Sinomenine

DescriptionIsolated by Ohta from Cocculus diversifolius DC., this alkaloid forms colourless crystals from MeOH. It is stated to possess a powerful reflex action and to be aspasm stimulant, finally causing paralysis and death in toxic doses. It is also said to suppress the hypotensive action of dihydroxyphenylethanolethylamine.

HistoryThe chemical structure of sinomenine is composed of four rings, A, B, C, and D, similar to the structure of morphine. Ring A is a benzene ring, and ring B is a half-chair-shaped, six-member ring. The C ring is a twisted-chair-type, sixmember ring that has an a, β-unsaturated ketone structure attached to the B ring. The D ring is a nitrogen-containing, sixmember ring under the B ring. Its structure is shown below; the current structural modification of sinomenine is mainly focused on the A/C active group. Based on the transformation of the A ring, it was found that the 1-substituted formyl derivative of sinomenine showed the strongest inhibitory effect on the inflammatory response of the mouse ear. The 4-substituted p-chlorobenzoyl-sinomenine has the strongest anti-inflammatory and analgesic activity. The biotransformation and chemical synthesis were also used to prepare the di-sinomenine derivatives linked by carbon and carbon, which was stronger than that of sinomenine and had a strong inhibitory effect on cell inflammatory factors. Sinomenine derivatives of the C ring with a pyrazine ring have a strong inhibitory effect on T, B lymphocyte proliferation reaction, which can be used for the preparation of immunomodulatory drugs. The transformation of C ring carbonyl yielded a series of shift alkali derivatives, with strong anti-inflammatory and analgesic effects. These attempts are important for the development of new drugs.

Usesweak abortifacient, immunosuppressant, analgesic, antiinflammatory; LD50 (po) 580 mg/kg; (ip) 285 mg/kg(mouse)