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The isolation and identification of a new glycoside, eriodictyol 5-O-methyl ether 7-O-β-D-xylopyranosyl-β-D-arabinopyranoside, from seeds of Sapium sebiferum is reported.  相似文献   

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Two new acylated flavanone glycosides have been isolated from Nierembergia hippomanica and identified by spectral data as pinocembrin 7-O-β-(3?-O-acetyl)neohesperidoside and pinocembrin 7-O-β-(6″-O-acetyl)neohesperidoside.  相似文献   

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Enhanced shoot growth and a decrease in flavonoid concentration in apple trees grown under high nitrogen (N) supply was observed in previous studies, along with increasing scab susceptibility of cultivar "Golden Delicious" after high N nutrition. Several hypotheses have suggested that there is a trade-off between primary and secondary metabolism because of competition for common substrates, but nothing is known about regulation at the enzyme level. In this study, a set of experiments was performed to elucidate the effect of N nutrition on the activities of key enzymes involved in flavonoid biosynthesis (phenylalanine ammonia-lyase [PAL], chalcone synthase/chalcone isomerase [CHS/CHI}, flavanone 3-hydroxylase [FHT], flavonol synthase [FLS], dihydroflavonol 4-reductase [DFR]) and the accumulation of different groups of phenylpropanoids. The inhibition of flavonoid accumulation by high N nutrition could be confirmed, but the influence of N supply on the flavonoid enzymes CHS/CHI, FHT, DFR, and FLS was not evident. However, PAL activity seems to be downregulated, thus forming a bottleneck resulting in a generally decreased flavonoid accumulation. Furthermore, the response of the scab-resistant cultivar "Rewena" to high N nutrition was not as strong as that of the susceptible cultivar "Golden Delicious".  相似文献   

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The isolation of a new prenylated flavanone, erythrisenegalone, from the stem-bark of Erythrina senegalensis is described. Its structure was established by spectroscopic methods and a few chemical transformations.  相似文献   

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A new flavanone glycoside was isolated from the aerial parts of Nierembergia hippomanica and identified as the 4?-acetate of pinocembrin 7-neohesperidoside.  相似文献   

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In dependence on endurance, the reaction of chalcones with thiosemicarbazide resulted in chalcone or flavanone thiosemicarbazones, whose structures were proven by 1H NMR.  相似文献   

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An isomerization of 2"-hydroxychalcones into the corresponding flavanones in ethanol in the presence of triethylamine is described.  相似文献   

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A diprenylated chromenoflavanone has been characterized from the root bark of Amorpha fruticosa.  相似文献   

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Isosakuranetin and a new chalcone, odoratin, have been isolated from the leaves of Eupatorium odoratum. The structure of odoratin has been shown to be 2′-hydroxy-4,4′,5′,6′-tetramethoxy chalcone.  相似文献   

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Two new flavonoid glycosides, naringenin 7-galactosyl(1 → 4)glucoside and dihydroquercetin 5- galactoside, have been characterized from stem tissue of Dillenia pentagyna. Rhamnetin 3-glucoside was also isolated.  相似文献   

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This study investigated the protective potential of Naringin (NIN) against cadmium chloride (CdCl2) mediated hepatotoxicity using human hepatocellular carcinoma (HepG2) cells. An optimal concentration of NIN (5 μM) was potent enough to confer cytoprotection against CdCl2 (50 μM) as was observed by MTT assay. Preconditioning with NIN maintained redox homeostasis, mitochondrial membrane potential, and reduced apoptosis as marked by decrease in the percentage sub‐G0/G1 and Annexin V‐FITC/propidium iodide positive cells (apoptotic). NIN pretreatment maintained the levels of protein thiol along with endogenous activities of Superoxide dismutase, Glutathione S‐transferase, and Catalase and lowered lipid peroxidation. Decreased Bax/Bcl2 ratio along with reduced Caspase 3 cleavage and Cytochrome c release indicated that NIN conditioning blocked mitochondrial‐mediated apoptosis. Increased Nrf2 and metallothionein (MT) acted as adaptive response in the presence of cadmium. Thus, the protective mechanism of NIN is attributed to its antioxidant potential which aids in redox homeostasis and prevents CdCl2 mediated cytotoxicity.  相似文献   

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2′,6′-Dihydroxy-4′-methoxy-3′-methylchalcone has been isolated from the exudate farina of the ceroptin chemotype of Pityrogramma triangularis. The analogous flavanone was also detected as a minor component in the extract.  相似文献   

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该研究以自育茶菊品种‘14-C-1’为材料,克隆了一个黄烷酮3-羟化酶(F3H)基因,命名为CmF3H.生物信息学分析表明,‘14-C-1’CmF3H的cDNA序列(GenBank登录号MW454869)全长为1284 bp,开放阅读框为1095 bp,编码364个氨基酸,编码蛋白的理论分子量为41.19kD,等电点为...  相似文献   

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In our ongoing investigation of the bioactive compounds from the extract of the roots of Sophora flavescens, two novel prenylated flavanones, named sophoflavanones A (1) and B (2), each with an unusual pyran ring were isolated. Their structures, as well as their absolute configurations, were elucidated based on spectroscopic data including a comparison of their experimental and calculated electronic circular dichroism (ECD) spectra. Additionally, compounds 1 and 2 showed moderate antioxidant activities against Fe2+/cysteine-induced toxicity at a concentration of 0.1 µM (inhibition values of 71.65% and 72.49%, respectively, using vitamin C as a positive control (87.83%)).  相似文献   

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