Ramesh R.,CSIR - National Chemical Laboratory |
Swaroop P.S.,CSIR - National Chemical Laboratory |
Gonnade R.G.,CSIR - National Chemical Laboratory |
Thirupathi C.,Daicel Chiral Technologies India Pvt. Ltd. |
And 3 more authors.
Journal of Organic Chemistry | Year: 2013
Preparation and assignment of absolute configurations to both enantiomers of the sex pheromone of the longtailed mealybug, an irregular monoterpenoid with extraordinary biological activity, has been completed. Comparison of the biological activities of both enantiomers and the racemate in field trials showed that the (S)-(+)-enantiomer was highly attractive to male mealybugs, strongly suggesting that female longtailed mealybugs produce this enantiomer. The (R)-(-)-enantiomer was benign, being neither attractive nor inhibitory. © 2013 American Chemical Society.
Chennuru L.N.,Daicel Chiral Technologies India Pvt. Ltd |
Choppari T.,Daicel Chiral Technologies India Pvt. Ltd |
Duvvuri S.,Rational Laboratories Pvt. Ltd |
Dubey P.K.,Jawaharlal Nehru Technological University Anantapur
Journal of Separation Science | Year: 2013
The enantioselectivity of proton pump inhibitors, namely, omeprazole, lansoprazole, rabeprazole, pantoprazole, tenatoprazole, and ilaprazole were studied using new generation chiral packing materials: CHIRALPAK IA, CHIRALPAK IB, and CHIRALPAK IC. Two versatile techniques, HPLC and supercritical fluid chromatography (SFC) were used in this study. CHIRALPAK IC has shown superior selectivity under both LC and SFC conditions, whereas CHIRALPAK IA has shown good selectivity in SFC when compared to LC under primary screening conditions. The chiral recognition ability in LC and SFC modes were found to be in the order CHIRALPAK IC > CHIRALPAK IA > CHIRALPAK IB. In addition to diode array detection, chiral detection was carried out using a laser polarimeter and the elution orders were found to be the same in both LC and SFC elution modes. Mobile phase modifiers and column temperature effects were also studied. In SFC, modifiers (cosolvent) elution strength was found to be in the order ethanol > methanol > 2-propanol > acetonitrile. In both LC and SFC, a decrease in retention and increase in resolution with an increase in temperature was noticed for all the proton pump inhibitors. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Adepu R.,University of Hyderabad |
Rambabu D.,University of Hyderabad |
Rambabu D.,Koneru Lakshmaiah College of Engineering |
Prasad B.,University of Hyderabad |
And 7 more authors.
Organic and Biomolecular Chemistry | Year: 2012
Novel thieno[2,3-d]pyrimidines containing a cyclohexane ring fused with a six- or five-membered heterocyclic moiety along with a benzylic nitrile were designed as potential inhibitors of PDE4. Expeditious synthesis of these compounds was carried out via a multi-step sequence consisting of a few key steps such as Gewald reaction, Dieckmann type cyclisation and Krapcho decarboxylation. This newly developed strategy involved construction of the thienopyrimidine ring followed by the cyclohexanone moiety and subsequently the fused heterocyclic ring. A number of thieno[2,3-d]pyrimidine based derivatives were synthesized using this method some of which showed promising PDE4B inhibitory properties. One of them was tested for PDE4D inhibition in vitro and dose dependent inhibition of TNF-α. A few selected molecules were docked into the PE4B protein the results of which showed good overall correlations to their observed PDE4B inhibitory properties in vitro. The crystal structure analysis of representative compounds along with hydrogen bonding patterns and molecular arrangement present within the molecule is described. © 2012 The Royal Society of Chemistry.
Srinivasu G.,Daicel Chiral Technologies India Pvt Ltd |
Kumar K.N.,Daicel Chiral Technologies India Pvt Ltd |
Thirupathi C.,Daicel Chiral Technologies India Pvt Ltd |
Narayana C.L.,Daicel Chiral Technologies India Pvt Ltd |
Murthy C.P.,Osmania University
Chromatographia | Year: 2016
A selective and specific high-performance liquid chromatography method for the determination of daclatasvir enantiomers has been developed and validated. Various immobilized polysaccharide-based chiral stationary phases were used to define a separation strategy utilizing normal-phase and polar organic chromatography modes. Excellent resolution between daclatasvir and its enantiomer was achieved on amylose tris (3-chlorophenylcarbamate) stationary phase, namely CHIRALPAK ID-3, using binary gradient containing acetonitrile:diethylamine and methanol:diethylamine as the mobile phase. The flow rate of the mobile phases was maintained at 1.0 mL min−1 while the column oven temperature was maintained at 40 °C. The column effluent was monitored by UV detection at 315 nm. In comparison with isocratic method, the binary gradient method offered excellent peak shape and improved resolution between daclatasvir and its enantiomer while maintaining the specificity with diastereomers. The method was found to be precise, accurate, and linear (R2 > 0.999). Limit of detection and limit of quantitation of the enantiomer were found to be 0.083 µg mL−1 as and 0.25 µg mL−1, respectively. Recovery of the enantiomer was found to be in the range of 90 to 112 %. © 2016 Springer-Verlag Berlin Heidelberg