Classical and advanced chemical sciences
Ten novel usnic acid based imidazolium salts were synthesized by employing a two-step protocol. The anti-inflammatory potential of the newly synthesised compounds was evaluated in vitro against cytokine proteins TNF- α and IL-1 β secreted from U937 cells. Some of the imidazolium salts exhibited promising anti-inflammatory activity against the TNF-α and IL-1β with IC50 values ranging between 5.3 μM - 7.5 μM, which are many folds lower than that of the parent compound (>100 μM). Most significantly, substitution with electronegative groups in imidazolium salts of usnic acid found to be more potent and exhibiting enhanced anti-inflammatory activity.
Keywords: Usnic acid; imidazolium salts; anti-inflammatory activity; cytokine proteins; U937 cells
A series of 4-fluorophenylpyrazole clubbed 1,3,4-oxadiazole and 3,4-dihydropyrimidin-2(1H)-ones were prepared by cyclization of Biginelli-type adducts. Their structures were assigned on the basis of known spectral techniques. All the scaffolds were evaluated for in vitro antimicrobial activity by broth microdilution bioassay method and in vitro antitubercular property by microplate alamar blue assay method. Compounds 3j and 3l containing -OH and -CH3 groups were found to act as potent antimicrobials and antitubercular candidates with relatively low cytotoxicity on VERO cells.
Keywords: Pyrazole; 3,4-dihydropyrimidin-2(1H)-one; 1,3,4-Oxadiazole; Antimicrobial; Antitubercular; MIC
The purpose of this study was the synthesis of a novel series of 1,2,3-triazole-1,4-dihydropyridine-3,5-dicarbonitrile derivatives (3a-3o) via Cu(I) catalyzed reaction between a terminal alkyne and substituted alkyl or aryl azides. The synthesized triazoles were characterized by 1H NMR, 13C NMR, and single crystal X-Ray. They were screened in vitro for antibacterial activity against a set of 10 bacterial cultures by the broth microdilution method. The significant antibacterial activity with MIC: 50 μg mL-1 was displayed by compounds 3j and 3h against Pseudomonas aeruginosa and compounds 3c and 3g against Salmonella paratyphi as well as compound 3f against Enterobacter aerogenes, Klebsiella pneumoniae, Proteus vulgaris, and Shigella flexneri. Compound 3e was the only compound that was found to inhibit Escherichia coli with MIC: 200 μg mL-1.
Keywords: Antibacterial; 1,4-Dihydropyridines, 1,2,3-Triazoles
Three distyryl-containing compounds, namely, 2-((cyanomethyl)thio)-4,6-distyrylnicotinonitrile (2), 3-amino-4,6-distyrylthieno[2,3-b]pyridine-2-carbonitrile (3) and 2-((2-cyanoethyl)thio)-4,6-distyrylnicotinonitrile (4) have been prepared and characterized by elemental and spectroscopic analyses. The three compounds contain the pyridine moiety and are considered neonicotinoids analogues. Because neonicotinoids were considered the most effective pesticides, the biological activity of the distyryl-containing compounds as potential insecticides against cowpea aphid, Aphis craccivora Koch was evaluated. The agricultural bioactivity results of these compounds showed that the insecticidal activity varied from good to moderate against cowpea aphid insects.
Keywords: Synthesis, distyryl-containing compounds, agricultural bioactivity, acetamiprid, cowpea aphid
Bombax ceiba Linn. is a deciduous tree known as Red silk cotton tree. Bombax ceiba stem, stem bark and prickle are used for the treatment of rheumatism, swellings, asthma and inflammation of the legs. The stem bark of Bombax ceiba is official in the ayurvedic Pharmacopoeia of India recommends its use in acne. Prickles are also used and recommended in anti-acne marketed formulation. However, limited work was carried out on the prickle toward establishing quality control parameters. Studies were therefore carried out to determine the phytochemical and pharmacognostic profile of prickle of Bombax ceiba Linn. The study, including determination of macroscopic, microscopic characters, ash values, extractive values, loss on drying, phytochemical screening, total phenolic content, TLC and HPTLC fingerprinting were carried out. Successive extracts were prepared using soxhlet extraction. The phytochemical analysis of extracts revealed the presence of tannin, saponin, phenol, carbohydrate, steroids, triterpenoids and flavonoids. Total phenolic and tannin content of methanol extract was found 327.78±1.09mg GAE/gm equivalent and 4.98±0.22%w/w, respectively. The mobile phase showing distinct spots in TLC was found in Toluene: Ethyl acetate (9.5:0.5) and (9:1) for petroleum ether and methanol extracts, respectively. HPTLC fingerprinting shows 8 and 3 peaks at 366nm for petroleum ether and methanol extract, respectively.
Keywords: Bombax ceiba Linn.; pharmacognostic; phytochemical; prickle; quality control
Abraham model L solute descriptors have been determined for an additional 33 linear C7-C14 alkynes based on published gas chromatographic retention indices for solutes eluted from capillary columns coated with squalane and apiezon L stationary phases. Standard molar enthalpies of vaporization and sublimation at 298 K are calculated for the 33 linear alkynes using the reported solute descriptors and our recently published Abraham model correlations. Calculated vaporization enthalpies derived from the Abraham model compare very favourably with values based on a popular atom-group additivity model.
Keywords: Linear alkynes, Abraham model, solute descriptors, enthalpy of vaporization, Kovats retention indices
The active components of Chelidonium majus (greater celandine) is based on its sensitive and effective biologically active agents. The active components of greater celandine extracts and, therefore, their usability depends on the extraction methods. This project was to evaluate and compare the components in the extracts obtained by different new and traditional extraction methods. The extracts were obtained by aqueous and alcoholic extraction, supercritical fluid extraction, pressing-centrifugation method, microwave extraction and were examined for alkaloids, elements, and antioxidant activity. The rhizome has the highest tannin, polyphenol, and alkaloid content, while aerial parts of the plant show the highest flavonoid contents and antioxidant activities. The extracts also contain metal ions contributing to the favourable therapeutic effects that can be mainly Cu, Fe, Mn, Cr, and Zn. The traditional pressed extracts rich in alkaloids confirm their usage for the treatment of warts and these extracts also contain Cu and Fe in concentrations that are effective against viruses.
Keywords: Chelidonium majus L., alkaloids, flavonoids, metal ions, antioxidant value, supercritical fluid extraction
Ten novel usnic acid based imidazolium salts were synthesized by employing a two-step protocol. The anti-inflammatory potential of the newly synthesised compounds was evaluated in vitro against cytokine proteins TNF- α and IL-1 β secreted from U937 cells. Some of the imidazolium salts exhibited promising anti-inflammatory activity against the TNF-α and IL-1β with IC50 values ranging between 5.3 μM - 7.5 μM, which are many folds lower than that of the parent compound (>100 μM). Most significantly, substitution with electronegative groups in imidazolium salts of usnic acid found to be more potent and exhibiting enhanced anti-inflammatory activity.
Keywords: Usnic acid; imidazolium salts; anti-inflammatory activity; cytokine proteins; U937 cells