共查询到20条相似文献,搜索用时 125 毫秒
1.
《Magnetic resonance in chemistry : MRC》2003,41(9):731-734
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. 相似文献
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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. 相似文献
3.
《Magnetic resonance in chemistry : MRC》2003,41(12):1009-1014
Conventional 1D NMR methods and 2D shift‐correlated NMR experiments (COSY, HMQC, HMBC) were used for the structural elucidation and 1H and 13C chemical shifts assignments of four new types of chalcone dimers isolated from Myracrodruon urundeuva. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
4.
《Magnetic resonance in chemistry : MRC》2003,41(8):641-643
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. 相似文献
5.
Xiongming Luo Shuhua Qi Hao Yin Zhihui Xiao Si Zhang 《Magnetic resonance in chemistry : MRC》2009,47(12):1110-1114
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. 相似文献
6.
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. 相似文献
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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). 相似文献
9.
Complete NMR analyses with full assignments for (1)H and (13)C NMR spectral data for both epimers of menthane-1-carboxylic acid are described. The NMR properties of the recently synthesized axial isomer had not been previously described, and through use of a variety of 1D and 2D techniques, additional information is provided for the equatorial isomer. As well as assignments of chemical shifts, homonuclear coupling constants were determined for the equatorial isomer and most of coupling constants were measured for the axial isomer. 相似文献
10.
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. 相似文献
11.
Wu J Huang J Xiao Q Zhang S Xiao Z Li Q Long L Huang L 《Magnetic resonance in chemistry : MRC》2004,42(7):659-662
Ten phenylethanoid glycosides, including two new ones, isolated from the aerial parts of the mangrove plant Acanthus ilicifolius were identified. The first complete assignments of the 1H and 13C NMR chemical shifts for these glycosides were achieved by means of 2D NMR techniques, including 1H-1H COSY, TOCSY, HSQC and HMBC spectra. 相似文献
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《Magnetic resonance in chemistry : MRC》2003,41(2):147-151
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. 相似文献
14.
Two novel unsaturated E-ring pentacyclic triterpenoid saponins, ilexhainanoside A and ilexhainanoside B, were isolated from the leaves of Ilex hainanensis. Their chemical structures were determined by MS, NMR spectroscopy and chemical analysis. Complete assignments of the 1H and 13C NMR spectroscopic data were achieved by 1D and 2D NMR experiments (HSQC, HMBC, ROESY and 1H-1H COSY). 相似文献
15.
Three labdane diterpenoids were isolated from an acetone extract of Plectranthus ornatus. Their structures, closely related to that of forskolin, were determined by NMR studies. Unambiguous and complete assignments of the 1H and 13C NMR chemical shifts for these substances are presented. The assignments are based on 2D shift-correlated [1H, 1H-COSY, 1H, 13C-gHSQC-1J (C,H), 1H, 13C-gHMBC-(n)J (C,H) (n = 2 and 3)] and NOE experiments. 相似文献
16.
Three new steroidal saponins, Vernoniosides S1 ( 1 ), Vernoniosides S2 ( 2 ) and Vernoniosides S3 ( 3 ) were isolated from the stem of Vernonia cumingian. Their chemical structures were elucidated on the basis of MS, NMR spectroscopic and chemical analysis. Complete assignment of 1H and 13C NMR spectroscopic data were achieved by 1D and 2D NMR experiments (HMQC, HMBC, ROESY). Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
17.
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). 相似文献
18.
The structure of 3beta-hydroxyballotinone, a new labdane diterpenoid isolated from Ballota undulata, has been established by NMR spectroscopic studies. In addition, complete and unambiguous assignments of the (1)H and (13)C NMR spectra of three other already known labdanes (ballotinone, ballonigrin and ballonigrinone) isolated from the same source have been achieved. The assignments are based on 2D shift-correlated (1)H--(1)H COSY, (1)H--(13)C gHSQC [(1)J(C,H)] and (1)H--(13)C gHMBC [(n)J(C,H) (n = 2 and 3)], and NOE experiments. 相似文献
19.
Quezada E Delogu G Viña D Santana L Picciau C Podda G Uriarte E 《Magnetic resonance in chemistry : MRC》2008,46(7):701-705
The synthesis of four pyranocoumarins starting from phloroglucinol and the complete (1)H and (13)C NMR assignment of seven pyranocoumarins has been performed using 1D and 2D NMR techniques including COSY, HMQC and HMBC experiments. 相似文献
20.
The complete 1H and 13C NMR assignment of four 6,7-benzo-fused furocoumarins (1-4) and three 3,4-benzo-fused furocoumarins (5-7) has been performed using 1D and 2D NMR techniques, including COSY, HMQC and HMBC experiments. 相似文献