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1.
The investigations of the 1H and 13C resonances of a series of 9 shikimic acid derivatives were carried out using one‐ and two‐dimensional methods. 1H and 13C spectral data were assigned by DEPT, 1H‐1H COSY, HSQC, HMBC, and the stereo configuration was confirmed by 1D selective NOESY experiments. 相似文献
2.
Tian Jiewei Wang Lei Long Xiufeng Zhang Heming Li Xiaoguang Fu Haiyan 《Natural product research》2018,32(19):2343-2346
Resveratrol (1) undergoes microbial transformation when fermented with Streptomyces sp. A12 to yield 3, 5, 4′-trimethoxy-trans-stilbene (2). The structure of the compound 2 was elucidated using the modern spectroscopic techniques. This is the first report of the microbial transformation of resveratrol to compound 2 using the endophyte isolated from Polygonum cuspidatum. 相似文献
3.
The direct oxidative C(sp3)-H functionalization reaction has long been considered as one of the most efficient and straightforward synthetic protocol for the construction of C-C bonds. Recently, the synthesis of substituted quinolines via C(sp3)-H functionalization of glycine derivatives has gained widespread attention from the chemists. Recent progresses on the C(sp3)-H functionalization of glycine derivatives and their applications in the synthesis of substituted quinolines are described in this paper. The aims are to broaden students' vision and stimulate their interest in scientific research through the introduction of innovative scientific research. 相似文献
4.
Six pentacyclic triterpene acids, ursolic acid, oleanolic acid, betulinic acid, 23-hydroxybetulinic acid, glycyrrhetinic acid, and senegenin, were metabolized by the microbe Nocardia sp. NRRL 5646 to selectively furnish their corresponding 28-methyl esters. Notably, ursolic acid (1) was converted to oleanolic acid methyl ester (4) via two intermediates, oleanolic acid (2), and ursolic acid methyl ester (3), which are formed by participation of ‘retro-biosynthetic’ methyl migration from C-19 to C-20. Senegenin (11) was selectively converted to a nortriterpene methyl ester, senegenic acid methyl ester (12), via an unprecedented C-C bond cleavage. The stereochemical assignments of compounds 11 and 12 were made unambiguously for the first time using 2D NMR spectroscopy. 相似文献
5.
Dan Zheng Li Han Yi Jiang Yan‐Ru Cao Jiang Liu Xiu Chen Yi‐Qing Li Xue‐Shi Huang 《Magnetic resonance in chemistry : MRC》2013,51(3):188-191
Four new prenylindole derivatives, (R)‐6‐(2,3‐dihydroxy‐3‐methylbutyl)indole (1), (R)‐6‐(2,3‐dihydroxy‐3‐methylbutyl)indolin‐2‐one (2), and an unseparated mixture of (Z)‐6‐(4‐hydroxy‐3‐methylbut‐2‐en‐1‐yl)indolin‐2‐one (3a) and (E)‐6‐(4‐hydroxy‐3‐methylbut‐2‐en‐1‐yl)indolin‐2‐one (3b) with a ratio of 3 : 2, were isolated from the culture broth of a streptomycete isolated from Ailuropoda melanoleuca feces. Their structures were elucidated on the basis of 1D and 2D NMR spectroscopic techniques. The absolute configuration of 1 was determined by Mosher's method. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
6.
区别齐墩果-12-烯和乌苏-12-烯三萜的~13C NMR特征化学位移 总被引:1,自引:0,他引:1
齐墩果-12-烯(olean-12-ene)(Ⅰ)和乌苏-12-烯(urs-12-ene)(Ⅱ)型五环三萜的差别仅在于 E 环上甲基位置的不同。曾有多种光谱和 相似文献
7.
The (1)H and (13)C NMR signal assignment of the data of 13 scopadulane-type diterpenes is reported. It was based on one- and two- dimensional NMR techniques which included (1)H, (13)C, DEPT, HMQC and 1D NOE difference spectroscopy. 相似文献
8.
Zhang‐Gui Ding Jiang‐Yuan Zhao Pei‐Wen Yang Ming‐Gang Li Rong Huang Xiao‐Long Cui Meng‐Liang Wen 《Magnetic resonance in chemistry : MRC》2009,47(4):366-370
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 30243T), 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. 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.
Tang JS Gao H Hong K Yu Y Jiang MM Lin HP Ye WC Yao XS 《Magnetic resonance in chemistry : MRC》2007,45(9):792-796
A new surfactin isomer (1) was isolated from a mangrove bacteria strain 'Bacillus sp'. Its structure was identified, and full assignments of (1)H and (13)C NMR spectral data were achieved for the first time by a combination of mass spectrometry and 1D and 2D NMR experiments including DEPT, (1)H-(1)H COSY, HSQC, HMBC, TOCSY, ROESY, and HSQC-TOCSY. The NMR spectral data of eight known analogs (2-9) are also reported. 相似文献
11.
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
12.
Xia XK Liu F She ZG Yang LG Li MF Vrijmoed LL Lin YC 《Magnetic resonance in chemistry : MRC》2008,46(7):693-696
One new compound 6-demethylvermistatin (1), together with two known compounds, the penicillide derivatives (2) and (3) were isolated from the mangrove fungus Guignardia sp. No. 4382 obtained from the South China Sea. Their structures were assigned using high-resolution electron ionization mass spectrometry(HREIMS), (1)H and (13)C NMR spectra, DEPT, and by 2D COSY, HMQC, and HMBC experiments. The absolute configuration of 1 was established by comparison of its CD with that of vermistatin. 相似文献
13.
Guo Z She Z Shao C Wen L Liu F Zheng Z Lin Y 《Magnetic resonance in chemistry : MRC》2007,45(9):777-780
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. 相似文献
14.
《Magnetic resonance in chemistry : MRC》2002,40(3):175-181
A 1H, 13C and 31P NMR study of monoethyl (HL1) and monobutyl (HL2) esters of (α‐anilinobenzyl)phosphonic acid and their metallocyclic dipalladium complexes (Pd2L4,L = L1, L2) in DMSO‐d6 was performed, based on 1D and 2D homo‐ and heteronuclear experiments including 1H,13C,31P,APT,1H–1H COSY, 1H–13C COSY, gs‐HMQC and gs‐HMBC NMR techniques. The results obtained are discussed with respect to those for some palladium(II) complexes reported for various anilinobenzylphosphonate derivatives. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
15.
Yiguang Chen Xiaoling Cai Jiahui Pan Junping Gao Jing Li Jie Yuan Liwu Fu Zhigang She Yongcheng Lin 《Magnetic resonance in chemistry : MRC》2009,47(4):362-365
The structure elucidations and complete 1H and 13C NMR assignments are reported for three new anthraquinone derivatives: Fusaquinon A (1), B (2), and C (3) isolated from the fermentation medium of the marine fungus Fusarium sp. (No. ZH‐210). HREIMS, Fourier transform infrared absorption spectrometry (FT‐IR), NMR experiments including gCOSY, gHMQC, gHMBC, and NOESY were used for the determination of the structures and NMR spectral assignments. Preliminary pharmacological test showed that they exhibited low cytotoxic activity towards KB, KBv200, and MCF‐7 cell lines. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
16.
A. M. C. Arriaga J. Q. Lima J. N. Vasconcelos M. C. F. de Oliveira M. Andrade‐Neto G. M. P. Santiago D. E. A. Uchoa G. T. Malcher J. Mafezoli R. Braz‐Filho 《Magnetic resonance in chemistry : MRC》2009,47(6):537-540
1H and 13C NMR chemical shifts of praecansone B, pongaflavone and dehydrorotenone isolated from Tephrosia egregia Sandw and obovatin from T. toxicaria Pers. were unambiguously assigned by 1D and 2D NMR experiments including 1H, 1H COSY, gHMQC and gHMBC, allowing the correction of literature assignments.Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
17.
Xia XK Huang HR She ZG Shao CL Liu F Cai XL Vrijmoed LL Lin YC 《Magnetic resonance in chemistry : MRC》2007,45(11):1006-1009
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. 相似文献
18.
Random and block copolymers of poly (ether sulfone) (PES) and poly (ether ether sulfone) (PEES) were synthesized by the nucleophilic polycondensation of 4,4′‐dichlorodiphenyl sulfone (DCDPS) with 4,4′‐dihydroxydiphenyl sulfone (DHDPS) and hydroquinone (HQ). Chemical structures of these copolymers were characterized by 13C NMR. The monomer molar fraction, sequential distribution, and degree of randomness of the copolymers were determined through analyses of the resonances of quaternary carbons in the DCDPS unit. Experimental results show that the molar fractions of the comonomer determined by 13C NMR analyses are close to the charged values in the synthetic step. Moreover, these copolymers, which were prepared by different polymerization methods, revealed different number‐average sequential length and degree of randomness. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1624–1630, 2005 相似文献
19.
本文用平均络合平衡常数的测定及~(13)C NMR两种方法对一些单糖、糖苷和硼酸生成的络合物进行了研究。研究结果表明醛戊糖、醛己糖虽在溶液中主要以吡喃环存在,但当它们与硼酸络合时即由吡喃转变成呋喃。 相似文献
20.
The complete 1H and 13C NMR assignments are reported for the new natural products, 7-hydroxy-3-(hydroxymethyl)-1-methoxy-9H-xanthen-9-one (1) and 2,5-dihydroxy-8-methoxy-6-methyl-9-oxo-9H-xanthene -1-carboxylic acid (2). Both of these secondary metabolites were isolated from the fermentation culture of the endophytic fungus Xylaria sp. FRR 5657. 1D and 2D NMR experiments that included 1H, gCOSY, gHSQC and gHMBC were used for the determination of the structure and assignment of these xanthones. 相似文献