Harno Dwi Pranowo

Preferential Cu2+ solvation in aqueous ammonia solution of various concentrations

Abstract Monte Carlo simulations were performed for Cu 2+ in 4.8%, 10%, 18.6% and 30% aqueous ammonia solution at temperature of 293.16 K, using ab initio pair potential and three-body potentials for Cu 2+ –H 2 O–H 2 O, Cu 2+ –H 2 O–NH 3 and Cu 2+ –NH 3 –NH 3 . The fully solvated Cu 2+ in 4.8%, 10%, 18.6% and 30% aqueous ammonia solution can be characterised as [Cu(H 2 O) 6 ][(H 2 O) 22 ] 2+ , [Cu(H 2 O) 4 (NH 3 ) 2 ][(H 2 O) 20 ] 2+ , [Cu(H 2 O) 3 (NH 3 ) 3 ][(H 2 O) 11.6 (NH 3 ) 10,2 ] 2+ (J. Chem. Phys. 112 (2000) 4212) and [Cu(H 2 O) 2 (NH 3 ) 4 ][(H 2 O) 5.9 (NH 3 ) 17.5 ] 2+ , respectively. The structure of the solvated ion is discussed in terms of radial distribution functions, coordination number and angular distribution.

SYNTHESIS OF TERPINEOL FROM α-PINENE CATALYZED BY TCA/Y-ZEOLITE

The hydration of -pinene has been studied in the presence of TCA/Y-Zeolite catalyse. The catalyst was prepared by impregnating trichloroacetic acid (TCA) on support of Y-Zeolite. The TCA/Y-Zeolite catalyst converted -pinene into hydrocarbons, while the TCA/Y-Zeolite catalyst was active and selective for producing alcohols, with a conversion of 66% and showed 55% selectivity for -terpineol at 10 min. The reaction taken place in a solid–liquid mode and most of the -terpineol is extracted out by the organic phase during the course of the reaction. TCA/YZeolite was found as good catalyst for hydration of -pinene to produce -terpineol.

Monte Carlo simulation of CuCl2 in 18.6% aqueous ammonia solution

A Monte Carlo simulation was performed for a basic box containing 171 water molecules, 39 ammonia molecules, 5 Cu2+, and 10 Cl− ions, corresponding to a 1.3 molal CuCl2 solution in 18.6% aqueous ammonia, at a temperature of 293.16 K. The results of the Monte Carlo simulation demonstrate that [Cu(NH3)4(H2O)2]2+ is the main species present (49.5%), besides [Cu(NH3)2(H2O)4]2+ (8.0%), [Cu(NH3)3(H2O)3]2+ (14.1%), [Cu(NH3)5(H2O)]2+ (28.2%) and small amounts of [Cu(NH3)1(H2O)5]2+ (0.2%). The structure of the solvated ion is discussed in terms of radial distribution functions, coordination number and angular distribution.

Theoretical study of substituent effects on Cs+/Sr2+–dibenzo-18-crown-6 complexes

The effect of electron-donating and -withdrawing substituents of Cs+/Sr2+–dibenzo-18-crown-6 complexes was studied by density functional theory (DFT) calculations. For the investigations the interaction energies were correlated to the second-order interaction energies, charge-transfer effects, and HOMO energies. Electron-donating substituents increase the crown ethers’ ability to complex metal ions, whereas electron-withdrawing substituents have the opposite effect. Natural bond orbital analysis indicates a small contribution of these substituents to the complex stability in the gas phase. In the condensed phase, the interaction energy of the complexes is significantly reduced because of solvation effects. The results demonstrate a discrepancy between gas and condensed phase in which Cs+ is bound to dibenzo-18-crown-6 better than Sr2+. We speculate that the species in water form 2:1 complexes consisting of two dibenzo-18-crown-6 molecules and one cation.Graphical abstract

The Effect of Freeze-Thaw Treatment to the Properties of Gelatin-Carbonated Hydroxypatite Membrane for Nerve Regeneration Scaffold

One of the major challenges in the development of scaffold for nerve regeneration is enhancing mechanical strength of the material to avoid the scaffold to rapidly degrade during regeneration process in nerve system. The aim of this study was to reveal the effect of freeze-thaw to the properties of gelatin-carbonated hydroxy apatite (CHA) membrane in two ratios 7 to 3 and 6 to 4 for gelatin to CHA respectively. Some variations of freeze-thaw cycles were applied for both ratios, which is referred for its biocompatibility in cells.The CHA was synthesized by wet precipitating method of calcium hydroxide and phosphoric acid in gelatin solution at room temperature and open system. The X-Ray Diffraction (XRD) and FTIR analysis was conducted to confirm the formation of type-B CHA in gelatin matrix. The resulted membrane was then subject for membrane characterization.It was known from the study that freeze-thaw treatment during membrane fabrication affects several properties of the membrane. Platelet loading capability decreased when freeze-thaw cycles increased. Meanwhile, the platelet was released more rapidly by freeze-thawed gelatin-CHA membrane compared to non-freeze-thawed one. The degradation percentage of the membrane decreased with the increasing freeze-thaw cycles, showing 4 hours slower degradation in the freeze-thawed membrane compared to the unfreeze-thawed one.Furthermore, it was observed that freeze-thaw improved the tensile strength of the membrane and the modulus elasticity increased simultaneously. Moreover, in general it was observed from this study that freeze-thaw treatment did not affect permeability of the membranes towards glucose transport.

Synthesis, in vitro and Molecular Docking Studies of 1-(3,4-Dimethoxy-phenyl)-5-(4-hydroxy-3-methoxy-phenyl)-penta-1,4-dien-3-one as New Potential Anti-inflammatory

Inflammation is a localized physical condition with heat, swelling, redness and usually pain. It is mediated by the release of proinflammatory mediators (bradykinin and cytokines), which in turn increases the rate of prostaglandin synthesis [1,2]. Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit the biosynthesis of prostaglandins by inhibiting cyclooxygenases (COXs). It exists in two isoforms i.e., a constitutive form (COX-1) and an inducible form (COX-2) [3,4]. COX-1 enzyme is responsible for maintenance of gastric integrity and kidney function [5-7] whereas COX-2 is involved in the inflammation and pain [8,9]. All classical NSAIDs, such as aspirin and indomethacin are non selective inhibitors for both COX-1 and COX-2, but bind more tightly to COX-1. In order to prevent or decrease these side effects, a current strategy consists of designing selective COX-2 inhibitors with an improved gastric safety profile [10,11]. Curcuminoids exhibited many interesting biological activities [12], for example, antioxidant activity [13,14], antiinflammatory activity [15,16], anticancer activity [13,17,18], antiprotozoal activity [19] and anti-HIV activity [20]. On the other hand, curcumin analogue such as modification of the dienone functional group curcumin into monoketone and side chain of aromatic ring with symmetrical or asymmetrical substituents possessed structural features which conferred potential biological activity and pharmaceutical use [21,22]. Synthesis, in vitro and Molecular Docking Studies of 1-(3,4-Dimethoxy-phenyl)-5-(4-hydroxy3-methoxy-phenyl)-penta-1,4-dien-3-one as New Potential Anti-inflammatory

Molecular docking analysis of curcumin analogues with COX-2

Curcumin analogues were evaluated for COX-2 inhibitory as anti-inflammatory activities. The designed analogues significantly enhance COX-2 selectivity. The three compounds could dock into the active site of COX-2 successfully. The binding energies of -8.2, - 7.6 and -7.5 kcal/mol were obtained for three analogues of curcumin respectively. Molecular docking study revealed the binding orientations of curcumin analogues in the active sites of COX-2 towards the design of potent inhibitors.

Design a better metalloporphyrin semiconductor: A theoretical studies on the effect of substituents and central ions

We have studied the effects on central metal and substituent group on the complex compounds metalloporphyrin as a semiconductor material. Cd2+, Hg2+, and Pt2+ were chosen as the central metal to see the effect of the elements on the nature of the group and the same period and reviewed the effect of substituent groups pull and push the electrons to the electronic properties of complex metalloporphyrin. The DFT/B3LYP/LANL2DZ and TD-DFT calculation were used to generate the optimized structure of, electronic and photophysical properties. The parameter is an Eg complex compound, DOS, and electronic absorption spectra. The calculations showed electron donating complexes tend to be better as a semiconductor because it lowers Eg complex compounds metalloporphyrin, NH2 group gave the smallest Eg compared to other groups.