Abstract: [Problem]A compound useful for the prevention and/or treatment of chronic obstructive pulmonary disease (COPD) or asthma, and a pharmaceutical composition containing the compound as an active ingredient are provided. [Means for Solution]The present inventors have made extensive studies on the pharmacological actions of naturally fermented materials, and as a result, they have found that a cyclic depsipeptide compound derived from a soil bacterium belonging to the genus Chromobacterium which is collected in Okutama-machi, Tokyo has both an inhibitory action on airway contraction and an inhibitory action on airway inflammation, and thus, is useful as an agent for preventing or treating COPD or asthma, thereby completing the present invention.

Abstract: [Object] Disclosed is a compound useful as an active ingredient for a pharmaceutical composition having an ?-amylase inhibitory activity, particularly a pharmaceutical composition for the treatment of diabetes. [Solution] An investigation has been made on a compound having an ?-amylase inhibitory activity among the compounds produced by Streptomyces sp. strain 6982, which is a actinomycetes belonging to the genus Streptomyces, and it was confirmed that an aminosugar compound has an ?-amylase inhibitory activity, thus completing the invention. The aminosugar compound of the present invention has an ?-amylase-inhibitory activity, and therefore can be used as a prophylactic or therapeutic agent for diabetes, obesity, NASH (non-alcoholic steatohepatitis), particularly as an ameliorating agent for postprandial blood glucose elevation.