Synthesis, Characterization, Antimicrobial and Antioxidant Activities of The Homocyclotrimer Of 4-Oxo-4h-Thieno[3,4-C]Chromene-3-Diazonium Sulfate
Emmanuel Sopbue Fondjo*, a, Djeukoua Dimo Kamal Sorela, Tamokou Jean-de-Dieub, Tsemeugne Josepha, Kouamo Sylviana, Ngouanet Dorianea, Chouna Jean Rodolphea, Nkeng-Efouet-Alango Pepina, Kuiate Jules-Rogerb, Ngongang Ndjintchui Arnaudc, Sondengam Beibam Lucasd
Identifiers and Pagination:Year: 2016
First Page: 21
Last Page: 32
Publisher Id: TOMCJ-10-21
Article History:Received Date: 02/10/2015
Revision Received Date: 09/05/2016
Acceptance Date: 12/5/2016
Electronic publication date: 30/06/2016
Collection year: 2016
open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution-Non-Commercial 4.0 International Public License (CC BY-NC 4.0) (https://creativecommons.org/licenses/by-nc/4.0/legalcode), which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
The in situ formed 4-oxo-4H-thieno[3,4-c]chromene-3-diazonium sulfate (5) in the coupling reactions involving the parent 2-aminothiophene (4) and various phenolic and arylamines’ couplers, readily undergoes homocyclotrimerization at low temperature to afford in fairly good yield the first ever reported eighteen member ring heteroaromatic holigomer 6. Compound 6 was fully characterized by its elemental analysis, IR, UV-Vis, 1H-NMR, 13C-NMR and HRMS spectral data. The HMBC and HSQC techniques were used to ascertain the structural assignments. A comparative study on the antimicrobial and antioxidant activities of compounds 3, 4 and 6 was carried out to assess the SAR due to the transformations (from 3 to 6 via 4) on the tested compounds. It was found that compounds 6 and 4 were respectively the most active compounds against bacteria (MIC = 32-64 μg/ml) and yeasts (MIC = 16–64 μg/ml). Compound 6 also showed high radical-scavenging activities and ferric reducing power when compared with vitamin C and BHT used as reference antioxidants.