Three New C21 Steroidal Glycosides from the Stems of Marsdenia tenacissima

Three new glycosides, (3β,5α,8α,11α,12β,14β,17α,20R)‐3‐[(2,6‐dideoxy‐4‐O‐(6‐deoxy‐3‐O‐methyl‐β‐D ‐allopyranosyl)‐3‐O‐methyl‐β‐D ‐arabino‐hexopyranosyl)oxy]‐12‐O‐tigloyl‐8,20 : 11,20‐diepoxypregnane‐12,14‐diol ( 1 ), (3β,5α,8α,11α,12β,14β,17α,20R)‐3‐[(2,6‐dideoxy‐4‐O‐(6‐deoxy‐3‐O‐methyl‐β‐D ‐ allopyranosyl)‐3‐O‐methyl‐β‐D ‐arabino‐hexopyranosyl)oxy]‐12‐O‐(2‐methylbutanoyl)‐8,20 : 11,20‐diepoxypregnane‐12,14‐diol ( 2 ), and (3β,5α,11α,12β,14β,17α)‐12‐acetoxy‐3‐[(2,6‐dideoxy‐4‐O‐(6‐deoxy‐3‐O‐methyl‐β‐D ‐allopyranosyl)‐3‐O‐methyl‐β‐D ‐arabino‐hexopyranosyl)oxy]‐20‐oxo‐8,14‐epoxypregnan‐ 11‐yl isobutyrate ( 3 ) were isolated from the stems of Marsdenia tenacissima. The structures of the new compounds were elucidated by means of spectral data, including HR‐ESI‐MS, and 1D‐ and 2D‐NMR.     

Three New Polyoxypregnane Glycosides from Marsdenia tenacissima

Three new polyoxypregnane glycosides, marsdenosides I–K ( 1 – 3 ), were isolated from the stem of Marsdenia tenacissima. The structures were elucidated on the basis of in‐depth spectroscopic analyses, and by means of chemical evidence. Marsdenoside I ( = (3β,5α,11α,12β,14β,17α,20R)‐3‐[(2,6‐dideoxy‐4‐O‐(6‐deoxy‐3‐O‐methyl‐β‐D ‐allopyranosyl)‐3‐O‐methyl‐β‐D ‐arabino‐hexopyranosyl)oxy]‐8,20 : 11,20‐diepoxypregnane‐12,14‐diol; 1 ) is the first C₂₁ steroidal glycoside with a rigid cage. Also, the isolation of 1 demonstrated that tenacigenin A ( 1a ) is a true natural product as well, rather than an artifact.     

Foetidissimosides C–F,Novel Glycosides from the Roots of Cucurbita foetidissima

Two novel echinocystic acid (=(3β,16α)‐3,16‐dihydroxyolean‐12‐en‐28‐oic acid) glycosides, foetidissimosides C ( 1 ), and D ( 2 ), along with new cucurbitane glycosides, i.e., foetidissimosides E/F ( 3 / 4 ) as an 1 : 1 mixture of the (24R)/(24S) epimers, were obtained from the roots of Cucurbita foetidissima. Their structures were elucidated by means of a combination of homo‐ and heteronuclear 2D‐NMR techniques (COSY, TOCSY, NOESY, ROESY, HSQC, and HMBC), and by FAB‐MS. The new compounds were characterized as (3β,16α)‐28‐{[O‐β‐D ‐glucopyranosyl‐(1→3)‐O‐β‐D ‐xylopyranosyl‐(1→4)‐O‐6‐deoxy‐α‐L ‐mannopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl]oxy}‐16‐hydroxy‐28‐oxoolean ‐12‐en‐3‐yl β‐D ‐glucopyranosiduronic acid ( 1 ), (3β,16α)‐16‐hydroxy‐28‐oxo‐28‐{{O‐β‐D ‐xylopyranosyl‐(1→3)‐O‐[β‐D ‐xylopyranosyl‐(1→4)]‐O‐6‐deoxy‐α‐L ‐mannopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl}oxy}olean‐12‐en‐3‐yl β‐D ‐glucopyranosiduronic acid ( 2 ), and (3β,9β,10α,11α,24R)‐ and (3β,9β,10α,11α,24S)‐25‐(β‐D ‐glucopyranosyloxy)‐9‐methyl‐19‐norlanost‐5‐en‐3‐yl 2‐O‐β‐D ‐glucopyranosyl‐β‐D ‐glucopyranoside ( 3 and 4 , resp.).     

Diterpene Glycosides from the Dry Fronds of Conyza japonica

Phytochemical investigation of the 95% EtOH extract of the dry fronds of Conyza japonica (Thunb .) Less. resulted in the isolation of three new labdane diterpene glycosides, (3β,13S)‐13‐O‐α‐L ‐rhamnopyranosyllabda‐8(17),14‐dien‐3‐yl α‐L ‐rhamnopyranoside ( 1 ), (3β,13S)‐13‐O‐α‐L ‐rhamnopyranosyllabda‐8(17),14‐diene‐3‐yl 2‐O‐acetyl‐α‐L ‐rhamnopyranoside ( 2 ), and (3β,13S)‐13‐O‐α‐L ‐rhamnopyranosylabda‐8(17),14‐dien‐3‐yl 6‐O‐acetyl‐β‐D ‐glucopyranosyl‐(1→2)‐α‐L ‐rhamnopyranoside ( 3 ), together with their aglycone, (13S)‐labda‐8(17),14‐diene‐3,13‐diol ( 4 ). Their structures were characterized by spectroscopic analyses and chemical correlations, including 1D‐ and 2D‐NMR, and HR‐ESI‐MS. Furthermore, compounds 1 – 3 appeared to be promising as active agents against the tested pathogen fungi and oral pathogens as they possessed moderate cytotoxic properties.     

Two New Iridoid Glycosides from Hedyotis tenelliflora Blume

Two new iridoid glycosides, teneoside A (=(2aR,5S)‐5‐[(β‐D ‐glucopyranosyl)oxy]‐2a,4a,5,7b‐tetrahydro‐4‐{[(α‐L ‐rhamnopyranosyl)oxy]methyl}‐1H‐2,6‐dioxacyclopenta[cd]inden‐1‐one; 1 ) and teneoside B (=methyl (1S,5R)‐1‐[(β‐D ‐glucopyranosyl)oxy]‐1,4a,5,7a‐tetrahydro‐5‐hydroxy‐7‐{[(α‐L ‐rhamnopyranosyl)oxy]methyl}cyclopenta[c]pyran‐4‐carboxylate; 2 ), were isolated from the roots of Hedyotis tenelliflora Blume , along with two known compounds, deacetylasperuloside ( 3 ) and scandoside methyl ester ( 4 ). Their structures were elucidated by chemical methods (acid hydrolysis) and spectroscopic analyses.     

Three New Kaempferol Glycosides from Cardamine leucantha

Three new kaempferol glycosides, kaempferol 3‐O‐β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐galactopyranosyl‐7‐O‐α‐L ‐rhamnopyranoside ( 1 ), kaempferol 3‐O‐β‐D ‐galactopyranosyl‐7‐O‐β‐D ‐glucopyranosyl‐(1→3)‐α‐L ‐rhamnopyranoside ( 2 ), and kaempferol 3‐O‐β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐galactopyranosyl‐7‐O‐β‐D ‐glucopyranosyl‐(1→3)‐α‐L ‐rhamnopyranoside ( 3 ), were isolated from the whole herbs of Cardamine leucantha, along with three known kaempferol glycosides, kaempferol 7‐O‐α‐L ‐rhamnopyranoside, kaempferitrin, and kaempferol 3‐O‐β‐D ‐galactopyranosyl‐7‐O‐α‐L ‐rhamnopyranoside. Their structures were elucidated on the basis of spectroscopic methods.     

Terpenoids from Two Dicranopteris Species

Two new compounds, (6S,13S)‐6‐{[β‐D ‐glucopyranosyl‐(1→4)‐α‐L ‐rhamnopyranosyl]oxy}cleroda‐3,14‐dien‐13‐ol ( 1 ) and kadsuric acid 3‐methyl ester ( 2 ), together with nine known compounds, (6S,13E)‐6‐{[β‐D ‐glucopyranosyl‐(1→4)‐α‐L ‐rhamnopyranosyl]oxy}cleroda‐3,13‐dien‐15‐ol ( 3 ), (6S,13S)‐6‐[6‐O‐acetyl‐β‐D ‐glucopyranosyl‐(1→4)‐α‐L ‐rhamnopyranosyl]oxy}‐13‐{[α‐L ‐rhamnopyranosyl‐(1→4)‐β‐D ‐fucopyranosyl]oxy}cleroda‐3,14‐diene ( 4 ), (6S,13S)‐6‐{[6‐O‐β‐D ‐glucopyranosyl‐(1→4)‐α‐L ‐rhamnopyranosyl]oxy}‐13‐{[α‐L ‐rhamnopyranosyl‐(1→4)‐β‐D ‐fucopyranosyl]oxy}cleroda‐3,14‐diene ( 5 ), 15‐hydroxydehydroabietic acid ( 6 ), 15‐hydroxylabd‐8(17)‐en‐19‐oic acid ( 7 ), junicedric acid ( 8 ), (4β)‐kaur‐16‐en‐18‐oic acid ( 9 ), (4β)‐16‐hydroxykauran‐18‐oic acid ( 10 ), and (4β,16β)‐16‐hydroxykauran‐18‐oic acid ( 11 ) were isolated from the fronds of Dicranopteris linearis or D. ampla. Their structures were established by extensive 1D‐ and 2D‐NMR spectroscopy. Compounds 1 and 3 – 8 showed no anti‐HIV activities.     

Two New Steroidal Saponins from the Fresh Leaves of Agave sisalana

A new furostanol saponin, sisalasaponin C ( 1 ), and a new spirostanol saponin, sisalasaponin D ( 2 ), were isolated from the fresh leaves of Agave sisalana, along with three other known steroidal saponins and two stilbenes. Their structures were identified as (3β,5α,6α,22α,25R)‐3,26‐bis[(β‐D ‐glucopyrano‐ syl)oxy]‐22‐hydroxyfurostan‐6‐yl β‐D ‐glucopyranoside ( 1 ), (3β,5α,25R)‐12‐oxospirostan‐3‐yl 6‐deoxy‐α‐L ‐mannopyranosyl‐(1→4)‐β‐D ‐glucopyranosyl‐(1→3)‐[β‐D ‐xylopyranosyl‐(1→3)‐β‐D ‐glucopyranosyl‐(1→2)]‐β‐D ‐glucopyranosyl‐(1→4)‐β‐D ‐galactopyranoside ( 2 ), (3β,5α,6α,22α,25R)‐22‐methoxyfurostane‐3,6,26‐triyl tris‐β‐D ‐glucopyranoside, cantalasaponin‐1, polianthoside D, (E)‐ and (Z)‐2,3,4′,5‐tetrahydroxystilbene 2‐O‐β‐D ‐glucopyranosides. The last three known compounds were isolated from the fresh leaves of Agavaceae for the first time. The structures of the new compounds were elucidated by detailed spectroscopic analysis, including 1D‐ and 2D‐NMR experiments, and chemical techniques.     

New Flavonoids from Lysimachia christinae Hance

A chemical investigation of Lysimachia christinae, a traditional Chinese medicine used as an effective conservative treatment for gall stones, hepatolithiasis, and urinary calculi, resulted in the isolation of two new flavonoids, myricetin 3,3′‐di‐α‐L ‐rhamnopyranoside ( 1 ) and quercetin 3,3′‐di‐α‐L ‐rhamnopyranoside ( 2 ), along with the five known flavonoids quercetin 3‐[O‐α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐galactopyranoside], amentoflavone, hyperin, quercetin 3‐β‐D ‐glucopyranoside, and kaempferol 3‐α‐L ‐rhamnopyranoside. Amentoflavone was reported for the first time from the genus Lysimachia, and quercetin 3‐[O‐α‐L ‐rhamopyranosyl‐(1→2)‐β‐D ‐galactopyranoside] was isolated from this plant for the first time. The structures of the new compounds were elucidated on the basis of their chemical reactions and extensive spectroscopic analyses, including UV, mass, and NMR spectra.     

Clintoniosides A – C,New Polyhydroxylated Spirostanol Glycosides from the Rhizomes of Clintonia udensis

Phytochemical analyses were carried out on the rhizomes of Clintonia udensis (Liliaceae) with particular attention paid to the steroidal glycoside constituents, resulting in the isolation of three new polyhydroxylated spirostanol glycosides, named clintonioside A ( 1 ), B ( 2 ), and C ( 3 ). On the basis of their spectroscopic data, including 2D‐NMR spectroscopy, in combination with acetylation and hydrolytic cleavage, the structures of 1 – 3 were determined to be (1β,3β,23S,24S,25R)‐1,23,24‐trihydroxyspirost‐5‐en‐3‐yl O‐β‐D ‐glucopyranosyl‐(1→4)‐O‐[α‐L ‐rhamnopyranosyl‐(1→2)]‐β‐D ‐glucopyranoside ( 1 ), (1β,3β,23S,24S)‐3,21,23,24‐tetrahydroxyspirosta‐5,25(27)‐dien‐1‐yl O‐α‐L ‐rhamnopyranosyl‐(1→2)‐O‐[β‐D ‐xylopyranosyl‐(1→3)]‐β‐D ‐glucopyranoside ( 2 ), and (1β,3β,23S,24S)‐21‐(acetyloxy)‐24‐[(6‐deoxy‐β‐D ‐gulopyranosyl)oxy]‐3,23‐dihydroxyspirosta‐5,25(27)‐dien‐1‐yl O‐α‐L ‐rhamnopyranosyl‐(1→2)‐O‐[β‐D ‐xylopyranosyl‐(1→3)]‐β‐D ‐glucopyranoside ( 3 ).     

Chemical Constituents from the Roots of Schnabelia tetradonta

The new rearranged‐abietane diterpene 1 , the four new triterpenoids 2 – 5 , and the new aminoethylphenyl oligoglycoside 6 , besides 19 known compounds, were isolated from the roots of Schnabelia tetradonta, a Chinese endemic herb. The structures of the new compounds were elucidated on the basis of spectroscopic evidence as 12,17‐epoxy‐11,14,16‐trihydroxy‐17(15→16)‐abeo‐abieta‐8,11,13,15‐tetraen‐7‐one ( 1 ), 21β‐(β‐D ‐glucopyranosyloxy)‐2α,3α‐dihydroxyolean‐12‐en‐28‐oic acid ( 2 ), 2β,3β,16β‐trihydroxy‐15‐oxo‐28‐norolean‐12‐en‐23‐oic acid ( 3 ), 3β‐[(4‐O‐acetyl‐β‐D ‐glucopyranuronosyl)oxy]‐2β,16β‐dihydroxy‐28‐norolean‐15‐oxo‐12‐en‐23‐oic acid ( 4 ), 3β‐[(4‐O‐acetyl‐6‐O‐methyl‐β‐D ‐glucopyranuronosyl)oxy]‐2β,16β‐dihydroxy‐15‐oxo‐28‐norolean‐12‐en‐23‐oic acid ( 5 ), and 4‐[2‐(acetylamino)ethyl]phenyl O‐6‐O‐[(Z)‐p‐methoxycinnamoyl]‐β‐D ‐glucopyranosyl‐(1→2)]‐O‐[β‐D ‐glucopyranosyl‐(1→3)]‐4‐O‐acetyl‐α‐L ‐rhamnopyranoside ( 6 ), respectively.     

Novel Polyoxygenated Spirostanol Glycosides from the Rhizomes of Helleborus orientalis

The two new polyoxygenated spirostanol bisdesmosides 1 and 2 and the new trisdesmoside 3 , named hellebosaponin A ( 1 ), B ( 2 ), and C ( 3 ), respectively, were isolated from the MeOH extract of the rhizomes of Helleborus orientalis. The structures of the new compounds were elucidated as (1β,3β,23S,24S)‐21‐(acetyloxy)‐24‐[(β‐D ‐fucopyranosyl)oxy]‐3,23‐dihydroxyspirosta‐5,25(27)‐dien‐1‐yl O‐β‐D ‐apiofuranosyl‐(1→3)‐O‐(4‐O‐acetyl‐α‐L ‐rhamnopyranosyl)‐(1→2)‐O‐[β‐D ‐xylopyranosyl‐(1→3)]‐α‐L ‐arabinopyranoside ( 1 ), (1β,3β,23S,24S)‐ 21‐(acetyloxy)‐24‐{[O‐β‐D ‐glucopyranosyl‐(1→4)‐β‐D ‐fucopyranosyl]oxy}‐3,23‐dihydroxyspirosta‐5,25(27)‐dien‐1‐yl O‐β‐D ‐apiofuranosyl‐(1→3)‐O‐(4‐O‐acetyl‐α‐L ‐rhamnopyranosyl)‐(1→2)‐O‐[β‐D ‐xylopyranosyl‐(1→3)]‐ α‐L ‐arabinopyranoside ( 2 ), and (1β,3β,23S,24S)‐24‐[(β‐D ‐fucopyranosyl)oxy]‐21‐{[O‐β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐galactopyranosyl]oxy}‐3,23‐dihydroxyspirosta‐5,25(27)‐dien‐1‐yl O‐β‐D ‐apiofuranosyl‐(1→3)‐O‐(4‐O‐acetyl‐α‐L ‐rhamnopyranosyl)‐(1→2)‐O‐[β‐D ‐xylopyranosyl‐(1→3)]‐α‐L ‐arabinopyranoside ( 3 ), respectively, on the basis of detailed spectroscopic studies and chemical evidence.     

Steroidal Saponins from Disporopsis pernyi

Four new steroidal saponins, named disporosides A–D ( 1 – 4 ), corresponding to (3β,25R)‐3‐[(β‐D ‐glucopyranosyl‐(1→2)‐[β‐D ‐glucopyranosyl‐(1→6)]‐β‐D ‐glucopyranosyl)oxy]‐5β‐spirostan ( 1 ), (3β,25R)‐3‐[(β‐D ‐glucopyranosyl‐(1→2)‐[6‐O‐hexadecanoyl‐β‐D ‐glucopyranosyl‐(1→6)]‐β‐D ‐glucopyranosyl)oxy]‐5β‐spirostan ( 2 ), (3β,22R,25R)‐26‐[(β‐D ‐glucopyranosyl)oxy]‐3‐[(β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl)oxy]‐5β‐furostan ( 3 ), and (3β,22R,25R)‐26‐[(β‐D ‐glucopyranosyl)oxy]‐3‐[(β‐D ‐glucopyranosyl‐(1→2)‐[β‐D ‐glucopyranosyl‐(1→6)]‐β‐D ‐glucopyranosyl)oxy]‐5β‐furostan ( 4 ), have been isolated from the fresh rhizomes of Disporopsis pernyi, together with the three known compounds Ys‐I, agavoside B, and (3β,25R)‐3‐[(β‐D ‐xylopyranosyl‐(1→3)‐β‐D ‐glucopyranosyl‐(1→4)‐β‐D ‐galactopyranosyl)oxy]‐5α‐spirostan‐12‐one. Their structures were elucidated by spectroscopic analyses, chemical transformations (acid hydrolysis), and comparison with literature data.     

Baimantuoluolines D – F,Three New Withanolides from the Flower of Datura metel L.

Three new withanolide compounds, named baimantuoluolines D–F, along with three known withanolides and a lignan were isolated from the flower of Datura metel L., the parts effective against psoriasis. The structures of the new compounds were elucidated as (5α,6β,12β,20R,22R,24R,25S)‐21,24‐epoxy‐5,6,12‐trihydroxy‐27‐methoxy‐1‐oxowith‐2‐enolide ( 1 ), (5α,6β,12β,20R,22R,24R,25S)‐21,24‐epoxy‐5,6,12,27‐tetrahydroxy‐1‐oxowith‐2‐enolide ( 2 ), and (5α,6β,12β,22R)‐5,6,12,21‐tetrahydroxy‐1‐oxowith‐24‐enolide( 3 ) on the basis of physicochemical evidence.     

Two Novel Triterpenoids from Portulaca oleracea L.

Two novel triterpenoids, (2α,3α)‐3‐{[4‐O‐(β‐D ‐glucopyranosyl)‐β‐D ‐xylopyranosyl]oxy}‐2,23‐dihydroxy‐30‐methoxy‐30‐oxoolean‐12‐en‐28‐oic acid ( 1 ) and (2α,3α)‐2,23,30‐trihydroxy‐3‐[(β‐D ‐xylopyranosyl)oxy]olean‐12‐en‐28‐oic acid ( 2 ) were isolated from Portulaca oleracea L., and they both showed weak cytotoxic activity assayed with the MTT method.     

Hydrolytic Reaction of Plant Extracts to Generate Molecular Diversity: New Dammarane Glycosides from the Mild Acid Hydrolysate of Root Saponins of Panax notoginseng

Molecular diversity was generated by hydrolyzing the crude root saponins of Panax notoginseng (Burk .) F. H. Chen under mild acidic condition (AcOH/EtOH 1 : 1). From the acid hydrolysate, five new dammarane glycosides, named notoginsenoside T₁ (=(3β,6α,12β,20E,23RS)‐24,25‐epoxy‐6‐[(β‐D ‐glucopyranosyl)oxy]‐dammar‐20(22)‐ene‐3,12,23‐triol; 1 ), notoginsenoside T₂ (=(3β,6α,12β,20E,23RS)‐24,25‐epoxy‐6‐[(β‐D ‐glucopyranosyl)oxy]‐23‐methoxydammar‐20(22)‐ene‐3,12‐diol; 2 ), notoginsenoside T₃ (=(3β,6α,12β,20S)‐6‐[(β‐D ‐glucopyranosyl)oxy]‐20‐ethoxydammar‐24‐ene‐3,12‐diol; 3 ), notoginsenoside T₄ (=(3β,6α,12β,20S,22E,24RS)‐6‐[(β‐D ‐glucopyranosyl)oxy]dammar‐22‐ene‐3,12,20,24,25‐pentol; 4 ), and notoginsenoside T₅ (=(3β,6α,12β, 24E)‐6‐[(β‐D ‐xylopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl)oxy]dammara‐20(21),24‐diene‐3,12‐diol; 5 ), were isolated, together with 15 known dammarane glycosides, and their structures were elucidated on the basis of spectroscopic evidence. Among the known compounds, ginsenosides Rg₃ and Rh₁ were isolated as major constituents, in addition to ginsenosides Rg₅, Rh₄, and a mixture of (20R)‐ and (20S)‐25‐hydroxyginsenoside Rh₁, all of which were obtained from P. notoginseng for the first time.     

Novel Triterpene Saponins from Zizyphus joazeiro

Two dammarane‐type saponins with a novel aglycone derived from the parent 16,22‐epoxy‐24‐methylidenedammarane and lotoside A, a new lotogenin derivative, were isolated from the MeOH extract of the stem bark of the Brazilian medicinal plant Zizyphus joazeiro, in addition to the known saponin 3β‐{{O‐[O‐[α‐L ‐arabinofuranosyl‐(1→2)]‐O‐[β‐D ‐glucopyranosyl‐(1→3)]]‐α‐L ‐arabinopyranosyl}oxy}jujubogenin ( 1 ). The structures of the new compounds were determined as 16,22‐epoxy‐3β‐[(β‐D ‐glucopyranosyl)oxy]‐24‐methylidenedammarane‐15α,16α,20β‐triol ( 2 ), 16,22‐epoxy‐3β‐{{O‐[O‐[β‐D ‐glucopyranosyl‐(1→2)]‐O‐[β‐D ‐apiofuranosyl‐(1→3)]]‐β‐D ‐glucopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl}oxy}‐24‐methylidenedammarane‐15α,16α,20β‐triol ( 3 ), and 3β‐{{O‐[O‐[β‐D ‐glucopyranosyl‐(1→2)]‐O‐[β‐D ‐apiofuranosyl‐(1→3)]]‐β‐D ‐glucopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl}oxy}lotogenin ( 4 ) by means of 1D‐ and 2D‐NMR spectroscopy, as well as FAB mass spectrometry. For the novel aglycone, we propose the name joazeirogenin and, for the new saponins, joazeiroside A ( 2 ) and B ( 3 ). Joazeirogenin was found to be 16,22‐epoxy‐24‐methylidenedammarane‐3β,15α,16α,20β‐tetrol.     

New Triterpenoidal Saponins Acylated with Monoterpenic Acid from Albizia adianthifolia

Four new triterpenoidal saponins acylated with monoterpenic acid, i.e., adianthifoliosides C, D, E, and F ( 1 – 4 ), besides the two known julibroside III and the monodesmonoterpenyl elliptoside A, were isolated from the roots of Albizia adianthifolia. Their structures were elucidated on the basis of extensive 1D‐ and 2D‐NMR studies and mass spectrometry as 3‐O‐{O‐α‐L ‐arabinopyranosyl‐(1→2)‐O‐β‐d‐ fucopyranosyl‐(1→6)‐O‐[β‐d‐ glucopyranosyl‐(1→2)]‐β‐d‐ glucopyranosyl}‐21‐O‐{(2E,6S)‐6‐{{4‐O‐[(2E,6S)‐2,6‐dimethyl‐6‐(β‐D ‐quinovopyranosyloxy)octa‐2,7‐dienoyl]‐β‐d‐ quinovopyranosyl}oxy}‐2‐(hydroxymethyl)‐6‐methylocta‐2,7‐dienoyl}acacic acid 28‐{O‐α‐L ‐arabinofuranosyl‐(1→4)‐O‐[β‐d‐ glucopyranosyl‐(1→3)]‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐β‐d‐ glucopyranosyl} ester ( 1 ), 21‐O‐{(2E,6S)‐6‐{{4‐O‐[(2E,6S)‐2,6‐dimethyl‐6‐(β‐d‐ quinovopyranosyloxy)octa‐2,7‐dienoyl]‐β‐d‐ quinovopyranosyl}oxy}‐2‐(hydroxymethyl)‐6‐methylocta‐2,7‐dienoyl}‐3‐O‐{O‐β‐D ‐xylopyranosyl‐(1→2)‐O‐β‐d‐ fucopyranosyl‐(1→6)‐2‐(acetylamino)‐2‐deoxy‐β‐d‐ glucopyranosyl}acacic acid 28‐{O‐α‐L ‐arabinofuranosyl‐(1→4)‐O‐[β‐d‐ glucopyranosyl‐(1→3)]‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐β‐d‐ glucopyranosyl} ester ( 2 ), 21‐O‐{(2E,6S)‐6‐{{3‐O‐[(2E,6S)‐2,6‐dimethyl‐6‐(β‐d‐ quinovopyranosyloxy)octa‐2,7‐dienoyl]‐β‐d‐ quinovopyranosyl}oxy}‐2,6‐dimethylocta‐2,7‐dienoyl}‐3‐O‐{O‐β‐D ‐xylopyranosyl‐(1→2)‐O‐β‐d‐ fucopyranosyl‐(1→6)‐2‐(acetylamino)‐2‐deoxy‐β‐d‐ glucopyranosyl}acacic acid 28‐{O‐α‐L ‐arabinofuranosyl‐(1→4)‐O‐[β‐d‐ glucopyranosyl‐(1→3)]‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐β‐d‐ glucopyranosyl} ester ( 3 ), and 3‐O‐{O‐α‐L ‐arabinopyranosyl‐(1→2)‐O‐β‐d‐ fucopyranosyl‐(1→6)‐O‐[β‐d‐ glucopyranosyl‐(1→2)]‐β‐d‐ glucopyranosyl}‐21‐O‐{(2E,6S)‐2,6‐dimethyl‐6‐(β‐d‐ quinovopyranosyloxy)octa‐2,7‐dienoyl}acacic acid 28‐{O‐α‐L ‐arabinofuranosyl‐(1→4)‐O‐[β‐d‐ glucopyranosyl‐(1→3)]‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐β‐d‐ glucopyranosyl} ester ( 4 ).     

Immunomodulating Steroidal Glycosides from the Roots of Stephanotis mucronata

Guided by in vitro immunological tests, three immunomodulating steroidal glycosides, stemucronatosides A ( 1 ), B ( 2 ), and C ( 3 ), were isolated from the roots of Stephanotis mucronata. On the basis of chemical evidence and extensive spectroscopic methods including 1D and 2D NMR, their structures were determined as 12‐O‐deacetylmetaplexigenin 3‐[O‐6‐deoxy‐3‐O‐methyl‐β‐D ‐allopyranosyl‐(1→4)‐O‐β‐D ‐cymaropyranosyl‐(1→4)‐β‐D ‐cymaropyranoside], 12‐O‐deacetylmetaplexigenin 3‐[O‐β‐D ‐thevetopyranosyl‐(1→4)‐O‐β‐D ‐cymaropyranosyl‐(1→4)‐β‐D ‐cymaropyranoside], and metaplexigenin 3‐[O‐β‐D ‐glucopyranosyl‐(1→4)‐O‐6‐deoxy‐3‐O‐methyl‐β‐D ‐allopyranosyl‐(1→4)‐O‐β‐D ‐cymaropyranosyl‐(1→4)‐β‐D ‐cymaropyranoside], respectively. These compounds showed immunomodulating activities in vitro.     

New Acetylcholinesterase‐Inhibitory Pregnane Glycosides of Cynanchum atratum Roots

Three new pregnane glycosides, cynatroside A ( 1 ), cynatroside B ( 2 ), and cynatroside C ( 3 ), isolated from the roots of Cynanchum atratum (Asclepiadaceae), were characterized as 7β‐{[O‐α‐L ‐cymaropyranosyl‐(1→4)‐O‐β‐D ‐digitoxopyranosyl‐(1→4)‐β‐D ‐oleandropyranosyl]oxy}‐3,4,4a,4b,5,6,7,8,10,10a‐decahydro‐6α‐hydroxy‐4b‐ methyl‐2‐(2‐methyl‐3‐furyl)phenanthren‐1(2H)‐one ( 1 ), 7β‐{[O‐β‐D ‐cymaropyranosyl‐(1→4)‐O‐α‐L ‐diginopyranosyl‐(1→4)‐β‐D ‐cymaropyranosyl]oxy}‐3,4,4a,4b,5,6,7,8,10,10a‐decahydro‐2,6α‐dihydroxy‐4b‐methyl‐2‐(2‐methyl‐3‐furyl)phenanthren‐1(2H)‐one ( 2 ), and 7β‐{[O‐α‐L ‐cymaropyranosyl‐(1→4)‐O‐β‐D ‐digitoxopyranosyl‐(1→4)‐β‐L ‐cymaropyranosyl]oxy}‐3,4,4a,4b,5,6,7,8,10,10a‐decahydro‐2,6α‐dihydroxy‐4b‐methyl‐2‐(2‐methyl‐3‐furyl)phenanthren‐1(2H)‐one ( 3 ), respectively. In addition, ten known constituents were identified, i.e., cynascyroside D ( 4 ), glaucoside C ( 5 ), glaucoside D ( 6 ), atratoside A ( 7 ), 2,4‐dihydroxyacetophenone ( 8 ), 4‐hydroxyacetophenone ( 9 ), syringic acid ( 10 ), azelaic acid ( 11 ), suberic acid ( 12 ), and succinic acid ( 13 ). Among these compounds, 1 – 4 significantly inhibit acetylcholinesterase activity.