Molecular interaction and/or recognition play an important role generally in the crucial situation for biological process. Our laboratory is focusing such molecular recognition from a viewpoint of organic chemistry. The host-cell recognition of bacteriophage and epidemic penetration of medical drugs are investigated for development of new drugs and functional material. In those studies, phages, bacterial cell, and animal skin are studied using methods of decompositional manner. Application researches for developing a new method for organic synthesis of materials for drugs and exploring substances account for palatability of beverage are also our interest.