Volumetric microdetermination of sulphonamides

Abstract

A rapid and convenient method for the determination of sulphonamides was based upon the reaction with bromine monochloride and titration of excess reagent by iodometry.The method has been applied to the determination of sulphapyridine, sulphathiazole, sulphaguanidine and sulphadiazine. The number of moles of BrC1 consumed per mole of these compounds is 8, 7, 5 and 7, respectively. 2--10mg were determined with deviations of =k 1 ~ on the average.Procedure. An aliquot containing 2--10rag os the sample is placed in a i00mI iodine flask. Add 5ml of glacial acetic acid and 5ml of BrC1 solution (1.3917g KBrO a -}-1.9835 KBr in 125ml of water, after cooling addition of 100ml of cone. hydrochloric acid and dilution to 500ml), stopper and shake. Cool for 20rain in ice bath, wash stopper with 5ml of water, add 5ml of 15~ KI solution and titrate the liberated iodine with 0.02N sodium thiosulphate solution using starch as indicator. Run a blank under the same conditions.

The human hnRNP-M proteins: structure and relation with early heat shock-induced splicing arrest and chromosome mapping

“…In contrast to what has been shown following 1-2 h heat shocks (3,4,17), early induced splicing arrest cannot be ascribed to U-snRNP disruption, since normal extracts, in which U-snRNPs are hydrolyzed, still restore the splicing capacity of nuclear extracts from cells stressed for 10 min at 45_C. This is in agreement with immunocytofluorescence data showing that anti-snRNP monoclonal antibodies did not reveal any difference in the nuclear speckled pattern between normal cells and cells stressed at 45_C for 10 min (unpublished observation), whereas after 15 min the signal is uniformly distributed throughout the nucleoplasm (48).…”

“…It has been shown by others that nuclear extracts from HeLa cells heat shocked for 1-2 h at the upper temperature range of the stress response are inactive in splicing in vitro; in such conditions the structure of U-snRNPs, which are essential splicing components (28,29), was found to be altered (3,17). Whether a 10 min heat (MN, lane 7).…”

“…The latter aspect is all the more interesting since most published data describe heat-shock effects on splicing following stress periods of 1-2 h (3,4,17). Since the original 6D12 monoclonal antibody (IgM) was of limited use in such functional studies, we cloned and sequenced the cDNA encoding this antigen doublet and further raised monoclonal and polyclonal anti-peptide antibodies.…”

Associations between distinct pre-mRNA splicing components and the cell nucleus.

“…The speckles detected with ctSC-35 antibodies became more rounded or compact in appearance upon heat shock, and the connections between speckles were no longer apparent. In addition, splicing activity was shown to be abolished in HeLa cell nuclear extracts prepared from cells exposed to a severe heat stress (Bond, 1988;Shukla et al, 1990). These findings are of particular interest in light of earlier biochemical studies showing that treatment of cells with heat shock blocks RNA processing (Yost and Lindquist, 1987;Bond.…”

Principal Component Analysis towards viability of Cicer arietinum seeds using electric field under laboratory condition

“…Average germination percentage is estimated using the following equation [13]. Where N i = total number of germinated seeds on the ith day and D i = Number of seeds used.…”