Complete assignments of 1H and 13C NMR data for three new arylnaphthalene lignan from Justicia procumbens

Three new arylnaphthalene lignans, named neojusticin C (1), procumbenoside C (2) and procumbenoside D (3), have been isolated from the whole plant of Justicia procumbens, together with three known ones, justicidinoside B (4), justicidinoside C (5), and diphyllin-1-O-beta-D-apiofuranoside (6). The complete assignments of 1H and 13C NMR data for three new lignans were first obtained by means of 2D NMR techniques, including HSQC and HMBC.     

Four new prenylated flavonoids from the roots of Cudrania tricuspidata

Four new prenylated flavonoids, cudraflavanones E‐F (1–2) and cudraflavones F‐G (6–7), together with eight known compounds were isolated from the roots of Cudrania tricuspidata. The structures of new compounds were elucidated on the basis of extensive spectroscopic analyses, including 1D and 2D NMR, HRESIMS and CD. Copyright © 2013 John Wiley & Sons, Ltd.     

Complete NMR data assignments for novel pterocarpans from Harpalyce brasiliana

A NMR study of two new pterocarpans isolated from the roots of Harpalyce brasiliana is described. In addition to 1D NMR, 2D shift-correlated NMR pulse sequences ((1)H-(1)H-COSY, HSQC and HMBC) were used to establish the structures, and unambiguously perform the (1)H and (13)C chemical shift assignments.     

Two new complex triterpenoid saponins from Gledistsia dolavayi Franch.

Two new triterpenoid saponins, gledistside A ( 1 ) and gledistside B ( 2 ), isolated from the fruits of Gledistsia dolavayi Franch., were characterized as the 3,28‐O‐bisdesmoside of echinocystic acid acylated with monoterpene carboxylic acids. On the basis of spectroscopic and chemical evidence, their structures were elucidated as 3‐O‐β‐D ‐xylopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl‐28‐O‐β‐D ‐xylopyranosyl‐(1→3)‐β‐D ‐xylopyranosyl‐(1→4)‐[β‐D ‐galactopyranosyl‐(1→2)]‐α‐L ‐rhamnopyranosyl‐(1→2)‐{6‐O‐[2,6‐dimethyl‐6(S)‐hydroxy‐2‐trans‐2,7‐octadienoyl]}‐β‐D ‐glucopyranosylechinocystic acid ( 1 ) and 3‐O‐β‐D ‐xylopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl‐28‐O‐β‐D ‐xylopyranosyl‐(1→3)‐β‐D ‐xylopyranosyl‐(1→4)‐[β‐D ‐galactopyranosyl‐(1→2)]‐α‐L ‐rhamnopyranosyl‐(1→2)‐{6‐O‐[2‐hydroxymethyl‐6‐methyl‐6(S)‐hydroxy‐2‐trans‐2,7‐octadienoyl]}‐β‐D ‐glucopyranosylechinocystic acid ( 2 ). The complete ¹H and ¹³C assignments of saponins 1 and 2 were achieved on the basis of 2D NMR spectra including HMQC‐TOCSY, TOCSY, ¹H–¹H COSY, HMBC, ROESY and HMQC spectra. Copyright © 2002 John Wiley & Sons, Ltd.     

Structure elucidation of two new xanthone derivatives from the marine fungus Penicillium sp. (ZZF 32#) from the South China Sea

Two new xanthones, 8-(methoxycarbonyl)-1-hydroxy-9-oxo-9H-xanthene-3-carboxylic acid (1) and dimethyl 8-methoxy-9-oxo-9H-xanthene-1,6-dicarboxylate (2) and one known xanthone methyl 8-hydroxy-6-methyl-9-oxo-9H-xanthene-1-carboxylate (3) were isolated from the culture broth of the mangrove fungus Penicillium sp. (ZZF 32#) collected from the South China Sea. Their structures were established by comprehensive analysis of one-dimensional (1D) and two-dimensional (2D) NMR data. The structure of compound 3 was confirmed by X-ray crystallography, which led to the suggestion that janthinone (4) might have the same structure as 3. Compounds 1-3 were inactive against KB or KBv200 cells during cytotoxicity evaluations.     

NMR assignments of unusual flavonoids from the kino of Eucalyptus citriodora

Two unusual flavonoids, 3,5,4',5'-tetrahydroxy-7-methoxy-6-[1-(p-hydroxy-phenyl)ethyl]flavanone (1) and 3,5,7,4',5'-pentahydroxy-6-[1-(p-hydroxy-phenyl)ethyl] flavanone (2), were isolated from the kino of Eucalyptus citriodora. Structural elucidation of the new compounds were established on the basis of spectral data, particularly by the use of 1D NMR and several 2D shift-correlated NMR pulse sequences ((1)H, (1)H-COSY, HMQC, HMBC).     

Two new compounds from Coriaria nepalensis

Two new compounds,corialins A(1) and B(2) were isolated from Coriaria nepalensis Wall.These new compounds were established as 7-hydroxy-3-[2,3-acetonide-(3-methylbutane)]coumarin(1) and 3-O-β-D-glucopyranosyl-3,4,5-trihydroxy-1-(3- methyl-2-butenyl)-benzene(2),on the basis of 1D and 2D NMR techniques.     

(1)H and (13)C NMR signal assignments of paecilin A and B, two new chromone derivatives from mangrove endophytic fungus Paecilomyces sp. (tree 1-7)

Two new natural products, named paecilin A (1) and B (2), together with two known compounds secalonic acid D (3) and (11)-cytochalasa-6(12),13-diene-1,21-dione-16,18-dimethyl-7-hydroxy-10-phenyl-(7S*,13E,16S*,18S*) (4), were isolated from the mangrove endophytic fungus, Paecilomyces sp. (tree 1-7) from the South China Sea. 1D and 2D NMR experiments including COSY, HMQC, and HMBC were used for the determination of their structures. In our cytotoxicity assays, secalonic D (3) showed cytotoxicity toward KB cells with IC(50) < 1 microg ml(-1) and inhibiting human topoisomerase I with IC(50) at 0.16 micromol ml(-1). 1, 2, and 4 showed no activity to KB cells.     

New tricyclic and tetracyclic pyranocoumarins with an unprecedented C‐4 substituent. Structure elucidation of tamanolide,tamanolide D and tamanolide P from Calophyllum inophyllum of French Polynesia

Three new pyranocoumarin derivatives, tamanolide (1), tamanolide D (2) and tamanolide P (3), were isolated from the almond seeds of Calophyllum inophyllum L. (Clusiaceae) grown in French Polynesia. These compounds, having an unprecedented C‐4 isobutyl substituent, have been characterized as a new class of pyranocoumarins called tamanolides. Their structures were elucidated on the basis of 1D and 2D NMR techniques (COSY, NOESY, HSQC and HMBC) in association with MS (HR‐ESI‐MS) data analysis. Copyright © 2009 John Wiley & Sons, Ltd.     

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.     

Complete assignments of (1)H and (13)C NMR spectroscopic data for two new triterpenoid saponins from Ilex pernyi

Ilexpernoside A and ilexpernoside B, two new pentacyclic C(4)-nortriterpenoid saponins, were isolated from the leaves of Ilex pernyi Franch. Their chemical structures were determined by MS, NMR spectroscopy and chemical analysis. Complete assignments of the (1)H and (13)C NMR spectroscopic data were achieved by 1D and 2D NMR experiments (HSQC, HMBC, (1)H-(1)H COSY and NOESY).     

The NMR studies on two new furostanol saponins from Agave sisalana leaves

The detailed NMR studies and full assignments of the 1H and 13C spectral data for two new furostanol saponins isolated from Agave sisalana leaves are described. Their structures were established using a combination of 1D and 2D NMR techniques including 1H, 13C, 1H-1H COSY, TOCSY, HSQC, HMBC and HSQC-TOCSY, and also FAB-MS spectrometry and chemical methods. The structures were established as (25S)-26-(beta-D-glucopyranosyl)-22 xi-hydroxyfurost-12-one-3beta-yl-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)-O-[O-beta-D-glucopyranosyl-(1-->2)]-O-beta-D-glucopyranosyl-(1-->4)-beta-D-galacto- pyranoside (1) and (25S)-26-(beta-D-glucopyranosyl)-22xi-hydroxyfurost-5-en-12-one-3beta-yl-O-alpha-L-rhamno- pyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)-O-[O-beta-D-glucopyranosyl-(1-->2)]-O-beta-D-glucopyranosyl- (1-->4)-beta-D-galactopyranoside (2).     

Carbon-13 and proton NMR assignments of a new agathisflavone derivative

The (1)H and (13)C NMR spectra of 5-acetyl-7,4'-dimethoxyflavone-(6-8')-5'-acetyl-7',4'-dimethoxyflavone, a new agathisflavone derivative, were completely assigned on the basis of 1D and 2D NMR techniques.     

Structural and spectral assignment by 2D NMR of a new prenylated benzopyrancarboxylic acid and structural reassignment of a related compound

A new prenylated benzopyrancarboxylic acid, 1a (3,4‐dihydro‐5‐hydroxy‐2,7‐dimethyl‐8‐(2‐methyl‐2‐butenyl)‐ 2‐(4‐methyl‐1, 3‐pentadienyl)‐2H‐1‐benzopyran‐6‐carboxylic acid) was isolated from Peperomia amplexicaulis and fully characterized by 1D and 2D NMR and high‐resolution mass spectrometry. In the course of this investigation, the structure of a related compound (minus the carboxylic acid group) which was previously assigned as 2b was corrected to structure 1b . Copyright © 2003 John Wiley & Sons, Ltd.     

Structure elucidation and NMR spectral assignment of five new xanthones from the bark of Garcinia xanthochymus

Five new xanthones, namely Garcinexanthones A-E (1-5), were isolated from the barks of Garcinia xanthochymus. Their structures were elucidated by spectral analysis, primarily NMR, MS, and UV. The complete assignments of the (1)H NMR and (13)C NMR chemical shifts for the compounds were achieved by using 1D and 2D NMR techniques, including DEPT, HSQC, and HMBC NMR experiments.     

1H and 13C NMR assignments for two new steroids from the coral Chromonephthea sp.

Two new steroids isolated from EtOH extracts of the South China Sea soft coral Chromonephthea sp. were identified. One‐dimensional (1D) and two‐dimensional (2D) NMR experiments including COSY, HSQC, HMBC and NOESY were used for the determination of their structure. Copyright © 2008 John Wiley & Sons, Ltd.     

Complete 1H- and 13C NMR assignments of saponins from roots of Gypsophila trichotoma Wend

The assignments of 1H and 13C NMR spectra of two new aminoacyl triterpene saponins from roots of Gypsophila trichotoma Wend. are reported. In addition to 1D NMR methods, 2D NMR techniques (COSY, TOCSY, ROESY, HSQC, HMBC, and HSQC-TOCSY) were used for the assignments. The structures were completed by analysis of HR-ESI-MS and ESI-MS(n).     

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.     

1H and 13C NMR assignments for two anthraquinones and two xanthones from the mangrove fungus (ZSUH-36)

We report the unambiguous assignments of the (1)H and (13)C NMR spectra of one new natural product, namely, 6,8-di-O-methyl versiconol (1) together with one known anthraquinone aversin (2) and two xanthones 5-methoxysterigmatocystin (3) and sterigmatocystin (4). These compounds were all isolated from the mangrove endophytic fungus ZSUH-36 from the South China Sea. 1D and 2D NMR experiments including COSY, HMQC and HMBC were used to elucidate the structures. Variations in the (1)H NMR spectrum of 6,8-di-O-methyl versiconol (1) were also observed in the temperature range 25-75 degrees C. In addition, the plausible biogenetic path from 1 to 2 is discussed.     

Complete assignments of 1H and 13C NMR data for seven arylnaphthalide lignans from Justicia procumbens

Three new arylnaphthalide lignans named 6'-hydroxy justicidin A (1), 6'-hydroxy justicidin B (2) and 6'-hydroxy justicidin C (3) have been isolated from the whole plant of Justicia procumbens, together with four known ones, neojusticin A (4), chinensinaphthol methyl ester (5), isodiphyllin (6) and taiwanin C (7). The complete assignments of 1H and 13C NMR chemical shifts for the new lignans and the 13C NMR chemical shifts for the known lignans were obtained for the first time by means of 2D NMR techniques, including HSQC and HMBC.