Synthesis and in vitro aldose reductase inhibitory activity of compounds containing an N-acylglycine moiety.

A number of N-benzoylglycines (6), N-acetyl-N-phenylglycines (7), N-benzoyl-N-phenylglycines (8), and tricyclic N-acetic acids (9-12) were synthesized as analogues of the N-acylglycine-containing aldose reductase inhibitors alrestatin and 2-oxoquinoline-1-acetic acid. Derivatives of 6, which represent ring-simplified analogues of alrestatin, are very weak inhibitors of aldose reductase obtained from rat lens, producing 50% inhibition only at concentrations exceeding 100 microM. Compounds of series 7 were designed as ring-opened analogues of the 2-oxoquinolines. While these derivatives are more potent than compounds of series 6 (IC50S of 6-80 microM), they are less active than the corresponding 2-oxoquinolines. Analogues of series 8 were designed as hybrid structures of both alrestatin and the 2-oxoquinoline-1-acetic acids. These compounds are substantially more potent than compounds of series 6 and 7 and display inhibitory activities comparable to or greater than alrestatin or the 2-oxoquinolines (IC50S of 0.1-10 microM). Of the rigid analogues of 8, the most potent derivative is benzoxindole (12) with an IC50 of 0.67 microM, suggesting that fusion of the two aromatic rings of 8 in a coplanar conformation may optimize affinity for aldose reductase in this series.

Salmeterol compared with current therapies in chronic asthma.

BACKGROUND: Therapy with salmeterol, a long-acting, selective, inhaled beta 2-adrenergic agonist, is effective and safe for patients with persistent asthma; however, few long-term studies comparing salmeterol with current combination treatment regimens have been reported. METHODS: A multicenter, randomized, placebo-controlled, double-blind study was conducted in 386 patients over 41 to 46 weeks in 27 medical centers (two thirds of the investigators were primary care physicians). Patients were randomized to receive either salmeterol or placebo, and further randomized to weaning or nonweaning from current asthma therapies (except inhaled corticosteroids). Treatment groups were: salmeterol/weaning (S + W), placebo/weaning (P + W), salmeterol/no weaning (S + NW), and placebo/no weaning (P + NW). Attempts at active weaning were carried out at the discretion of the investigator for 2 to 6 weeks. Pulmonary function, albuterol use, and asthma symptoms were measured. RESULTS: The clinical benefits of salmeterol occurred despite weaning off existing nonsteroidal asthma medications. The mean morning peak expiratory flow rate was significantly increased in the S + W group (32.3 L/min) compared with both the P + W (4.9 L/min) and P + NW (6.8 L/min) groups (P < .001). Compared with the P + W and P + NW groups, the S + W group experienced significant (P < .05) improvements in overall mean asthma symptom scores, mean number of puffs of supplemental albuterol, the percentage of days with no supplemental albuterol use, and the mean number of awakenings caused by asthma (except for the P + NW comparison, P = .090). No significant differences were noted between treatment groups in any safety evaluation, including 12-lead electrocardiograms. CONCLUSIONS: The addition of salmeterol in the treatment of persistent asthma resulted in sustained improvement in pulmonary function and symptoms. The long-term use of salmeterol is safe and improves the clinical course and stability of asthma following reductions in nonsteroidal asthma therapy.