Cycloartenol synthase from Arabidopsis thaliana and lanosterol synthase from Trypanosoma cruzi an... more Cycloartenol synthase from Arabidopsis thaliana and lanosterol synthase from Trypanosoma cruzi and Pneumocystis carinii were expressed in yeast, and their subcellular distribution in the expressing cells was compared. Determination of enzymatic (oxidosqualene cyclase, OSC) activity and SDS-PAGE analysis of subcellular fractions proved that enzymes from T. cruzi and A. thaliana have high affinity for lipid particles, a subcellular compartment rich in triacylglycerols, and steryl esters, harboring several enzymes of lipid metabolism. In lipid particles of strains expressing the P. carinii enzyme, neither OSC activity nor the electrophoretic band at the appropriate M.W. were detected. Microsomes from the three expressing strains retained some OSC activity. Affinity of enzymes from A. thaliana and T. cruzi for lipid particles is similar to that of OSC of Saccharomyces cerevisiae, which is mainly located in this compartment. A different distribution of OSC in yeast cells suggests that they differ in some structural features critical for the interaction with the surface of lipid particles. Computer analysis supports the hypothesis of the structural difference since OSC from S. cerevisiae, A. thaliana, and T. cruzi lack or contain only one transmembrane spanning domain (a structural feature that makes a protein poorly inclined to associate with lipid particles), whereas OSC from P. carinii possesses six transmembrane domains. In the strain expressing cycloartenol synthase from A. thaliana, the accumulation of lipid particles largely exceeded that of the other strains.
European Journal of Medicinal Chemistry, Nov 1, 1988
... squalenoid oxaziridine and other new classes of squalene derivatives, as inhibitors of sterol... more ... squalenoid oxaziridine and other new classes of squalene derivatives, as inhibitors of sterol biosynthesis Maurizio CERUTIl, Franca VIOLA, Gianni BALLIANOl, Giorgio ... Narula AS, Cattel L., Anding C. Place P. (19S6) Lipids 21, 52 Crosby LO, van Tamelen EE Clayton RB (1969 ...
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
A new metabolite of the diuretic drug bumetanide, the 4-[(4'-hydroxy)-phenoxy] analog (7), wa... more A new metabolite of the diuretic drug bumetanide, the 4-[(4'-hydroxy)-phenoxy] analog (7), was identified in incubation mixtures of rat liver microsomes. Phenobarbital and clofibrate pretreatment to induce microsomal enzymes changed the relative amounts of the six metabolites formed. Compound 7was the most prevalent metabolite after clofibrate pretreatment.
Aberrant cholesterol homeostasis and biosynthesis has been observed in different tumour types. Th... more Aberrant cholesterol homeostasis and biosynthesis has been observed in different tumour types. This paper investigates the role of the post-squalenic enzyme of cholesterol biosynthesis, oxidosqualene cyclase (OSC), in regulating tumour angiogenesis and metastasis dissemination in mouse models of cancer. We showed that Ro 48-8071, a selective inhibitor of OSC, reduced vascular density and increased pericyte coverage, with a consequent inhibition of tumour growth in a spontaneous mouse model of pancreatic tumour (RIP-Tag2) and two metastatic mouse models of human colon carcinoma (HCT116) and pancreatic adenocarcinoma (HPAF-II). Remarkably, the inhibition of OSC hampered metastasis formation in HCT116 and HPAF-II models. Ro 48-8071 induced tumour vessel normalization and enhanced the anti-tumoral and anti-metastatic effects of 5-fluorouracil (5-FU) in HCT116 mice. Ro 48-8071 exerted a strong anti-angiogenic activity by impairing endothelial cell adhesion and migration, and by blocking ...
Journal of the Chemical Society, Perkin Transactions 1, 1988
... Maurizio Ceruti, Franca Viola, Franco Dosio, and Luigi Cattel* lstituto di Chimica Farmaceuti... more ... Maurizio Ceruti, Franca Viola, Franco Dosio, and Luigi Cattel* lstituto di Chimica Farmaceutica Applicata, Corso Raffaello 3 I, TO725 Torino, Italy Pierrette Bouvier-Nave Laboratoire de Biochimie Vegetale et de Chimie Enzymatique (UA 5 7 0 ) lnstitut de Botanique, 28 Rue ...
The Aspergillus aureofulgens ability to cleave the side chain of progesterone (I) and the related... more The Aspergillus aureofulgens ability to cleave the side chain of progesterone (I) and the related C-21 steroids was studied. The enzymic system responsible for the progesterone side chain degradation was demonstrated to be adaptative and to operate by a Baeyer-Villiger mechanism. The cleavage of the side chain of the progesterone and of the related compounds was followed by the stereospecific reduction of the formed androst-4-ene-3,17-dione(II) to the 5 beta-androstan derivatives. Both the oxygenase and reductase activities seemed to be influenced by the growth conditions. Several steroids bearing different skeleton functions and different side chains were also tested in order to correlate the chemical structure with the microbial activity.
2,3-Epoxy-10-aza-10,11-dihydrosqualene, a high-energy intermediate analogue inhibitor of 2,3-oxid... more 2,3-Epoxy-10-aza-10,11-dihydrosqualene, a high-energy intermediate analogue inhibitor of 2,3-oxidosqualene (SO) cyclase was obtained by total synthesis. This involved the preparation of three main building blocks: (1) C17 squalenoid N-methylamine, (2) 3-(diphenylphosphinoyl)propanal, and (3) 5,6-epoxy-6-methylheptan-2-one. The final stages of the reconstruction of the 6E double bond were obtained by a Wittig-Horner reaction which was modified for poorly reactive systems. This compound was designed to mimic the C-8 carbonium ion formed during SO cyclization. Its inhibitory activity on various SO cyclases was evaluated and compared with the 6 Z isomer which has an unfavorable geometry. Only isomer 6 E, the carbocation analogue, was active on SO cyclases from rat liver, pig liver, S. cerevisiae, and C. albicans microsomes, with an I50 varying from 3 to 5 microM. Both E and Z isomers were inactive on squalene epoxidase at the higher concentrations tested.
Journal of the Chemical Society, Perkin Transactions 1, 1995
ABSTRACT Z-Fluorosqualene derivatives having one or more fluorine atoms at the terminal methyls o... more ABSTRACT Z-Fluorosqualene derivatives having one or more fluorine atoms at the terminal methyls of the squalene skeleton have been synthesized. A highly stereoselective synthesis, based on a Wittig reaction, was developed together with a new method for obtaining bifunctional derivatives of squalene. The compounds tested showed poor inhibitory activity on squalene epoxidase and 2,3-oxidosqualene cyclase from microsomes of Saccharomyces cerevisiae, Candida albicans and rat liver, and on S. cerevisiae and 3T3 fibroblast cell cultures.
Various classes of inhibitor of 2,3-oxido squalene cyclase have been synthesized and tested on ra... more Various classes of inhibitor of 2,3-oxido squalene cyclase have been synthesized and tested on rat liver and Saccharomyces cerevisiae microsomes, 3T3 fibroblast cultures, and various bacteria, fungi, and yeasts. The compounds include azasqualenes, azasqualanes, bis-azasqualenes, bis-azasqualanes, and N-oxide and ammonium derivatives of squalene. In order to better mimic the transition state involved in the SN2-like opening of 2,3-oxidosqualene, we synthesized squalene N-methyloxaziridine. Other derivatives tested were N-methylimine, aminalic hydroperoxide, and N-methylamide. We also attempted to produce new "suicide" inhibitors of SO cyclase, such as a squalenoid epoxide vinyl ether. Many of the products described inhibited the various cyclases, the best having an IC50 of 0.3 microM on plants and 1.5 microM on rat liver microsomes, and good antibacterial and antifungal activity. In a search for inhibitors of squalene epoxidase, a series of mono- and bifunctional squalenoid acetylenes and allenes were synthesized. Some of them proved to be inhibitors of squalene epoxidase.
Various (1E,3E)- and (1Z,3E)-conjugated methylthio derivatives of oxidosqualene (OS) and conjugat... more Various (1E,3E)- and (1Z,3E)-conjugated methylthio derivatives of oxidosqualene (OS) and conjugated and non-conjugated phenylthio derivatives of OS were obtained. These compounds, designed as inhibitors of pig liver and Saccharomyces cerevisiae 2,3-oxidosqualene-lanosterol cyclases (OSC) (EC 5.4.99.7) and of Alicyclobacillus acidocaldarius squalene-hopene cyclase (SHC) (EC 5.4.99.-), contain the reactive function adjacent to carbons involved in the formation of the third and the fourth cycle during OS cyclization. All the new compounds are inhibitors of OSC and SHC, with various degrees of selectivity. The conjugated methylthio derivatives behaved as potent inhibitors of S. cerevisiae OSC, whereas most of the phenylthio derivatives were especially active toward SHC.
Cycloartenol synthase from Arabidopsis thaliana and lanosterol synthase from Trypanosoma cruzi an... more Cycloartenol synthase from Arabidopsis thaliana and lanosterol synthase from Trypanosoma cruzi and Pneumocystis carinii were expressed in yeast, and their subcellular distribution in the expressing cells was compared. Determination of enzymatic (oxidosqualene cyclase, OSC) activity and SDS-PAGE analysis of subcellular fractions proved that enzymes from T. cruzi and A. thaliana have high affinity for lipid particles, a subcellular compartment rich in triacylglycerols, and steryl esters, harboring several enzymes of lipid metabolism. In lipid particles of strains expressing the P. carinii enzyme, neither OSC activity nor the electrophoretic band at the appropriate M.W. were detected. Microsomes from the three expressing strains retained some OSC activity. Affinity of enzymes from A. thaliana and T. cruzi for lipid particles is similar to that of OSC of Saccharomyces cerevisiae, which is mainly located in this compartment. A different distribution of OSC in yeast cells suggests that they differ in some structural features critical for the interaction with the surface of lipid particles. Computer analysis supports the hypothesis of the structural difference since OSC from S. cerevisiae, A. thaliana, and T. cruzi lack or contain only one transmembrane spanning domain (a structural feature that makes a protein poorly inclined to associate with lipid particles), whereas OSC from P. carinii possesses six transmembrane domains. In the strain expressing cycloartenol synthase from A. thaliana, the accumulation of lipid particles largely exceeded that of the other strains.
European Journal of Medicinal Chemistry, Nov 1, 1988
... squalenoid oxaziridine and other new classes of squalene derivatives, as inhibitors of sterol... more ... squalenoid oxaziridine and other new classes of squalene derivatives, as inhibitors of sterol biosynthesis Maurizio CERUTIl, Franca VIOLA, Gianni BALLIANOl, Giorgio ... Narula AS, Cattel L., Anding C. Place P. (19S6) Lipids 21, 52 Crosby LO, van Tamelen EE Clayton RB (1969 ...
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
A new metabolite of the diuretic drug bumetanide, the 4-[(4'-hydroxy)-phenoxy] analog (7), wa... more A new metabolite of the diuretic drug bumetanide, the 4-[(4'-hydroxy)-phenoxy] analog (7), was identified in incubation mixtures of rat liver microsomes. Phenobarbital and clofibrate pretreatment to induce microsomal enzymes changed the relative amounts of the six metabolites formed. Compound 7was the most prevalent metabolite after clofibrate pretreatment.
Aberrant cholesterol homeostasis and biosynthesis has been observed in different tumour types. Th... more Aberrant cholesterol homeostasis and biosynthesis has been observed in different tumour types. This paper investigates the role of the post-squalenic enzyme of cholesterol biosynthesis, oxidosqualene cyclase (OSC), in regulating tumour angiogenesis and metastasis dissemination in mouse models of cancer. We showed that Ro 48-8071, a selective inhibitor of OSC, reduced vascular density and increased pericyte coverage, with a consequent inhibition of tumour growth in a spontaneous mouse model of pancreatic tumour (RIP-Tag2) and two metastatic mouse models of human colon carcinoma (HCT116) and pancreatic adenocarcinoma (HPAF-II). Remarkably, the inhibition of OSC hampered metastasis formation in HCT116 and HPAF-II models. Ro 48-8071 induced tumour vessel normalization and enhanced the anti-tumoral and anti-metastatic effects of 5-fluorouracil (5-FU) in HCT116 mice. Ro 48-8071 exerted a strong anti-angiogenic activity by impairing endothelial cell adhesion and migration, and by blocking ...
Journal of the Chemical Society, Perkin Transactions 1, 1988
... Maurizio Ceruti, Franca Viola, Franco Dosio, and Luigi Cattel* lstituto di Chimica Farmaceuti... more ... Maurizio Ceruti, Franca Viola, Franco Dosio, and Luigi Cattel* lstituto di Chimica Farmaceutica Applicata, Corso Raffaello 3 I, TO725 Torino, Italy Pierrette Bouvier-Nave Laboratoire de Biochimie Vegetale et de Chimie Enzymatique (UA 5 7 0 ) lnstitut de Botanique, 28 Rue ...
The Aspergillus aureofulgens ability to cleave the side chain of progesterone (I) and the related... more The Aspergillus aureofulgens ability to cleave the side chain of progesterone (I) and the related C-21 steroids was studied. The enzymic system responsible for the progesterone side chain degradation was demonstrated to be adaptative and to operate by a Baeyer-Villiger mechanism. The cleavage of the side chain of the progesterone and of the related compounds was followed by the stereospecific reduction of the formed androst-4-ene-3,17-dione(II) to the 5 beta-androstan derivatives. Both the oxygenase and reductase activities seemed to be influenced by the growth conditions. Several steroids bearing different skeleton functions and different side chains were also tested in order to correlate the chemical structure with the microbial activity.
2,3-Epoxy-10-aza-10,11-dihydrosqualene, a high-energy intermediate analogue inhibitor of 2,3-oxid... more 2,3-Epoxy-10-aza-10,11-dihydrosqualene, a high-energy intermediate analogue inhibitor of 2,3-oxidosqualene (SO) cyclase was obtained by total synthesis. This involved the preparation of three main building blocks: (1) C17 squalenoid N-methylamine, (2) 3-(diphenylphosphinoyl)propanal, and (3) 5,6-epoxy-6-methylheptan-2-one. The final stages of the reconstruction of the 6E double bond were obtained by a Wittig-Horner reaction which was modified for poorly reactive systems. This compound was designed to mimic the C-8 carbonium ion formed during SO cyclization. Its inhibitory activity on various SO cyclases was evaluated and compared with the 6 Z isomer which has an unfavorable geometry. Only isomer 6 E, the carbocation analogue, was active on SO cyclases from rat liver, pig liver, S. cerevisiae, and C. albicans microsomes, with an I50 varying from 3 to 5 microM. Both E and Z isomers were inactive on squalene epoxidase at the higher concentrations tested.
Journal of the Chemical Society, Perkin Transactions 1, 1995
ABSTRACT Z-Fluorosqualene derivatives having one or more fluorine atoms at the terminal methyls o... more ABSTRACT Z-Fluorosqualene derivatives having one or more fluorine atoms at the terminal methyls of the squalene skeleton have been synthesized. A highly stereoselective synthesis, based on a Wittig reaction, was developed together with a new method for obtaining bifunctional derivatives of squalene. The compounds tested showed poor inhibitory activity on squalene epoxidase and 2,3-oxidosqualene cyclase from microsomes of Saccharomyces cerevisiae, Candida albicans and rat liver, and on S. cerevisiae and 3T3 fibroblast cell cultures.
Various classes of inhibitor of 2,3-oxido squalene cyclase have been synthesized and tested on ra... more Various classes of inhibitor of 2,3-oxido squalene cyclase have been synthesized and tested on rat liver and Saccharomyces cerevisiae microsomes, 3T3 fibroblast cultures, and various bacteria, fungi, and yeasts. The compounds include azasqualenes, azasqualanes, bis-azasqualenes, bis-azasqualanes, and N-oxide and ammonium derivatives of squalene. In order to better mimic the transition state involved in the SN2-like opening of 2,3-oxidosqualene, we synthesized squalene N-methyloxaziridine. Other derivatives tested were N-methylimine, aminalic hydroperoxide, and N-methylamide. We also attempted to produce new "suicide" inhibitors of SO cyclase, such as a squalenoid epoxide vinyl ether. Many of the products described inhibited the various cyclases, the best having an IC50 of 0.3 microM on plants and 1.5 microM on rat liver microsomes, and good antibacterial and antifungal activity. In a search for inhibitors of squalene epoxidase, a series of mono- and bifunctional squalenoid acetylenes and allenes were synthesized. Some of them proved to be inhibitors of squalene epoxidase.
Various (1E,3E)- and (1Z,3E)-conjugated methylthio derivatives of oxidosqualene (OS) and conjugat... more Various (1E,3E)- and (1Z,3E)-conjugated methylthio derivatives of oxidosqualene (OS) and conjugated and non-conjugated phenylthio derivatives of OS were obtained. These compounds, designed as inhibitors of pig liver and Saccharomyces cerevisiae 2,3-oxidosqualene-lanosterol cyclases (OSC) (EC 5.4.99.7) and of Alicyclobacillus acidocaldarius squalene-hopene cyclase (SHC) (EC 5.4.99.-), contain the reactive function adjacent to carbons involved in the formation of the third and the fourth cycle during OS cyclization. All the new compounds are inhibitors of OSC and SHC, with various degrees of selectivity. The conjugated methylthio derivatives behaved as potent inhibitors of S. cerevisiae OSC, whereas most of the phenylthio derivatives were especially active toward SHC.
Uploads
Papers