Pierangela Ciuffreda

Co‐administration of ibuprofen and nitric oxide is an effective experimental therapy for muscular dystrophy, with immediate applicability to humans

Background and purpose:  Current therapies for muscular dystrophy are based on corticosteroids. Significant side effects associated with these therapies have prompted several studies aimed at identifying possible alternative strategies. As inflammation and defects of nitric oxide (NO) generation are key pathogenic events in muscular dystrophies, we have studied the effects of combining the NO donor isosorbide dinitrate (ISDN) and the non‐steroidal anti‐inflammatory drug ibuprofen.

Lipase-catalysed chemoselective monoacetylation of hydroxyalkylphenols and chemoselective removal of a single acetyl group from their diacetates

Abstract It was demonstrated that Pseudomonas cepacia PS lipase adsorbed on Celite, has the ability to catalyse the chemoselective monoacetylation of various hydroxyalkylphenols or the chemoselective removal of a single acetyl group from the corresponding acetate.

Lipase catalysed resolution of (R)- and (S)-1-trimethylsilyl-1-alkyn-3-ols: useful intermediates for the synthesis of optically active γ-lactones

Abstract Various ( R )- and ( S )-1-trimethylsilyl-1-alkyn-3-ols, chiral building units useful for the synthesis of biologically active compounds, have been efficiently resolved by enantioselective acetylation mediated by immobilized lipase PS. The resolution is applied to the synthesis of ( R )- and ( S )-5-octyl-2-(5H)-furanones.

Structural requirements of aldehydes produced in LPO for the activation of the heat-shock genes in Hela cells

The ability of various aldehydes, some of which are produced in lipid peroxidation, to effect heat-shock gene expression and heat-shock proteins synthesis was evaluated in HeLa cells. Only (E)-4-hydroxyalk-2-enals were active both in racemic and homochiral form. Between the reported primary metabolic products of (E)-4-hydroxynon-2-enal, only the glutathione conjugates were active, whereas (E)-4-hydroxynon-2-enoic acid and 2-nonen-1,4-diol were inactive. Also, unnatural (E)-5-hydroxynon-2-enal and (E)-5-hydroxyhex-2-enal were active, whereas (E)-6-hydroxynon-2-enal was inactive. Thus, it was established that the active aldehydic compounds must possess an (E)-2 double bond and an hydroxy group in a position suitable for the formation of a cyclic hemiacetal in a possible adduct of these aldehydes with proteins. An irreversible binding to proteins could be the first step of the mechanism by which these compounds exert their biological activity.

Epimerization of α- to β-C-glucopyranosides under mild basic conditions

A number of β-C-glucopyranosides having an activated methylene or methine group bonded to the anomeric carbon are obtainable in quantitative yield from the corresponding α-isomers by simple equilibration catalysed by various bases at room temperature.

Deamination of 5′-substituted-2′,3′-isopropylidene adenosine derivatives catalyzed by adenosine deaminase (ADA, EC 3.5.4.4) and complementary enzymatic biotransformations catalyzed by adenylate deaminase (AMPDA, EC 3.5.4.6): a viable route for the preparation of 5′-substituted inosine derivatives

Abstract Adenosine deaminase (ADA) catalyzes the deamination of 2′,3′-isopropylidene adenosine and the corresponding 5′-amino derivative in a 3% dimethylsulfoxide aqueous solution. Whereas ADA is unable to convert other 5′-substituted derivatives (acetate, acetamido, azide), the enzyme adenylate deaminase (AMPDA) accepts all the above compounds as substrates for their biotransformation to the corresponding 5′-substituted inosine derivatives.

The Action of Adenosine Deaminase (E.C. 3.5.4.4.) on Adenosine and Deoxyadenosine Acetates: The Crucial Role of the 5′-Hydroxy Group for the Enzyme Activity

Abstract From adenosine 1 , 2′-deoxyadenosine 3 and 3′-deoxyadenosine 5 all the acetates were prepared by lipase-catalyzed reactions. Only the acetates with free 5′-hydroxy group were deaminated by adenosine deaminase (ADA), confirming the crucial role of 5′-OH for the enzyme activity.

N6-Alkyladenosines: Synthesis and evaluation of in vitro anticancer activity

A series of adenosine analogues differently substituted in N⁶-position were synthesized to continue our studies on the relationships between structure and biological activity of iPA. The structures of the compounds were confirmed by standard studies of ¹H NMR, MS and elemental analysis. These molecules were then evaluated for their anti-proliferative activity on bladder cancer cells. We found that some of these compounds possess anti-proliferative activity but have no effect on cell invasion and metalloprotease activity.

Pharmacogenomics and analogues of the antitumour agent N6-isopentenyladenosine

N6‐isopentenyladenosine (i6A), a member of the cytokinin family of plant hormones, has potent in vitro antitumour activity in different types of human epithelial cancer cell lines. Gene expression profile analysis of i6A‐treated cells revealed induction of genes (e.g., PPP1R15A, DNAJB9, DDIT3, and HBP1) involved in the negative regulation of cell cycle progression and reportedly up‐regulated during cell cycle arrest in stress conditions. Of 6 i6A analogues synthesized, only the 1 with a saturated double bond of the isopentenyl side chain had in vitro antitumour activity, although weaker than that of i6A, suggesting that i6A biological activity is highly linked to its structure. In vivo analysis of i6A and the active analogue revealed no significant inhibition of cancer cell growth in mice by either reagent. Thus, although i6A may inhibit cell proliferation by regulating the cell cycle, further studies are needed to identify active analogues potentially useful in vivo.

Regioselective Hydrolysis of Diacetoxynaphthalenes Catalyzed by Pseudomonas sp. Lipase in an Organic Solvent

Abstract Depending on the relative positions of the acetyl groups in the aromatic rings, the Pseudomonas sp. lipase-catalyzed hydrolysis of diacetoxynaphthalenes in tert-butylmethyl ether proceeds regioselectively to afford the corresponding monoacetates.