One of the compound that is present in rancid butter and body odor is BUTYRIC ACID.
Butyric acid is a fatty acid that occurs in form of esters in animal fats. It has the chemical formula C4H802. When butter goes rancid, butyric acid is liberated from the glycerides of butyric acid by hydrolysis leading to an unpleasant odour. Butyric acid is also present in body odour.
