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排序方式: 共有785条查询结果,搜索用时 15 毫秒
1.
Ehsan Ullah Mughal Amina Sadiq Shahzad Murtaza Hummera Rafique Muhammad Naveed Zafar Tauqeer Riaz Bilal Ahmad Khan Abdul Hameed Khalid Mohammed Khan 《Bioorganic & medicinal chemistry》2017,25(1):100-106
The present study describes efficient and facile syntheses of varyingly substituted 3-thioaurones from the corresponding 3-oxoaurones using Lawesson’s reagent and phosphorous pentasulfide. In comparison, the latter methodology was proved more convenient, giving higher yields and required short and simple methodology. The structures of synthetic compounds were unambiguously elucidated by IR, MS and NMR spectroscopy. All synthetic compounds were screened for their inhibitory potential against in vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. Molecular docking studies were also performed in order to examine their binding interactions with AChE and BChE human proteins. Both studies revealed that some of these compounds were found to be good inhibitors against AChE and BChE. 相似文献
2.
Comparison of Chemical Composition in Tuber aestivum Vittad. of Different Geographical Origin 下载免费PDF全文
Dorota Hilszczańska Marta Siebyła Jakub Horak Marek Król Piotr Podsadni Piotr Steckiewicz Magdalena Bamburowicz‐Klimkowska Mirosław Szutowski Jadwiga Turło 《化学与生物多样性》2016,13(12):1617-1629
Truffles are prized and nutrition‐rich edible hypogeous fungi. The aim of this study was a comprehensive investigation of chemical composition of Burgundy truffle (Tuber aestivum Vittad .). We tried to answer the question: what is the impact of the environment on the truffle quality. To know the nutritional value of Burgundy truffle we compared lipids, proteins, saccharides, polyphenolics, flavonoids, total sterols, ergosterol, volatile flavour and aroma compounds content in fruit bodies of the fungus collected in three different geographical regions, i.e., Poland, Slovakia, and Italy. A comparison of the above mentioned compounds is especially interesting due to environmental and climatic differences among the studied geographical regions. Results revealed that fruit bodies of T. aestivum from Poland and Slovakia possessed nearly similar content of proteins, total sterols, and saccharides. The fruiting bodies from Italy contained significantly larger amounts of most of the investigated compounds. In turn, Polish specimens had higher content of lipids and polyphenolics than Slovak and Italian ones. We have found higher similarity of volatile compounds composition between Polish and Italian specimens than those of Polish and Slovak origin. 相似文献
3.
The genera Leontodon s.str. and Hedypnois are so far the only known sources of hydroxyhypocretenolides, a rare subclass of guaianolide type sesquiterpene lactones. In this study the three endemic species from the Azorean Archipelago, L. filii, L. hochstetteri, and L. rigens, were analyzed together with L. hispidus and L. × grassiorum, a hybrid originating from L. hispidus and L. hochstetteri. Flowering heads were analyzed by UHPLC-DAD-MS with regards to their phenolics' profiles, establishing qualitatively identical profiles for all taxa. The following phenolics were detected in flowering heads of all investigated taxa: caffeoyltartaric acid, cichoric acid, chlorogenic acid, 3,5-di-O-caffeoylquinic acid, luteolin, luteolin 7-O-β-d-glucopyranoside, luteolin 4′-O-β-d-glucopyranoside, and luteolin 7-O-β-d-glucuronide.In UHPLC-DAD-MS analyses of the rhizomes, no flavonoids were detected. In rhizomes, caffeoyltartaric acid was only detected in L. hispidus. However, in addition to caffeoylquinic acid derivatives already found in the flowering heads, 1,5-di-O-caffeoylquinic acid, 3,4-di-O-caffeoylquinic acid, and 4,5-di-O-caffeoylquinic acid were detected in rhizomes of all investigated taxa.The chemophenetically most interesting group of hydroxyhypocretenolides was detected in rhizomes of all investigated taxa. 11,13β-Dihydro-14-dihydroxyhypocretenolide was detected in L. filii and L. hochstetteri, while 11,13β-dihydro-14-hydroxyhypocretenolide-β-d-glucopyranoside was present in all Azorean taxa. 1,10-Epoxy-14-hydroxyhypocretenolide-β-d-glucopyranoside and 1,10-epoxy-14-hydroxyhypocretenolide-β-d-glucopyranoside-6′-O-p-hydroxyphenylacetic acid ester were restricted to the Azorean taxa and the hybrid L. × grassiorum, while the dimeric sesquiterpenoid 14-hydroxyhypocretenolide-β-d-glucopyranoside-4′,14″-hydroxyhypocretenoate ester was restricted to L. hispidus and L. × grassiorum. 相似文献
4.
Sayan Chowdhury Rupkatha Mukhopadhyay Sourav Saha Amartya Mishra Souvik Sengupta Syamal Roy Hemanta K. Majumder 《The Journal of biological chemistry》2014,289(23):16129-16147
In parasites, ATP-binding cassette (ABC) transporters represent an important family of proteins related to drug resistance and other biological activities. Resistance of leishmanial parasites to therapeutic drugs continues to escalate in developing countries, and in many instances, it is due to overexpressed ABC efflux pumps. Progressively adapted baicalein (BLN)-resistant parasites (pB25R) show overexpression of a novel ABC transporter, which was classified as ABCC2 or Leishmania donovani multidrug resistance protein 2 (LdMRP2). The protein is primarily localized in the flagellar pocket region and in internal vesicles. Overexpressed LdABCC2 confers substantial BLN resistance to the parasites by rapid drug efflux. The BLN-resistant promastigotes when transformed into amastigotes in macrophage cells cannot be cured by treatment of macrophages with BLN. Amastigote resistance is concomitant with the overexpression of macrophage MRP2 transporter. Reporter analysis and site-directed mutagenesis assays demonstrated that antioxidant response element 1 is activated upon infection. The expression of this phase II detoxifying gene is regulated by NFE2-related factor 2 (Nrf2)-mediated antioxidant response element activation. In view of the fact that the signaling pathway of phosphoinositol 3-kinase controls microfilament rearrangement and translocation of actin-associated proteins, the current study correlates with the intricate pathway of phosphoinositol 3-kinase-mediated nuclear translocation of Nrf2, which activates MRP2 expression in macrophages upon infection by the parasites. In contrast, phalloidin, an agent that prevents depolymerization of actin filaments, inhibits Nrf2 translocation and Mrp2 gene activation by pB25R infection. Taken together, these results provide insight into the mechanisms by which resistant clinical isolates of L. donovani induce intracellular events relevant to drug resistance. 相似文献
5.
Kazuo Ishii Takashi Furuta Yasuji Kasuya 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1996,683(2):225
An HPLC method for determining a flavonoid, naringin, and its metabolite, naringenin, in human plasma is presented for application to the pharmacokinetic study of naringin. Isocratic reversed-phase HPLC was employed for the quantitative analysis by using genistin (for naringin) or daidzein (for naringenin) as an internal standard and solid-phase extraction using a Sep-Pak t C18 cartridge. For the determination, HPLC was carried out using an Inertsil ODS-2 column (250x4.6 m I.D., 5 μm particle size). The mobile phases were acetonitrile-0.1 M ammonium acetate solution (20:80, v/v; pH 7.1) for naringin and acetonitrile-0.1 M ammonium acetate solution-acetic acid (30:69:1, v/v; pH 4.9) for naringenin. The flow-rate was 1 ml min−1. The analyses were performed by monitoring the wavelength of maximum UV absorbance at 280 nm for naringin and at 292 nm for naringenin. The detection limits on-column were about 0.2 ng for the two flavonoids. 相似文献
6.
This work describes the isolation of seven (1–7) secondary metabolites from Espeletia barclayana (Asteraceae, Espeletiinae) and their identification by spectroscopic (NMR) and spectrometric (MS) techniques. Ten (8–17) additional compounds were identified based on their retention times, high-resolution mass spectrometry data, and comparison with reference substances or data from literature. The systematic significance of some of the identified substances – the sesquiterpene lactone longipilin acetate, four caffeoylquinic acids and two tri-caffeoylaltraric acids – is discussed with the aim of providing insights into the complex relationships among Espeletiinae taxa and its closest relatives. Five of the isolated metabolites [5-O-(E)-caffeoylquinic acid (1), 1,3-di-O-(E)-caffeoylquinic acid (2), 1,5-di-O-(E)-caffeoylquinic acid (3), 3,4-di-O-(E)-caffeoylquinic acid (4) and 3-O-methylquercetin 7-O-β-glucopyranoside (7)] constitute new reports for the genus Espeletia and for the subtribe Espeletiinae. Chemical data suggest that Espeletiinae might have a closer relationship with Smallanthus than with Ichthyothere, i.e., the two genera suggested to be the sister groups of Espeletiinae based on molecular markers. 相似文献
7.
Species in the genera Gomphostemma, Chelonopsis and Bostrychanthera were systematically studied with reference to their flavonoid and phenolic acid compounds in order to investigate whether the profiles of these compounds would support a classification of the genus and related genera based on morphological characters. Thirty-five flavonoid glycosides, eight phenolic acids and derivatives were identified by LC-UV-MS/MS analysis of aqueous 80% MeOH extracts on the basis of their UV and mass spectra, retention times and comparison with in-house library. The occurrence of individual compounds was not particularly informative in Gomphostemma, although the overall chemical profile supported G. subgen. Pogosiphon and vicenin-2 was a characteristic component of Gomphostemma leptodon and Gomphostemma curtisii. In contrast, the flavonoids and phenolic acids of Chelonopsis were informative at infrageneric level. Glycosides of 6-substituted flavones were well represented in Ch. subgen. Aequidens, including Ch. forrestii, Ch. rosea, Ch. odontochila, Ch. lichiangensis and C. giraldii. A dicaffeoylquinic acid was produced in Ch. subgen. Chelonopsis, (for example, in Ch. longipes and Ch. Moschata), but absent from Ch. subgen. Aequidens. The same dicaffeoylquinic acid was also found in the genus Bostrychanthera and suggests a close relationship with Ch. subgen. Chelonopsis, in agreement with a recent DNA based phylogeny. There is correlation between trichome type and phenolic acid compound distribution in Chelonopsis, but this is not observed in Gomphostemma. 相似文献
8.
Eight compounds exuded from young roots of black locust (Robinia pseudoacacia) were separated by two-dimensional HPTLC, by HPLC and GC, and were identified by spectroscopic methods (ultraviolet/visible
spectroscopy and mass spectrometry) as 4′,7-dihydroxyflavone, apigenin, naringenin, chrysoeriol and isoliquiritigenin. Structural
assignments were confirmed by comparison with authentic standards. The capacity to induce β-galactosidase activity in Rhizobium sp. NGR234 containing a nod box::lacZ fusion on plasmid pA27 identified these flavonoids and the chalcone as nod gene inducers. This indicates the important role of these compounds in nodulation of this legume tree.
Received: 26 July 1996 / Accepted: 9 September 1996 相似文献
9.
The order Brassicales, sensu APG III, belongs to Eurosids, and comprises 17 families and 398 genera. The present work discusses the chemical features of Brassicales through the micromolecular chemical data of its taxa and selected taxonomic markers to assess pertinent affinities between its families by correlating their chemosystematic parameters. Although the chemical data of all families were obtained, the data of Brassicaceae, Capparaceae, and Cleomaceae were the most studied. The chemistry of the Brassicales species is diverse, but it reveals the chemical affinity of its families due to occurrence of flavonoids (35%) and glucosinolates (25%), which were characterized as good chemical markers. The flavonoids consist primarily of flavones and flavonols, presenting a low flavone/flavonol ratio. These micromolecules commonly contain unprotected hydroxyls, which are mainly protected by glucosilation, revealing the basal features of its taxa. In Brassicales, the predominantly allyl glucosinolates are usually found in Brassicaceae, Capparaceae, and Cleomaceae families. In the present study, the results of the chemosystematic analysis confirmed the affinity among the Brassicaceae, Capparaceae, and Cleomaceae families, and supported the concept of their monophyly in the Brassicales order. However, more chemical data of the other families is required to improve the chemosystematic conclusions. 相似文献
10.
Yaping Huang Geng Sun Pengfei Wang Rui Shi Yanchun Zhang Xiaoan Wen Hongbin Sun Caiping Chen 《Bioorganic & medicinal chemistry letters》2018,28(17):2957-2960
In this study, Complex I inhibitor R419 was firstly revealed to have significant anticancer activity against HepG2 cells (IC50?=?5.2?±?0.9?μM). Based on this finding, a series of R419 derivatives were synthesized and biologically evaluated. As results, 9 derivatives were found to have obvious anticancer activity. Among them, H20 exhibited the most potent activity (IC50?=?2.8?±?0.4?μM). Mechanism study revealed that H20 caused severe depletion of cellular ATP, dose-dependently activated AMPK, decreased Bcl-2/Bax ratio and induced necrotic cell death. Most importantly, H20 displayed definite inhibitory activity against Complex I. 相似文献