A rapid procedure for the isolation of phycobilisomes from cyanobacteria

This paper describes a method for the rapid isolation of phycobilisomes using a cationic detergent, CTAB (cetyltrimethylammonium bromide). The method has distinct advantages over those currently in use in that (i) release of intact phycobilisomes from cells in the presence of CTAB occurs in 40 s (as compared to 40-60 min of incubation required with Triton X-100), thereby reducing the chances of proteolysis of the component phycobiliproteins; and (ii) these phycobilisome preparations have reduced chlorophyll contamination in the initial stages. In addition this method also helps retain the structural and functional properties, as evidenced by spectroscopy and sodium dodecyl sulfate-polyacrylamide gel analysis.     

Therapeutic monitoring of anticonvulsant drugs in psychiatric patients: rapid, simultaneous gas-chromatographic determination of six commonly used anticonvulsants without interference from other drugs

A simple, sensitive and precise gas-chromatographic method for simultaneous extraction, derivatization and determination of methsuximide, ethosuximide, diphenylhydantoin, carbamazepine, phenobarbital and primidone in the presence of other drugs has been described. The method is especially useful for drug monitoring in patients on multiple anticonvulsant therapy while also on combination therapy with psychotropic drugs. It overcomes the analytical interferences between mephenytoin and phenobarbital; methsuximide and primidone; kemadrin and primidone; cholesterol and primidone; prolixin, haldol and other drugs; encountered in other methods using underivatized, trimethylsilylated or methylated drugs. As little as 0.5 microgram/ml of a drug can be determined and if needed the method can be scaled down to 0.3 ml plasma. The method yielded recoveries of 97-103% with standard deviations of 0.7-1.8. For a constant check of the precision, an internal quality control using daily analysis of a sample from a frozen plasma pool supplemented with known concentrations of the anticonvulsants was used. The method is suitable for use in routine clinical laboratory.     

New isoflavonoid glycosides from Dalbergia paniculata

The methanolic extract of the bark of Dalbergia paniculata has yielded three new isoflavonoid glycosides whose structures have been determined. They are 8-C-glucosylprunetin and biochanin-A and formononetin 7-rutinosides.     

Axial dispersion in plate-pulsed columns

The residence time distribution (RTD) of the phase under continuous flow and dispersed flow was measured in a plate-pulsed column under countercurrent liquid-liquid flow, and modelled using (i) the axial dispersion model and (ii) the noninteger ideal stage cascade model. The axial mixing in the continuous phase was found to be significantly higher than in the dispersed phase. The model parameters were related to the operating conditions and system variables.     

Drop size distributions in liquid pulsed columns

Drop size distributions with and without mass transfer between the phases are measured in liquid pulsed column over a wide range in experimental conditions. The data are comprehensively analysed and correlations are proposed for Sauter mean diameter based on the data including the data reported in literature.