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R Cappelletti

Publications and source records attributed to R Cappelletti.

At least 19 recordsLinked to original sources
PubMed1993

Structural characterization of terflavoxate.

Data are reported on the structural characterization of 3-methyl-4-oxo-2-phenyl-4H-1-benzopyran-8-carboxylic acid 1,1-dimethyl-2-(N-piperidinyl)ethyl ester hydrochloride (terflavoxate-HCl, Rec 15/2053, CAS 86433-39-8), a new antispasmodic for the lower urinary tract. UV, IR, NMR and MS spectra fully confirmed the structure. The X-ray crystal structure determination revealed that the molecular structure consists of a rigid platform, formed by the chromone system, with two arms, the phenyl group at C(2) and the ester chain at C(8). The ester chain conformation generates a small hollow where two oxygen atoms face.

Chemical Phenomena↗
PubMed1986

Heparan sulfate endoglycosidase and metastatic potential in murine fibrosarcoma and melanoma.

Several fibroblast and melanoma cell lines were studied with respect to their ability to degrade heparan sulfate (HS). The optimum pH for HS degradation by HS endoglycosidase (heparanase) for all cell lines is about 5.6, but the activity of the enzyme is still present at physiological pH. The gel permeation analysis of degradation products revealed that heparanase cuts HS in fragments about one-seventh of their original size. Since the optimum pH of HS endoglycosidase activity and the terminal molecular weight of degraded HS are the same in both cell lines, it is likely that fibrosarcoma and melanoma heparanases are identical enzymes. Cell extracts and intact cells of metastatic sublines degrade HS faster than do their nonmetastatic counterparts. The degradative activity of intact cells parallels those of cell extracts, but at a much lower level; moreover, conditioned media do not appreciably degrade HS, suggesting that heparanase is scarcely released into the medium; thus, considering the differences in degradative activity between cell extracts and intact cells or conditioned medium and the occurrence of cell lysis in a tumor in vivo, we suggest that the measure of degradative activity of intact cells in vitro is not indicative of a relationship to metastasis. The total cellular content of lytic enzymes could represent the real metastatic potential of proliferating cells, but it is also necessary to find an in vitro model better representing the behavior of neoplastic cells in vivo.

Animals↗
PubMed1983

Involvement of chondroitin sulphate in preventing adhesive cellular interactions.

Glycosaminoglycans isolated from native non-adhesive surfaces of both endothelial and mesothelial origin and from endothelial cells cultured in vitro were analyzed by electrophoresis and characterized by chemical and enzymatic breakdown. All the surfaces examined expose in vivo chondroitin 6-sulphate as the main glycosaminoglycan. Under in vitro culture, the exposure of chondroitin sulphate is reduced. Paper chromatography of hydrolysis products upon degradation by chondroitinase AC shows equal amounts of both 6- and 4-sulphated disaccharides. At the same time, the surfaces lose their non-adhesiveness to leukocytes. The addition of fibroblast growth factor to endothelial monolayers restores both non-adhesiveness to leukocytes and exposure of chondroitin sulphate. These results seem to indicate that the exposure of chondroitin sulphate is important in preventing cellular adhesion.

Cell Adhesion↗
PubMed1982

Glycosaminoglycan changes involved in polymorphonuclear leukocyte activation in vitro.

The changes of cell coat and endocellular glycosaminoglycans associated with adhesion of polymorphonuclear leukocytes to tissue culture dishes were studied by electrophoresis on cellulose acetate. Polymorphonuclear leukocytes are coated by chondroitin 4 sulphate, while undersulphated chondroitin 4 sulphate and heparan sulphate are present in the cytoplasm. Upon adhesion polymorphonuclear leukocytes shed into the culture medium chondroitin 4 sulphate and concomitantly hyaluronic acid and heparan sulphate are exposed at the cell surface and shed into the culture medium. The role of these compounds in polymorphonuclear leukocyte physiology is discussed.

Cell Adhesion↗
PubMed1981

Binding of the basement-membrane glycoprotein laminin to glycosaminoglycans. An affinity-chromatography study.

The binding of the basement-membrane glycoprotein laminin to glycosaminoglycans (aggregating and non-aggregating subsets of heparan sulphates and dermatan sulphates, as well as heparin, chondroitin sulphates and hyaluronic acid) was studied by affinity chromatography. Partially periodate-oxidized chains of glycosaminoglycans were coupled to adipic acid dihydrazide-substituted agarose. Co-polymeric glycosaminoglycans reveal high affinity for laminin, whereas hyaluronic acid does not. Competitive-release experiments indicate that glycosaminoglycans share a common binding site on the laminin molecule.

Animals↗
PubMed1981

Involvement of glycosaminoglycans in detachment of early myeloid precursors from bone-marrow stromal cells.

Fibroblast-like cells were obtained by in vitro cultivation of needle aspirations of human bone-marrow. These cells show a unique composition of coat-associated glycosaminoglycans: 10% chondroitin 4-sulfate, 30% hyaluronic acid and 60% heparan sulfate which were resolved and characterized by electrophoresis, nitrous acid treatment and enzymatic degradation. Chondroitin 4-sulfate is the only glycosaminoglycan detectable on the surface of mature granulocytes, whereas the immature cells do not seem to possess surface glycosaminoglycans. Immature hemopoietic cells can adhere on to marrow-derived fibroblast cells, whereas mature granulocytes cannot. Treatment with mucopolysaccharidases of both mature leukocytes and marrow stromal cells can interfere in these adhesive relationships, suggesting a role of glycosaminoglycans in regulating short-range interactions during hematopoiesis.

Bone Marrow Cells↗
PubMed1981

Synthesis and antimycotic activity of alpha-aryl-beta,N-imidazolylalkyl benzyl ethers.

A new series of alpha-aryl-beta,N-imidazolylalkyl benzyl ethers was synthesized and tested for antimycotic and antimicrobial activity. Most of the compounds was highly active in vitro against fungi and gram-positive bacteria. The alpha,4-phenylthiophenyl-beta,N-imidazolylethyl benzyl ether (7) and the alpha,4-biphenyl-beta,N-imidazolylethyl benzyl ether (17) showed higher antifungal activity than 1-[2,4,dichloro-beta-(2,4-dichlorobenzyloxy)phenethyl]imidazole (miconazole) against Candida albicans. None of the compounds was more active than miconazole against Trichophyton mentagrophytes. The most interesting compounds of the series were assayed in vivo, but their activity was inconstant and always lower than that of miconazole.

Animals↗
PubMed1981

New alpha-aryl-beta,N-imidzolylethyl benzyl and naphthylmethyl ethers with antimycotic and antibacterial activity.

A new series of alpha-aryl-beta,N-imidazolylethyl benzyl and naphthylmethyl ethers was synthesized and tested for antimycotic and antimicrobial activity. All compounds showed antifungal activity; most of them were also active against gram-positive bacteria, whereas no activity was detected against gram-negative bacteria. Structure-activity relationships are discussed. The alpha-(2,4-dichlorophenyl)-beta,N-imidazolylethyl 4-phenylthiobenzyl ether nitrate (8), which showed good skin tolerability and in vivo antimycotic activity comparable with or better than 1-[2,4-dichloro-beta-(2,4-dichlorobenzyloxy)phenethyl]imidazole (miconazole) and 1-(alpha-(o-chlorophenyl)benzhydryl]imidazole (clotrimazole), was selected for further researches.

Animals↗
PubMed1980

Cell surface glycosaminoglycans in normal and leukemic leukocytes.

The intracellular and extracellular glycosaminoglycans (GAGs) of peripheral leukocytes in normal subjects and leukemic patients were characterized by electrophoresis and enzyme sensitivity. Normal peripheral granulocytes (PMN) are very rich in trypsin removable surface GAGs, while none are present on the surface of leukemic cells in acute myeloid leukemia. The intracellular and extracellular GAGs have also been analysed in the pig and compared to normal pig bone marrow haematopoietic cells. Mysenchymal cells cultured in vitro from marrow matrix and peripheral endothelial cells have also been studied. The results suggest that the exposure of cell surface chondroitin sulphate A is an important step involved in the peripheralisation of PMN.

Anemia↗