1H and 13C NMR assignments of two new diaryl ethers phomopsides A and B from the mangrove endophytic fungus (ZZF08)

Two new diaryl ethers, named phomopside A (1) and B (2), together with known excelsione (3) were isolated from the mangrove endophytic fungus Phomopsis sp. (ZZF08) obtained from the South China Sea coast. The structure of 1 was elucidated by NMR spectroscopy and confirmed by X-ray crystallography. Compounds 2 and 3 were identified by NMR spectroscopy and comparing the spectroscopic data with literature values. In addition, the plausible biogenetic path of 1, 2 and 3 is discussed.     

1H and 13C NMR assignments for two oxaphenalenones bacillosporin C and D from the mangrove endophytic fungus SBE-14

The complete (1)H and (13)C NMR assignments are reported for the novel natural product Bacillosporin D together with the known compound Bacillosporin C. These compounds containing seven rings were isolated from the mangrove endophytic fungus SBE-14 from the South China Sea. 1D and 2D NMR experiments, including COSY, HMQC and HMBC were used to the determination of the structures and NMR assignments. It is proposed that 1 was biogenetically produced by transforming 2. Transforming a lactone to an anhydride is unusual in nature.     

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.     

(1)H and (13)C NMR assignments for five anthraquinones from the mangrove endophytic fungus Halorosellinia sp. (No. 1403)

We report the unambiguous assignments of the (1)H and (13)C NMR spectra of two new natural products, namely, 1,4,5,6,7,9-hexahydroxy-2-methoxy-7-methyl-5beta,9beta,8abeta, 6alpha,10aalpha-hexahydroanthracen-10 (10aH)-one (1) and 1,4,6-trihydroxy-2-methoxy-7-methylanthracene-9, 10-dione (2), together with three known anthraquinones. These compounds were all isolated from the marine endophytic fungus No. 1403 collected from the South China Sea. Compounds 3 and 4 were isolated from the marine fungus for the first time. The structures were elucidated by the spectroscopic methods 1D and 2D NMR including COSY, HMQC, HMBC and NOE, and HREIMS. In our cytotoxicity assays, compound 5 showed cytotoxicity toward KB and KBv-200 cells with IC(50) of 1.40 and 2.58 microg/ml, respectively. In addition, the plausible biogenic relationship of compounds 1, 2, 3 and 4 is discussed.     

1H and 13C NMR assignments of two new indolic enamide diastereomers from a mangrove endophytic fungus Aspergillus sp

Terpeptin A (1) and B (2), two new members of the indolic enamides, along with three known compounds (3-5) were identified from a strain of Aspergillus sp. (w-6), an endophytic fungus associated with Acanthus ilicifolius. The complete (1)H and (13)C NMR assignments for these compounds were carried out using (1)H, (13)C, DEPT, COSY, HMQC, and HMBC NMR experiments. Terpeptin A and B exhibited modest cytotoxicity against A-549 cell line.     

Structure elucidation and NMR assignments for two xanthone derivatives from a mangrove endophytic fungus (No. ZH19)

The structure elucidations and complete ¹H and ¹³C NMR assignments are reported for two new xanthone derivatives: 1,7‐dihydroxy‐2‐methoxy‐3‐(3‐methylbut‐2‐enyl)‐9H‐xanthen‐9‐one (1) and 1‐hydroxy‐4,7‐dimethoxy‐6‐(3‐oxobutyl)‐9H‐xanthen‐9‐one (2). Both of these secondary metabolites were isolated from the fermentation medium of a mangrove endophytic fungus (No. ZH19). High‐resolution electron impact mass spectrometry (HREIMS), Fourier transform infrared (FT‐IR) absorption spectrometry, and NMR experiments including gCOSY, gHMQC, and gHMBC were used for the determination of the structures and NMR spectral assignments. Preliminary pharmacological test showed that compounds (1) and (2) inhibited KB cells with IC₅₀ values of 20 and 35 µmol/ml, and KB_V200 cells with IC₅₀ values of 30 and 41 µmol/ml, respectively. Copyright © 2009 John Wiley & Sons, Ltd.     

1H and 13C NMR assignments of eight nitrogen containing compounds from Nocardia alba sp.nov (YIM 30243T)

An unprecedented new natural product named nocarsin A (1), 5H‐4a,6,7a‐triazacyclopenta[cd]indene‐5,7(6H)‐dione (1), together with seven known compounds lumichrome (2), cyclo (L ‐Leu‐L ‐Tyr) (3), cyclo (L ‐Ala‐L ‐Ile) (4), cyclo (L ‐Ala‐L ‐Leu) (5), cyclo (L ‐Val‐L ‐Ala) (6), 5‐methyluracil (7) and uracil (8), was isolated from Nocardia alba sp.nov (YIM 30243^T), which was isolated from a soil sample collected from Yunnan Province, P. R. China. NMR techniques including COSY, HSQC, ROESY, and HMBC were used to elucidate the structures of these compounds. We report the unambiguous assignments of the ¹H and ¹³C NMR spectra of the new compound nocarsin A (1). Copyright © 2009 John Wiley & Sons, Ltd.     

Structural and spectral assignments of six anthraquinone derivatives from the mangrove fungus (ZSUH-36)

A new natural product named 6,8,1'-tri-O-methyl averantin (1) has been isolated together with five known anthraquinones 1'-O-methyl averantin (2), 6,8-di-O-methyl averufin (3) averufin (4), versicolorin C (5) and 6,8-di-O-methyl averufanin (6) from a mangrove endophytic fungus ZSUH-36 collected from the South China Sea. NMR techniques including COSY, HMQC, and HMBC were used to elucidate the structures of these compounds. We report the unambiguous assignments of the (1)H and (13)C NMR spectra of the new compound 6,8,1'-tri-O-methyl averantin(1).     

Complete 1H and 13C NMR assignments of three labdane diterpenoids isolated from Leonotis ocymifolia and six other related compounds

Unambiguous and complete assignments of ¹H and ¹³C NMR chemical shifts for three structurally complex labadane diterpenoids isolated from Leonotis ocymifolia (leonotin, leonotinin and nepetaefolin) and six other related compounds (hispanolone, 7α‐ and 7β‐hispanols, marrubiin, villenol and andalusol), previously isolated from Labiatae species, are presented. The assignments are based on 2D shift‐correlated [¹H, ¹H‐COSY, ¹H, ¹³C‐gHSQC–¹J(C,H), ¹H,¹³C‐gHMBC–ⁿJ(C,H) (n = 2 and 3)] and DPFGSE 1D‐NOE experiments. Copyright © 2003 John Wiley & Sons, Ltd.     

(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.     

1H and 13C NMR assignments of abietane diterpenes from Aegiphila lhotzkyana

An NMR study of one new and several known abietane diterpenes isolated from the roots of Aegiphila lhotzkyana is described. In addition to 1D NMR, several 2D shift‐correlated NMR pulse sequences (¹H–¹H‐COSY, NOESY, HMQC and HMBC) were used to establish all the structures, and unambiguously perform the ¹H and ¹³C chemical shift assignments of the new natural diterpene and three derivatives, the NMR data for which have not been reported previously. Revision of current data assignment for teuvincenone H is also suggested. Copyright © 2003 John Wiley & Sons, Ltd.     

1H and 13C NMR assignments of new methoxylated furanoflavonoids from Lonchocarpus araripensis

Two new polymethoxylated flavonoids, 2',5',6'-trimethoxy-[2',3' : 3',4']furano dihydrochalcone and 2,4',4,5-tetramethoxy-[2',3' : 6,7]-furanodihydroaurone, were isolated from the root barks of Lonchocarpus araripensis, along with the known compounds 3,4,5,6-tetramethoxy-[2',3' : 7,8]-furanoflavan, 3,6-dimethoxy-1',1'-dimethylcromene-[2',3' : 7,8]-flavone, 3',4'-methylenodioxy-5,6-dimethoxy-[2',3' : 7,8]-furanoflavone, 3,5,6-trimethoxy-[2',3' : 7,8]-furanoflavanone, 3,5,6-trimethoxy-[2',3' : 7,8]-furanoflavone, and 6alpha-hydroxy-medicarpin. The complete (1)H and (13)C NMR assignments of the new furan flavonoids were performed using 1D and 2D pulse sequences, including COSY, HSQC, and HMBC experiments, and comparison with spectral data for analog compounds from the literature, particularly for the new furanodihydroaurone because of several inconsistencies on the carbonyl chemical shifts from the literature.     

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.     

1H and 13C NMR assignments and X-ray structures for three monocyclic benzoannelated dilactam polyethers

Three monocyclic polyether dilactams, 17,18-dihydro-5H, 9H-dibenzo[e,n]1,4,10,7,13trioxadiazacyclopentadecine-6,10(7H,11H)-dione (1); 9,10,20,21-tetrahydro-5H, 12H-dibenzo[e,q]1,4,10,13,7,16tetraoxadiazacyclooctadecine-6, 13(7H,14H)-dione (2); and 6,7,9,10-tetrahydro-16H, 20H-dibenzo[h,q]1,4,7,13, 10,16tetraoxadiazacyclooctadecine-17, 21(18H,22H)-dione (3) were isolated during the synthesis of several benzoannelated cryptands. The complete assignments of the 1H and 13C NMR spectra of 1, 2 and 3 in CDCl3 were made using gCOSY, gHMBC, gHMQC, HMQC, HSQC, and NOESY 1D techniques. The ortho (H2) benzene protons show significant downfield shifts (1.16-1.43 ppm) that are consistent with an exodentate orientation for the amide carbonyl groups. The X-ray crystal structures of 1, 2 and 3 show that the carbonyl groups adopt an exodentate conformation in the solid state.     

Detailed assignments of 1H and 13C NMR spectral data of 14 cyclopentane derivatives

Detailed assignments of ¹H and ¹³C NMR spectral data for 14 cyclopentane derivatives are reported. The assignments are based on 1D ¹H and ¹³C NMR and on 2D shift‐correlated [¹H, ¹³C‐HMQC], J‐resolved and NOEDIF experiments. Copyright © 2003 John Wiley & Sons, Ltd.     

1H and 13C NMR spectral assignments of novel chromenylchalcones

Several types of chalcones containing 2H‐chromen group were synthesized. Claisen–Schmidt condensation of 2H‐chromen‐3‐carbaldehydes (I) with methoxy substituted acetophenones afforded (E)‐3‐(2H‐chromen‐3‐yl)‐1‐(methoxyphenyl)prop‐2‐en‐1‐ones (chromenylchalcones, 1–7). Other types of chromenylchalcone, (E)‐1‐(6‐methoxy‐2H‐chromen‐3‐yl)‐3‐(methoxyphenyl)prop‐2‐en‐1‐ones (8–13) were also obtained between reaction of methoxy substituted benzaldehydes and 1‐(6‐methoxy‐2H‐chromen‐3‐yl)ethanone (II). Dichromenylchalcones (14–16) were also synthesized through the same reaction between aldehydes (I) and ketone (II). Their complete ¹H‐NMR and ¹³C‐NMR assignments are reported here and more polysubstituted chromenylchalcones synthesized or isolated from the natural sources in the future can be identified on the basis of the NMR data reported here. Copyright © 2012 John Wiley & Sons, Ltd.     

1H and 13C NMR spectral assignments of isoquinuclidine-3,5-dione derivatives

The 1H and 13C NMR spectra of six 5-substituted 2-azabicyclo[2.2.2]octane derivatives were fully assigned by COSY and HSQC experiments.     

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 of two new isomeric bisbenzylisoquinoline alkaloids from Cissampelos sympodialis Eichl. (Menispermaceae)

des‐7′‐O‐methylroraimine (compound 1) and epi‐des‐7′‐O‐methylroraimine (compound 2), two new isomeric bisbenzylisoquinoline alkaloids were isolated and characterized as a mixture from the rhizomes of Cissampelos sympodialis Eichl. The unambiguous structural elucidation of both isomers was performed with the aid of HR‐ESI‐MS, FT‐IR, and NMR techniques including COSY, HMQC, HMBC, and NOESY. Copyright © 2013 John Wiley & Sons, Ltd.     

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.