- Condensation of salicylaldehydes with ethyl 4,4,4-trichloro-3-oxobutanoate: A facile approach for the synthesis of substituted 2H-chromene-3-carboxylates
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A highly efficient and simple protocol has been developed for the preparation of ethyl 2-oxo-2H-chromene-3-carboxylates 3a-v by the condensation of salicylaldehydes 1a-v with ethyl 4,4,4-trichloro-3-oxobutanoate 2 for the first time. The reaction is proceeding via Knoevenagel pathway followed by a selective addition of the phenolic hydroxyl group to the carbonyl group adjacent to the CCl3 group rather than ester carbonyl due to a strong electron withdrawing effect and produced coumarin derivative 3a with the elimination of CHCl3.
- Sairam, Mudulkar,Saidachary, Gannerla,Raju, Bhimapaka China
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supporting information
p. 1338 - 1343
(2015/03/04)
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- Synthesis and biological evaluation of (6- and 7-Phenyl) coumarin derivatives as selective nonsteroidal inhibitors of 17β-hydroxysteroid dehydrogenase type 1
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17β-Hydroxysteroid dehydrogenase type 1 (17β-HSD1) is an enzyme that catalyzes NADPH-dependent reduction of the weak estrogen, estrone, into the most potent estrogen, estradiol, which exerts proliferative effects via the estrogen receptors. Overexpression of 17β-HSD1 in estrogen-responsive tissues is related to the development of hormone-dependent diseases, such as breast cancer and endometriosis; thus, 17β-HSD1 represents an attractive target for the development of new therapies. We have discovered that simple coumarines 1 and 2 significantly inhibit 17β-HSD1 in a recombinant enzyme assay, with high selectivity against 17β-HSD2. We postulated that the introduction of various p-substituted phenyl moieties to position 6 or 7 of the coumarin core using the Suzuki-Miyaura cross-coupling reaction would provide mimetics of steroidal structures with improved inhibition of 17β-HSD1. The best inhibitor in the series proved to be 6a, with an IC50 of 270 nM, and with exceptional selectivity for 17β-HSD1 over 17β-HSD2 and against the α and β estrogen receptors.
- Star?evi?, ?tefan,Bro?i?, Petra,Turk, Samo,Cesar, Jo?ko,Lani?nik Ri?ner, Tea,Gobec, Stanislav
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p. 248 - 261
(2011/03/22)
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- α-Glucosidase inhibitory antihyperglycemic activity of substituted chromenone derivatives
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Series of 3,4- and 3,6-disubstituted chromenones including new chromenone derivatives were synthesized applying various synthetic strategies including Pechmann condensation, Knoevenagel condensation, Reimer-Tiemann reaction and Suzuki coupling in very good yields. Synthesized compounds (4a-z) were screened for in vitro α-glucosidase inhibitory and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activities. Majority of compounds displayed varying degrees of α-glucosidase inhibitory and DPPH scavenging activity. Compound 4x emerged as the most potent α-glucosidase inhibitor in present series of compounds owing to the presence of 3-acetyl-6-(6-methoxy-3-pyridyl) group on chromenone; however, it could not display DPPH scavenging activity and was found to be mixed non-competitive type inhibitor of rat intestinal α-glucosidase. When tested in vivo for antihyperglycemic activity in starch loaded Wistar rats, it displayed significant antihyperglycemic property. This is the first report assigning rat intestinal α-glucosidase inhibitory property for this class of new chromenones and presents new family of compounds possessing α-glucosidase inhibitory activities and antihyperglycemic property. Compound 4x may serve as an interesting new compound for the development of therapeutics targeted against diet-induced hyperglycemia in diabetes.
- Raju, B. China,Tiwari, Ashok K.,Kumar, J. Ashok,Ali, A. Zehra,Agawane, Sachin B.,Saidachary,Madhusudana
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experimental part
p. 358 - 365
(2010/04/02)
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