Vassil St. Georgiev

Immunomodulatory activity of small peptides

Abstract The activity of the immune system can be modulated by a wide variety of natural and synthetic peptides. Here , Vassil St Georgiev summarizes the actions of some of the immunostimulatory and immunosuppressant small peftides that have shown most promise as therapeutic agents. Some are already in use as vaccine adjuvants or to prevent graft rejection. There are now indications that these peptides may also be of benefit in conditions in which the immune system is compromised, in autoimmune disease and in cancer .

New synthetic immunomodulating agents

Abstract Efforts aimed at developing drugs that effectively modulate the hosts natural defenses and restore impaired immune functions have led to the discovery of new classes of synthetic compounds . Vassil St Georgiev describes some of the recent developments in this continuing search, Novel immunomodulating agents currently being studied include mitoxantrone, oxamisole, bropirimine and compounds LS 2616 and ADA 202–718, as well as a number of germaniumcontaining derivatives. They all offer potential new approaches for the treatment of various disease states such as infections, organ transplantation, cancer, rheumatoid arthritis, systemic lupus erythematosus, Down syndrome, Crohns and autoimmune diseases and, more recently, the acquired immune deficiency syndrome .

Studies on antifungal agents. 27. Novel 5-{[(substituted phenyl)thio]-methyl}isoxazolidines

Abstract The synthesis and antifungal activity of a series of novel 5-(substituted phenyl)thio]methylisoxazolidine derivatives are discussed. The title compounds were prepared by 1,3-dipolar cycloaddition reaction of α-substituted ketonitrones with allyl phenyl sulfides to provide diastereometric mixtures of the corresponding cis/trans -analogues. When tested in solid agar cultures, the title derivatives exerted moderate to potent in vitro antifungal activity against a number of dermatophytes and fungi causing systemic infections. The minimum inhibitory concentration (MIC) values ranged between

Adamantylmethyl analogues of chloramphenicol

Abstract The synthesis and biological activity of novel adamantylmethyl analogues of chloramphenicol are described. Substituting the polar para -nitro group on the phenyl ring with a non-polar lipophilic adamantylmethyl moiety resulted in a diminished antimicrobial activity. At a daily dose of 3 mg/kg the threo -4-[2′-tricyclo[3.3.1.1 3,7 ]decylidene)-methyl-1-[1″, 3″-dihydroxy-2″-(α,α-dichloroacetamido)propyl]benzene caused a significant loss of humoral immuno-competence in the T-dependent Kennedy plaque assay in mice.

Drug-induced modifications of the immune response 13. Potassium 2,5-dihydro-3-ethoxycarbonyl-2-phenylimino-4-furanyloxides as novel anti-allergic agents

Abstract The synthesis and anti-allergic activity of novel potassium 2,5-dihydro-3-ethoxycarbonyl-2-phenylimino-4-furanyloxides are described. The salts were found to exert moderate to potent activity in vivo in the mediator-induced dermal vascular permeability and active anaphylaxis assays in rats. The 2-(4-acetylphenyl)imino derivative 6c was the most active compound. Following its intraperitoneal administration to rats at a dose of 100 mg/kg, derivative 6c inhibited both the wheal reaction caused by serotonin, histamine and bradykinin (by 79, 88 and 86%, respectively) and active anaphylaxis by 56%.