Asian Journal of Green Chemistry

Abstract

Abstract An efficient and simple procedure for the preparation of silver functionalized on hydroxyapatite-core-shell magnetic γ-Fe₂O₃ nanoparticles (γ-Fe₂O₃@HAp-Ag)as an enviromentaly efficient magnetically recoverable and reusable catalyst is described, and it is used for the one-pot synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes via a cost-effective and atom-economical procedure from substituted benzaldehydes and β-naphthol under solvent-free conditions at 60 °C. The attractiveness of this protocol lies in its green approach in that the catalyst is easily recoverable using an external magnet, which makes the process economical.

Abstract In this study, the green procedure for synthesis of the β-enaminones is described. The reaction of aromatic amines with β-dicarbonyl compounds under solvent and catalyst-free conditions at 120 °C affords the β-enaminone and β-enamino esters in high-to-excellent yields, in short reaction time, easy separation, work up and purification without need to column chromatography. Also, some new derivatives of β-enaminones were synthesized using this method. The prominent advantages of this new method is operational simplicity, good yields in short reaction times, easy work-up procedures, catalyst and solvent free condition.
 

Abstract In this research a novel drug polymer was prepared. The gelatin  as a natural polymer has been used in the pharmaceutical and biomedical for the controlled release through grafted copolymerization with un saturated acid anhydride  such as methyl nadic anhydride (Methyl-5-norbornene-2,3-dicarboxylic anhydride), formatted gelatin-g-methyl nadic anhydride copolymer A₁, then modified to its corresponding polymer A₂ by substituted amoxilline as useful derivative as biomaterial. The prepared drug biopolymer was characterization by FT-IR spectroscopy and controlled drug release was considered in different buffer solution at 37 °C as in vitro study and controlled drug release was compared at zero time and after many days, the methyl nadic anhydride which was used as a spacer between gelatin and amoxilline. It can provide functional groups which are pendant through backbone of polymer substituted with drug through amide groups lead to good sustain release rate for hydrolysis through amide attachment gradually for many days. This design of carries for controlled delivery of the therapeutic agent which could release the entrapped drug over an extended period and control the drug release was compared at zero time and after few days, indicated the rate of hydrolysis in basic medium is higher than acidic medium through hydrolysis of amide groups. It was observed that modified drug release with extended drug action via slow release, also this study gave a new drug polymer and in vivo performance was indicated that it will be talented for some bio active applications.

Abstract A green approach to synthesis of the polyfunctionalized pyrazole [4′,3′:5,6]pyrido[2,3-d] pyrimidines derivatives was successfully achieved via one-pot, four component reactions of β-aminocrotonitrile, phenyhydrazine, arylglyoxals, barbituric acid derivatives in the presence of TEA (Triethylamine) as a catalyst in water under the reflux conditions. This protocol provided mild reaction conditions, short reaction times, high yields, low cost, easy isolation of products and possible biological, and pharmaceutical activities.

Abstract A green and facile methodology for the synthesis of nitrile has been established from the corresponding aldehydes and hydroxylamine hydrochloride on silica-gel in hot condition. The protocol is equally effective for aliphatic as well as aromatic aldehydes, and has wide range of functional group tolerance. In addition, this methodology is solvent-free, inexpensive, environmental friendly and involves simple work-up process.

Abstract Chelating adsorbents have been considered to be suitable materials for the recovery of cadmium in water treatments. Adsorption of Cadmium (II) ions on melamine-butanedioic acid, modified poly (Styrene-alternative-maleic anhydride) cross-linked by 1, 2-diaminobutane (CSMA-MB) and pit shell of sour cherry (Prunus cerasus rock) (PCR) as an ion exchange adsorbents have been investigated in aqueous solution. The adsorption behavior of these Cadmium (II) ions on the adsorbents was studied by varying the parameters such as pH (2-8), adsorbent dose (0-4.0 g/L^-1), contact time (0‒240 min), and Cadmium (II) ion concentration (20-300 mg/L^-1). Adsorption percentage was increased by increasing each of these parameters. The isotherm models such as Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich were used to describe adsorption equilibrium. The results showed that the best fit was achieved with the Langmuir isotherm equation, yielding maximum adsorption capacities of 81.30, 80.42 mg/g^-1 for Cd (II) with CSMA-MB and PCR respectively. Both adsorbents, CSMA-MB and PCR, are very suitable for the removal Cadmium (II) ions from aqueous solutions. The adsorbents were characterized by fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), x-ray diffraction analysis (XRD).

Abstract Phycocyanin is a blue pigment and water-soluble biliprotein from the spirulina platensis. It has great medical and medicinal properties and has been used as a nutritional supplements. Phycocyanin is also a natural and powerful antioxidant and anti-inflammatory. In this study, the phycocyanin of Spirulina platensis was extracted by using two enzymatic and ultrasonic methods and purified by ammonium sulfate precipitation and dialysis. The UV spectrophotometer absorption of the extracted sample showed a broad peak range at 280, 615, and 652 nm. By using The FT-IR results confirmed the structure and molecular bonds from extracted and purificated phycocyanin. The concentrations obtained at the enzymatically was 0.405 mg/mL and for sonication 0.422 mg/mL. By using the SDS PAGE method, bands of phycocyanin were identified and the molecular weight was determined between 19-14 KD. The antioxidant and anti-inflammatory activity of the phycocyanin was approved with the reaction by DPPH and HOCl.

Abstract The coffee and tea powders were investigated to be as a novel low-cost non-conventional biosorbent for the removal of Fe (III) from aqueous solutions. Biosorption isotherms and kinetics were also assessed. The studied operating parameters were initial Fe (III) concentration, contact time, pH, and biosorbent dose. The adsorption capacity was significantly increased from 9.18 mg/g to 54.14 mg/g when the initial metal ion concentration increased from 20 to 120 ppm. However, the adsorbed amount of Fe was improved from 2.29 to 23.31 mg/g when the biosorbent dose decreased from 1.0 to 0.1 g. Biosorption isothermal data could be well simulated by Langmuir, Freundlich, and then Temkin models denoted by high correlation coefficient values (R2 > 0.95). However, the Dubinin-Radushkevich isotherms model gives the least fit to experimental data. Langmuir adsorption capacities of coffee and tea were 85.5 and 285 mg/g, respectively. The kinetic data fitted very well to the pseudo-second-order kinetic model. As indicated by the biosorption capacity, coffee and tea powder are considered to be an efficient, low cost, and environmentally friendly biosorbent for the removal of Fe (III) ions from aqueous solutions.