Synthesis and in vitro LTD4 antagonist activity of bicyclic and monocyclic cyclopentylurethane and cyclopentylacetamide N-arylsulfonyl amides

The dissociation constants (KB) at the LTD4 receptor on guinea pig trachea of a series of monocyclic and bicyclic cyclopentylurethane and cyclopentylacetamide N-arylsulfonyl amides have been measured. The KB was found to be remarkably tolerant of changes in the electronic constitution and lipophilicity of the bicyclic ring system (template). Thus, N-[4[[6-[[(cyclopentyloxy)carbonyl]amino]benzimidazol-1- yl]methyl]-3-methoxybenzoyl]benzenesulfonamide (11a) and N-[4-[[5-[[(cyclopentyloxy)carbonyl]amino]benzo[b]thien-3- yl]methyl]-3-methoxybenzoyl]benzene-sulfonamide (25a) had closely similar affinities (pKB, 9.20 and 9.31, respectively; LTE4 as agonist). It has been shown that the hetero-ring of the template need not be aromatic in order to achieve high affinity, since indoline 31 and 2,3-dihydrobenz-1,4-oxazines 37a-c had pKBs greater than 9. Further, it has been shown that an o-aminophenone (see 42 and Figure 3) can function as a template; the template in 42 [see iii] is bicyclic by virtue of the presence of an intramolecular hydrogen bond. In contrast, when the template is a phenyl ring (48), receptor affinity is markedly reduced. These findings support the notion that central bicyclic ring system in this family of peptidoleukotriene antagonists is a molecular feature which helps to preorganize the acylamino and acidic chains and thereby facilitate the molecular recognition event.     

Cryptococcal Meningitis in Patients with the Acquired Immunodeficiency Syndrome

The optimum therapy for cryptococcal meningitis in patients with the acquired immunodeficiency syndrome (AIDS) remains unresolved. Traditional therapy consists of amphotericin B with or without flucytosine. Obstacles exist in administering these agents to patients with AIDS. Mortality rates during initial therapy are relatively high. Given the lack of proved benefit, we do not recommend adding flucytosine to amphotericin B routinely. The search for more efficacious and less toxic agents continues. The oral triazoles, especially fluconazole, have increased the options for treatment of this disease. New strategies and novel approaches in managing cryptococcal meningitis in patients with AIDS continue to be developed.