共查询到20条相似文献,搜索用时 31 毫秒
1.
Ahmad Z Mehmood S Fatima I Malik A Ifzal R Afza N Iqbal L Latif M Nizami TA 《Magnetic resonance in chemistry : MRC》2008,46(1):94-98
Salsolins A (1) and B (2), the new triterpenes, have been isolated from the chloroform soluble fraction of Salsola baryosma along with 2alpha,3beta,23,24-tetrahydroxyurs-12-en-28-oic acid (3) reported for the first time from this species. Their structures have been assigned from 1H and 13C NMR spectra, DEPT and by 2D COSY, NOESY, HMQC and HMBC experiments. The compounds 1-3 showed significant antioxidant activity. 相似文献
2.
Compounds 1-7 form a novel group of dithiocarbamates, first synthesized from the reaction of a series of primary amines with carbon disulfide and 3-bromo ethyl pyruvate in the presence of anhydrous potassium phosphate. Structure elucidation of this group of compounds was accomplished using extensive 1D and 2D NMR spectroscopic studies, including (1)H, (13)C, COSY, NOESY, HSQC, and gHMBC experiments. The distinction between the linear structures I, II and the cyclic structure III was made mainly on the basis of the analysis of the cross peak between H-2 and H-4a in the COSY spectra, in combination with the long-range correlation between H-2 and C-4, 6 in the gHMBC spectra. 相似文献
3.
Muhammad Imran Muhammad Ibrahim Naheed Riaz Prof. Dr. Abdul Malik 《Magnetic resonance in chemistry : MRC》2009,47(6):532-536
Aervins A‐D (1‐4), four new coumaronochromone analogues have been isolated from the CHCl3‐soluble fraction of the MeOH extract of the whole plant of Aerva persica. Their structures were assigned based on 1H NMR, 13C NMR spectra, DEPT, and by 2DNMR experiments. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
4.
Yuan Cao Ji‐Jun Chen Ning‐Hua Tan Yong‐Ping Wu Jie Yang Qiang Wang 《Magnetic resonance in chemistry : MRC》2010,48(8):656-659
Selaginellins G ( 1 ) and H ( 2 ), two new selaginellin derivatives, were isolated from the whole plant of Selaginella pulvinata. Their structures were elucidated, and complete assignments of the 1H and 13C NMR spectroscopic data were achieved by 1D and 2D NMR experiments (HSQC, HMBC, COSY and ROESY). Compound 1 displayed good antifungal activity against Candida albicans with an IC50 value of 5.3 µg/ml. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
5.
Structural determination of kochiosides A-C, new steroidal glucosides from Kochia prostrata, by 1D and 2D NMR spectroscopy 总被引:1,自引:0,他引:1
Kochiosides A-C, three new steroidal glucosides, have been isolated from the ethyl acetate fraction of Kochia prostrata and their structures assigned from its (1)H and (13)C NMR spectra, DEPT and by 2D COSY, NOESY, HMQC and HMBC experiments. 相似文献
6.
Benish Iftikhar Shagufta Perveen Abdul Malik Najma Sultana Saeed Arayne Pir Muhammad 《Magnetic resonance in chemistry : MRC》2009,47(7):605-608
Quercusides A and B, new flavonoid glucosides have been isolated from the chloroform soluble fractions of Quercus incana. Their structures were assigned from 1H and 13C nuclear magnetic resonance spectra, distortionless enhancement by polarization transfer (DEPT) and by correlation spectroscopy, heteronuclear multiple quantum correlation (HMQC) and heteronuclear multiple bond correlation (HMBC) experiments. Lupeol, β‐sitosterol and ursolic acid have also been reported from this species. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
7.
《Magnetic resonance in chemistry : MRC》2002,40(11):705-715
Quantitative analysis of complex mixtures by NMR is often hampered by heavily overlapping signals in 1D 1H or 13C spectra. To resolve the overlap problem, we have been looking at the possibilities of using heteronuclear correlated 2D NMR methods for quantification. In this work, we applied 2D INEPT to analyze mixtures of tetradecane and squalane, which represent typical substructures of lube oil fractions. The factors affecting correlation peak volumes, namely the polarization transfer delays within pulse sequence, multiplicity of CHn group and the magnitude of 1J(C, H) couplings were taken into account by product operator formalism calculations. The results indicate that if absolute precision in quantification is not essential, the current approach can be used for the quantitative analysis of the molecular composition of complex mixtures when conventional 1D NMR methods fail. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
8.
Atricins A (1) and B (2), two new oleanane-type triterpenes have been isolated from the chloroform-soluble fractions of Perovskia atriplicifolia and their structures assigned from (1)H and (13)C-NMR spectra, Distortion Enhancement by Polarization Trasfer (DEPT) and by 2D-COSY, HMQC, Nuclear Overhauser Enhancement Spectroscopy (NOESY) and Hetronuclear mutiple-bond correlation (HMBC) experiments. 相似文献
9.
Structure determination of two new indole‐diterpenoids from Penicillium sp. CM‐7 by NMR spectroscopy
Yu‐Hong Zhang Sheng‐Dong Huang Hua‐Qi Pan Xi‐Qing Bian Zai‐Ying Wang Ai‐Hong Han Jiao Bai 《Magnetic resonance in chemistry : MRC》2014,52(6):306-309
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. 相似文献
10.
Song‐Ya Zhang Zhan‐Lin Li Li‐Ping Guan Xin Wu Hua‐Qi Pan Jiao Bai Hui‐Ming Hua 《Magnetic resonance in chemistry : MRC》2012,50(9):632-636
Two new trichothecenes, named 8α‐hydroxyroridin H and myrothecin A, along with six known compounds, 8α‐acetoxy roridin H, isororidin K, verrucarin A, verrucarin J, verrucarin L and 8α‐acetoxy verrucarin L, were isolated from the fermentation broth of a halotolerant fungus Myrothecium sp. GS‐17, which was separated from the soil sample of a salina. Structure elucidation and NMR signal assignments were achieved on the basis of spectroscopy. In addition, compounds 1 and 2 were active against plant pathogenic fungi Rhizoctonia solani and Fusarium oxysporum. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
11.
Fazuo Wang Tianjiao Zhu Min Zhang Aiqun Lin Weiming Zhu Qianqun Gu 《Magnetic resonance in chemistry : MRC》2010,48(2):155-158
Three new furan and pyran derivatives named aspericins A? C (1–3), as well as a known asperic acid (4), have been isolated from the marine‐derived fungus Rhizopus sp. 2‐PDA‐61. The complete 1H and 13C NMR assignments for the new compounds were carried out using 1H, 13C, DEPT, COSY, HMQC, HMBC, and NOESY NMR experiments. Compounds 1–3 were evaluated for their cytotoxic activities on P388, A549, HL‐60, and BEL‐7420 cell lines by the MTT and SRB methods. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
12.
Bakhat Ali Muhammad Imran Riaz Hussain Zaheer Ahmed Abdul Malik 《Magnetic resonance in chemistry : MRC》2010,48(2):159-163
Two new flavonoids, abutilin A and B, were isolated from the chloroform soluble fraction of Abutilon pakistanicum and their structures assigned from 1H and 13C NMR spectra, DEPT and by 2D COSY, HMQC and HMBC experiments. Ferulic acid (3), (E)‐cinnamic acid (4), 5‐hydroxy‐4′,6,7,8‐tetramethoxyflavone (5), kaempferol (6), luteolin (7) and luteolin 7‐O‐β‐D ‐glucopyranoside (8) have also been reported from this species. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
13.
Silymins A (1) and B (2), the new pentacyclic triterpenes, have been isolated from ethyl acetate fraction of Silybum marianum and their structures assigned from 1H and 13C NMR spectra, DEPT and by 2D COSY, NOE and HMBC experiments. 相似文献
14.
Azhar Mahmood Itrat Fatima Shaheen Kosar Rehana Ahmed Abdul Malik 《Magnetic resonance in chemistry : MRC》2010,48(2):151-154
Prunusins A (1) and B (2), the new C‐alkylated flavonoids, have been isolated from the seed kernels of Prunus domestica. Their structures were assigned from 1H and 13C nuclear magnetic resonating spectra, DEPT and by correlation spectroscopy, HMQC and HMBC experiments. 3, 5, 7, 4′‐Tetrahydroxyflavone (3) and 3, 5, 7‐trihydroxy‐8, 4′‐dimethoxyflavone (4) have also been reported from this species. Both compounds (1) and (2) showed significant antifungal activity against pathogenic fungus Trichophyton simmi. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
15.
Kazmi MH Ahmed E Hameed S Malik A Ashraf M 《Magnetic resonance in chemistry : MRC》2007,45(5):416-419
Two new pentacyclic triterpenes, sorbinols A (1) and B (2) have been isolated from the ethyl acetate fraction of Sorbus cashmariana and their structures assigned from (1)H and (13)C NMR spectra, DEPT and by 2D COSY, NOE, HMQC and HMBC experiments. Both 1 and 2 showed moderate inhibitory potential against the enzyme lipoxygenase. 相似文献
16.
Miranda RR Silva GD Duarte LP Fortes IC Filho SA 《Magnetic resonance in chemistry : MRC》2006,44(2):127-131
Six pentacyclic triterpenoids, 3beta-stearyloxy-urs-12-ene (1), friedelin (2), 3beta-friedelinol (3), alpha-amyrin (4), beta-amyrin (5), and lupeol (6), have been isolated from the hexane extract of Maytenus salicifolia Reissek (Celastraceae) leaves. The molecular and structural formula as well as the stereochemistry of a new pentacyclic triterpene (1) were determined using data obtained from 1H and 13C NMR spectra, DEPT135 and by 2D HSQC, HMBC, COSY and NOESY experiments. The molecular formula C48H84O2 was established using quantitative 13C NMR, and the molecular weight (692 Da) was confirmed by elemental analysis and mass spectrometry (GC-MS). 相似文献
17.
Jaécio Carlos Diniz Francisco Arnaldo Viana Odaci Fernandes Oliveira Maria Aparecida M. Maciel Maria da Conceição de Menezes Torres Raimundo Braz‐Filho Edilberto R. Silveira Otília Deusdênia L. Pessoa 《Magnetic resonance in chemistry : MRC》2009,47(2):190-193
From the roots of Cordia leucocephala (Boraginaceae), two new meroterpenoid naphthoquinones, 6‐[10‐(12,12‐dimethyl‐13α‐hydroxy‐16‐methenyl‐cyclohexyl)ethyl]‐1,4‐naphthalenedione (cordiaquinone L) and 5‐methyl‐6‐[10‐(12,12‐dimethyl‐13β‐hydroxy‐16‐methenyl‐cyclohexyl)methyl‐1,4‐naphthalenedione (cordiaquinone M) were isolated. Their structures were elucidated after detailed 1D and 2D NMR (COSY, HSQC, HMBC and NOESY) data analyses and comparison with literature data for analogous compounds. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
18.
Assignments of 1H and 13C NMR chemical shifts were made by means of heteronuclear single quantum coherence (HSQC) and heteronuclear multiple bond correlation (HMBC) experiments for ondansetron, and by means of 1H-1H correlation spectroscopy (1H-1H COSY) and two-dimensional nuclear Overhauser effect spectroscopy (NOESY) experiments for two novel metabolites (M1 and M2) of ondansetron. These two metabolites were isolated for the first time from Mucor circinelloides. 相似文献
19.
Khan SB Afza N Malik A ul Haq A Ahmed Z 《Magnetic resonance in chemistry : MRC》2004,42(12):1063-1065
Ramosine, a new sesquiterpene lactone, was isolated from the chloroform fraction of Amberboa ramosa and the structure was assigned as 4beta-(hydroxymethyl)-3beta,4alpha-dihydroxy-8alpha-[(S)-3-hydroxy-2-ethylenepropionyloxy]-1alphaH, 5alphaH,6betaH,7alphaH,11betaH,11alpha-methylguaia-10(14)-en-6, 12-olide by extensive NMR studies. 相似文献
20.
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. 相似文献