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G Rapi

Publications and source records attributed to G Rapi.

13 recordsLinked to original sources
PubMed1992

X-ray structure analysis of 3,11,17-trioxoandrostane-5 alpha-carbonitrile and of 17 alpha-ethoxycarbonyloxy-3-oxoandrost-4-ene-17-carbonitrile.

The crystal and molecular structures of the title compounds were determined by x-ray diffractometric analysis. Torsion angles and puckering parameters are reported for both compounds. In 1 the 5 alpha-cyano group influences the A-ring conformation. The carbonate ester 3 crystallizes in the monoclinic P2(1) space group with two molecules (I and II) in the asymmetric unit. The D-ring conformation is to some extent different between I and II.

Androstanes↗
PubMed1990

Highly efficient synthesis of steroid-17-spiro-5'-oxazolidine-2',4'-diones from 17-keto steroids.

Spiro[androst-4-en-17 alpha,5'-oxazolidine]-2',3,4'-trione 8a and spiro[androst-4-en-17 alpha,5'-oxazolidine]-2',3,4',11-tetraone 8b, two potentially bioactive spiranes, were prepared from the parent 17-ketones in four steps (64% and 49.5% yield, respectively). The key intermediates were the hydroxyimidates 5a and 5b, which easily underwent cyclization to the corresponding spirooxazolinone 4'-enol ethers when treated with alkylchlorocarbonates. The respective N-amyl derivatives of the spiranes 8a and 8b were obtained with n-pentyl bromide in the presence of KF. A new method for the synthesis of steroid 17 alpha-hydroxy-17-carboxyesters and 17 alpha-hydroxy-17-carboxamides is described. Attempts to synthesize the title compounds from these products were unsuccessful.

17-Ketosteroids↗
PubMed1985

Reaction of some antiinflammatory 17 beta-(2-aminooxazol-4-yl) steroids with hydrogen peroxide. Synthesis of steroid-17-spiro-5'-oxazolidine-2',4'-diones.

The heterocyclic moiety of 17 beta-(2-aminooxazol-4-yl) steroids is sensitive to the oxidizing action of hydrogen peroxide and yields products mainly from the opening of the amino-oxazole ring. Unlike simple 2-aminooxazoles, it does not rearrange to 2-imidazolone and the expected steroidal hydroperoxyimidazolidinones were not detected. Among the substances we isolated, N-(aminocarbonyl)-17 alpha-hydroxy-17-carboxamides (2a) and (3a) undergo spontaneous cyclization, in the reaction conditions, giving steroid-17-spirooxazolidinediones (2d) and (3d). Spirane (2d) was synthesized in high yields from (2a) in strongly alkaline medium.

Anti-Inflammatory Agents↗
PubMed1983

[Phosphoric esters of vitamin D2 and D3, new substrates for alkaline phosphatase of the bovine intestine].

Phosphate esters of vitamins D2 and D3 (D2-O-P and D3-O-P) are hydrolyzed by the alkaline phosphatase from calf intestine (CAPase). pH optimum and Km values are in agreement with those reported for other substrates for intestinal alkaline phosphatase. No effect of activation was noted at low concentrations of D2-O-P and D3-O-P (10(-5)-10(-4)M) in contrast with that stated in earlier works. At higher concentrations (1-4 mM) of the phosphorilated vitamins, accordingly with their function as substrates of CAPase, an inhibitory effect on the hydrolysis of p-nitrophenylphosphate was observed.

Alkaline Phosphatase↗
PubMedDate not supplied

[Sensitivity and specificity of antigliadine antibodies in the diagnosis of celiac disease in a population of children in Toscana].

The aim of this study was to determine the value of IgA and IgG antigliadin antibody test (AGA) for screening, diagnosis and follow-up of coeliac disease. A rapid, simple, sensitive and accurate immunosorbent assay (ELISA) was used to determine AGA IgA and IgG in the sera of patients with untreated coeliac disease (I stage), coeliac patients in gluten withdrawal, healthy controls, children with gastroenterological disorders other than coeliac disease and children with constitutional short stature. In the I stage of coeliac disease the AGA IgA gave a sensitivity of 90.9% and a specificity of 97.9%, the IgG assay resulted in a sensitivity of 100% and a specificity of 82.3%. AGA IgG resulted positive in 17.7% of control disease group, but it's interesting to remark that they had a mean level significantly lower than in coeliac patients. On gluten free diet the titres of AGA IgA returned to normal value in three months, while the AGA IgG showed a slower decrease.

Adolescent↗
PubMedDate not supplied

A case of multiple sensitization to three halogeno-substituted mono-nitrobenzenes.

A case of occupational contact dermatitis in a female chemical pharmaceutical laboratory researcher is described. The allergological investigation revealed a state of sensitization to three mono-nitrobenzenes with halogen substitutions in the nucleus or a side chain. Problems related to sensitization to these substances and to possible cross-allergy with DNCB are discussed.

Adult↗