Withanolides from Aureliana fasciculata var. fasciculata

In the first phytochemical study of the Aureliana genus (Solanaceae), two new withanolides, 1 and 2 , together with two known sterols, were isolated from the MeOH extract of the leaves of Aureliana fasciculata var. fasciculata. The structures were established as (4S,22R)‐16α‐acetoxy‐5β,6β‐epoxy‐4β,17α‐dihydroxy‐1‐oxowitha‐2,24‐dienolide (aurelianolide A) and (4S,22R)‐16α‐acetoxy‐4β,17α‐dihydroxy‐1‐oxowitha‐2,5,24‐trienolide (aurelianolide B). The new compounds possessed the unusual 16α,17α‐dioxygenated group and were fully characterized by spectroscopic techniques, including ¹H‐ and ¹³C‐NMR (DEPT), as well as 2D‐NMR (HMBC, HMQC, ¹H,¹H‐COSY, NOESY) experiments, and HR‐MS.     

Withanolide Compounds from the Flower of Datura metel L.

Three new withanolide compounds named baimantuoluoline A ( 1 ), B ( 2 ), and C ( 3 ) and the two known withanolides withafastuosin E ( 4 ) and withametelin C ( 5 ) were isolated from the fraction exhibiting activity for psoriasis in the flower of Datura metel L. The three new structures were determined as (5α,6α,7α,12β,15β,22R)‐6,7‐epoxy‐5,12,15‐trihydroxy‐1‐oxowitha‐2,24‐dienolide ( 1 ), (5α,6β,15β,22R)‐ 5,6,15,21‐tetrahydroxy‐1‐oxowith‐24‐enolide ( 2 ), and (5α,6β,12β,22R)‐5,6,12,21‐tetrahydroxy‐27‐methoxy‐1‐oxowitha‐2,24‐dienolide ( 3 ) on the basis of extensive spectroscopic data (HR‐ESI‐MS, ¹H‐ and ¹³C‐NMR, ¹H,¹H‐COSY, HSQC, HMBC, and NOESY) (withanolide=22‐hydroxyergostan‐26‐oic acid δ‐lactone).     

Sesquiterpene Lactones from Anthemis melanolepis

From the aerial parts of A. melanolepis, two new sesquiterpene lactones, melanolepin B ( = 1α,4β,8α‐trihydroxyeudesm‐11(13)‐en‐12,6α‐olide; 1 ) and melanolepin C (= 1α,10β‐epoxy‐8β‐hydroxygermacra‐4(15),11(13)‐dien‐12,6α‐olide; 2 ), were isolated, together with four known compounds, desacetyllaurenobiolide, dentatin A, taraxasterol, and (3S,5R)‐loliolide. Compound 1 was found to have the rare cis‐fused eudesmane skeleton. The structures of the isolated compounds were established by means of NMR (¹H, ¹H‐COSY, ¹H,¹³C‐HSQC, HMBC, NOESY) and MS analyses.     

Triumfettosterol Id and Triumfettosaponin,a New (Fatty Acyl)‐Substituted Steroid and a Triterpenoid ‘Dimer’ Bis(β‐D‐glucopyranosyl) Ester from the Leaves of Wild Triumfetta cordifolia A. Rich. (Tiliaceae)

Two new triterpenoid derivatives were isolated from the leaves of wild Triumfetta cordifolia A. Rich . and identified to be a (fatty acyl)‐substituted steroid 1 and a triterpenoid saponin ‘dimer’ 2 , named (3β)‐stigmasta‐5,22‐diene‐3,29‐diol 3‐propanoate 29‐triacontanoate and (2α,3β,19α)‐2,3,19‐trimethoxyurs‐12‐ene‐24,28‐dioic acid 24‐[(2α,3β)‐24,28‐bis(β‐D ‐glucopyranosyloxy)‐2‐hydroxy‐24,28‐dioxours‐12‐en‐3‐yl] ester, respectively. These compounds were obtained together with a mixture of known sterols (stigmasterol/β‐sitosterol=(3β,22E)‐stigmasta‐5,22‐dien‐3‐ol/(3β)‐stigmast‐5‐en‐3‐ol) and trans‐tiliroside ( 3 ). The structures 1 and 2 were determined on the basis of NMR data (¹H‐, ¹³C‐, and 2D‐NMR analyses) and mass spectrometry and confirmed by chemical transformations. The antimicrobial activities of trans‐tiliroside ( 3 ) against eight bacterial and two fungal strains were evaluated. This compound showed weak activities on some bacterial strains.     

A New Lycopodine Alkaloid from Phlegmariurus yunnanensis Ching

A new lycopodine alkaloid, 15α‐methyllycopodane‐5β,6β‐diol N‐oxide ( 1 ), was isolated from the whole plants of Phlegmariurus yunnanensis Ching , together with the two known alkaloids 15α‐methyllycopodane‐5β,6β‐diol ( 2 ) and lycoposerramine H ( 3 ), and four serratene‐type triterpenoids, serratenediol‐3‐acetate ( 4 ), serratenediol ( 5 ), lycocryptol ( 6 ), and serratriol ( 7 ). Their structures were elucidated on the basis of spectroscopic analyses, including HR‐ESI‐MS, ¹H‐ and ¹³C‐NMR, DEPT, ¹H,¹H‐COSY, HSQC, HMBC, and NOESY.     

Bruceines K and L from the Ripe Fruits of Brucea javanica

Bruceine K ( 1 ), a pentacyclic C₂₀‐quassinoid bearing a unique 12,20‐epoxy moiety, and bruceine L ( 2 ), along with the ten known compounds (6S,7E)‐6,9,10‐trihydroxy‐ and (6S,7E)‐6,9‐dihydroxymegastigma‐4,7‐dien‐3‐one ( 3 and 4 , resp.), cleomiscosins A–C, luteoline, quercetine, bruceantinol, pinoresinol, and thevetiaflavone, were isolated from the ripe fruits of Brucea javanica. Bruceines K ( 1 ) and L ( 2 ) were determined to be (1β,2α,11β,12β,14ξ,15β)‐12,20‐epoxy‐1,2,11,13,14,15‐hexahydroxypicras‐3‐en‐16‐one and (1β,2α,11β,12β,15β)‐13,20‐epoxy‐1,2,11,12‐tetrahydroxy‐16‐oxo‐15‐(senecioyloxy)picras‐3‐en‐21‐oic acid methyl ester (senecioic acid=3‐methylbut‐2‐enoic acid), respectively, on the basis of NMR (¹H‐ and ¹³C‐NMR, DEPT, ¹H,¹H‐COSY, NOESY, HMQC, and HMBC) and ESI‐MS data. Among the known compounds, (6S,7E)‐6,9,10‐trihydroxy‐ and (6S,7E)‐6,9‐dihydroxymegastigma‐4,7‐dien‐3‐one ( 3 and 4 , resp.), cleomiscosin C, luteoline, quercetine, and thevetiaflavone were isolated for the first time from the Brucea plants.     

Two New Lycopodine Alkaloids from Huperzia serrata

Two new lycopodine alkaloids, (12β)‐12‐hydroxyhuperzine G ( 1 ) and (5β,6β,15α)‐15‐methyllycopodane‐5,6‐diol ( 2 ), were isolated from the whole plants of Huperzia serrata, together with six known compounds, huperzines A, B, and G, phlegmariurine B, (8β)‐8‐hydroxyphlegmariurine B, and lycoposerramine D. Their structures were elucidated on the basis of spectroscopic analysis, including HR‐ESI‐MS, ¹H‐ and ¹³C‐NMR, DEPT, ¹H,¹H‐COSY, HSQC, HMBC, and NOESY data.     

New Cytotoxic Triterpenoids from the Aerial Parts of Euphorbia sieboldiana

Phytochemical investigation of the EtOH extract of Euphorbia sieboldiana led to the isolation of four new oleanane‐type triterpenoids, (1β,2α,3β,19β)‐1,2,3,19‐tetrahydroxyolean‐12‐en‐28‐oic acid, (1β,3β,19β)‐1,3,19‐trihydroxyolean‐12‐en‐28‐oic acid, (1β,2α,3β,16β,19β)‐1,2,3,16,19‐pentahydroxyolean‐12‐en‐28‐oic acid, and (1β,2α,3β,19β,23)‐1,2,3,19,23‐pentahydroxyolean‐12‐en‐28‐oic acid, along with 16 known compounds. Their structures were established by extensive 1D‐ and 2D‐NMR, as well as other spectral analyses. Biological evaluation of the four new triterpenoids revealed potent cytotoxic activities against HeLa and Hep‐G2 cells.     

Thrombin Inhibitory Constituents from Duranta repens

The C‐alkylated flavonoids 3,7,4′‐trihydroxy‐3′‐(4‐hydroxy‐3‐methylbutyl)‐5,6‐dimethoxyflavone ( 1 ), 3,7‐dihydroxy‐3′‐(4‐hydroxy‐3‐methylbutyl)‐5,6,4′‐trimethoxyflavone ( 2 ) and the trans‐clerodane diterpenoids 6β‐hydroxy‐15,16‐epoxy‐5β,8β,9β,10α‐cleroda‐3,13(16),14‐trien‐18‐oic acid ( 3 ) and 2β‐hydroxy‐15,16‐epoxy‐5β,8β,9β,10α‐cleroda‐3,13(16),14‐trien‐18‐oic acid ( 4 ) were isolated from Duranta repens. Their structures and the relative configuration of 3 and 4 were determined by spectroscopic methods (¹H‐ and ¹³C‐NMR, IR, and MS) and 2D‐NMR experiments. The known flavonoid 5 is also reported for the first time from this species. The compounds 1 , 3 , and 5 showed significant enzyme‐inhibitory activity against thrombin.     

New Triterpenoid Glycosides from Centella asiatica

Four new triterpenoid glycosides named asiaticoside C ( 1 ), D ( 2 ), E ( 3 ), and F ( 4 ) were isolated from the BuOH fraction of the EtOH extract of whole plants of Centella asiatica, together with three known compounds, asiaticoside ( 5 ), madecassoside ( 6 ), and scheffuroside B ( 7 ). Based on FAB‐MS, IR, ¹H‐ and ¹³C‐NMR, and 2D‐NMR data (HMQC, HMBC, COSY), the structures of the new compounds were determined as (2α,3β,4α)‐23‐(acetyloxy)‐2,3‐dihydroxyurs‐12‐en‐28‐oic acid O‐α‐L ‐rhamnopyranosyl‐(1→4)‐O‐β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl ester ( 1 ), (2α,3β)‐2,3‐dihydroxyurs‐12‐en‐28‐oic acid O‐α‐L ‐rhamnopyranosyl‐(1→4)‐O‐β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl ester ( 2 ), asiatic acid 6‐O‐β‐D ‐glycopyranosyl‐β‐D ‐glucopyranosyl ester ( 3 ), (3β,4α)‐3,23‐dihydroxyurs‐12‐en‐28‐oic acid O‐α‐L ‐rhamnopyranosyl‐(1→4)‐O‐β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl ester ( 4 ).     

Stereoselective Preparation of 3‐Amino‐2‐fluoro Carboxylic Acid Derivatives,and Their Incorporation in Tetrahydropyrimidin‐4(1H)‐ones,and in Open‐Chain and Cyclic β‐Peptides

The preparation of (2S,3S)‐ and (2R,3S)‐2‐fluoro and of (3S)‐2,2‐difluoro‐3‐amino carboxylic acid derivatives, 1 – 3 , from alanine, valine, leucine, threonine, and β³h‐alanine (Schemes 1 and 2, Table) is described. The stereochemical course of (diethylamino)sulfur trifluoride (DAST) reactions with N,N‐dibenzyl‐2‐amino‐3‐hydroxy and 3‐amino‐2‐hydroxy carboxylic acid esters is discussed (Fig. 1). The fluoro‐β‐amino acid residues have been incorporated into pyrimidinones ( 11 – 13 ; Fig. 2) and into cyclic β‐tri‐ and β‐tetrapeptides 17 – 19 and 21 – 23 (Scheme 3) with rigid skeletons, so that reliable structural data (bond lengths, bond angles, and Karplus parameters) can be obtained. β‐Hexapeptides Boc[(2S)‐β³hXaa(αF)]₆OBn and Boc[β³hXaa(α,αF₂)]₆‐OBn, 24 – 26 , with the side chains of Ala, Val, and Leu, have been synthesized (Scheme 4), and their CD spectra (Fig. 3) are discussed. Most compounds and many intermediates are fully characterized by IR‐ and ¹H‐, ¹³C‐ and ¹⁹F‐NMR spectroscopy, by MS spectrometry, and by elemental analyses, [α]_D and melting‐point values.     

Structure elucidation and complete NMR spectral assignments of two new oleanane‐type pentacyclic triterpenoid saponins from the husks of Xanthoceras sorbifolia Bunge

Two new saponins were isolated from husks of Xanthoceras sorbifolia Bunge and their structures were elucidated as 3‐O‐[β‐D‐galactopyranosyl(1→2)]‐α‐L‐arabinofuranosyl(1→3)‐β‐D‐methyl glucuronic acid‐21‐O‐(3,4‐diangeloyl)‐α‐L‐rhamnose‐3β, 16α, 21β, 22α, 28β‐pentahydroxyl‐22‐acetoxy‐olean‐12‐ene(1) and 3‐O‐[β‐D‐galactopyranosyl(1→2)]‐α‐L‐arabinofuranosyl(1→3)‐β‐D‐methyl glucuronic acid‐21,22‐O‐diangeloyl‐3β,15α,16α,21β,22α,28β‐hexahydroxyl‐olean‐12‐ene(2) on the basis of 1D and 2D NMR (including ¹H, ¹³C‐NMR, ¹H? ¹H COSY, HSQC, HMBC and DEPT), ESI‐MS spectrometry and chemical methods. Copyright © 2009 John Wiley & Sons, Ltd.     

New Triterpenoid and Ergostane Glycosides from the Leaves of Hydrocotyle umbellata L.

Two new triterpenoid glycosides, together with two new ergostane glycosides, umbellatosides A–D ( 1 – 4 , resp.), have been isolated from the leaves of Hydrocotyle umbellata L. Their structures were established by 2D‐NMR spectroscopic techniques (¹H,¹H‐COSY, TOCSY, NOESY, HSQC, and HMBC) and mass spectrometry as 3β,22β‐dihydroxy‐3‐O‐[α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐glucuronopyranosyl]olean‐12‐en‐28‐oic acid 28‐O‐β‐D ‐glucopyranosyl ester ( 1 ), 3‐O‐[α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐glucuronopyranosyl]oleanolic acid 28‐O‐β‐D ‐glucopyranosyl ester ( 2 ), (3β,11α,26)‐ergosta‐5,24(28)‐diene‐3,11,26‐triol 3‐O‐(β‐D ‐glucopyranosyl)‐11‐O‐(α‐L ‐rhamnopyranosyl)‐26‐O‐β‐D ‐glucopyranoside ( 3 ), and (3β,11α,21,26)‐ergosta‐5,24(28)‐diene‐3,11,21,26‐tetrol 3‐O‐(β‐D ‐glucopyranosyl)‐11‐O‐(α‐L ‐rhamnopyranosyl)‐26‐O‐β‐D ‐glucopyranoside ( 4 ).     

Further Withaphysalin Derivatives from Acnistus arborescens

Two new epimeric chlorinated withaphysalins, rel‐(4β,5β,6α,18S,22R)‐ and rel‐(4β,5β,6α,18R,22R)‐6‐chloro‐18,20‐epoxy‐18‐ethoxy‐4,5‐dihydroxy‐1‐oxowitha‐2,24‐diene‐26,22‐lactone ( 1 and 2 resp.), together with the new rel‐(4β,5β,6α,18R,22R)‐6‐chloro‐18,20‐epoxy‐4,5‐dihydroxy‐18‐methoxy‐1‐oxowitha‐2,24‐diene‐26,22‐lactone ( 3 ) and rel‐(3β,4β,5β,6β,18R,22R)‐5,6:18,20‐diepoxy‐3,18‐diethoxy‐4‐hydroxy‐1‐oxowith‐24‐ene‐26,22‐lactone ( 4 ) were isolated from the leaves of Acnistus arborescens and named withaphysalins T–W, respectively. The final structures and the complete ¹H‐ and ¹³C‐NMR assignments of the three chlorowithaphysalins 1 – 3 were performed by means of HR‐ESI‐MS and 1D‐ and 2D‐NMR experiments, including COSY, HSQC, and HMBC, beside comparison with spectral data of analogous compounds from the literature. The structure of 4 was also confirmed by means of a single‐crystal X‐ray diffraction analysis.     

Three New Clerodane Diterpenoids from the Bulbils of Dioscorea bulbifera L. var. sativa

From the bulbils of Dioscorea bulbifera L. var. sativa, three new clerodane diterpenoids, bafoudiosbulbin C (=methyl (2β,8α,12S)‐17‐oxo‐2,19 : 8,19 : 12,17 : 15,16‐tetraepoxycleroda‐3,13(16), 14‐triene‐18‐carboxylate; 1 ), bafoudiosbulbin D (=methyl (2β,6β,12R)‐17,19‐dioxo‐2,19 : 6,17 : 8,12 : 15,16‐tetraepoxycleroda‐13(16),14‐diene‐18‐carboxylate; 2 ), and bafoudiosbulbin E (=methyl (2β,3α,4α,6β,12R)‐17,19‐dioxo‐2,19 : 3,4 : 6,17 : 8,12 : 15,16‐pentaepoxycleroda‐13(16),14‐diene‐18‐carboxylate; 3 ) were isolated, together with the known compounds bafoudiosbulbins A and B, 3‐O‐β‐D ‐glucopyranosyl‐β‐sitosterol, and 6′‐stearoyl‐3‐O‐β‐D ‐glucopyranosyl‐β‐sitosterol. Their structures were established by high‐field NMR techniques (¹H,¹H‐COSY, ¹³C‐DEPT, HSQC, HMBC, and NOESY), MS analyses, as well as by comparison of their spectral data with those of related compounds.     

Vibratilicin: a Novel Compound from the Basidiomycete Cortinarius vibratilis

A novel N‐containing compound, vibratilicin (=3‐[3‐(dimethylamino)‐4‐(hydroxyamino)‐4‐oxobutoxy]‐2‐(palmitoyloxy)propyl (9E,12E)‐octadeca‐9,12‐dienoate; 1 ), was isolated from the fruiting bodies of the basidiomycete Cortinarius vibratilis Fr. Compound 1 is a representative of the rare natural products containing hydroxamic acid moieties, and can be viewed as a derivative of neoengleromycin ( 2 ). Also isolated from the same fungus were five known compounds: ergosta‐5,7,22‐trien‐3β‐ol, 5α,8α‐epidioxyergosta‐6,22‐dien‐3β‐ol, p‐anisic acid, N‐(2‐hydroxyhexadecanoyl)‐4‐sphingenine, and (4E,8E)‐2‐N‐(2′‐hydroxypalmitoyl)‐1‐O‐(β‐D ‐glucopyranosyl)‐9‐methyl‐4,8‐sphingadienine. Their structures were determined mainly spectroscopically, including 2D‐NMR techniques (HMBC, HMQC, ¹H,¹H‐COSY).     

New Sesquiterpenoids from Ligularia duciformis

From the whole plants of Ligularia duciformis, four new sesquiterpenoids, 3β‐acetoxy‐6β‐methoxyeremophila‐7(11),9(10)‐dien‐12,8β‐olide ( 1 ), 3β‐acetoxy‐8α‐hydroxy‐6β‐methoxyeremophila‐7(11),9(10)‐dien‐12,8β‐olide ( 2 ), 3β‐acetoxy‐10β‐hydroxy‐6β,8β‐dimethoxyeremophil‐7(11)‐en‐12,8α‐olide ( 3 ), and 3β‐acetoxy‐6β,8β,10β‐trihydroxyeremophil‐7(11)‐en‐12,8α‐olide ( 4 ) were isolated. Their structures were established by high‐field NMR techniques (¹H,¹H‐COSY, ¹³C‐APT, HMQC, HMBC, and NOESY) and HR‐ESI‐MS analysis, together with comparison of the spectroscopic data with those of structurally related compounds. In addition, the cytotoxicity of the new compounds against human hepatic cancer cells Bel‐7402, human pneumonic cancer cells A‐549, and human colonic cancer cells HCT‐8 were evaluated, the new compounds showed no cytotoxicity against the three tumor cells (all IC₅₀ values >200 μM ).     

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.     

A New ent‐Kaurane Diterpene from Stems of Alibertia macrophylla K. Schum. (Rubiaceae)

Phytochemical investigations of the stems of a specimen of Alibertia macrophylla led to the isolation and characterization of the new diterpene ent‐kaurane‐2β,3α,16α‐triol ( 1 ), along with triterpenes 2 – 8 , iridoids 9 – 12 , and phenolic acids 13 – 15 . The structure of 1 was established based on spectroscopic studies (¹H‐ and ¹³C‐NMR, IR, and HR‐ESI‐MS). This is the first report of the isolation of a diterpene from the Alibertia genus in Rubiaceae.     

Complete 1H NMR assignments of pyrrolizidine alkaloids and a new eudesmanoid from Senecio polypodioides

Chemical investigation of the aerial parts of Senecio polypodioides lead to the isolation of the new eudesmanoid 1β‐angeloyloxyeudesm‐7‐ene‐4β,9α‐diol ( 1 ) and the known dirhamnosyl flavonoid lespidin ( 3 ), while from roots, the known 7β‐angeloyloxy‐1‐methylene‐8α‐pyrrolizidine ( 5 ) and sarracine N‐oxide ( 6 ), as well as the new neosarracine N‐oxide ( 8 ), were obtained. The structure of 1 and 8 was elucidated by spectral means. Complete assignments of the ¹H NMR data for 5 , 6 , sarracine ( 7 ), and 8 were made using one‐dimensional and two‐dimensional NMR experiments and by application of the iterative full spin analysis of the PERCH NMR software. Copyright © 2014 John Wiley & Sons, Ltd.