178804-07-4

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• 92-36-4 2-(4-aminophenyl)-6-methyl-1,3-benzothiazole 

Relevant academic research and scientific papers

Syntheses and DNA-binding studies of a series of unsymmetrical cyanine dyes: Structural influence on the degree of minor groove binding to natural DNA

Twelve crescent-shaped unsymmetrical dyes have been synthesized and their interactions with DNA have been investigated by spectroscopic methods. A new facile synthetic route to this type of cyanine dyes has been developed, involving the preparation of 6-substituted 2-thiomethyl-benzothiazoles in good yields. The new dyes are analogues to the minor groove binding unsymmetrical cyanine dye, BEBO, recently reported by us. In this dye, the structure of the known intercalating cyanine dye BO was extended with a 6-methylbenzothiazole substituent. Herein we further investigate the role of the extending benzazole heterocycle, as well as of the pyridine or quinoline moiety of the cyanine chromophore, for the binding mode of these crescent-shaped dyes to calf thymus DNA. Flow LD and CD studies of the 12 dyes show that the extent of minor groove binding to mixed sequence DNA varies significantly between the dyes. We find that hydrophobicity and size are the crucial parameters for recognition of the minor groove. The relatively high fluorescence quantum yield of many of these cyanines bound to DNA, combined with their absorption at long wavelengths, may render them useful in biological applications. In particular, two of the benzoxazole containing dyes BOXTO and 2-BOXTO show a high degree of minor groove binding and quantum yields of 0.52 and 0.32, respectively, when bound to DNA.

2-arylbenzazole compounds

There are disclosed herein 2-phenylbenzazole compounds having a 3'-substituent and a 4'-NR2R6 substituent in the phenyl group where R5 and R6 are each hydrogen or alkyl, or where the $'-NR5R6 substituent is N-acyl (or N-benzoyl). There are also disclosed

Antitumor benzothiazoles. 3. Synthesis of 2-(4- aminophenyl)benzothiazoles and evaluation of their activities against breast cancer cell lines in vitro and in vivo

A new series of 2-(4-aminophenyl)benzothiazoles substituted in the phenyl ring and benzothiazole moiety has been synthesized by simple, high- yielding routes. The parent molecule 5a shows potent inhibitory activity in vitro in the nanomolar range against a panel of human breast cancer cell lines, but is inactive (IC50 > 30 μM) against other cell types: activity against the sensitive breast lines MCF-7 and MDA 468 is characterized by a biphasic dose-response relationship. Structure-activity relationships derived using these cell types has revealed that activity follows the heterocyclic sequence benzothiazole > benzoxazole >> benzimidazole and that 2-(4-aminophenyl)benzothiazoles bearing a 3'-methyl- 9a, 3'-bromo- 9c, 3'- iodo- 9f, and 3'-chloro-substituent 9i are especially potent and their activity extends to ovarian, lung, and renal cell lines. Four compounds have been evaluated in vivo against human mammary carcinoma models in nude mice. Compound 9a showed the most potent growth inhibition against the ER+ (MCF- 7 and BO) and ER- (MT-1 and MT-3) tumors. Our efforts to identify a pharmacological mechanism of action for these intriguing compounds have not, as yet, been successful.