Natural and synthetic compounds having a lactone structure methods for using and making the compounds have been disclosed. The compounds are useful as anti-bacterial, anti-fungal and anti-inflammatory agents, and for treating proliferation disorders such as melanoma, leukemia, breast cancer, lung cancer, ovarian cancer, colon cancer, esophagus cancer, liver cancer, and lymphatic cancer. The compounds are also effective for treatment or prevention of inflammatory diseases such as atherosclerosis, lung fibrosis, systemic lupus erythematosus, pancreatitis, sarcoidosis, glomerulitis, and organ transplant rejection. They are also effective for treatment or prevention of bacterial and fungal infections, including treatment of peptic ulcers, gastritis, dyspepsia and gastric cancer, gingivitis and periodontitis.