Gastroprotective activity and physicochemical analysis of carboxymethylated gum from Anadenanthera colubrina.

Biotechnological advancements require the physicochemical alteration of molecules to enhance their biological efficacy for the effective treatment of gastric ulcers. The study aimed to produce a polyelectrolytic compound from red angico gum (AG) by carboxymethylation, evaluate its physicochemical characteristics and investigate gastric protection against ethanol-induced ulcers. AG and carboxymethylated angico gum (CAG) were characterized by Fourier transform infrared spectroscopy, determination of the degree of substitution and gel permeation chromatography (GPC) and 13C NMR techniques. The results demonstrated that the modification of the polymer was satisfactory, presenting conformational changes e improving the interaction with the gastric mucosa. AG and CAG reduced macroscopic and microscopic damage such as edema, hemorrhage and cell loss caused by exposure of the mucosa to alcohol. Both demonstrated antioxidant activity in vitro, and in vivo, pretreatment with gums led to the restoration of superoxide dismutase and glutathione levels compared to the injured group. Concurrently, the levels of malondialdehyde and nitrite decreased. Atomic force microscopy showed that CAG presented better conformational properties of affinity and protection with the gastric mucosa compared to AG in the acidic pH. Based on our findings, it is suggested that this compound holds promise as a prospective product for future biotechnological applications.

Synthesis and anticancer activities of some novel 2-(benzo[d]thiazol-2-yl)-8-substituted-2H-pyrazolo[4,3-c]quinolin-3(5H)-ones.

A series of 2-(benzo[d]thiazol-2-yl)-8-substituted-2H-pyrazolo[4,3-c]quinolin-3(5H)-ones (3a-g) have been synthesized and evaluated for their in vitro antiproliferative activities against four human cancer cell lines: MDA-MB-435 (breast), HL-60 (leukemia), HCT-8 (colon) and SF-295 (central nervous system). The results showed that the compounds 3b (2-(benzo[d]thiazol-2-yl)-8-methyl-2H-pyrazolo[4,3-c]quinolin-3(5H)-one) and 3c (2-(benzo[d]thiazol-2-yl)-8-bromo-2H-pyrazolo[4,3-c]quinolin-3(5H)-one) exhibited good cytotoxicity for three cell lines with IC(50) values lower than 5 µg/mL. Analysis of theoretical toxicity risks have shown medium tumorigenic and irritant risks related to 3b and 3c in contrast to doxorubicin, the positive control.

Novel platinum(II) complexes of 3-(aminomethyl)naphthoquinone Mannich bases: synthesis, crystal structure and cytotoxic activities.

The first examples of platinum(II) complexes of 3-(aminomethyl)naphthoquinone Mannich bases have been synthesised and their crystal structures are described. Neutral and charged complexes have been obtained, fully characterised and their cytotoxic activities have also been investigated. 3-[(R(1)-amino)(pyridin-2-yl)methyl]-2-hydroxy-1,4-naphthoquinones (R(1) = n-Bu, HL1; Bn, HL2; furfuryl, HL3; n-heptyl, HL4 and n-decyl, HL5) coordinate to platinum(II) through the two nitrogen atoms. The neutral complexes cis-[Pt(HL)Cl(2)] 1a-5a are analogous to cisplatin with the bidentate ligand HL and two chlorine atoms occupying cis positions. In the charged complexes cis-[Pt(L(-))(NH(3))(2)]NO(3)1b-5b the deprotonated form of the ligand L(-) also coordinates via the nitrogen atoms, and the other two positions around the platinum(II) ion are completed with NH(3) ligands. The cytotoxic activities of all compounds have been tested for six different cancer cell lines: MDA-MB-435 (melanoma), HL-60 (promyelocytic leukaemia), HCT-8 (colon), SF-295 (brain), OVCAR-8 (ovary) and PC-3 (prostate). Proligands HL4 and HL5 have exhibited high activity against HL-60 (IC(50) = 1.9 and 3.8 µmol L(-1), respectively), HCT-8 (IC(50) = 1.6 and 1.7 µmol L(-1), respectively) and SF-295 (IC(50) = 1.1 and 1.7 µmol L(-1), respectively). The chlorido complexes 1a-5a have shown high to moderate cytotoxic activities, complex 4a (R(1) = n-heptyl) being more active than proligand HL4 against melanoma (IC(50) = 6.4 and > 40 µmol L(-1), respectively) and more active than cisplatin against all tested cell lines. Among the amine charged complexes only 4b and 5b have exhibited significant cytotoxic activity against the tested cell lines, although they were only moderately active against the PC-3 cell line (IC(50) = 29.9 and 15.6 µmol L(-1), respectively). In general the compounds with the longest carbon chains (R(1) = n-heptyl and n-decyl) have exhibited the highest activities.