共查询到20条相似文献,搜索用时 15 毫秒
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Reiko Tanaka Shun‐ichi Wada Hitoshi Aoki Shunyo Matsunaga Takao Yamori 《Helvetica chimica acta》2004,87(1):240-249
Two new skeletal triterpene lactones, spiromarienonols A ( 1a ) and B ( 2a ), were isolated from the stem bark of Abies mariesii Masters (Pinaceae). Based on spectral data and biogenetic considerations, their unique three‐dimensional structures were determined to be (3R,7S,9R,23R)‐ ( 1a ) and (3R,7S,9S,23R)‐3,7‐dihydroxy‐8‐oxo‐7(8→9)abeo‐lanost‐24‐eno‐26,23‐lactone ( 2a ). Moreover, the potent activity of abiesenonic acid methyl ester ( 3 ) and abieslactone ( 4 ) against a disease‐oriented panel of 39 human cancer cell lines were investigated. 相似文献
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Qing Zhang Yan‐Fei Qiao Min Huang Hong‐Dong Liang Ru‐Jin Zhou 《Heteroatom Chemistry》2009,20(7):425-430
1‐Phenylpentane‐1, 4‐diones, and (E)‐5‐hydroxy‐5‐phenylpent‐3‐en‐2‐ones were synthesized via organophosphine‐catalyzed addition reaction of but‐3‐en‐2‐one with aldehydes. The features of the present protocols include high selectivity, operational simplicity, atom economy, and mild reaction conditions without transition metals. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 20:425–430, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20568 相似文献
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Anions of enolized heteroaromatic 1,3‐dicarbonyl systems, such as the title compounds 1, 9,14 , and 19 , react in dimethylformamide in the presence of potassium carbonate with diaryl disulfides 2 to yield arylsulfenyl derivatives ( 3, 10, 15, 20 ). The arylthiolate anions 4 formed in this reaction can be oxidized by air to yield the starting disulfides 2 again. Tetraalkylthiuram disulfides 7 react in the same manner to yield dialkylaminothiocarbonylthio derivatives ( 8, 13, 18 ) of the title compounds. Oxidation of the arylsulfenyl derivatives with hydrogen peroxide in sodium hydroxide solution usually leads to sulfoxides ( 5, 11, 16 ), whereas oxidation with peracetic acid affords sulfones ( 6, 12, 17 ). 相似文献
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Two new 20(10→5)abeo-abietune diterpenoids, pygmaeooins B ( 1 ) and C ( 2 ), have been isolated from the roots of Pygmaeopremna herbacea (Verbenaceae). Their structures were elucidated on the basis of spectroscopic data, and chemically, both compounds were correlated with each other. The absolute configurations were assigned tentatively on the basis of biogenetic pathway. 相似文献
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Mamiko Odoko Kyouta Yamamoto Nobuo Okabe 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(9):m469-m470
In the title compound, [Ca(C6H5O4)2(C6H6O4)2]·4H2O, which is a kojic acid–Ca2+ complex, the Ca atom is on a twofold axis and is octacoordinated by O atoms from four pyrone ligand molecules. The hydroxyl and ketone O atoms of each ligand form a five‐membered chelate ring with the Ca atom. The crystal structure is stabilized by partial stacking and O—H?O hydrogen bonds. 相似文献
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Ai‐Hua Zhao Sheng‐Hong Li Qin‐Shi Zhao Zhong‐Wen Lin Han‐Dong Sun Yang Lu Li‐Li Zhang Qi‐Tai Zheng 《Helvetica chimica acta》2003,86(10):3470-3475
A novel 13(12→11)abeo‐abietane skeletal diterpenoid, micranthin C ( 1 ), was isolated from Isodon lophanthoids var. micranthus. Its structure was determined by various spectroscopic techniques and finally confirmed by single‐crystal X‐ray diffraction. 相似文献
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Wu‐Wu Li Zun‐Ting Zhang 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(4):m176-m178
The title compound, [Co(H2O)6](C16H11O7S)2·4H2O, with cobalt(II) at the centre of symmetry, exhibits alternating hydrophilic and hydrophobic regions. Hydrophilic regions are generated by O—H...O hydrogen bonds among sulfonate groups, involving solvent water molecules and coordinated water molecules; π–π stacking interactions assemble the flavone skeletons into columns which form the hydrophobic regions. A three‐dimensional network is built up from an extensive array of hydrogen bonds, π–π stacking interactions and electrostatic interactions between the cation and anion. As a salt of the sulfonated derivative of naturally occurring tectochrysin (5‐hydroxy‐7‐methoxyflavone), this compound offers enhanced solubility and potential biological activity over the natural product. 相似文献
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Ayta Gürhan Gke Cumali elik Muhittin Aygün Nüket
cal Orhan Büyükgüngr 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(2):o98-o100
The structure of the title compound, C15H15NO4, comprises a racemic mixture of chiral molecules containing five stereogenic centres. The cyclohexane ring tends towards a boat conformation and the two tetrahydrofuran rings adopt envelope conformations. Molecules are linked into sheets parallel to (100) by a combination of O—H...O, C—H...O and C—H...π hydrogen bonds, leading to a two‐dimensional supramolecular structure. 相似文献
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Chang‐Shuai He Lu‐Fang Liu Lei Guo Jian‐Zhong Wu 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(3):289-292
Both 10‐(2‐hydroxyethyl)acridin‐9(10H)‐one, C15H13NO2, and 10‐(2‐chloroethyl)acridin‐9(10H)‐one, C15H12ClNO, have monoclinic (P21/c) symmetry and supramolecular three‐dimensional networks. But the differences in the intermolecular interactions displayed by the hydroxy group and the chlorine substituent lead to stronger intermolecular π‐stacking interactions and hydrogen bonding, and hence a significantly higher melting point for the former. 相似文献
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Graham Smith Urs D. Wermuth Peter C. Healy 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(7):o405-o407
The crystal structures of the proton‐transfer compounds of ferron (8‐hydroxy‐7‐iodoquinoline‐5‐sulfonic acid) with 4‐chloroaniline and 4‐bromoaniline, namely 4‐chloroanilinium 8‐hydroxy‐7‐iodoquinoline‐5‐sulfonate monohydrate, C6H7ClN+·C9H5INO4S−·H2O, and 4‐bromoanilinium 8‐hydroxy‐7‐iodoquinoline‐5‐sulfonate monohydrate, C6H7BrN+·C9H5INO4S−·H2O, have been determined. The compounds are isomorphous and comprise sheets of hydrogen‐bonded cations, anions and water molecules which are extended into a three‐dimensional framework structure through centrosymmetric R22(10) O—H...N hydrogen‐bonded ferron dimer interactions. 相似文献
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A new triterpenoid, fornicatin C (= (3β)‐3‐hydroxy‐18(13 → 12β)‐abeo‐lanosta‐13(17),24‐dien‐18‐oic acid; 1 ), was isolated from the fruiting bodies of Ganoderma fornicatum, together with the known compounds fornicatin A ( 2 ) and fornicatin B ( 3 ), among other constituents. The structure of 1 was elucidated by means of spectroscopic techniques, and those of 2 and 3 were identified by comparing their spectroscopic data with those reported in the literature. 相似文献
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Jyh‐Horng Wu Yi‐Fu Chang Yu‐Tang Tung Minoru Tsuzuki Akira Izuka Sheng‐Yang Wang Yueh‐Hsiung Kuo 《Helvetica chimica acta》2010,93(4):753-756
Two novel 15(10→1)abeomuurolane sesquiterpenes, cosmosoic acid ( 1 ) and cosmosaldehyde ( 2 ), were isolated from the whole plant of Cosmos sulfurous. Their structures were established by a combination of 1D‐ and 2D‐NMR spectroscopic techniques. Additionally, a chemical correlation between 1 and 2 was also established. 相似文献
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Slobodanka Stankovi Duan Lazar Ljubica Medi‐Mija
evi Katarina Penov‐Gai Marija Saka
Silvana Andri Bruvo Milenko 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(3):o172-o173
The title molecule, C26H30O3, shows a novel chemical rearrangement of the substituents at position 17, i.e. an α‐orientation of the hydroxy group and a β‐orientation of the bulky benzyl moiety. The packing arrangement consists of coils formed by O2?O3 hydrogen bonds along the c axis. The compound shows complete loss of oestrogenic activity, and neither does it exhibit an antagonistic effect. 相似文献