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1.
《Journal of separation science》2017,40(11):2515-2521
In our present study, two groups of xanthones isomers (1‐hydroxy‐3,5,8‐trimethoxyxanthone and 1‐hydroxy‐3,7,8‐trimethoxyxanthone; 1,8‐dihydroxy‐3,7‐dimethoxyxanthone and 1,8‐dihydroxy‐3,5‐dimethanolxanthone) and other two xanthones (3‐methoxy‐1,5,8‐trihydroxyxanthone and 3,5‐dimethoxy‐1‐hydroxyxanthone) were separated from Swertia franchetiana . First, a solvent system composed of petroleum ether/methanol/water (2:1:0.6, v/v) was developed for the liquid–liquid extraction of these xanthones from the crude extract. Then, an efficient method was established for the one‐step separation of these six xanthones by high‐speed countercurrent chromatography using n‐hexane/ethyl acetate/methanol/ethanol/water (HEMEW; 6:4:4:2:4, v/v) as the solvent system. The results showed that liquid–liquid extraction could be well developed for efficient enrichment of target compounds. Additionally, high‐speed countercurrent chromatography could be a powerful technology for separation xanthones isomers. It was found ethanol could be a good methanol substitute when the HEMEW system could not provide good separation factors. 相似文献
2.
Jia‐Hui Pan Juan‐Juan Deng Yi‐Guang Chen Jun‐Ping Gao Yong‐Cheng Lin Zhi‐Gang She Yu‐Cheng Gu 《Helvetica chimica acta》2010,93(7):1369-1374
A new lactone, 1,8‐dihydroxy‐10‐methoxy‐3‐methyldibenzo[b,e]oxepine‐6,11‐dione ( 1 ), and two new xanthones, 1‐hydroxy‐8‐(hydroxymethyl)‐6‐methoxy‐3‐methyl‐9H‐xanthen‐9‐one ( 2 ) and 1‐hydroxy‐8‐(hydroxymethyl)‐3‐methoxy‐6‐methyl‐9H‐xanthen‐9‐one ( 3 ), were isolated from a mangrove endophytic fungus Phoma sp. SK3RW1M collected from the South China Sea. This is the first report on xanthone derivatives isolated as secondary metabolites from Phoma species. Their structures were elucidated by spectroscopic methods, mainly 1D‐ and 2D‐NMR techniques, and the structure of compound 2 was confirmed by X‐ray crystallography. Cytotoxicity assays showed that compounds 1 – 3 were inactive against KB and KBv200 cells. 相似文献
3.
Two new unusual xanthones, 5‐O‐β‐d ‐glucopyranosyl‐1,3,8‐trihydroxy‐5,6,7,8‐tetrahydroxanthone (1) and 1,3,5,8‐tetrahydroxy‐5,6,7,8‐tetrahydroxanthone (2), were isolated from Lomatogonium carinthiacum (Wulf) Reichb. Their structures were elucidated on the basis of spectroscopic methods including UV, IR, ESI‐MS, 1D NMR, and 2D NMR. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
4.
Wei‐Hua Jiao Hao Gao Chen‐Yang Li Guang‐Xiong Zhou Susumu Kitanaka Atsuko Ohmura Xin‐Sheng Yao 《Magnetic resonance in chemistry : MRC》2010,48(6):490-495
Five new β‐carboline alkaloids, 6,12‐dimethoxy‐3‐(2‐hydroxylethyl)‐β‐carboline (1), 3,10‐dihydroxy‐β‐carboline (2), 6,12‐dimethoxy‐3‐(1‐hydroxylethyl)‐β‐carboline (3), 6,12‐dimethoxy‐3‐(1,2‐dihydroxylethyl)‐β‐carboline (4), and 6‐methoxy‐3‐(2‐hydroxyl‐1‐ethoxylethyl)‐β‐carboline (5), and two new natural products, 6‐methoxy‐12‐hydroxy‐3‐methoxycarbonyl‐β‐carboline (6) and 3‐hydroxy‐β‐carboline (7) were isolated from the stems of Picrasma quassioides along with 16 known β‐carboline alkaloids (8–23). The structures of new compounds were determined by extensive spectroscopic analyses, and the 1D and 2D NMR data of compounds 6, 7 and 10 were reported for the first time. The bioassays showed that only compounds 14 and 16 could enhance the differentiation of 3T3‐L1 preadiocytes accompanied by secretion of adiponectin proteins among these 23 compounds. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
5.
从人面果乙酸乙酯提取物中分离出5个新的口 山 酮 化合物garcinenone A (1), B (3), C (4), D (7) and E (8)和7个已知化合物,其结构经过波谱技术,特别是2D-NMR技术来鉴定。Jacareubin (2), 1,4,6-trihydroxy-5-methoxy-7-(3-methyl-2-buteny1)xanthone (6), subeliptenone B (11) 和symphoxanthone (12)为首次从该植物中分离出来。在DPPH自由基的清除活性实验中,所有的化合物都显示抗氧化活性,其IC50的值在 6.0-23.2 mM。结果表明人面果是潜在的有前景的天然抗氧化剂。 相似文献
6.
《Magnetic resonance in chemistry : MRC》2003,41(11):962-964
Methanol extracts from Perezia hebeclada roots yielded the new 8‐β‐D ‐glucopyranosyloxy‐4‐methoxy‐5‐methylcoumarin ( 1 ) together with the known 4‐β‐D ‐glucopyranosyloxy‐5‐methylcoumarin ( 2 ). Their structures were determined and verified, respectively, by MS and NMR studies, including 1D and 2D experiments. Two 13C NMR signals of the sugar residue of 2 were reassigned. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
7.
Charles Pathirana Chris Sfouggatakis Venkatapuram Palaniswamy 《Magnetic resonance in chemistry : MRC》2013,51(3):184-187
During a synthesis of 5‐amino‐4‐(6‐methoxy‐2‐methylpyridin‐3‐yl)‐3‐methyl‐1H‐pyrazole‐1‐carboxamide (see Scheme 1), a side‐reaction produced 3‐amino‐4‐(6‐methoxy‐2‐methylpyridin‐3‐yl)‐5‐methyl‐1H‐pyrazole‐1‐carboxamide as a by‐product that forms an equilibrium with the target‐compound. The structure of the by‐product was elucidated by the interpretation of 1D and 2D (HMQC, HMBC) NMR data where 1H‐15 N HMBC correlations revealed the position of carbamoyl group attachment on the pyrazole. Comparison of structures of the target‐compound and the by‐product showed that the latter resulted from N‐N migration of the carbamoyl group in the target‐compound. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
8.
Du‐Qiang Luo Yu‐Peng Chen Jun Zhang Bao‐Zhong Shi Zi‐Qi Yang Chuan Chen 《Helvetica chimica acta》2013,96(2):309-312
A new glycine derivative, podocarpiamide ( 1 ), a new indole alkaloid, 1‐methoxy‐1H‐indol‐3‐ethanol ( 2 ), together with two known compounds, 1‐methoxy‐1H‐indole‐3‐acetic acid ( 3 ) and methyl 1‐methoxy‐1H‐indole‐3‐acetate ( 4 ), were isolated from the fermentation broth of the plant endophytic fungus Pestalotiopsis podocarpi. Their structures were elucidated by extensive spectroscopic analysis including 1D‐ and 2D‐NMR (HSQC, HMBC, and COSY) and MS experiments. Compound 1 has an interesting unusual carbamic acid structure. 相似文献
9.
《Magnetic resonance in chemistry : MRC》2002,40(12):793-794
A new prenylated flavanone, floranol ( 1 ) 3,5,7,2′‐ tetrahydroxy‐6‐methoxy‐8‐prenylflavanone and a known flavanone (dioclein) were isolated from the roots of Dioclea grandiflora (Fabaceae). The structure and the relative stereochemistry were established by 2D NMR spectroscopic techniques (HMQC and HMBC) Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
10.
《Magnetic resonance in chemistry : MRC》2002,40(12):797-799
Complete 1H and 13C NMR assignments for selected carotenoids from purple and green phototropic bacteria are reported for the first time. Assignments are made for the all‐E isomers of OH‐rhodopin ( 1 , 1,2,1′,2′‐tetrahydro‐ψ,ψ‐carotene‐1,1′‐diol), rhodovibrin ( 2 , 1′‐methoxy‐3′,4′‐didehydro‐1,2,1′,2′‐tetrahydro‐ψ,ψ‐carotene‐1‐ol), anhydrorhodovibrin ( 3 , 1‐methoxy‐3,4‐didehydro‐1,2‐dihydro‐ψ,ψ‐carotene), 2‐ketorhodovibrin ( 4 , 1′‐hydroxy‐1‐methoxy‐3,4,3′,4′‐tetradehydro‐1,2, 1′,2′‐tetrahydro‐ψ,ψ‐carotene‐2‐one) and chlorobactene ( 5 , ?,ψ‐carotene). Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
11.
Hongbo Huang Qing Li Xiaojun Feng Bin Chen Jun Wang Lan Liu Zhigang She Yongcheng Lin 《Magnetic resonance in chemistry : MRC》2010,48(6):496-499
Two new aromatic lactones, 6‐hydroxy‐4‐hydroxymethyl‐8‐methoxy‐3‐ methylisocoumarin (1) and 1,10‐dihydroxy‐8‐methyl‐dibenz[b, e]oxepin‐6,11‐dione (2), together with two known compounds, 1,10‐dihydroxy‐dibenz[b, e]oxepin‐6,11‐dione (3) and 3‐hydroxymethyl‐6,8‐dimethoxycoumarin (4), were isolated from a mangrove endophytic fungus (No. GX4‐1B) collected from the South China Sea. Their structures were elucidated and the data of 1H and 13C NMR were assigned completely by HREIMS, 1D and 2D NMR experiments including HMQC, HMBC and NOESY. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
12.
岩黄芪属植物中的多序岩黄芪作为传统中药“红芪”有着广泛的药用价值,而同属的红花岩黄芪也报道具有良好的药用活性。我们对该属中的细枝岩黄芪根部的化学成份进行了研究,从中分离得到了三个新的异戊烯基呋喃异黄酮,分别为:5-羟基-7-(2-羟基异丙基)-4′-甲氧基-9-苯并呋喃[3,2-g]异黄酮(1),5-羟基-4′-甲氧基-9-苯并呋喃[3,2-g]异黄酮(2),5-羟基-7-(2-羟基异丙基)-4′-甲氧基-7-苯并呋喃[2,3-h]异黄酮(3),并对这三个新化合物的清除自由基能力进行了测试。 相似文献
13.
Hyuk Yoon Seunghyun Ahn Doseok Hwang Geunhyeong Jo Dong Woon Kim Sang Ho Kim Dongsoo Koh Yoongho Lim 《Magnetic resonance in chemistry : MRC》2012,50(11):759-764
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. 相似文献
14.
Ran‐Ran Sun Feng‐Ping Miao Jing Zhang Gang Wang Xiu‐Li Yin Nai‐Yun Ji 《Magnetic resonance in chemistry : MRC》2013,51(1):65-68
Three new xanthone derivatives, yicathin A (1), yicathin B (2), and yicathin C (3), and three known anthraquinone derivatives, alatinone (4), 1,5‐dihydroxy‐3‐methoxy‐7‐methylanthraquinone (5), and 5‐hydroxy‐1,3‐dimethoxy‐7‐methylanthraquinone (6), were isolated from the cultures of Aspergillus wentii pt‐1, an endophytic fungus isolated from the marine red alga Gymnogongrus flabelliformis. Their structures were unambiguously elucidated by NMR and mass spectroscopic methods as well as quantum chemical calculations. Compound 2 was active against Escherichia coli, and 3 could inhibit E. coli, Staphylococcus aureus, and Colletotrichum lagenarium. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
15.
High‐speed countercurrent chromatography isolation of flavans from Ixeris chinensis and their identification by NMR spectroscopy
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Qing‐hu Wang Bai‐yin‐mu‐qi‐er Bao Jing‐jing Han Rong‐jun Wu 《Journal of separation science》2016,39(11):2172-2178
High‐speed countercurrent chromatography, combined with macroporous resin chromatography were applied to the separation and purification of flavans from Ixeris chinensis. Four flavans, namely, 5‐methoxy‐7,4′‐dihydroxyflavan‐3‐ol ( 1 ), 5,7‐dimethoxy‐4′‐hydroxyflavan‐3‐ol ( 2 ), 5,7‐dimethoxy‐4′‐hydroxyflavan ( 3 ), and 5,7‐dimethoxy‐8‐methyl‐4′‐hydroxyflavan ( 4 ), were obtained from I. chinensis for the first time. Their chemical structural identification was carried out by spectroscopic methods, including 1D and 2D NMR spectroscopy. Amounts of 13.2 mg of compound 1 , 6.4 mg of compound 2 , 5.8 mg of compound 3 , and 14.5 mg of compound 4 were separated from 120 mg 75% ethanol fraction. The purities of 1 – 4 were 99.1, 99.2, 97.3, and 98.6 %, respectively. 相似文献
16.
Qing‐An Zheng Hai‐Zhou Li Ying‐Jun Zhang Chong‐Ren Yang 《Helvetica chimica acta》2004,87(5):1167-1171
Chemical investigation of the red herbal resin of Dracaena cochinchinensis resulted in the isolation of three new configurationally isomeric flavonoids: 6,4′‐dihydroxy‐7‐methoxy‐8‐methylflavane (=3,4‐dihydro‐2‐(4‐hydroxyphenyl)‐7‐methoxy‐8‐methyl‐2H‐[1]benzopyran‐6‐ol; 1 ), 5,4′‐dihydroxy‐7‐methoxy‐6‐methylflavane (=3,4‐dihydro‐2‐(4‐hydroxyphenyl)‐7‐methoxy‐6‐methyl‐2H‐[1]benzopyran‐5‐ol; 2 ), and 7,4′‐dihydroxy‐5‐ methoxyhomoisoflavane (=3,4‐dihydro‐3‐[(4‐hydroxyphenyl)methyl]‐5‐methoxy‐2H‐[1]benzopyran‐7‐ol; 3 ). Their structures were identified by means of detailed spectral analysis. In addition, thirteen known compounds were isolated from D. cochinchinensis: 7‐hydroxy‐4′‐methoxyflavane ( 4 ), 2,4,6‐trimethoxy‐4′‐hydroxydihydrochalcone ( 5 ), 2,4‐dimethoxy‐4′‐hydroxydihydrochalcone ( 6 ), 7,8‐(methylenedioxy)‐4′‐hydroxyhomoisoflavane ( 7 ), 4′,7‐dihydroxy‐8‐methylflavane ( 8 ), 2,6‐dimethoxy‐4,4′‐dihydroxydihydrochalcone ( 9 ), 2‐methoxy‐4,4′‐dihydroxydihydrochalcone ( 10 ), 7‐methoxy‐6,4′‐dihydroxyhomoisoflavane ( 11 ), 2‐methoxy‐4,4′‐dihydroxychalcone ( 12 ), 4′,7‐dihydroxyflavane ( 13 ), 7,4′‐dihydroxyhomoisoflavane ( 14 ), 7,4′‐dihydroxyhomoisoflavone ( 15 ), and 7,4′‐dihydroxyflavone ( 16 ). Compounds 7, 8, 9, 14 , and 15 have been isolated for the first time from this type of herbal source. 相似文献
17.
Two new xanthone glycosides and six known compounds were isolated from the roots of Pteris multifida. Based on spectroscopic and chemical methods, the structures of the new compounds were elucidated as 1‐hydroxy‐4,7‐dimethoxy‐8‐(3‐methyl‐2‐butenyl)‐6‐O‐α‐L‐rhamnopyranosyl‐(1→2)‐[β‐D‐glucopyranosyl‐(1→3)]‐β‐D‐glucopyranosylxanthone ( 1 ), and 1,3‐dihydroxy‐7‐methoxy‐8‐(3‐methyl‐2‐butenyl)‐6‐O‐α‐L‐rhamnopyranosyl‐(1 →2)‐[β‐D‐glucopyranosyl‐(1→3)]‐β‐D‐glucopyranosylxanthone ( 2 ), respectively. 相似文献
18.
Ezugwu Christopher Erdal Bedir Chuck Dunbar IkhlasA. Khan ChristopherO. Okunji BrianM. Schuster MauriceM. Iwu 《Helvetica chimica acta》2003,86(8):2914-2918
Three new indoloquinazolidine‐type alkaloids, 8,13‐dihydro‐2‐methoxyindolo[2′,3′: 3,4]pyrido[2,1‐b]quinazolin‐5(7H)‐one ( 1 ), 8,13‐dihydro‐2‐methoxy‐13‐methylindolo[2′,3′: 3,4]pyrido[2,1‐b]quinazolin‐5(7H)‐one ( 2 ), and 5,8,13,14‐tetrahydro‐2‐methoxy‐14‐methyl‐5‐oxo‐7H‐indolo[2′,3′: 3,4]pyrido[2,1‐b]quinazolim‐6‐iun chloride ( 3 ) were isolated from Araliopsis tabouensis, together with three known compounds. The structures of the new compounds were determined primarily from 1D‐ and 2D‐NMR analysis. The antimalarial activities of compounds 1 – 5 were evaluated against Plasmodium falciparum D6 and W2 clones. The IC50 values in antimalarial bioassay for compounds 2 – 5 varied from 1.8 to 4.7 μg/ml. 相似文献
19.
Water hyacinth (Eichhornia crassipes) is a cause of great concern in terms of environmental and agricultural impacts in many parts of the world. Phytochemical investigation of water hyacinth led to the isolation of six new phenylphenalenes, 2,3‐dihydro‐3,9‐dihydroxy‐5‐methoxy‐4‐phenyl‐1H‐phenalen‐1‐one ( 1 ), 2,3‐dihydro‐8‐methoxy‐9‐phenyl‐1H‐phenalene‐1,4‐diol ( 2 ), 2,3‐dihydro‐4,8‐dimethoxy‐9‐phenyl‐1H‐phenalen‐1‐ol ( 3 ), 2,3‐dihydro‐9‐(4‐hydroxyphenyl)‐8‐methoxy‐1H‐phenalene‐1,4‐diol ( 4 ), 2,6‐dimethoxy‐9‐phenyl‐1H‐phenalen‐1‐one ( 5 ), and 7‐(4‐hydroxyphenyl)‐5,6‐dimethoxy‐1H‐phenalen‐1‐one ( 6 ), together with the four known compounds 7 – 10 . Their structures were elucidated by spectrometric methods including 1D‐ and 2D‐NMR, and MS analysis. These compounds may be involved in allelopathic interactions of water hyacinth with neighboring plants. 相似文献
20.
Xanthones with α‐Glucosidase Inhibitory Activities from Aspergillus versicolor,a Fungal Endophyte of Huperzia serrata
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Tian‐Tian Ma Wei‐Guang Shan You‐Min Ying Lie‐Feng Ma Wen‐Hong Liu Zha‐Jun Zhan 《Helvetica chimica acta》2015,98(1):148-152
Three new xanthones, namely huperxanthones A–C ( 1 – 3 , resp.), were obtained from the cultures of Aspergillus versicolor, a fungal endophyte of Huperzia serrata, together with 1,7‐dihydroxy‐8‐(methoxycarbonyl)xanthone‐3‐carboxylic acid ( 4 ), β‐diversonolic acid methyl ester ( 5 ), 4‐hydroxyvertixanthone ( 6 ), and sydowinin B ( 7 ). The structures of the new compounds were established by detailed NMR and MS analysis, especially by 2D‐NMR experiments. All xanthones were evaluated for their effects on α‐glucosidase. Compound 4 exhibited a potent inhibitory activity against α‐glucosidase with an IC50 value of 0.24 mM (vs. 0.38 mM for acarbose). The rest of the compounds showed weak or no activity against α‐glucosidase. 相似文献