The biochemistry of aromatic amines. 2-Formamido-1-naphthyl hydrogen sulphate, a metabolite of 2-naphthylamine

1. 2-Formamido-1-naphthyl hydrogen sulphate is excreted by dogs and rats dosed with 2-naphthylamine or with 2-amino-1-naphthyl hydrogen sulphate and was isolated from dog urine. 2. 2-Formamido-1-naphthol, naphtho[2,1-d]oxazole and N-formyl-2-naphthylhydroxylamine are excreted as (2-formamido-1-naphthyl glucosid)uronic acid. 2-Formamidonaphthalene is converted into conjugates of 2-amino-6-naphthol and 2-amino-8-naphthol, but 2-methylaminonaphthalene is excreted as 2-amino-1-naphthyl hydrogen sulphate and its N-methyl and N-formyl derivatives and (2-amino-1-naphthyl glucosid)uronic acid. 3. 2-Methylamino-1-naphthyl hydrogen sulphate is converted into 2-formamido-1-naphthyl hydrogen sulphate and 2-amino-1-naphthyl hydrogen sulphate on charcoal. 2-Amino-1-naphthyl hydrogen sulphate and formaldehyde react on charcoal to yield 2-methylamino- and 2-formamido-1-naphthyl hydrogen sulphate. 4. 2-Formamido-1-naphthol, 2-formamido-1-naphthyl hydrogen sulphate, N-formyl-2-naphthylhydroxylamine and N-formyl-2-naphthylhydroxylamine-O-sulphonic acid were synthesized.     

Isolation and characterization of dermatan sulphate and heparan sulphate proteoglycans from fibroblast culture.

35SO42(-)- and [3H]leucine-labelled proteoglycans were isolated from the medium and cell layer of human skin fibroblast cultures. Measures were taken to avoid proteolytic modifications during isolation by adding guanidinium chloride and proteolysis inhibitors immediately after harvest. The proteoglycans were purified and fractionated by density-gradient centrifugation, followed by gel and ion-exchange chromatography. Our procedure permitted the isolation of two major proteoglycan fractions from the medium, one large, containing glucuronic acid-rich dermatan sulphate chains, and one small, containing iduronic acid-rich ones. The protein core of the latter proteoglycan had an apparent molecular weight of 47000 as determined by polyacrylamide-gel electrophoresis, whereas the protein core of the former was considerably larger. The major dermatan sulphate proteoglycan of the cell layer was similar to the large proteoglycan of the medium. Only small amounts of the iduronic acid-rich dermatan sulphate proteoglycan could be isolated from the cell layer. Instead most of the iduronic acid-rich glycans appeared as free chains. The heparan sulphate proteoglycans found in the cell culture were largely confined to the cell layer. This proteoglycan was of rather low buoyant density and seemed to contain a high proportion of protein. The major part of the heparan sulphate proteoglycan from the medium had a higher buoyant density and contained a smaller amount of protein.     

Isolation of a trisaccharide containing 2-amino-2-deoxy-D-galacturonic acid from the Bordetella pertussis endotoxin

4-O-(2-Amino-2-deoxy-alpha-D-glucopyranosyl-6-O-(2-amino-2-deoxy-alpha-D-galactopyranuronyl)-D-glucopyranose, a branched-chain trisaccharide, was isolated after hydrolysis of Bordetella pertussis endotoxin with 4 M HCl for 1 h at 100 degrees C. The trisaccharide was present in both polysaccharide moieties of the two constituent lipopolysaccharides of this endotoxin. Its structure was established by analysis of the 400-MHz nuclear magnetic resonance spectrum and by chemical and enzymatic degradation.     

Isolation and partial characterization of keratan sulphate from human brain

A sulphated glycoconjugate was isolated from adult human brain from a glycosaminoglycan fraction which was not precipitated with 1% cetylpyridinium chloride or ethanol below 50% concentration. It appeared heterogeneous on gel filtration, exhibiting a molecular weight range from about 7000 to over 10 000. Its main covalent structure was shown to contain sulphated, repeating disaccharide units of (beta-D-galactose-(1----4)-N-acetyl-D-glucosamine-(1----3)). In addition, it was susceptible to degradation by keratan sulphate endo-beta-galactosidase and thus was assumed to be keratan sulphate.     

Inhibition of hydrogen peroxide-induced necrotic cell death with 3-amino-2-indolylmaleimide derivatives

Novel analogs of indolylmaleimide derivatives (IM derivatives) were synthesized and tested for cell death-inhibitory activity. 2-(1H-Indol-3-yl)-3-pentylamino-maleimide IM-54 was the most effective cell death inhibitor among the compounds tested. IM-54 inhibited necrotic cell death induced by H2O2, but not apoptotic cell death induced by etoposide. These results indicated that this novel cell death inhibitor is distinct from the well-known caspase inhibitor, Z-VAD, which can block apoptotic cell death, but not necrotic cell death. IM-54 is expected to be a powerful bioprobe for clarifying the unique signaling pathway of necrotic cell death.     

Isolation and characterization of dermatan sulphate proteoglycans from bovine sclera.

1. Proteoglycans were extracted from sclera with 4 M-guanidine hydrochloride in the presence of proteinase inhibitors and purified by ion-exchange chromatography and density-gradient centrifugation. 2. The entire proteoglycan pool was characterized by compositional analyses and by specific chemical (periodate oxidation) and enzymic (chondroitinases) degradations. The glycan moieties of the molecules were exclusively galactosaminoglycans (dermatan sulphate-chondroitin sulphate co-polymers). In addition, the preparations contained small amounts of oligosaccharides. 3. The scleral proteodermatan sulphates were fractionated into one larger (I) and one smaller (II) component by gel chromatography. Proteoglycan I was eluted in a more excluded position on gel chromatography in 0.5 M-sodium acetate than in 4.0 M-guanidine hydrochloride. Reduced and alkylated proteoglycan I was eluted in the same position (in 0.5 M-sodium acetate) as was the starting material (in 4.0 M-guanidine hydrochloride). The elution position of proteoglycan II was the same in both solvents. Proteoglycans I and II had s0 20,w values of 2.8 x 10(-13) and 2.2 x 10(-13) s respectively in 6.0 M-guanidine hydrochloride. 4. The two proteoglycans differed with respect to the nature of the protein core and the co-polymeric structure of their side chains. Also proteoglycan I contained more side chains than did proteoglycan II. The dermatan sulphate side chains of proteoglycan I were D-glucuronic acid-rich (80%), whereas those of proteoglycan II contained equal amounts of D-glucuronic acid and L-iduronic acid. Furthermore, the co-polymeric features of the side chains of proteoglycans I and II were different. The protein core of proteoglycan I was of larger size than that of proteoglycan II. The latter had an apparent molecular weight of 46 000 (estimated by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis), whereas the former was greater than 100 000. In addition, the amino-acid composition of the two core preparations was different. 5. As proteoglycan I altered its elution position on gel chromatography in 4 M-guanidine hydrochloride compared with 0.5 M-sodium acetate it is proposed that a change in conformation or a disaggregation took place. If the latter hypothesis is favoured, aggregation may be due to self-association or mediated by an extrinsic molecule, e.g. hyaluronic acid.     

Isolation and identification of chemical constituents from tomato

采用机械破碎法和果胶酶酶解法,使成熟番茄果实细胞内含物充分释放,上清液经D-101大孔树脂富集吸附后,再经一系列柱色谱分离得到6个化合物,根据其理化性质和波谱分析,分别鉴定为:芦丁(1)、槲皮素(2)、木犀草素(3)、番茄皂苷A(4)、豆甾醇(5)、熊果酸(6).其中,化合物1、2、3、5、6为首次从该植物中分离得到.