Colorimetric Studies on the Interaction of Quinhydrone with Monosodium Glutamate (MSG) in Aqueous Medium

The interaction of quinhydrone with monosodium glutamate (MSG) in aqueous medium has been investigated using colorimetric method at different pH conditions. Quinhydrone is a mixture of quinone and hydroquinone. In acidic pH, hydroquinone is dominating and the hydroxyl group of hydroquinone interacts with the amino/carboxylic acid group of glutamate ion due to hydrogen bonds thus influences the solution. While in alkaline pH, the colour of the quinhydrone is brown due to benzoquinone being dominating component and can interact with amino group of glutamate ion thus resulting in the formation of di-anilido-quinone. This will lead to an increase of intensity of quinhydrone solution. Glutamate being amphoteric in nature, provides an option to examine it in both acidic and alkaline pH. The effectiveness of detection of MSG in alkaline medium is better due to its favourable interactions.

Syntheses of Enantiopure 1,2-Ethylenediamines with Tethered Secondary Amines of the Formula H2NCH2CH[(CH2) n NHMe]NH2 (n = 1–4) from α-Amino Acids: New Agents for Asymmetric Catalysis

Tris(hydrochloride) adducts of the title compounds­ are prepared from the inexpensive α-amino acids H2N(C=O)CH2CH(NH2)CO2H, HO(C=O)(CH2) n′CH(NH2)CO2H (n′ = 1, 2), and H2N(CH2)4CH(NH2)CO2H, respectively (steps/overall yield = 5/32%, 7/30%, 7/33%, 5/38%). The NH2 group that is remote from the secondary amine is installed via BH3 reduction of an amide [–(C=O)NR2] derived­ from an α-amino carboxylic acid. The MeNHCH2 units are introduced by BH3 reductions of alkyl carbamate [RO(C=O)NHCH2–; R = Et, t-Bu] or amide [MeHN(C=O)–] moieties.

Synthesis, Characterization and In vitro Evaluation of N-Substituted- Sulfomoyl-Phenyl-Amino Carboxylic Acid Derivatives as Squalene Synthase Inhibitors

Background:Squalene Synthase is one of the cholesterol biosynthetic pathway enzymes, inhibition of which produces potent lipid lowering action. A variety of chemical classes have been evaluated for its inhibition to provide alternate antihyperlipidemic agents to statins.Methods:A series of N-substituted-sulfomoyl-phenyl-amino carboxylic acid derivatives were designed through pharmacophore modelling as Squalene Synthase inhibitors. We report here the synthesis, characterization and in vitro pharmacological screening of the designed molecules as Squalene synthase inhibitors. The target molecules were synthesized by a simple procedure and each molecule was characterized by IR, Mass, 1HNMR and 13CNMR spectroscopic techniques. As a primary site of action for cholesterol biosynthesis is liver, each of the molecules were first screened for in vitro cytotoxicity over human hepatic cell line (HepG2) by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay method. The enzyme inhibition assay was performed on cell lysates prepared from HepG2 cells by Human Squalene Synthase ELISA kit, where test compounds were added in the nontoxic concentrations only.Results:Compound 5f was found to be most potent with the IC50 value of 11.91 µM. The CTC50 value for 5f on human hepatic cell line was > 1000 µM so it was considered that the compound was relatively safe and might be free of hepatotoxicity.Conclusion:From the results of our studies, it was observed that compounds with poly nuclear aromatic or hetero aromatic substituent on a side chain were more potent enzyme inhibitors and a distance of 4-5 atoms is optimum between amide nitrogen and hydroxyl group of carboxylic acid.

A Novel Synthetic Route of Fused Tricyclic Framework Quinoline Derivatives from Readily Available Aliphatic Amino Carboxylic Acid Substrates

A novel and an efficient strategy of fused tricyclic quinoline heterocycle compounds from aliphatic amino carboxylic acid substrates is disclosed. The protocol here is proceed over main reaction processes including: cyclization, protection, amidine formation, further cyclization and finally coupling with boronic acid substrate through Suzuki reaction. These reactions afforded the corresponding products in high yields. Furthermore, all synthesized compounds were identified by spectral data.

Adsorption of Pb(II) by a polyvinylidene fluoride membrane bearing chelating poly(amino phosphonic acid) and poly(amino carboxylic acid) groups

Pb(II) can cause a hazardous effect on ecosystem and public health due to its high biotoxicity. A polyvinylidene fluoride-type membrane bearing both poly(amino phosphonic acid) and poly(amino carboxylic acid) functional groups was fabricated for the purpose of Pb(II) removal from the aqueous solutions. The adsorption behaviors of the fabricated chelating membrane toward Pb(II) were studied by the series of static and continuous adsorption experiments. When the pH, adsorption equilibrium time, initial Pb(II) concentration, and temperature were 5.1, 300 min, 1.0 mmol g−1, and 298 K, respectively, Pb(II) uptake of the membrane was 1.1 mmol g−1. The presence of coexisting metal ions and complexing reagents decreased the Pb(II) uptake. The adsorption kinetic and isotherm adsorption followed pseudo-second-order equation and Langmuir model, respectively; this adsorption process showed a spontaneous and exothermic feature. The bed depth service time and Thomas models were suitable for describing obtained breakthrough curves.

Direct carbon–carbon bond formation via reductive soft enolization: a syn-selective Mannich addition of α-iodo thioesters

The β-amino carboxylic acid moiety is a key feature of numerous important biologically active compounds.