Melek Gul

Evaluation of the Antioxidative Properties of N-Acylamino-Substituted Tricyclic Imides

New N-acylamino-substituted tricyclic imides have been screened for scavenging ability against the free radical 2,2-diphenyl-1-picryl-hydrazyl (DPPH•), chelating activity on ferrous ions, and reductive potential. The results were compared with synthetic antioxidants BHT, BHA, and Trolox. The compounds exhibited different levels of antioxidant activity in all tests.

Heck-type hydroarylations and 1,3-dipolar cycloaddition reactions of new tricyclic hydrazones

The C–C coupling of the new tricyclic hydrazones 3–7 with aryl and heteroaryl halides gave under reductive Heck conditions the tricyclic 1-(arylideneamino)pyrolidine-2,5-diones 8–11a, 9–11b, 10c, a...

Hydroarylation reactions of N -acylaminosubstituted tricyclic imides

The palladium-catalysed hydroarylation of unsaturated N-acylamino-substituted tricyclic imides provided a new stereoselective synthesis of exo-aryl(heteroaryl)-substituted tricyclic N-acylamino imides.

Synthesis of PhTAD-substituted dihydropyrrole derivatives via stereospecific C–H amination

Stereospecific α-amination has been accomplished via addition of N-phenyltriazolinedione (PhTAD) to the allylic position of dihydropyrroles. The aim of this study is to evaluate new PhTAD derivatives of biologically active bicyclic dihydropyrroles. Ene reaction was accomplished via addition of PhTAD to the allylic position to react with syn and anti diastereomers for α-amination. The α-amination depends on the stereochemistry, proceeding faster with syn than anti diastereoisomers. Steric hindrance from sulfide substituent slows down the transformation. Although the results are in accordance with an ene reaction followed by 1,3-shift of the urazole moiety, deuteration at the allylic position by simply stirring the diastereoisomeric dihydropyrroles in MeOD revealed a [1,3-H] shift. The stereospecificity of the transformation is attributed to steric hindrance during the allylic transposition step.

CCDC 1435966: Experimental Crystal Structure Determination

Related Article: Emel Pelit, Kosmas Oikonomou, Melek Gul, Dimitra Georgiou, Slawomir Szafert, Sotirios Katsamakas, Dimitra Hadjipavlou-Litina, Yiannis Elemes|2017|Comptes Rendus Chimie|20|424|doi:10.1016/j.crci.2016.05.024

Evaluation of phytochemical content, antioxidant, antimicrobial activity and DNA cleavage effect of endemic Linaria corifolia Desf. (Plantaginaceae)

Abstract The aim of this study is to isolate Linaria corifolia Desf. (Plantaginaceae) and identify new apigenine derivatives 6,3′-dimethoxyapigenin-7-O-[(rhamnosyl)-(1–2)-6″-acetyl glucoside]. Moreover, we analyzed biological activity and flavonoids by using HPLC methods from extracts. The L. corifolia Desf. samples were collected in Black Sea Region of Turkey. Ethanol (EtOH), ethyl acetate (EtOAc) and dichloromethane (DCM) extracts in aerial and under solid parts of plant were evaluated for antioxidant, antimicrobial activity and effect of DNA cleavage. Quercetin, gallic acid and catechin as flavonoids were identified in EtOH, EtOAc, DCM extracts.