1.Removal of mercury(II) ions in aqueous solution using the peel biomass of Pachira aquatica Aubl: kinetics and adsorption equilibrium studies.
Santana AJ1, Dos Santos WN1, Silva LO1, das Virgens CF2. Environ Monit Assess. 2016 May;188(5):293. doi: 10.1007/s10661-016-5266-7. Epub 2016 Apr 15.
Mercury is a highly toxic substance that is a health hazard to humans. This study aims to investigate powders obtained from the peel of the fruit of Pachira aquatica Aubl, in its in natura and/or acidified form, as an adsorbent for the removal of mercury ions in aqueous solution. The materials were characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis. The infrared spectra showed bands corresponding to the axial deformation of carbonyls from carboxylic acids, the most important functional group responsible for fixing the metal species to the adsorbent material. The thermograms displayed mass losses related to the decomposition of three major components, i.e., hemicellulose, cellulose, and lignin. The adsorption process was evaluated using cold-vapor atomic fluorescence spectrometry (CV AFS) and cold-vapor atomic absorption spectrometry (CV AAS). Three isotherm models were employed. The adsorption isotherm model, Langmuir-Freundlich, best represented the adsorption process, and the maximum adsorption capacity was predicted to be 0.
2.Coumarins from Angelica decursiva inhibit α-glucosidase activity and protein tyrosine phosphatase 1B.
Ali MY1, Jannat S1, Jung HA2, Jeong HO3, Chung HY3, Choi JS4. Chem Biol Interact. 2016 Apr 13. pii: S0009-2797(16)30143-0. doi: 10.1016/j.cbi.2016.04.020. [Epub ahead of print]
In the present study, we investigated the anti-diabetic potential of six natural coumarins, 4-hydroxy Pd-C-III (1), 4'-methoxy Pd-C-I (2), decursinol (3), decursidin (4), umbelliferone 6-carboxylic acid (5), and 2'-isopropyl psoralene (6) isolated from Angelica decursiva and evaluated their inhibitory activities against protein tyrosine phosphatase 1B (PTP1B), α-glucosidase, and ONOO--mediated protein tyrosine nitration. Coumarins 1-6 showed potent PTP1B and α-glucosidase inhibitory activities with ranges of IC50 values of 5.39-58.90 μM and 65.29-172.10 μM, respectively. In the kinetic study for PTP1B enzyme inhibition, compounds 1, 5, and 6 were competitive, whereas 2 and 4 showed mixed type, and 3 displayed noncompetitive type inhibition. For α-glucosidase enzyme inhibition, compounds 1 and 3 exhibited good mixed-type, while 2, 5, and 6 showed noncompetitive and 4 displayed competitive type inhibition. Furthermore, these coumarins also effectively suppressed ONOO--mediated tyrosine nitration in a dose-dependent manner.
3.A new approach in compatibilization of the poly(lactic acid)/thermoplastic starch (PLA/TPS) blends.
Akrami M1, Ghasemi I2, Azizi H1, Karrabi M1, Seyedabadi M3. Carbohydr Polym. 2016 Jun 25;144:254-62. doi: 10.1016/j.carbpol.2016.02.035. Epub 2016 Feb 23.
In this study, a new compatibilizer was synthesized to improve the compatibility of the poly(lactic acid)/thermoplastic starch blends. The compatibilizer was based on maleic anhydride grafted polyethylene glycol grafted starch (mPEG-g-St), and was characterized using Fourier transform infrared spectroscopy (FTIR), dynamic mechanical thermal analysis (DMTA) and back titration techniques. The results indicated successful accomplishment of the designed reactions and formation of a starch cored structure with many connections to m-PEG chains. To assess the performance of synthesized compatibilizer, several PLA/TPS blends were prepared using an internal mixer. Consequently, their morphology, dynamic-mechanical behavior, crystallization and mechanical properties were studied. The compatibilizer enhanced interfacial adhesion, possibly due to interaction between free end carboxylic acid groups of compatibilizer and active groups of TPS and PLA phases.
4.Investigation on Drug Solubility Enhancement Using Deep Eutectic Solvents and Their Derivatives.
Li Z1, Lee PI2. Int J Pharm. 2016 Apr 11. pii: S0378-5173(16)30301-5. doi: 10.1016/j.ijpharm.2016.04.018. [Epub ahead of print]
Deep eutectic solvent (DES) is a room temperature liquid typically formed by mixing two solid compounds, such as a quaternary ammonium salt (QAS) (e.g. choline chloride) and a hydrogen bond donor (HBD) (e.g. urea or a carboxylic acid) at their eutectic composition. Very often, a range of room temperature liquids can also be obtained near the eutectic composition. Hence, it is more convenient to introduce a more general term deep eutectic solvent derivatives (DESDs) to describe a wide range of DES-like derivatives including those derived from ternary mixtures. The melting point of the mixture is lowered because the hydrogen bonding between DESD components reduces the lattice energy of components of the eutectic system. Based on the analysis of available data for 22 such choline chloride-based DES pairs, we found that the observed melting point depression can be statistically correlated with the difference between the hydrogen bonding contribution (δh) and the polar contribution (δp) to the solubility parameter of the hydrogen bond donor (HBD) component.