Cocculus Coclaurine

From a chemical structural viewpoint, they may be divided into several groups. The alkaloids in which the aliphatic carbon atom of the benzyl group is connected only to positions 1 and 1 comprise the opiiun bases papaverine, xanthaline, laudanosine, and various phenolic derivatives of these tetramethoxy compounds, as well as the Cocculus base coclaurine, the Papaver alkaloid armepavine, the Mahonia base neprotine, and a constituent of Corydalis, corpaverine. This chapter is devoted to a discussion of this group. 

The alkaloid (+)-coclaurine is found in the evergreen menispermaceous shrub Cocculus laurifolius DC., which occurs principally in India, southern China, and Japan. The Chinese drug Koshiu-wyaku consists of the dried root of this tree. An alkaloid probably identical with coclaurine was isolated from the bark and leaves by Greshoff but the pure base was described first by H. and T. Kondo (106). It shows m.p. 221 , [a] -(-0.9 (in methanol), and it is soluble in alkali. Its hydrochloride melts at 264°. 

Bisbenzylisoquinoline Alkaloids.—The biosynthesis of several bisbenzyl-isoquinolines has now been investigated. All have been found to be based on coclaurine (bS). Investigation of the biosynthesis of oxyacanthine (69), in Cocculus laurifolius, has given results which show that this alkaloid too arises from coclaurine. Norcoclaurine (62), coclaurine (63), and N-methylcoclaurine were... 

The biosynthesis of cocsulin (63) and cocsulinin (64) in Cocculus laurifolius has been found to parallel that of tiliacorine and tiliacorinine (above). Thus bpth are formed from two units of iV-methylcoclaurine (60), without iV-demethylation [coclaurine (59) and norcoclaurine (58) were also incorporated an incorporation... 

Coclaurine was isolated from the bark and trunk (0.04%) of Cocculus laurifoliay a small shrub of Menispermaceae family. This alkaloid has been found in the plants of Menispermaceae Cocculus, Sarcopetalum), Lauraceae daphne, Mechilus), Euphorbiaceae Croton), and Rhamnaceae Rutanilla, Zizyphus),... 

The family Menispermaceae comprises over 60 genera and about 400 species, distributed mainly in the tropical and subtropical regions in the world. Most species are lianas but some are bushes or low trees. Biscoclaurine-type alkaloids occur in many of the plants of this family. From the bark and trunks of Cocculus laurifolius, 0.13% crude base was obtained. Trilobine (0.004%) was isolated from the base together with coclaurine (90, 157). 

In the Menispermaceae, the most frequently cited alkaloid of this type is coclaurine, responsible for 13 citations in plants of the genera Abuta (1), Ccayomem (1), Cocculus (4), Cyclea (2), Pachygam (1), Sarc< talum (1), Sciadotenia (1) and Stephania (2). Other important alkaloids are reticuline (5 citations), and oblongine (4 citations). 

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