Microwave assisted solvent-free mannich bases: synthesis, characterization and effects of these compounds on HCA I and HCA II isozymes

Mannich bases (2a–d) of aromatic amines were synthesized by using a conventional microwave technique under solvent-free conditions and characterized by IR and NMR (1H and 13C) and elemental analysis. The inhibitory effects of the synthesized Mannich bases were examined in vitro by using hydratase and esterase assays on carbonic anhydrase I and II isozymes (hCA, EC 4.2.1.1) purified from human erythrocyte cells. Acetazolamide was used as the control compound. The values of IC50, the half-maximum inhibitory concentration, were found for hydratase and esterase activities. Only two compounds (2b and 2d) exhibited poor hCA I and hCA II inhibition effects on esterase activity. In contrast, compounds 2a and 2c could be used as carbonic anhydrase activators as a result of the increased esterase activity of hCA I and hCA II isozymes.

Zymography for Picogram Detection of Lipase and Esterase Activities

Lipases and esterases are important catalysts with wide varieties of industrial applications. Although many methods have been established for detecting their activities, a simple and sensitive approach for picogram detection of lipolytic enzyme quantity is still highly desirable. Here we report a lipase detection assay which is 1000-fold more sensitive than previously reported methods. Our assay enables the detection of as low as 5 pg and 180 pg of lipolytic activity by direct spotting and zymography, respectively. Furthermore, we demonstrated that the detection sensitivity was adjustable by varying the buffering capacity, which allows for screening of both high and low abundance lipolytic enzymes. Coupled with liquid chromatography-mass spectrometry, our method provides a useful tool for sensitive detection and identification of lipolytic enzymes.

Phenolic Profile of Nipa Palm Vinegar and Evaluation of Its Antilipidemic Activities

Obesity and overweight are strongly associated with dyslipidemia which can promote the development of cardiovascular diseases. Recently, natural products have been suggested as alternative compounds for antioxidant and antilipidemic activity. The objective of this study was to determine the phenolic compounds and assess the inhibitory activities on pancreatic lipase, cholesterol esterase, and cholesterol micellization of nipa palm vinegar (NPV). Total phenolic content was assessed and phenolic compounds were determined using the Folin–Ciocalteu assay and liquid chromatography-mass spectrometry (LC-MS), respectively. Pancreatic lipase and cholesterol esterase inhibitory activities of the NPV were measured using enzymatic colorimetric assays. The formation of cholesterol micelles was assessed using a cholesterol assay kit. The phenolic content of NPV was 167.10 ± 10.15 µg GAE/mL, and LC-MS analyses indicated the presence of gallic acid, isoquercetin, quercetin, catechin, and rutin as bioactive compounds. Additionally, the NPV inhibited pancreatic lipase and cholesterol esterase activities in a concentration-dependent manner. Moreover, the NPV also suppressed the formation of cholesterol micellization. These results suggest that phenolic compounds, especially gallic acid, isoquercetin, quercetin, catechin, and rutin, from NPV may be the main active compounds with possible cholesterol-lowering effects through inhibition of pancreatic lipase and cholesterol esterase activities as well as the inhibition of solubility of cholesterol micelles. Therefore, NPV may delay postprandial dyslipidemia, and it could be used as a natural source of bioactive compounds with antilipidemic activity. However, NPV should be extensively evaluated by animal and clinical human studies.

Biofilm formation of Candida Spp. isolated from the vagina and antibiofilm activities of lactic acid bacteria on the these Candida Isolates

Background: In this study, it was aimed to investigate the effects of bacterial cells and cell-free filtrates of Lactobacillus acidophilus 8MR7 and Lactobacillus paracasei subspecies paracasei 10MR8 on the biofilm formation of 3 Candida tropicalis, 3 C. glabrata and 12 C. albicans isolated from the vagina and identified their virulence factors. Methods: Haemolytic activities esterase activities, and phospholipase activities as virulence factors of Candida strains were determined. Biofilm formations of these isolates were determined by Congo Red agar and microtitration plate method. Anti-biofilm activities of bacterial cells and cell-free filtrates of L. acidophilus 8MR7 and L. paracasei subspecies paracasei 10MR8 on Candida isolates were determined by the microtitration plate method. Results: Bacterial cells of L. acidophilus 8MR7 and L. paracasei subspecies paracasei 10MR8 were not very effective in the in- hibition of biofilm, whereas it has been observed that the cell-free filtrates of these bacteria inhibit the formation of biofilms of Candida strains. Although the main mechanism for inhibiting the formation of Candida spp. biofilm is the competition for adhesion, it is concluded that the substances contained in the cell-free filtrates of lactic acid bacteria are also important. Conclusion: These isolates promise hope as potential bacteria that can be used for anti-adhesion purposes in health-care materials. Keywords: Lactobacillus acidophilus; L. paracesei subspecies paracesei; vagina; biofilm.

O-acetylated Gangliosides as Targets for Cancer Immunotherapy

O-acetylation of sialic acid residues is one of the main modifications of gangliosides, and modulates ganglioside functions. O-acetylation of gangliosides is dependent on sialyl-O-acetyltransferases and sialyl-O-acetyl-esterase activities. CAS1 Domain-Containing Protein 1 (CASD1) is the only human sialyl-O-acetyltransferases (SOAT) described until now. O-acetylated ganglioside species are mainly expressed during embryonic development and in the central nervous system in healthy adults, but are re-expressed during cancer development and are considered as markers of cancers of neuroectodermal origin. However, the specific biological roles of O-acetylated gangliosides in developing and malignant tissues have not been extensively studied, mostly because of the requirement of specific approaches and tools for sample preparation and analysis. In this review, we summarize our current knowledge of ganglioside biosynthesis and expression in normal and pathological conditions, of ganglioside O-acetylation analysis and expression in cancers, and of the possible use of O-acetylated gangliosides as targets for cancer immunotherapy.

Improving the conjugated linoleic acid content and the sensorial characteristics of Argentinean semi-hard goat cheeses by adding cultures of native lactic acid bacteria

In this study the physicochemical, microbiological, and fatty acid compositions together with the specific esterase activities of semi-hard goat cheeses made from native strains as starter and adjunct cultures were evaluated and compared against those of manufactured using commercial culture cheeses. The physicochemical composition was similar among cheeses, while the lactic acid bacteria were the predominant microbiota in all samples. The highest specific esterase activities were detected in cheeses with native strains. The fatty acid profile was significantly affected by native strains during the ripening time (60 days) since the conjugated linoleic acid (CLA) level increased from 0.60 to 1.03 g 100 g-1 of fatty acids, whereas cheeses with commercial starter showed a CLA content of about 0.60 g of fatty acids. In cheeses with native strains, it was detected the highest desirable fatty acids, Δ9-desaturase and CLA desaturase indexes and the lowest atherogenicity index. The native strains inoculated as starter and adjunct cultures, grew conveniently in the cheese, developed their full potential as reflected by the profile of the metabolites released during ripening and in the global sensory perception of cheeses, and contributed thus to the development of a healthier food.