Chemistry and Pharmacological Properties of Morusin and Morusinol from Morus alba: An Overview

Morusin or mulberrochromene is a prenylated flavone from the root bark of Morus alba. Structurally, the compound has three benzene rings (A–C) with one OH group at C5 of ring A, and two OH groups at C2' and C4' of ring B. There is a prenyl moiety with two methyl units at C3 of the oxygenated ring C. There is another prenyl moiety with two methyl units at C8 of ring A. Together with ring D, the 2,2-dimethyl pyran group is formed across C7 and C8. Ring D has five carbon atoms and one oxygen atom. The double bond at C2–C3 and carbonyl functional group at C4 of morusin are essential for its bioactivities. Morusinol, is another prenylated flavone with a chemical structure that is very similar to that of morusin. Exceptions are an extra OH group at C13 and a lack of the C12−C13 double bond. Morusin has been reported to exert antitumor effects on multiple types of cancer cells such as breast, liver, lung, cervical, prostate, colorectal, skin, gastric, nasopharyngeal, ovarian, pancreatic and renal cancer cells, including those of glioblastoma and osteosarcoma. The anti-cancer properties of morusinol towards melanoma and colorectal cancer cells were reported. Briefly mentioned was a case study of retraction of a paper on the selective and potent antitumor activity of morusinol towards liver carcinoma. Other pharmacological properties of morusin and morusinol were also presented. Some aspects that warrant further and more in-depth research into morusin and morusinol were suggested.