Xanthones from the stems of Cratoxylum cochinchinense

Four new xanthones, 1‐methoxy‐3,7,8‐trihydroxyxanthone (1), 1‐methoxy‐4,7,8‐trihydroxyxanthone (2), 1‐methoxy‐4,7‐dihydroxyxanthone (3), and 1,4‐dimethoxy‐2,7‐dihydroxyxanthone (4) were isolated from the stems of Cratoxylum cochinchinense along with four known xanthones (5–8). The structures of new compounds were determined by extensive spectroscopic analyses, mainly 1D and 2D NMR and HRESIMS data. Copyright © 2012 John Wiley & Sons, Ltd.     

Structure elucidation of new fusarielins from Fusarium sp. and their antimicrobial activity

Three new fusarielins, 3‐epi‐fusarielin H ( 1 ), 3‐O‐methyl‐fusarielin H ( 2 ), and 3‐O‐methyl‐epi‐fusarielin H ( 3 ), were isolated from the fungus Fusarium sp. together with the known analogues, fusarielins F ( 4 ) and G ( 5 ). The structures of these compounds were elucidated by analysis of their ESI‐HRTOFMS, 1D and 2D NMR spectroscopic data. The new compounds exhibited weak antibacterial effect against Staphylococcus aureus.     

Four new ursane‐type saponins from Morina nepalensis var. alba

Four new ursane‐type saponins, monepalosides C–F, together with a known saponin, mazusaponin II, were isolated from Morina nepalensis var. alba Hand.‐Mazz. Their structures were determined to be 3‐O‐α‐L ‐arabinopyranosyl‐(1 → 3)‐&[alpha;‐L ‐rhamnopyranosyl‐(1 → 2)]‐α‐L ‐arabinopyranosylpomolic acid 28‐O‐β‐D ‐glucopyranosyl‐(1 → 6)‐β‐D ‐glucopyranoside (monepaloside C, 1 ), 3‐O‐α‐L ‐arabinopyranosyl‐(1 → 3)‐&[alpha;‐L ‐rhamnopyranosyl‐(1 → 2)]‐β‐D ‐xylopyranosylpomolic acid 28‐O‐β‐D ‐glucopyranosyl‐(1 → 6)‐β‐D ‐glucopyranoside (monepaloside D, 2 ), 3‐O‐α‐L ‐arabinopyranosyl‐(1 → 3)‐&[beta;‐D ‐glucopyranosy‐(1 → 2)]‐α‐L ‐arabinopyranosylpomolic acid 28‐O‐β‐D ‐glucopyranosyl‐(1 → 6)‐β‐D ‐glucopyranoside (monepaloside E, 3 ) and 3‐O‐β‐D ‐xylopyranosylpomolic acid 28‐O‐β‐D ‐glucopyranoside (monepaloside F, 4 ) on the basis of chemical and spectroscopic evidence. 2D NMR techniques, including ¹H–¹H COSY, HMQC, 2D HMQC‐TOCSY, HMBC and ROESY, and selective excitation experiments, including SELTOCSY and SELNOESY, were utilized in the structure elucidation and complete assignments of ¹H and ¹³C NMR spectra. Copyright © 2002 John Wiley & Sons, Ltd.     

β‐Carboline alkaloids from the stems of Picrasma quassioides

Five new β‐carboline alkaloids, 6,12‐dimethoxy‐3‐(2‐hydroxylethyl)‐β‐carboline (1), 3,10‐dihydroxy‐β‐carboline (2), 6,12‐dimethoxy‐3‐(1‐hydroxylethyl)‐β‐carboline (3), 6,12‐dimethoxy‐3‐(1,2‐dihydroxylethyl)‐β‐carboline (4), and 6‐methoxy‐3‐(2‐hydroxyl‐1‐ethoxylethyl)‐β‐carboline (5), and two new natural products, 6‐methoxy‐12‐hydroxy‐3‐methoxycarbonyl‐β‐carboline (6) and 3‐hydroxy‐β‐carboline (7) were isolated from the stems of Picrasma quassioides along with 16 known β‐carboline alkaloids (8–23). The structures of new compounds were determined by extensive spectroscopic analyses, and the 1D and 2D NMR data of compounds 6, 7 and 10 were reported for the first time. The bioassays showed that only compounds 14 and 16 could enhance the differentiation of 3T3‐L1 preadiocytes accompanied by secretion of adiponectin proteins among these 23 compounds. Copyright © 2010 John Wiley & Sons, Ltd.     

Isolation and Characterization of Secondary Metabolites from Rhododendron microphyton

Four new iridoids, incarvoids D–F ( 1 – 3 , resp.) and incarvoid B 9‐O‐β‐D ‐glucopyranoside ( 4 ), and one new monoterpenoid, argutoid B ( 5 ), along with 14 known compounds, were isolated from Rhododendron microphyton. Their structures were established by comprehensive 1D‐ and 2D‐NMR spectroscopic analysis.     

Phochinenins A – F,Dimeric 9,10‐Dihydrophenanthrene Derivatives,from Pholidota chinensis

Six new compounds, phochinenins A–F ( 1 – 6 ), dimerized from 9,10‐dihydrophenanthrene and dihydrostilbene through direct coupling or an oxygen bridge, along with eight known compounds, were isolated from the whole plants of Pholidota chinensis. Their structures were elucidated on the basis of extensive spectroscopic investigations (1D‐, 2D‐NMR, and HR‐EI‐MS).     

Two new acylated flavonoid glycosides from Morina nepalensis var. alba Hand.‐Mazz.

From the whole plant of Morina nepalensis var. alba Hand.‐Mazz., two new acylated flavonoid glycosides ( 1 and 2 ), together with four known flavonoid glycosides ( 3–6 ), were isolated. Their structures were determined to be quercetin 3‐O‐[2″′‐O‐(E)‐caffeoyl]‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐galactopyranoside (monepalin A, 1 ), quercetin 3‐O‐[2″′‐O‐(E)‐caffeoyl]‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐glucopyranoside (monepalin B, 2 ), quercetin 3‐O‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐galactopyranoside (rumarin, 3 ), quercetin 3‐O‐β‐D ‐galactopyranoside ( 4 ), quercetin 3‐O‐β‐D ‐glucopyranoside ( 5 ) and apigenin 4^′‐O‐β‐D ‐glucopyranoside ( 6 ). Their structures were determined on the basis of chemical and spectroscopic evidence. Complete assignments of the ¹H and ¹³C NMR spectra of all compounds were achieved from the 2D NMR spectra, including H–H COSY, HMQC, HMBC and 2D HMQC‐TOCSY spectra. Copyright © 2002 John Wiley & Sons, Ltd.     

Micromelosides A–D,four new coumarins from the stem bark of Micromelum falcatum

Four new coumarins, micromelosides A–D, together with four known coumarins were isolated from the stem bark of Micromelum falcatum. The complete assignments of the ¹H and ¹³C NMR chemical shifts for these new compounds were achieved by means of 1D and 2D NMR techniques, including ¹H‐¹H COSY, HSQC, HMBC and NOE difference. Copyright © 2009 John Wiley & Sons, Ltd.     

Three New Diterpenoids from Isodon nervosus

Three new ent‐kaurane diterpenoids, rabdonervosins D–F ( 1 – 3 ), were isolated from the leaves and stems of Isodon nervosus. Their structures were elucidated on the basis of spectroscopic methods including 1D‐ and 2D‐NMR analyses. Compounds 1 – 3 were evaluated for their cytotoxicity against HepG2, CNE2, PC‐9/ZD, HeLa, MCF‐7, and HCT116 cell lines. No compounds exhibited potent cytotoxicity.     

New Eremophilane Sesquiterpenes from a Rhizome Extract of Petasites hybridus

A total of 21 natural products, 1 – 21 , were isolated from a supercritical CO₂ extract of the rhizomes of Petasites hybridus. Thereby, seven new eremophilane (= (1S,4aR,7R,8aR)‐decahydro‐1,8a‐dimethyl‐7‐(1‐methylethyl)naphthalene) sesquiterpenes, compounds 4, 5, 9, 11, 12, 15 , and 17 , were identified. The new constituent 9‐hydroxyisobakkenolide ( 15 ) is the first representative of a group of compounds closely related to the well‐known, but rare, bakkenolides. Tsoongianolide B ( 18 ) and its degradation product ligularenolide ( 19 ) were found as new Petasites constituents as well. The known eremophilanolide 2 was isolated from a plant source for the first time and the oxofuranopetasin 16 was isolated for the first time from the rhizomes of P. hybridus, together with eight other known compounds. The C(8)‐epimeric 2‐[(tigloyl)oxy]eremophilanolides 3 and 8 could clearly be differentiated. All structures were established by extensive 1D‐ and 2D‐NMR experiments (Tables 1–3), and confirmed by in‐depth GC/MS and HPLC/MS experiments.     

New saponins from Sechium mexicanum

The chemical study of Sechium mexicanum roots led to the isolation of the two new saponins {3‐O‐β‐D ‐glucopyranosyl (1 → 3)‐β‐D ‐glucopyranosyl‐2β,3β,16α,23‐tetrahydroxyolean‐12‐en‐28‐oic acid 28‐O‐α‐L ‐rhamnopyranosyl‐(1 → 3)‐β‐D ‐xylopyranosyl‐(1 → 4)‐α‐L ‐rhamnopyranosyl‐(1 → 2)‐α‐L ‐arabinopyranoside} (1) and {3‐O‐β‐D ‐glucopyranosyl (1 → 3)‐β‐D ‐glucopyranosyl‐2β,3β,16α,23‐tetrahydroxyolean‐12‐en‐28‐oic acid 28‐O‐α‐L ‐rhamnopyranosyl‐(1 → 3)‐β‐D ‐xylopyranosyl‐(1 → 4)‐[β‐D ‐apiosyl‐(1 → 3)]‐α‐L ‐rhamnopyranosyl‐(1 → 2)‐α‐L ‐arabinopyranoside} (2), together with the known compounds {3‐O‐β‐D ‐glucopyranosyl‐(1 → 3)‐β‐D ‐glucopyranosyl‐2β,3β,6β,16α,23‐pentahydroxyolean‐12‐en‐28‐oic acid 28‐O‐α‐L ‐rhamnopyranosyl‐(1 → 3)‐β‐D ‐xylopyranosyl‐(1 → 4)‐α‐L ‐rhamnopyranosyl‐(1 → 2)‐α‐L ‐arabinopyranoside} (3), tacacosides A₁ (4) and B₃ (5). The structures of saponins 1 and 2 were elucidated using a combination of ¹H and ¹³C 1D‐NMR, COSY, TOCSY, gHMBC and gHSQC 2D‐NMR, and FABMS of the natural compounds and their peracetylated derivates, as well as by chemical degradation. Compounds 1–3 are the first examples of saponins containing polygalacic and 16‐hydroxyprotobasic acids found in the genus Sechium, while 4 and 5, which had been characterized partially by NMR, are now characterized in detail. Copyright © 2009 John Wiley & Sons, Ltd.     

Structural determination of two new steroidal saponins from Smilax china

Two new steroidal saponins (1 and 2) were isolated from the BuOH fraction of the 70% EtOH extract of the tubes of Smilax china, together with four known analogues, 3–6. The structures of the new compounds were elucidated by means of chemical evidence and spectroscopic analyses, including HR‐MS, IR, ¹H‐ and ¹³C‐NMR, and 2D experiments (¹H–¹H COSY, HSQC and HMBC). Copyright © 2009 John Wiley & Sons, Ltd.     

Structure determination of two new indole‐diterpenoids from Penicillium sp. CM‐7 by NMR spectroscopy

Two new indole‐diterpenoids 4b‐deoxy‐1′‐O‐acetylpaxilline (1) and 4b‐deoxypenijanthine A (2) were isolated from the fermentation broth and the mycelia of the soil fungus Penicillium sp. CM‐7, along with three known structurally related compounds, 1′‐O‐acetylpaxilline (3), paspaline (4) and 3‐deoxo‐4b‐deoxypaxilline (5). The structures of compounds 1 and 2 were elucidated by extensive spectroscopic methods, especially 2D NMR, and their absolute configurations were suggested on the basis of the circular dichroism spectral analysis and the NOESY data. Copyright © 2014 John Wiley & Sons, Ltd.     

Steroidal saponins and pregnane glycosides from Smilax microphylla

Six steroidal saponins and two pregnane glycosides were isolated from the BuOH subfraction of 70% EtOH extract of Smilax microphylla C.H.Wright, among them two were new compounds (1 and 7). Pregnane glycosides were firstly isolated from the genus Smilax (Smilacaceae). Structures of the new compounds were determined on the basis of HR‐ESI‐MS, 1D and 2D NMR spectroscopic analysis. Copyright © 2012 John Wiley & Sons, Ltd.     

Structure elucidation of a sodium salified anthraquinone from the seeds of Cassia obtusifolia by NMR technique assisted with acid–alkali titration

A new sodium salt of anthraquinone named sodium emodin‐1‐O‐β‐gentiobioside, together with nine known compounds, viz. rubrofusarin‐6‐O‐β‐D ‐gentiobioside, chrysophanol‐1‐O‐β‐D ‐glucopyranosyl‐(1–3)‐β‐D ‐glucopyranosyl‐(1–6)‐β‐D ‐glucopyranoside, obtusifolin‐2‐O‐β‐D ‐glucopyranoside, aurantio‐obtusin‐6‐O‐β‐D ‐glucopyranoside, physcion‐8‐O‐β‐D ‐glucopyranoside, 1‐hydroxyl‐2‐acetyl‐3,8‐dimethoxy‐6‐O‐β‐D ‐apiofuranosyl‐(1–2)‐β‐D ‐glucosylnaphthalene, toralactone‐9‐O‐β‐D ‐gentiobioside, aurantio‐obtusin, rubrofusarin‐6‐O‐β‐D ‐apiofuranosyl‐(1–6)‐O‐β‐D ‐glucopyranoside, was isolated from the seeds of Cassia obtusifolia and its structure was elucidated by ¹H and ¹³C NMR technique assisted with acid–alkali titration. The change of chemical shifts of sodium emodin‐1‐O‐β‐gentiobioside before and after acid–alkali titration was also characterized. Copyright © 2011 John Wiley & Sons, Ltd.     

A New Lignan and Four New Lignan Glycosides from Mananthes patentiflora

A new lignan, 5‐hydroxyjusticidin A (= 9‐(1,3‐benzodioxol‐5‐yl)‐5‐hydroxy‐4,6,7‐trimethoxynaphtho[2,3‐c]furan‐1(3H)‐one; 1 ), and four new diphyllin‐type lignan glycosides, mananthosides C–F ( 2 – 5 ), containing glucosyl (Glc), arabinosyl (Ara), galactosyl (Gal), and/or apiosyl residues, have been isolated from Mananthes patentiflora, together with five known compounds. Their structures and configurations were elucidated by in‐depth 1D‐ and 2D‐NMR experiments, as well as MS analysis.     

Secoatisane‐ and Isopimarane‐Type Diterpenoids from the Chinese Mangrove Excoecaria agallocha L.

Phytochemical investigations of the stems and leaves of the Chinese mangrove Excoecaria agallocha L. yielded one new secoatisane‐type diterpenoid, agallochaol C ( 1 ), three new isopimarane‐type diterpenoids, agallochaols D–F ( 2 – 4 ), along with four known diterpenoids 5 – 8 . The structures of new compounds 1 – 4 were determined on the basis of spectroscopic‐data interpretation and chemical evidence.     

Five New Tetranortriterpenoids from the Seeds of Toona ciliata

Five new tetranortriterpenoids, toonaciliatones B–F ( 1 – 5 , resp.), together with four known compounds, dihydrocedrelone ( 6 ), cedrelone ( 7 ), 6α‐acetoxyazadirone ( 8 ), and 6α‐acetoxy‐14β,15β‐epoxyazadirone ( 9 ), were isolated from the seeds of Toona ciliata. Their structures were elucidated by spectroscopic methods, including 1D‐ and 2D‐NMR spectroscopy.     

Complete NMR assignments of bioactive rotameric (3 → 8) biflavonoids from the bark of Garcinia hombroniana

The genus Garcinia is reported to possess antimicrobial, anti‐inflammatory, anticancer, hepatoprotective and anti‐HIV activities. Garcinia hombroniana in Malaysia is used to treat itching and as a protective medicine after child birth. This study was aimed to isolate the chemical constituents from the bark of G. hombroniana and explore their possible pharmacological potential. Ethyl acetate extract afforded one new (1) and six (2–7) known 3 → 8 rotameric biflavonoids. Their structures were elucidated by UV, IR and NMR (1D and 2D) spectroscopy together with electron ionization/ESI mass spectrometric techniques and were identified as (2R, 3S) volkensiflavone‐7‐O‐rhamnopyranoside (1), volkensiflavone (2), 4″‐O‐methyl‐volkensiflavone (3), volkensiflavone‐7‐O‐glucopyranoside (4), morelloflavone (5), 3″‐O‐methyl‐morelloflavone (6) and morelloflavone‐7‐O‐glucopyranoside (7). The absolute configuration of compound 1 was assigned by circular dichroism spectroscopy as 2R, 3S. The coexistence of conformers of isolated biflavonoids in solution at 25 °C in different solvents was confirmed by variable temperature NMR studies. At room temperature (25 °C), compounds 1–7 exhibited duplicate NMR signals, while at elevated temperature (90 °C), a single set of signals was obtained. Compound 5 showed significant in vitro antioxidant activities against 1,1‐diphenyl‐2‐picrylhydrazyl and 2,2′‐azino‐bis‐3‐ethyl benzthiazoline‐6‐sulfonic acid radicals. The antibacterial studies showed that compounds 5 and 6 are the most active against Staphylococcus aureus, Bacillus subtilis and Escherichia coli. Compounds 3 and 6 also showed moderate antituberculosis activity against H₃₈Rv. Based on the research findings, G. hombroniana could be concluded as a rich source of flavanone–flavone (3 → 8) biflavonoids that exhibit rotameric behaviour at room temperature and display significant antioxidant and antibacterial activities. Copyright © 2014 John Wiley & Sons, Ltd.     

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.