Complete 1H and 13C NMR assignments of three new polyhydroxylated sterols from the South China Sea gorgonian Subergorgia suberosa

Three new polyhydroxylated sterols, 3beta,6alpha,11,20beta,24-pentahydroxy- 9,11-seco-5alpha-24-ethylcholest-7,28-diene-9-one (1), 3-(1',2'-ethandiol)-24- methylcholest-8(9),22E-diene-3beta,5alpha,6alpha,7alpha,11alpha-pentaol (2), 24-methylcholest-7,22 E-diene-3beta,5alpha,6beta,25-tetraol (3) together with five known sterols, were isolated from the EtOH/CH2Cl2 extract of the South China Sea gorgonian Subergorgia suberosa. 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 HSQC, HMBC, 1H--1H COSY, and NOESY spectra.     

Three diterpenoids (excoecarins V1-V3) and a flavanone glycoside from the fresh stem of Excoecaria agallocha

Three new diterpenoids, excoecarins V1-V3 (1-3) and a new flavanone glycoside (7) were isolated from the fresh stem of Excoecaria agallocha L. Their structures were elucidated as: 2alpha,3alpha,18-trihydroxy-3beta,20-epoxybeyer-15-ene (1), ent-2,3-secokaur-16-en-2,3-dioic acid (2), ent-3,4-seco-16alpha-hydroxyatis-4(19)-en-3-oic acid (3), and 3,5,7,3',5'-pentahydroxy-2R,3R-flavanonol 3-O-alpha-L-rhamnopyranoside (7) on the basis of spectroscopic data, chemical evidence, and/or X-ray analysis.     

Further bisabolenes and dammarane triterpenes of Commiphora kua resin

From the resins of Commiphora kua a novel bisabolene; 6-hydroxy-2-methyl-5-(5'-hydroxy-1'(R),5'-dimethylhex-3'-enyl)-phenol together with two new dammarane triterpenes, 3beta,16beta,20(S),25-tetrahydroxydammar-23-ene and 3beta-acetoxy-16beta,20(S),25-trihydroxydammar-23-ene, have been isolated. In addition, being reported are known compounds identified as 2-methyl-5-(4'(S)-hydroxy-1'(R),5'-dimethylhex-5'-enyl)-phenol, 2-acetoxyfuranodienone, 2-methoxyfuranodienone, 3beta,16beta,20(R)-trihydroxydammar-24-ene and its acetate derivative, 3beta-acetoxy-16beta,20(R)-dihydroxydammar-24-ene, and beta-amyrin and its acetate derivative. 2-Methyl-5-(4'(S)-hydroxy-1'(R),5'-dimethylhex-5'-enyl)-phenol displayed fungicidal activity against Cladosporium cucumernum on TLC assay.     

Three new steroidal saponins from the rhizome of Paris polyphylla

A mixture of a pair of stereoisomeric new spirostanol saponins (1a and 1b) and a new cholestane saponin (2) were isolated from the rhizome of Paris pollyphylla Smith var. yunnanensis. Their structures were elucidated as (25R)-spirost-5-en-3beta, 7beta-diol-3-O-alpha-L-arabinofuranosyl-(1 --> 4)-[alpha-L-rhamnopyranosyl-(1 --> 2)]-beta-D-glucopyranoside (1a), (25R)-spirost-5-en-3beta, 7alpha-diol-3-O-alpha-L-arabinofuranosyl-(1 --> 4)-[alpha-L-rhamnopyranosyl-(1 --> 2)]-beta-D-glucopyranoside (1b) and 26-O-beta-D-glucopyranosyl-(25R)-Delta(5(6), 17(20))-dien-16, 22-dione-cholestan-3beta, 26-diol-3-O-alpha-L-arabinofuranosyl-(1 --> 4)-[alpha-L-rhamnopyranosyl-(1 --> 2)]-beta-D-glucopyranoside (2) by a combination of HR-ESI-MS, FAB-MS, 1D and 2D NMR techniques (including (1)H-NMR, (13)C-NMR, (1)H--(1)H COSY, HSQC, HMBC and NOESY).     

Norlanostane and lanostane glycosides from the bulbs of Chionodoxa luciliae and their cytotoxic activity

Ten lanostane glycosides (1-10), including two new norlanostane glycosides (2 and 7) and a new lanostane glycoside with a spirolactone ring system (9), were isolated from the fresh bulbs of Chionodoxa luciliae (Liliaceae). The structures of the new compounds were determined on the basis of extensive spectroscopic analysis and the results of hydrolytic cleavage to be (23S)-3beta-[(O-beta-D-apiofuranosyl-(1-->2)-O-[beta-D-glucopyranosyl-(1-->3)]-O-beta-D-glucopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranosyl)oxy]-17alpha,23-epoxy-28,29-dihydroxy-27-norlanost-8-en-24-one (2), (23S)-17alpha,23-epoxy-29-hydroxy-3beta-[(O-alpha-L-rhamnopyranosyl-(1-->2)-O-[O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->3)]-O-beta-D-glucopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranosyl)oxy]-27-norlanost-8-ene-15,24-dione (7), and (23S,25R)-17alpha,23-epoxy-29-hydroxy-3beta-[(O-alpha-L-rhamnopyranosyl-(1-->2)-O-[beta-D-glucopyranosyl-(1-->3)]-O-beta-D-glucopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranosyl)oxy]lanost-8-en-23,26-olide (9), respectively. The cytotoxic activity of the isolated compounds against HSC-2 human oral squamous cell carcinoma cells are also reported.     

Synthesis of the aglycone of the shark repellent pavoninin-4 using remote functionalization

[reaction: see text] The aglycone of shark repellent pavoninin-4, (25R)-5alpha-cholestan-3alpha,15alpha,26-triol 26-acetate 1a, was synthesized from (25R)-cholest-5-en-3beta,26-diol 4 (26-hydroxycholesterol) in eight steps in 18% overall yield. Breslow's remote functionalization strategy was used as a key step to introduce the C-15alpha alcohol on a steroid D ring. An efficient synthesis of the 26-hydroxycholesterol from the 16beta hydroxyl steroid, (25R)-cholest-5-ene-3beta,16beta,26-triol (3a), is also reported.     

Complete assignments of 1H and 13C NMR spectral data for three polyhydroxylated 12-ursen-type triterpenoids from Dischidia esquirolii

The complete assignments of all the (1)H and (13)C NMR signals of three polyhydroxylated 12-ursen-type triterpenes, 6beta,19alpha,22alpha-trihydroxyurs-12-en-3-oxo-28-oic acid (1), 3beta,6alpha,19alpha,23-tetrahydroxyurs-12-en-28- oic acid (2) and 3beta,6beta,19alpha,23-tetrahydroxyurs-12-en-28-oic acid (3), were carried out by means of homo- and hetero-nuclear two-dimensional NMR experiments. Compounds 1-3 were isolated from the aerial parts of Dischidia esquirolii. Of them, 1 and 2 were identified as new polyhydroxylated ursolic acid derivatives. Compound 2 is the C-6 hydroxyl epimer of 3, which was isolated first from Adina rubella, and its structure is revised in this paper.     

Complete (1)H and (13)C assignments of the four major saponins from Dioscorea villosa (wild yam)

Complete (1)H and (13)C spectral assignments for the four major steroidal saponins isolated by methanolic extraction of the roots of Dioscorea villosa, collected in North Carolina, United States (in summer and autumn), are presented in this paper. The structures were determined by a combination of (1)H, (13)C and 2D NMR techniques and were found to be ((3beta,25R)-26-(beta-D-glucopyranosyloxy)-22-methoxyfurost-5-en-3-yl-O-beta-D-glucopyranosyl-(1 --> 3)-O-beta-D-glucopyranosyl-(1 --> 4)-O-[alpha-L-rhamnopyranosyl-(1 --> 2)]-beta-D-glucopyranoside (1) (or methyl parvifloside), ((3beta,25R)-26-(beta-D-glucopyranosyloxy)-22 methoxyfurost-5-en-3-yl-O-alpha-L-rhamnopyranosyl-(1 --> 2)-O-[beta-D-gluco- pyranosyl-(1 --> 4)]-beta-D-glucopyranoside (2) (or methyl protodeltonin), (3beta,25R)-spirost-5-en-3-yl-O-beta-D-glucopy ranosyl-(1 --> 3)-O-beta-D-glucopyranosyl-(1 --> 4)-O-[alpha-L-rhamnopyranosyl-(1 --> 2)]-beta-D-glucopyranoside (3) (or Zingiberensis saponin I) and (3beta,25R)-spirost-5-en-3-yl-O-alpha-L-rhamnopyranosyl-(1 --> 2)-O-[beta-Ds-glucopyranosyl -(1 --> 4)]-beta-D-glucopyranoside (4) (or deltonin).     

A new pyrrolidine derivative and steroids from an algicolous Gibberella zeae strain

A new pyrrolidine derivative, 3-hydroxy-5-(hydroxymethyl)-4-(4'-hydroxyphenoxy)pyrrolidin-2-one (1), and eight known steroids, (22E,24R)-7beta,8beta-epoxy-3beta,5alpha,9alpha-trihydroxyergosta-22-en-6-one (2, a reassigned structure of (22E,24R)-5alpha,6alpha-epoxy-3beta,8beta,14alpha-trihydroxyergosta-22-en-7-one), (22E,24R)-3beta,5alpha,9alpha-trihydroxyergosta-7,22-dien-6-one (3), (22E,24R)-3beta,5alpha-dihydroxyergosta-7,22-dien-6-one (4), (22E,24R)-ergosta-7,22-dien-3beta/,5alpha,6beta-triol (5), (22E,24R)-ergosta-5,22-dien-3beta-ol (6), (22E,24R)-5alpha,8alpha-epidioxyergosta-6,22-dien-3beta-ol (7), (22E,24R)-5alpha,8alpha-epidioxyergosta-6,9(11),22-trien-3beta-ol (8), and (22E,24R)-1(10 --> 6)-abeo-ergosta-5,7,9,22-tetraen-3alpha-ol (9), were isolated from the cultures of Gibberella zeae, an endophytic fungus isolated from the marine green alga Codium fragile. Their structures and relative stereochemistry were elucidated by 1D, 2D NMR and mass spectroscopic techniques. Compound 1 showed cytotoxicity against A-549 and BEL-7402 cell lines.     

Pregnane- and furostane-type oligoglycosides from the seeds of Allium tuberosum

Two furostane-type steroidal oligoglycosides (1, 2), together with a new pregnane-type oligoglycoside (3), were obtained from the seeds of Allium tuberosum ROTTLER. On the basis of spectroscopic analysis, the structures of three new oligoglycosides (1-3) were elucidated as 26-O-beta-D-glucopyranosyl-(25R)-3beta,22xi,26-trihydroxyl-5alpha-furostane 3-O-beta-chacotrioside, 26-O-beta-D-glucopyranosyl-(25S)-3beta,5beta,6alpha,22xi,26-pentahydroxyl-5beta-furostane 3-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranoside, and 3-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl 3beta,5beta,6alpha,16beta-tetrahydroxypregnane 16-(5-O-beta-D-glucopyranoyl-4(S)-methyl-5-hydroxypentanoic acid) ester, respectively.     

New triterpenoid saponins from Stelmatocrypton khasianum

Four new triterpenoid saponins, designated as stelmatotriterpenosides E-H (1-4), together with three known compounds, asterbatanoside B (5), 2alpha,3beta,19alpha,23-tetrahydroxy-olean-12-en-28-oic acid-3-O-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyl ester (6) and 2alpha,3beta,19alpha,23-tetrahydroxy-urs-12-en-28-oic acid-3-O-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyl ester (7), were isolated from the stems of Stelmatocrypton khasianum. On the basis of chemical and spectral evidence, the structures of 1-4 were established as 2alpha,3beta,23-trihydroxy-olean-12-en-28-oic acid-3-O-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester (1), 2alpha,3beta,23-trihydroxy-urs-12-en-28-oic acid-3-O-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester (2), 2alpha,3beta,19alpha-trihydroxy-urs-12-en-28-oic acid-3-O-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl ester (3), and 2beta,3beta,19alpha-trihydroxy-urs-12-en-24,28-dioic acid-24-O-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyl diester (4).     

Withanolide derivatives from the roots of Withania somnifera and their neurite outgrowth activities

Five new withanolide derivatives (1, 9-12) were isolated from the roots of Withania somnifera together with fourteen known compounds (2-8, 13-19). On the basis of spectroscopic and physiochemical evidence, compounds 1 and 9-12 were determined to be (20S,22R)-3 alpha,6 alpha-epoxy-4 beta,5 beta,27-trihydroxy-1-oxowitha-24-enolide (1), 27-O-beta-D-glucopyranosylpubesenolide 3-O-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranoside (withanoside VIII, 9), 27-O-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosylpubesenolide 3-O-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranoside (withanoside IX, 10), 27-O-beta-D-glucopyranosylpubesenolide 3-O-beta-D-glucopyranoside (withanoside X, 11), and (20R,22R)-1 alpha,3 beta,20,27-tetrahydroxywitha-5,24-dienolide 3-O-beta-D-glucopyranoside (withanoside XI, 12). Of the isolated compounds, 1, withanolide A (2), (20S,22R)-4 beta,5 beta,6 alpha,27-tetrahydroxy-1-oxowitha-2,24-dienolide (6), withanoside IV (14), withanoside VI (15) and coagulin Q (16) showed significant neurite outgrowth activity at a concentration of 1 microM on a human neuroblastoma SH-SY5Y cell line.     

云南植物——露水草中的一种新植物甾酮的分离与分析

云南植物露水草富含植物甾酮类成分。为了研究其中的生物活性成分,采用多种色谱分离方法(氧化铝柱色谱、硅胶柱色谱、常压反相C18柱色谱、制备薄层色谱及反相高效液相色谱等)相结合,从露水草中分离得到一种新植物甾酮。综合一维和二维核磁共振光谱以及电喷雾质谱数据分析,确定该化合物的结构为3β,4α,14α,20R,22R,25-hexahydroxy-5α-cholest-7-en-6-one,为一种较为少见的具有5α-H的植物甾酮。     

New triterpenoids from Corchorus trilocularis

Two new tetracyclic triterpenoid trilocularol A and trilocularol A 3-glucoside and one pentacyclic triterpenoid tirlocularoside A were isolated from Corchorus trilocularis L., their structure were elucidated as 3beta,6alpha,16alpha,20(S),27-pentahydroxydammar-24(Z)-ene (1), 3beta-D-glucopyranosyloxy-6alpha,16alpha,20(S),27-tetrahydroxydammar-24(Z)-ene (2) and 2alpha,3beta,19alpha,30-tetrahydroxyurs-12-en-24,28-dioic acid 28-O-beta-D-glucopyranosyl ester (3). respectively, on the basis of detailed spectroscopic studies.     

Two new polyporusterones isolated from the sclerotia of Polyporus umbellatus

In the course of searching for marker components, two new polyporusterones were isolated from the sclerotia of Polyporus umbellatus, together with another three known analogs. The structures of the new ones were elucidated as (20S,22R,24R)-16,22-epoxy-3beta,14alpha,23beta,25-tetrahydroxyergost-7-en-6-one (1) and (23R,24R,25R)-23,26-epoxy-3beta,14alpha,21alpha,22alpha-tetrahydroxyergost-7-en-6-one (2) by chemical and spectroscopic means, including HR-FAB-MS, 1D- and 2D-NMR.     

Synthesis of deuterium-labeled 16 alpha,19-dihydroxy C19 steroids as internal standards for gas chromatography-mass spectrometry.

[2 beta,7,7,16 beta-2H4]16 alpha,19-Dihydroxyandrost-4-ene-3,17-dione (14) and [7,7,16 beta-2H3]3 beta,16 alpha,19-trihydroxyandrost-5-en-17-one (16), with high isotopic purity, respectively, were synthesized from unlabeled 3 beta-(tert-butyldimethylsiloxy)-androst-5-ene-17 beta-yl acetate (1). The deuterium introduction at C-7 was carried out by reductive deoxygenation of the 7-keto compound 3 with dichloroaluminum deuteride and that at C-2 beta and/or C-16 beta by controlled alkaline hydrolysis of 16-bromo-17-ketone 11 or 12 with NaOD in D2O and pyridine. [7,7-2H2]3 beta-Hydroxyandrost-5-en-17-one (6), obtained from compound 1 by a five-step sequence, was converted to compound 14 or 16 by an eight-step or seven-step sequence, respectively. The labeled steroids 14 and 16 are useful as internal standards for gas chromatography-mass spectrometry analysis of the endogenous levels.     

Cytotoxic diterpenoids from Vietnamese medicinal plant Croton tonkinensis GAGNEP

Six new ent-kaurane-type diterpenoids were isolated from the leaves of the endemic Vietnamese medicinal plant Croton tonkinensis GAGNEP. (Euphorbiaceae) together with three known ent-11alpha-acetoxy-7beta,14alpha-dihydroxykaur-16-en-15-one (1), ent-kaur-16-en-15-one 18-oic acid (5) and ent-18-hydroxykaur-16-ene (7). Their structures were determined by spectroscopic analyses to be ent-7beta-acetoxy-11alpha-hydroxykaur-16-en-15-one (2), ent-18-acetoxy-11alpha-hydroxykaur-16-en-15-one (3), ent-11alpha-acetoxykaur-16-en-18-oic acid (4), ent-15alpha,18-dihydroxykaur-16-ene (6), ent-11alpha,18-diacetoxy-7beta-hydroxykaur-16-en-15-one (8), and ent-(16S)-1alpha,14alpha-diacetoxy-7beta-hydroxy-17-methoxykauran-15-one (14). ent-Kaurane-type diterpenoids from Croton tonkinensis 2-4, 6, and 9-13, were tested for toxicity in the brine shrimp lethality assay. Compounds 9, 10, and 12 demonstrated significant activity, compounds 2, 3, 6, and 11 showed weak activity, and compounds 4 and 13 were inactive.     

Six new dammarane-type triterpene saponins from the leaves of Panax ginseng

Six new minor saponins, together with known ginsenosides, were isolated from the leaves of Panax ginseng. The new saponins were named as ginsenoside-Rh5, -Rh6, -Rh7 -Rh8, -Rh9 and -Rg7, and their structures were elucidated on the basis of chemical and physicochemical evidence to be as follows: ginsenoside-Rh5: 3beta,6alpha,12beta,24zeta-tetrahydroxy-dammar-20(22),25-diene 6-O-beta-D-glucopyranoside (1), -Rh6: 3beta,6alpha12beta,20(S)-tetrahydroxy-25-hydroperoxy-dammar-23-ene 20-O-beta-D-glucopyranoside (2), -Rh7: 3beta,7beta,12beta,20(S)-tetrahydroxy-dammar-5,24-diene 20-O-beta-D-glucopyranoside (3), -Rh8: 3beta,6alpha,20(S)-trihydroxy-dammar-24-ene-12-one 20-O-beta-D-glucopyranoside (4), -Rh9: 3beta,6alpha,20(S)-trihydroxy-12beta,23-epoxy-dammar-24-ene 20-O-beta-D-glucopyranoside (5) and -Rg7: 3-O-beta-D-glucopyranosyl 3beta,12beta,20(S),24(R)-tetrahydroxy-dammar-25-ene 20-O-beta-D-glucopyranoside (6).     

Synthesis of 19-oxygenated 4beta,5beta-epoxy derivatives of 16alpha-hydroxyandrostenedione as mechanistic and catalytic probes for aromatase reaction

4Beta,5beta-epoxy derivatives of 16alpha-hydroxyandrostenedione (2), one of the natural substrates for aromatase, and its 19-oxygenated compounds 4 and 5 were synthesized as mechanistic and catalytic probes for the enzyme reaction. Treatment of 16alpha-bromoandrostenedione (13) or its 19-hydroxy analog 19 which was prepared from 3beta-hydroxy-19-(tert-butyldimethylsiloxy)androst-5-en-17-one (16) in three steps, with H2O2 and NaOH followed by controlled alkaline hydrolysis with NaOH in aqueous pyridine stereospecifically yielded 4beta,5beta-epoxy-16alpha-ol 15 or 4beta,5beta-epoxy-16alpha,19-diol 22, respectively. Oxidation of 16beta-bromo-4beta,5beta-epoxy-19-ol 21 with pyridinium dichromate followed by controlled alkaline hydrolysis produced 4beta,5beta-epoxy-16alpha-hydroxy-19-al 24.     

Trojanosides I-K: new cycloartane-type glycosides from the aerial parts of Astragalus trojanus.

Three new cycloartane-type triterpene glycosides have been isolated from the aerial parts of Astragalus trojanus. The structures were established mainly by a combination of one- and two-dimensional NMR techniques [1H-1H-correlation spectroscopy (COSY), 1H-13C-heteronuclear multiple quantum correlation spectroscopy (HMQC), and 1H-13C-heteronuclear multiple-bond correlation spectroscopy (HMBC)] and high resolution electrospray ionization mass spectrometry (HR-ESI-MS) as 3-O-beta-(2',3'-di-O-acetyl)-D-xylopyranosyl-6-O-beta-D-glucopyranosyl-16-O- acetoxy-20(R),24(S)-epoxycycloartane-3beta,6alpha,16beta,25-tetrol, 3-0-[alpha-L-rhamnopyranosyl-(1-->2)-beta-(3',4'-di-O-acetyl)-D-xylopyranosyll-6-O-beta-D-xylopyranosyl-20(R),24(S)-epoxycycloartane-3p,6alpha,16beta,25-tetrol, 3-O-beta-D-xylopyranosyl-6,16-di-O-beta-D-glucopyranosyl-20(R)24(S)-epoxycycloartane-3beta,6alpha,16beta,25-tetrol.