(29)‐en‐3‐one ( 3 ), were isolated from the mangrove plant Hibiscus tiliaceus. Additionally, five known triterpenoids including friedelin ( 4 ), 12‐oleanen‐3β‐ol ( 5 ), 3β‐hydroxy‐12‐oleanen‐28‐oic acid ( 6 ), 20(29)‐lupen‐3β,28‐diol ( 7 ), and cucurbita‐5,23‐dien‐3β,25‐diol ( 8 ) were also isolated and identified. The latter structures were elucidated by a detailed NMR and MS analyses, as well as by comparison with reported literature 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.     

Scyphiphorins A and B,Two New Iridoid Glycosides from the Stem Bark of a Chinese Mangrove Scyphiphora hydrophyllacea

Two new iridoid glycosides, named scyphiphorins A ( 1 ) and B ( 2 ), together with four known compounds, geniposidic acid (=(1S,4aS,7aS)‐1‐(β‐D ‐glucopyranosyloxy)‐1,4a,5,7a‐tetrahydro‐7‐(hydroxymethyl)cyclopenta[c]pyran‐4‐carboxylic acid; 3 ), 4‐(4‐hydroxy‐3‐methoxybenzyl)butan‐2‐one, oleanolic acid (=(3β)‐3‐hydroxyolean‐12‐en‐28‐oic acid), and stigmasterol β‐D ‐glucoside (=(3β,22E)‐stigmasta‐5,22‐dien‐3‐yl β‐D ‐glucopyranoside), were isolated for the first time from the stem bark of a Chinese mangrove, Scyphiphora hydrophyllacea Gaertn . f. The structures of compounds 1 and 2 were determined as 10‐O‐benzoylgeniposidic acid and 10‐O‐[(2E,6R)‐8‐hydroxy‐2,6‐dimethyl‐1‐oxooct‐2‐en‐1‐yl]geniposidic acid, respectively, on the basis of spectroscopic data and chemical methods, including 2D NMR techniques.     

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.     

Triterpenoids and other Constituents from Euphorbia Humifusa

A novel lupane‐type triterpenoid, 3,4‐seco‐lupa‐4(23), 20(29)‐dien‐24‐hydroxy‐3‐oic acid (1) and a new cycloartane‐type triterpenoid, 23(E)‐cycloart‐23‐en‐25‐ethoxy‐3β‐ol (7), as well as eighteen known compounds, were isolated from the hot ethanol extract of the whole plant of Euphorbia humifusa Willd. The new structures were characterized by means of spectroscopic methods including 1D, 2D NMR and HRESIMS, and the known ones were established on the basis of comparing their NMR data with those of the corresponding compounds in the literature. In addition, cytotoxicity against selected cancer cell human gastric carcinoma (SGC‐7901) of compounds 1,3,4,6 were measured in vitro.     

Separation of cucurbitane triterpenoids from bitter melon drinks and determination of partition coefficients using vortex‐assisted dispersive liquid‐phase microextraction followed by UHPLC analysis

A rapid, effective method applying vortex‐assisted liquid–liquid microextraction before ultra‐high performance liquid chromatography with mass spectrometry and evaporative light scattering detection was developed for the analysis of four cucurbitane triterpenoids (momordicoside L, momordicoside K, momordicoside F₂, and 3β,7β,25‐trihydroxy cucurbita‐5,23(E )‐dien‐19‐al) in bitter melon juices. Variables affecting the extraction efficiency including different extraction solvents, volume of extraction solvent, salt amount, acid condition, vortex speed and time were optimized thoroughly. Under the optimum conditions, precision was determined by the intra‐ and inter‐day tests in a range of 1.1–5.7% and 2.9–4.0% (RSD), respectively, with recoveries between 95.7 and 106.1%. The calibration curves showed good linearity with square correlation coefficient of 0.9936–0.9991 (evaporative light scattering detection) and 0.9858–0.9989 (MS). The detection limits ranged from 0.8–1.9 ng/mL (MS) to 3–10 ng/mL (evaporative light scattering detection) for these compounds. Enrichment factors of four target compounds were between 27 and 63 times. The proposed method was also used to determine the apparent solvent/water partition coefficients of analytes within the range of 53–120. The developed method can effectively enrich and quantify cucurbitane triterpenoids from bitter melon drinks.     

Four New Lanostane Triterpenoids from Euphorbia humifusa

Four new lanostane triterpenoids, namely (3β)‐3‐hydroxy‐24‐methylenelanost‐8‐ene‐7,11‐dione ( 1 ), (3β)‐3‐hydroxylanosta‐8,24‐diene‐7,11‐dione ( 2 ), (3β,7α)‐3,7‐dihydroxylanosta‐8,24‐dien‐11‐one ( 3 ), and (3β,11β)‐3,11‐dihydroxylanosta‐8,24‐dien‐7‐one ( 4 ) were isolated from Euphorbia humifusa, together with 2 known compounds. The structures of these new compounds were elucidated on the basis of extensive spectroscopic analysis and comparison with the related known compounds.     

Chemical Constituents from Annona Glabra

A new kaurane diterpenoid, annoglabasin G (16α‐hydro‐19‐acetoxy‐ent‐kauran‐17‐al) ( 1 ), along with 27 compounds including 18 kaurane diterpenoids, 16β‐hydro‐ent‐kauran‐17‐oic acid ( 2 ), 16α‐hydro‐ent‐kauran‐17‐oic acid ( 3 ), 19‐nor‐ent‐kauran‐4α‐ol‐17‐oic acid ( 4 ), 16α‐hydro‐19‐ol‐ent‐kauran‐17‐oic acid ( 5 ), ent‐kaur‐16‐en‐19‐oic acid ( 6 ), 16α‐hydroxy‐ent‐kauran‐19‐oic acid ( 7 ), 16α,17‐dihydroxy‐ent‐kauran‐19‐oic acid ( 8 ), 16β,17‐dihydroxy‐ent‐kauran‐19‐oic acid ( 9 ), 16α‐hydro‐ent‐kauran‐17,19‐dioic acid ( 10 ), 16β‐hydroxy‐17‐acetoxy‐ent‐kauran‐19‐oic acid ( 11 ), 16β‐hydro‐17‐hydroxy‐ent‐kauran‐19‐al ( 12 ), 16α‐hydro‐17‐hydroxy‐ent‐kauran‐19‐al ( 13 ), 16β,17‐dihydroxy‐ent‐kauran‐19‐al ( 14 ), 16α‐hydro‐19‐al‐ent‐kauran‐17‐oic acid ( 15 ), 16α‐hydro‐17‐acetoxy‐ent‐kauran‐19‐al ( 16 ), 16α‐hydro‐19‐acetoxy‐ent‐kauran‐17‐oic acid ( 17 ), ent‐kaur‐15‐en‐19‐oic acid ( 18 ) and ent‐kaur‐15‐en‐17‐ol‐19‐oic acid ( 19 ); four acetogenins, annomontacin ( 20 ), annonacin ( 21 ), isoannonacinone ( 22 ) and squamocin ( 23 ); four steroids, β‐sitosterol ( 24 ), stigmasterol ( 25 ), β‐sitosteryl‐D‐glucoside ( 26 ) and stigmasteryl‐D‐glucoside ( 27 ) and one oxoaporphine, liriodenine ( 28 ), were isolated from the fresh fruits of Annona glabra. These compounds were characterized and identified by physical and spectral evidence.     

Neoclerodane Diterpenes from Amoora stellato‐squamosa

From the twigs of Amoora stellato‐squamosa, five new neoclerodane diterpenes have been isolated and characterized, methyl (13E)‐2‐oxoneocleroda‐3,13‐dien‐15‐oate (=methyl (2E)‐3‐methyl‐5‐[(1S,2R,4aR,8aR)‐1,2,3,4,4a,7,8,8a‐octahydro‐1,2,4a,5‐tetramethyl‐7‐oxo‐naphthalen‐1‐yl]pent‐2‐enoate; 1 ), (13E)‐2‐oxoneocleroda‐3,13‐dien‐15‐ol (=(4aR,7R,8S,8aR)‐1,2,4a,5,6,7,8,8a‐octahydro‐8‐[(E)‐5‐hydroxy‐3‐methylpent‐3‐enyl]‐4,4a,7,8‐tetramethylnaphthalen‐2(1H)‐one; 2 ), (3α,4β,13E)‐neoclerod‐13‐ene‐3,4,15‐triol (=(1R,2R,4aR, 5S,6R,8aR)‐decahydro‐5‐[(E)‐5‐hydroxy‐3‐methylpent‐3‐enyl]‐1,5,6,8a‐tetramethylnaphthalene‐1,2‐diol; 3 ), (3α,4β,13E)‐4‐ethoxyneoclerod‐13‐ene‐3,15‐diol (=(1R,2R,4aR,5S,6R,8aR)‐1‐ethoxydecahydro‐5‐[(E)‐5‐hydroxy‐3‐methylpent‐3‐enyl]‐1,5,6,8a‐tetramethylnaphthalen‐2‐ol; 4 ), and (3α,4β,14RS)‐neoclerod‐13(16)‐ ene‐3,4,14,15‐tetrol (=(1R,2R,4aR,5S,6R,8aR)‐decahydro‐5‐[3‐(1,2‐dihydroxyethyl)but‐3‐enyl]‐1,5,6,8a‐tetramethylnaphthalene‐1,2‐diol; 5 ), together with two known compounds, (13E)‐neocleroda‐3,13‐diene‐15,18‐diol ( 6 ) and (13S)‐2‐oxoneocleroda‐3,14‐dien‐13‐ol ( 7 ).     

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 .     

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.     

A Rare New Cleistanthane Diterpene from the Pericarp of Trewia nudiflora

A minor, unprecedented diterpene, 3β,17‐dihydroxycleistantha‐12,15‐dien‐2‐one ( 1 ), was isolated from the CHCl₃‐soluble part of the EtOH extract of the pericarp of Trewia nudiflora. The structure of 1 was elucidated by means of 1D‐ and 2D‐NMR spectroscopic analyses as well as by HR‐MS. Also isolated were two known triterpenes, glutin‐5‐en‐3‐ol and olean‐18‐en‐3‐one (germanicone), as well as three known sterols, (22E,24R)‐5α,8α‐epidioxyergosta‐6,22‐dien‐3β‐ol, (22E,24R)‐5α,8α‐epidioxyergosta‐6,9(11),22‐trien‐3β‐ol, and (22E,24R)‐6‐methoxyergosta‐7,22‐dien‐3,5‐diol.     

Huangqiyenins G – J,Four New 9,10‐Secocycloartane (=9,19‐Cyclo‐9,10‐secolanostane) Triterpenoidal Saponins from Astragalus membranaceus Bunge Leaves

Four new 9,10‐secocycloartane (=9,19‐cyclo‐9,10‐secolanostane) triterpenoidal saponins, named huangqiyenins G–J ( 1 – 4 , resp.), were isolated from Astragalus membranaceus Bunge leaves. The acid hydrolysis of 1 – 4 with 1M aqueous HCl yielded D ‐glucose, which was identified by GC analysis after treatment with L ‐cysteine methyl ester hydrochloride. The structures of 1 – 4 were established by detailed spectroscopic analysis as (3β,6α,10α,16β,24E)‐3,6‐bis(acetyloxy)‐10,16‐dihydroxy‐12‐oxo‐9,19‐cyclo‐9,10‐secolanosta‐9(11),24‐dien‐26‐yl β‐D ‐glucopyranoside ( 1 ), (3β,6a,10α,24E)‐3,6‐bis(acetyloxy)‐10‐hydroxy‐12,16‐dioxo‐9,19‐cyclo‐9,10‐secolanosta‐9(11),24‐dien‐26‐yl β‐D ‐glucopyranoside ( 2 ), (3β,6α,9α,10α,16β,24E)‐3,6‐bis(acetyloxy)‐9,10,16‐trihydroxy‐9,19‐cyclo‐9,10‐secolanosta‐11,24‐dien‐26‐yl β‐D ‐glucopyranoside ( 3 ), and (3β,6α,10α,24E)‐3,6‐bis(acetyloxy)‐10‐hydroxy‐16‐oxo‐9,19‐cyclo‐9,10‐secolanosta‐9(11),24‐dien‐26‐yl β‐D ‐glucopyranoside ( 4 ).     

The Chemical Constituents from the Callus Culture of Trewia nudiflora

Five ent‐atisane diterpenoids, including three new ones, i.e., (16α)‐17‐hydroxy‐ent‐atisan‐19‐oic acid methyl ester ( 1 ), (16α)‐17‐dihydroxy‐ent‐atisan‐19‐oic acid methyl ester ( 2 ), (16α)‐ent‐atisan‐16,17,19‐triol ( 3 ), and two known compounds, i.e., 17‐hydroxy‐ent‐atisan‐19‐oic acid ( 4 ), (16α)‐16,17‐dihydroxy‐ent‐atisan‐19‐al ( 5 ), together with one known diterpene glycoside, i.e., sumogaside, two known triterpenes, i.e., germanicone and (3β)‐β‐amyrin, three known phenolic compounds, i.e., (+)‐gallocatechin, (+)‐catechin, and gallic acid, and two known sterols, i.e., β‐sitosterol and daucosterol, were isolated from the callus cultures of Trewia nudiflora. Their structures were elucidated by spectroscopic analysis including 1D‐ and 2D‐NMR experiments. No maytansinoids were isolated or detected by LC‐ESI‐MS in the extracts of the calli, which suggests that the callus cultures can not produce maytansinoids under these conditions.