Synthesis and biological activity of new 2-amino-8-chloro-5,5-dioxo[1,2,4]triazolo[2,3-b][1,4,2]benzodithiazines

Application of tris-(4,7-Diphenyl-1,10 phenanthroline)ruthenium(II) Dichloride to Detection of Microorganisms in Pharmaceutical Products

tris-[(4,7-diphenyl-1,10-phenanthroline)ruthenium(II)] dichloride (Ru(DPP)₃Cl₂), a fluorescent sensor which is sensitive to the amount of oxygen in the sample, was applied using the fluorescent optical respirometry (FOR) technique. The oxygen in the samples quenches the fluorescence. The fluorescence intensity depends on the metabolic rate of the viable microorganisms. The effect of DMSO and plant extracts on bacteria was determined by FOR. It was shown that the MIC values obtained by FOR were consistent with the results of the MIC determinations using the method of serial dilutions; at the same time, the effects of concentrations lower than the growth-inhibitory concentrations on microbial cells were demonstrated. The FOR method enables the detection of multiplying bacteria in sterile and non-sterile pharmaceutical preparations in real time, which significantly shortens the time required to obtain results and allows the introduction of repair processes in the production. This method also allows for quick, unambiguous detection and the counting of the viable cells of aerobic microorganisms in non-sterile pharmaceuticals.

Synthesis, cytotoxicity testing, and structure-activity relationships of novel 6-chloro-7-(4-phenylimino-4H-3,1-benzoxazin-2-yl)-3-(substituted)-1,4,2-benzodithiazine 1,1-dioxides

A new series of 16 6-chloro-1,1-dioxo-7-{4-[(4-R(1)-phenyl)imino]-4H-3,1-benzoxazin-2-yl}-3-(substituted amino)-1,4,2-benzodithiazines 7-22 was prepared in order to evaluate the cytotoxic activity against six human cancer cell lines. The structures of the new compounds were confirmed by IR, (1)H-, and (13)C-NMR, elemental analysis and in the cases of 11 and 31 by X-ray crystal structure analysis. This analysis showed that contrary to our earlier report the structures contain a benzoxazine ring instead of the proposed quinazolinone ring. The bioassay indicated that the benzodithiazine derivatives 7-22 possess cancer cell growth-inhibitory properties. Some compounds showed a high level of selectivity for certain cell lines. The most active compounds 11, 12, 16, 19, 21, and 22 exhibited potency higher or comparable to cisplatin. The compounds were particularly effective in LCLC-103H and MCF-7 cell lines with IC(50) values of 0.49-1.60 µM. Quantitative structure activity relationships (QSAR) revealed that a chloro substituent R(1) in the phenyl ring as well as the shape of the substituted amino group at R(2) (e.g., unsaturation is beneficial) are important for potency.

Synthesis and biological evaluation of mercapto triazolo-benzothiadiazine linked aminobenzothiazoles as potential anticancer agents

The synthesis of a series of 10-substituted 5,5-dioxo-5,10-dihydro[1,2,4]triazolo[4,3-b][1,2,4]benzothiadiazine coupled with sulfanylacetamido benzothiazole pharmacophores (5a-g) is described. All the synthesized compounds have been evaluated for their anticancer activity. Most of the compounds showed significant growth inhibitory activity against selected human tumor cell lines. Interestinlgy, one of the synthesized compounds 5d, exhibited GI(50) values of 1.4 and 2.1 microM against RPMI-8226 (leukemia) and HOP-62 (lungs) cell lines, respectively.

Synthesis of novel 3-amino-2-(4-chloro-2-mercaptobenzenesulfonyl)-guanidine derivatives as potential antitumor agents

Novel 3-amino-2-(4-chloro-2-mercaptobenzenesulfonyl)guanidine derivatives have been synthesized as potential anticancer agents. The in vitro antitumor activity of these compounds has been evaluated in the US National Cancer Institute (NCI), and relationships between structure and antitumor activity are discussed. The prominent compound was 1-allyl-2-[4-chloro-5-(4-chlorophenylcarbamoyl)-2-methylthiobenzenesulfonyl]-3-(5-nitrofurfurylideneamino)guanidine (8) with remarkable activity against 21 human tumor cell lines representing leukemia, lung, colon, melanoma, ovarian, renal, prostate and breast (GI(50)=0.3-3.0microM), and selectivity toward leukemia RPMI-8226 cell line (GI(50)=0.3microM, TGI=1.4microM).

Synthesis, structural characterization, and in vitro antitumor activity of novel N-(6-chloro-1,1-dioxo-1,4,2-benzodithiazin-3-yl)arylsulfonamides

A new series of N-(6-chloro-1,1-dioxo-1,4,2-benzodithiazin-3-yl)arylsulfonamides 23-48 have been synthesized as potential anticancer agents. All compounds were screened for their cytotoxic activity against six human tumor cell lines. The selected compounds 23-27, 30, 31, 33, 35, 38, 42, 45, and 46 were further tested at the US National Cancer Institute for their in vitro activities against a panel of 53-59 human tumor cell lines. The compounds 23-26, 30, 31, 33, 38, 42, 45, and 46 showed 50% growth inhibitory activity in low micromolar concentration (GI(50)=0.03-4.9 microM) against one or more human tumor cell lines (Table 3). The prominent compound with remarkable activity (GI(50)=0.03 microM, TGI=1.3 microM) and selectivity toward melanoma UACC-257 cell line was N-(6-chloro-7-cyano-1,1-dioxo-1,4,2-benzodithiazin-3-yl)-N-(phenyl)-5-bromothiophene-2-sulfonamide 46.