Synthesis and Antibacterial Activity of Novel Fused 1,3‐Thiazoles and 1,3‐Thiazines Incorporating a 2,4‐Dihydroxyphenyl Residue

Abstract

In an attempt to find a new class of antimicrobial agents, a series of benzothiazoles, 1,3-thiazolo[5,4-b]pyridines, 4H-3,1-benzothiazines, naphtho[2,3-d][1,3]thiazole-4,9-diones and other related compounds containing a 2,4-dihydroxyphenyl moiety were prepared. They were obtained via the reaction of aryl-modified sulfinyl[bis(2,4-dihydroxyphenylmethanethione)]s with appropriate commercial chemical reagents in the endocyclization processes. The MIC values of the compounds towards eight reference bacterial strains were assessed by the two-fold serial micro-dilution broth method. They exhibited inhibitory effects against the Gram-positive strains tested opposite to Gram-negative ones. Some compounds were more effective than the reference drug. 4-(6-Chloro-4H-3,1-benzothiazin-2-yl)-6-methylbenzene-1,3-diol (5b) due to its very good activity (MIC from 1.56 to 3.13 µg/mL) and low cytotoxicity (IC(50) > 50 µg/mL) may be regarded as a promising precursor for the development of novel antibacterial agents.

Synthesis and biological activity of novel benzoazoles, benzoazines and other analogs functionalized by 2,4-dihydroxyphenyl moiety

“…To extend our studies in this area, a set of new heterocyclic analogs with 2,4dihydroxyphenyl functionality were designed and obtained. Following from previous studies, this group of compounds exhibits strong antifungal and antiproliferative activity [34][35][36][37][38][39]. This paper presents the in vitro antifungal potency of compounds against the panel phytopathogenic fungi and Candida strains as well as cytotoxic potency against human cancer cell lines.…”

Spectroscopic studies, Density Functional Theory calculations, and non‐linear optical properties of binuclear Fe(III), Co(II), Ni(II), Cu(II), and Zn(II) complexes of OONN Schiff base ligand

“…[30,32,33] These complexes displaced three bands at 8,064, 17,865, and 31,715 cm −1 assigned to 4 T 1g ! 4 T 2g (F) (ν 1 ) and 4 T 1g ! 4 T 1g (P) (ν 2 ) and 4 T 1g !…”

“…4 T 2g (F) (ν 1 ) and 4 T 1g ! 4 T 1g (P) (ν 2 ) and 4 T 1g ! 3 A 2g (F) (ν 3 ) transitions, respectively, confirming the octahedral geometry.…”

Synthesis, antimicrobial, and antioxidant activities of new pyridyl‐ and thiazolyl‐bearing carbohydrazides

“…Thiazoles are five‐membered heterocyclic compounds bearing sulfur and nitrogen in the ring and plays an essential role in medicinal and pharmaceutical chemistry. Thiazoles are endowed with potential biological activities such as anticancer, antitubercular, α ‐glucosidase inhibitor, antioxidant, antibacterial, antiplatelet, anti‐inflammatory, anti‐Candida activity, and antifungal properties . In addition, thiamine or vitamin B 1 is one of the most important natural thiazoles.…”