Abstract
Aqueous extracts of cotton bracts inhibited luminol-dependent chemiluminescence of phagocytosing alveolar macrophages. The inhibitory compounds were partitioned into organic solvents. Chromotographic analysis indicated that these compounds were either lacinilene C or its 7-methyl ether and scopoletin. The fact that the inhibitory activity of these compounds was always less than that of the total extract suggests synergisti action. These compounds may function as etiological agents of byssinosis.