Synthesis and characterization of diaza analogues of podophyllotoxin

In an attempt to synthesize the novel diaza analogues of podophyllotoxin (7a-d) in five step reactions. The synthesis of title compounds has been achieved from tetralones, which were formylated with ethylformate; prepared via cyclization with hydrazine hydrate. Furthermore, these newly synthesized compounds were characterized by spectral and elemental analysis data

Synthesis and study of antimicrobial activity of new tetralone esters

Podophyllotoxin belongs to the class of cyclolignan family of natural products, which exhibits strong antimitotic, anti-AIDS (HIV), antitropical skin disease, antimalarial, virucidal, fungicidal and other biological activities. The new tetralone esters (9a-d) of podophyllotoxin analogues were synthesized in good yields by chalcone route to study their structure-activity relationship. All the products obtained were characterized by spectral and elemental analysis data and they were screened for antimicrobial activity. Compounds 9b and 9c were shown significant antibacterial and antifungal activities

Spectrophotometric Determination of Isoxsuprine Hydrochloride as Base Form in Pharmaceutical Formulation through Charge Transfer Complexation

Two simple and selective spectrophotometric methods are described for the determination of isoxsuprine hydrochloride (ISX·HCl) as base form in bulk drug and in injections and tablets. The methods are based on the molecular charge-transfer complexation of ISX base (ISX) with either p-chloranilic acid (PCA) or 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The intense colored radical anions formed on dissociation, are quantitated at 520 nm (PCA method) or 600 nm (DDQ method). The optimum assay conditions were optimized. Beer\u27s law is obeyed in the concentration ranges 5.28 × 10–5 to 42.2 × 10–5 mol dm–3 in PCA method and 0.79 × 10–5 to 10.6 × 10–5 mol dm–3 in DDQ method, with respective molar absorptivity values of 1.32 × 103 and 6.55 × 103 dm3 mol–1 cm–1. The reaction stoichiometry in both methods was evaluated by either Job’s method or limiting logarithmic method and was found to be 1:1 (ISX: PCA, ISX: DDQ). Developed methods were validated according to ICH guidelines and found to be accurate and precise

Synthesis and evaluation of antimitotic activity of new tetralone acid analogues of podophyllotoxin

The new tetralone acids (7a-e) were synthesized as analogues of podophyllotoxin. They were prepared by replacing 3,4,5-trimethoxyphenyl ring with cyclohexyl group in podophyllotoxin and 1,3-methylene dioxy ring with methoxy, hydrogen, methyl, thiomethyl, and fluorine atoms. The analogues of podophyllotoxin were synthesized using Gensler’s method with some changes in reagents and experimental procedure. The structures of the synthesized compounds were confirmed by IR, 1H NMR, 13C NMR, mass spectra and elemental analysis data. The synthesized tetralones acids were screened for their antimitotic activity. It is noteworthy that compound 7b possessed excellent antimitotic activity, 7c and 7e showed considerable activity and remaining 7a and 7d possessed low activity

Spectrophotometric Determination of Isoxsuprine Hydrochloride as Base Form in Pharmaceutical Formulation through Charge Transfer Complexation

Two simple and selective spectrophotometric methods are described for the determination of isoxsuprine hydrochloride (ISX·HCl) as base form in bulk drug and in injections and tablets. The methods are based on the molecular charge-transfer complexation of ISX base (ISX) with either p-chloranilic acid (PCA) or 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The intense colored radical anions formed on dissociation, are quantitated at 520 nm (PCA method) or 600 nm (DDQ method). The optimum assay conditions were optimized. Beer\u27s law is obeyed in the concentration ranges 5.28 × 10–5 to 42.2 × 10–5 mol dm–3 in PCA method and 0.79 × 10–5 to 10.6 × 10–5 mol dm–3 in DDQ method, with respective molar absorptivity values of 1.32 × 103 and 6.55 × 103 dm3 mol–1 cm–1. The reaction stoichiometry in both methods was evaluated by either Job’s method or limiting logarithmic method and was found to be 1:1 (ISX: PCA, ISX: DDQ). Developed methods were validated according to ICH guidelines and found to be accurate and precise

Extractive Spectrophotometric Determination of Quetiapine Fumarate in Pharmaceuticals and Spiked Human Urine

A simple, sensitive and selective extractive spectrophotometric method for the determination of quetiapine fumarate (QTF) in bulk drug, tablets and spiked human urine sample is described. The method is based on the formation of a chloroform extractable yellow ion-pair complex between basic nitrogen of the drug (QTF) and the dye quinoline yellow (QY) in acetate-hydrochloride buffer (pH 2.56) medium. The formed ion-pair complex exhibited an absorption maximum at 420 nm. Beer’s law is obeyed over the concentration range 2.5–25 µg mL–1 with an apparent molar absorptivity value of 2.02 × 104 L mol–1 cm–1. The Sandell sensitivity, limits of detection (LOD) and quantification values are also reported. The composition of the ion-pair was established by Job’s continuous variations method and it was found to be 1:1 (QTF:QY). The proposed method was successfully applied for the determination of QTF in bulk drug, tablets and spiked human urine without any interference. (doi: 10.5562/cca1770

Synthesis and characterization of tetralones as intermediates for podophyllotoxin analogues

Podophyllotoxin has captured the attention of chemists all over the world for its biological activity. It was isolated from many plants of Podophyllum species such as Podophyllum emodi, Podophyllum peltatum and others. It mainly exhibits anticancer, antimitotic, antimalarial, anti-aids and other activities. Its use is restricted due to its toxicity and unfavourable solubility. It was aimed to synthesize some new heterocyclic analogues of podophyllotoxin by changing the substituents by changing lactone ring with pyrazoline ring and substituents in ring C with hydrogen and methoxy group. Chalcones were prepared by Claisen-Schmidt reaction of 1,3-methylene dioxyacetophenone with benzaldehyde and p-anisaldehyde. The reaction of chalcone with trimethylsulphoxonium iodide in presence of sodium hydride gave cyclopropyl ketone. Intramolecular cyclization reaction of cyclopropyl ketone gave tetralone intermediates of podophyllotoxin. They are obtained in good yields. The structure of all the products was confirmed by spectral data

Applications of liver acetone powders in enantioselective synthesis

Applications of liver acetone powders (crude enzymes) as possible substitutes for purified enzyme preparations, hydrolases, in enantioselective organic transformations have been systematically investigated. (1R, 2R)-2-(4-Alkylphenoxy)cyclohexan-1-ols, (1R, 2R)- & (1S, 2S)- 2-nitroxycyclohexan-1-ols, (1R, 2S)-2-arylcyclohexan-1-ols, (3R, 4R)-6-methyl-3-phenylhept-1- en-4-ol, and (R)-1-(naphth-1-yl)ethanol have been synthesized in enantiomerically pure form via the enantioselective hydrolysis of the corresponding racemic acetates mediated by liver acetone powders

Determination of olanzapine by spectrophotometry using permanganate

Two new spectrophotometric methods using permanganate as the oxidimetric reagent for the determination of olanzapine (OLP) were developed and validated as per the current ICH guidelines. The methods involved the addition of known excess of permanganate to OLP in either acid or alkaline medium followed by the determination of unreacted permanganate at 550 nm (method A) or bluish-green color of manganate at 610 nm (method B). The decrease in absorbance in method A or increase in absorbance in method B as a function of concentration of OLP was measured and related to OLP concentration. Under optimized conditions, Beer's law was obeyed over the ranges 2.0 to 20 and 1.0 to 10 μg mL-1 in method A and method B, respectively. The calculated molar absorptivity values were 1.34 x 10(4) and 2.54 x 10(4) l mol-1cm-1 for method A and method B respectively, and the respective Sandell sensitivities were 0.0233 and 0.0123 μg cm-2. The LOD and LOQ for method A were calculated to be 0.37 and 1.13 μg mL-1and the corresponding values for method B were 0.16 and 0.48 μg mL-1. Intermediate precision, expressed as RSD was in the range 0.51 to 2.66 %, and accuracy, expressed as relative error ranged from 0.79 to 2.24 %. The proposed methods were successfully applied to the assay of OLP in commercial tablets with mean percentage recoveries of 102 ±1.59 % (method A) and 101 ±1.53 % (method B). The accuracy and reliability of the methods were further confirmed by performing recovery tests via standard addition procedure.Dois métodos espectrofotométricos novos, usando o permanganato como o reagente oxidimétrico para a determinação da olanzapina (OLP) foram utilizados e validados de acordo com as diretrizes atuais do ICH. Os métodos envolveram a adição de excesso conhecido de permanganato à OLP em meio ácido ou alcalino, determinando-se o permanganato que não reagiu em 550 nm (método A), ou pela cor verde-azulada do manganato a 610 nm (método B). A diminuição da absorbância no método A ou o aumento da absorbância no método B, em função da concentração de OLP, foi medida e relacionada à concentração de OLP. Sob condições otimizadas, a lei de Beer foi obedecida, nas faixas de concentração de 2,0 a 20 e 1,0 a 10 ao μg mL-1, no método A e no método B, respectivamente. Os valores de absortividade molar foram de 1,34 x 104 e 2,54 x 104 l mol-1cm-1 para o método A e para o método B, respectivamente, e as sensibilidades respectivas de Sandell foram de 0,0233 e 0,0123 μg cm-2. Os LOD e os LOQ para o método A calculados foram 0,37 e 1,13 μg mL-1e os valores correspondentes para o método B foram 0,16 e 0,48 μg mL-1. A precisão intermediária, expressa como RSD, encontrou-se na faixa de 0,51 a 2,66%, e a exatidão, expressa como o erro relativo, variou de 0,79 a 2,24%. Os métodos propostos foram aplicados com sucesso ao ensaio de OLP em comprimidos comerciais, com porcentagens médias de recuperação de 102± 1,59% (método A) e de 101± 1,53% (método B). A exatidão e a confiabilidade dos métodos foram confirmadas executando testes de recuperação através de procedimento padrão de adição

Constraints faced in the Adoption of Technologies by Chawki Rearing Centre Entrepreneurs

Chawki Rearing Centres (CRCs) act as backbone of silkworm rearing activity. The study was conducted in 100 CRCs of six traditional sericultural districts of Karnataka with the objective of understanding the constraints faced by CRC entrepreneurs in adoption of recommended technologies. Through pilot survey, 30 constraints were identified and they were ranked based on Garrett score. While shortage of farm laborers, scarcity of irrigation water, lack of technical guidance in pest and disease management, difficulty in harvesting leaf and shootlet alternatively and high labor wages were the major constraints in adoption of mulberry leaf production technologies, inadequate rearing space, scarcity of skilled workers, lack of space for supporting activities, lack of technical guidance to diagnose diseases and high wages of skilled workers were the major constraints in adoption of silkworm rearing technologies. Measures to be taken to overcome these constraints are suggested