Chemistry Central Journal

http://link.springer.com/journal/13065

List of Papers (Total 1,121)

Inhibitory effects against α-glucosidase and α-amylase of the flavonoids-rich extract from Scutellaria baicalensis shoots and interpretation of structure–activity relationship of its eight flavonoids by a refined assign-score method

A flavonoids-rich extract of Scutellaria baicalensis shoots and its eight high content flavonoids were investigated for their inhibitory effects against α-glucosidase and α-amylase. Results show that abilities of the extract in inhibiting the two enzymes were obviously higher than those of acarbose. Moreover, inhibitory abilities of all the eight individual flavonoids against the...

Removal of malachite green from aqueous solution using pulverized teak leaf litter: equilibrium, kinetic and thermodynamic studies

The removal of malachite green (MG) from aqueous solution using teak leaf litter powder (TLLP) was investigated. The process was influenced by initial concentration, pH and temperature of dye solution as well as TLLP dosage. Optimum removal of MG per gram of TLLP occurred at 2 g/L and at pH 6–8. Dubinin–Radushkevich and Freundlich isotherm models fit the batch adsorption data...

Preparation of polyetherimide membrane from non-toxic solvents for the separation of hydrogen from methane

Polymeric membranes are usually prepared from solvents like n-methylpyrrolidone (NMP) because of the strong dissolving power and high boiling point. Yet, the solvent is costly, toxic and has environmental issues. In this work, nontoxic solvents such as methyl l-lactate, ethyl lactate, propylene carbonate, tributyl o-acetylcitrate, tributyl citrate, triethyl phosphate, and...

Analysis of paracetamol, pseudoephedrine and cetirizine in Allercet Cold® capsules using spectrophotometric techniques

Paracetamol (PAR), Pseudoephedrine hydrochloride (PSE) and cetirizine dihydrochloride (CET) is a ternary mixture that composes tablets which are popular for the relief of flu in Egypt. The spectra of the drugs were overlapped and no spectrophotometric methods were reported to resolve the mixture. This research proposes four spectrophotometric methods that are efficient and...

Enhancement of oral bioavailability of doxorubicin through surface modified biodegradable polymeric nanoparticles

BackgroundDoxorubicin hydrochloride (DOX·HCl), an anthracycline glycoside antibiotic, exhibits low oral bioavailability due to active efflux from intestinal P-glycoprotein receptors. The oral administration of DOX remains a challenge hence; no oral formulation for DOX is marketed, till date.Aim of the studyTo improve the oral bioavailability of DOX through, preparation of a...

Determination of antioxidant and antimicrobial activities of leaf extracts of Otostegia integrifolia

BackgroundThe extracts from the leaves of Otostegia integrifolia have been reported to show phytochemical analysis, total flavonoid content, antioxidant and antibacterial activities.ResultsOur results revealed that the total flavonoid content of methanol and ethyl acetate extracts is 416.5 + 0.288 and 248.9 + 0.872 mgAAE/100 g respectively. The two extracts also showed good...

BODIPY dyads and triads: synthesis, optical, electrochemical and transistor properties

A series of D–A dyads and D–A–D triads molecular systems based on triphenylamine and 9-ethyl-carbarzole as donor (D) and BODIPY as acceptor (A) has been designed and synthesized. The optoelectronic properties including optical, electrochemical, and charge carrier mobility of these molecules have been investigated. We found that the D–A–D triads exhibited broader absorption...

Dihydroisocoumarins from Radix Glycyrrhizae

BackgroundRadix Glycyrrhizae is the rhizome of Glycyrrhiza inflata Bat., Glycyrrhiza uralensis Fisch. or Glycyrrhiza glabra L. The present paper describes the isolation and the structural elucidation of three new dihydroisocoumarins obtained from the 70% EtOH extract of Radix Glycyrrhizae. And the cytotoxic activities of these new compounds were also evaluated using four cell...

New fluorescence spectroscopic method for the simultaneous determination of alkaloids in aqueous extract of green coffee beans

BackgroundThere is no fluorescence spectroscopic method for the determination of trigonelline and theobromine in green coffee beans. Therefore, the objective of this study was to develop a new fluorescence spectroscopic method to determine the alkaloids simultaneously in the aqueous extract of green coffee beans.ResultsThe calibration curves were linear in the range 2–6, 1–6, 1–5...

Chemical variability in the essential oil of leaves of Araçá (Psidium guineense Sw.), with occurrence in the Amazon

BackgroundPsidium guineense, known as Araçá, is a Brazilian botanical resource with commercial application perspectives, based on the functional elements of its fruits and due to the use of its leaves as an anti-inflammatory and antibacterial agent. The essential oils of leaves of twelve specimens of Araçá were analyzed by GC and GC-MS to identify their volatile constituents and...

Validation of analytical method for rhynchophorol quantification and stability in inorganic matrix for the controlled release of this pheromone

A fast method for the identification and stability evaluation of the aggregation pheromone rhynchophorol, which is the main substance used for chemical communication by the beetle Rhynchophorus palmarum L., was validated. In addition, the technique was applied to the evaluation of two inorganic matrices, with the objective of using them as controlled-release devices. The...

Microwave assisted synthesis of some new thiazolopyrimidine and pyrimidothiazolopyrimidopyrimidine derivatives with potential antimicrobial activity

Background and objectiveA series of thiazolopyrimidine derivatives have been synthesized via multicomponent reaction and tested for biological activities. This research aims to develop a new synthetic method of poly fused pyrimidines under microwave irradiation. 6-Amino-4-aryl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitriles reacted with bromomalono-nitrile to give 3,7...

Study on the interaction between active components from traditional Chinese medicine and plasma proteins

Traditional Chinese medicine (TCM), as a unique form of natural medicine, has been used in Chinese traditional therapeutic systems over two thousand years. Active components in Chinese herbal medicine are the material basis for the prevention and treatment of diseases. Research on drug-protein binding is one of the important contents in the study of early stage clinical...

Development and validation of an HPLC–MS/MS method for the determination of arginine-vasopressin receptor blocker conivaptan in human plasma and rat liver microsomes: application to a metabolic stability study

PurposeTo develop and validate a bio-analytical HPLC–MS/MS method for the determination of conivaptan (CVA) an arginine-vasopressin receptor blocker in human plasma and in rat liver microsomes (RLMs).MethodsAnalytes were separated on a reversed phase C18 column (50 mm × 2.1 mm, 1.8 μm). The mobile phase was a mixture of acetonitrile and 10 mM ammonium formate (40:60 v/v, pH 4.0...

Preparation and application of melamine cross-linked poly ammonium as shale inhibitor

In this paper, a series of poly ammonium shale inhibitors were prepared from diethylamine, epichlorohydrin, and melamine (DEM) and their inhibition to shale were evaluated by bentonite linear expansion test, anti-swelling experiments, and mud ball experiments. Additionally, other properties of drilling fluid treated by poly ammonium were evaluated. Anti-swelling results showed...

The determination of Ochratoxin A based on the electrochemical aptasensor by carbon aerogels and methylene blue assisted signal amplification

In this work, a novel aptamer-based electrochemical biosensor was developed for the determination of Ochratoxin A (OTA) by using carbon aerogels (CAs) and methylene blue (MB) as signal amplification strategy. CAs was used as carrier to load the abundant of complementary DNA (cDNA), which could enhance the hybridization between CAs-cDNA and aptamer immobilized on the electrode...

Identification of characteristic aroma compounds in raw and thermally processed African giant snail (Achatina fulica)

BackgroundFood flavor appreciation is one of the first signals along with food appearance and texture encountered by consumers during eating of food. Also, it is well known that flavor can strongly influence consumer’s acceptability judgment. The increase in the consumption of snail meat across the world calls for the need to research into the aroma compounds responsible for the...

Exploration of Phyllanthus acidus mediated silver nanoparticles and its activity against infectious bacterial pathogen

In our present investigation, synthesis of nontoxic, eco friendly and cost effective silver nanoparticles, Phyllanthus acidus (P. acidus) was used as starting material. The influence of phyto-constituents present in aqueous extracts of Phyllanthus acidus was found to be effective in reduction of silver nitrate to free silver nanoparticles (PA-AgNPs). HPTLC finger print analysis...

Simultaneous identification and determination of flavonoids in Dendrobium officinale

BackgroundThe quality of material medicine resources has had a considerable impact on the development of the health industry, which has created a bottleneck for traditional Chinese medicine (TCM). Dendrobium officinale, which has been widely used for health prevention in TCM, has become a high-nutritive health food that is strongly recommended by many white-collar workers and...

5-Hydroxymethylfurfural (HMF) levels in honey and other food products: effects on bees and human health

An organic compound known as 5-hydroxymethylfurfural (HMF) is formed from reducing sugars in honey and various processed foods in acidic environments when they are heated through the Maillard reaction. In addition to processing, storage conditions affect the formation HMF, and HMF has become a suitable indicator of honey quality. HMF is easily absorbed from food through the...

Eugenol derivatives: synthesis, characterization, and evaluation of antibacterial and antioxidant activities

Eugenol is the major component of clove essential oil and has demonstrated relevant biological potential with well-known antimicrobial and antioxidant action. Therefore, this work carried out the synthesis, purification, characterization, and evaluation of the antioxidant and antibacterial potential of 19 eugenol derivatives. The derivatives were produced by esterification...