Cissampelos alkaloids from

Two closely related alkaloids from this group are curicycleatjenine (400) and curicycleatjine (401), compounds that contain a methylenedioxy function at C(S)/C(6). These two alkaloids differ only in the nature of the C(12) function, whereas in the former it is methoxy group and in the latter a hydroxy group. These alkaloids have only been isolated from Cyclea atjehensis (Menispermaceae). Hayatidine (136), an alkaloid of Cissampelos pareira (Menispermaceae), is a diastereoisomer of 12 -O-methylcurine (140). (-)-Tubocurarine (143), a diastereoisomer of (+)-tubocurarine (142), has only been isolated from Chondodendron lomentosum (Menispermaceae). 

Kupchan, S. M., Patel, A. C., and Fujita, E., Tumor inhibitors, IV cissampareine, new cytotoxic alkaloid from Cissampelos pareira, cytotoxicity of bisbenzylisoquinohne alkaloids, J. Pharm. Sci. (1965) 54(4), 580-583. 

Snedden W, Parker RB, Gorinsky C (1970) Electron-impact studies in medicine and biochemistry -II The mass spectra of the alkaloids from Cissampelos ovalifolia D.C. Org Mass Spectr 4 Suppl 607-614... 

These alkaloids were isolated, along with their unsaturated analogs (see Section II,B,4), from Cissampelos ovalifolia D.C., an alleged component of Mac-ushi curare, and characterized in 1970 by chemical interrelation and MS studies. At that time it was shown that the three bases have the same skeleton,... 

These alkaloids, also from Cissampelos ovalifolia D.C., show a mode of MS cleavage somewhat different from that of the dihydro bases (Section II,B,3) with principal scissions at a, b, c, and d. Diazomethane converted both 37 and 38 to 39 (27). MS data alone did not allow a choice between possible isomers, so X-ray work was done on methylwarifteine (38) (22) and dimethylwarifteine (39) (23). The structures of these bases, and therefore of warifteine (37), are as shown. Dimethylwarifteine is identical to O-methylcissampareine, isolated from Cissampelos pareira Linn (27). This family of alkaloids is unusual in having a benzyloxy bridge. 

Guatteria megalophylla Diels (Annonaceae) afforded (/ ,/ )- , 0-dimethylcur-ine (144), C38H42N206, mp 133-136°C (EtOAc-cyclohexane), identified by UV, NMR, MS, and ORD, and by comparison with a sample synthesized by CH2N2 methylation of (/ ,/ )-l2 -0-methyIcurme (145, Section II,C,64), also isolated from this plant (82). (/ ,/ )-< ,0,-Dimethylcurine had been prepared by methylation of (/ ,/ )-curine (75) (83), but was not previously reported in nature however, (5,S)-0,0-dimethylcurine is a known alkaloid of Cissampelos pareira (84). 

Methylation (CH2N2) of the alkaloid gave the known (R,./ )-dimethylcurine (144). Since by MS of 145 and 213 the tetrahydroisoquinoline ring bonded by an ether linkage to an unsubstituted p-tolyloxy contains a free OH, and this OH has no free ortho or para positions for deuterium exchange, the structure of 12 -0-methylcurine was proven (82). (R,R)-12 -0-Methylcurine is the enantiomer of (+, + )-4"-0-methylcurine, reported from Cissampelos pareira in 1966 (84). 

Investigation of the Thai folk medicine, krung kha mao, the roots of Cyclea barbata Miers (formerly identified as Cissampelos pareira L.), has yielded many bisbenzylisoquinolines. other alkaloids d/-tetrandrine, isotetrandrine, limacine, berbamine, and homoaromoline (4,5). From the same plant, d/-fangchinoline, thalrugosine (d-isofangchinoline) (6), and the... 

The one and only morphinandienone, (+)-milonine (8,14-Dihydromorphinandienone) (54), was isolated from the dried leaves of Cissampelos sympodialis, a plant used in medicine in northeastern Brazil [50]. Blasko and Cordell reviewed morphinandienone, homomorphinandienone, and other related alkaloids with respect to isolation, structure, elucidation, spectroscopy, and synthesis [94],... 

There are four alkaloids in the (-)-curine family (-)-curine (133), cycleacurine (134), O,O-dimethylcurine (135), and 12 -O-methyIcurine (140). These alkaloids differ in the position of various phenolic hydroxy groups and methoxy groups among the C(7), C(12), and C(6 ) positions. (-)-Curine (133) has been isolated from six genera of the Menispermaceae including Chondodendron, Cissampelos. Cyclea, Paracyclea, Pleogyne, and Stephania. In addition, this... 

Hayatine (137) and hayatinine (12-methylhayatine)(138) are alkaloids that have both been isolated from Cissampelos pareira (Menispermaceae), with the latter alkaloid also having been found in Cyclea hainanensis (Menispermaceae). The chirality ofthe C(l)and ( ) carbon atoms in these alkaloids has not been determined, although the two compounds are identical in molecular structure to (-)-curine (133) and 12 -O-methylcurine (140), respectively. The compound reported as (-)-tubocurine (I44)(thought to be enantiomeric with chondrocurine [(+)-tubocurine]) was not isolated in a pure form, and hence the physical properties were not determined [1]. 

Monocrotaline (63) from Crotalaria spectabilis (Legumy is responsible for the activity of Crotalaria extracts against adenocarcinoma-755 in mice. Similar alkaloids have been screened for anti-tumour activity by other researchers in general, however, pyrrolizidine alkaloids have liver toxicity and it is questionable whether they can be used in chemotherapy. Furthermore, cissampareine (64) from Cissampelos pareira (Menisperm.) and coronaridine (65) from Ervata-mia dichotoma (Apocyn.) have been investigated by the Kupchan group. 

In 1843 Maclagen (56) found two compounds of basic nature in Nectan-dra roots from British Guiana. One of these, an amorphous yellow powder, he named bebeerine (bebirine). Some time later a yellow powder was isolated from Buxus sempervirens L., whose fibers and leaves were used as a remedy for intermittant fever. This powder which was named buxin proved to be identical with bebeerine. Finally, the alkaloid known as pelosine which occurs in the roots of Cissampelos pareira L. and Radix pareira bravae was found to be identical with bebeerine (56, 59). Bebeerine also occurs in Chondodendron platyphyllum, Ch. microphyllum, Abula candicans Rich. Ch. candicans Sandwith) (68), and Pleogyne cunninghamii (136), as well as in the commerical powder known as bebeerum purum. 

This type of alkaloid has so far been found only in the family Menispermaceae. It is a good chemical marker for the mily, but so far, alkaloids of this type have been isolated only from the genera Abuta and Cissampelos. 

An interesting case is that of pareirubrine A, isolated from Cissampelos pareira (4(1). This alkaloid may exist as tautomers, in the solid state it assumes the form la and in solution it assumes the form lb. This compound exhibits anti-leukaemic activity (IC50 0.33 g/ml) (40). 

A new class of alkaloids, the OXOCAN were recently discovered in Stephania excentrica, and so far only five examples are described in the literature, all of them from the Menispermaceae. The first alkaloid of this kind, excentricine, was isolated in 1993 fi om Stephania excentrica 71). The second, stephaoxocanine, was isolated in 1996 from Stephania cepharantha (72). The third was preliminarily published as a poster in the 20" Annual Meeting of the Brazilian Society of Chemistry (578,579). It was named eletefine and was isolated fi om Cissampelos glaberrima (Figure 6). There has been no presentation, as yet, of their biogenesis. 

Alkaloid 8 from Strychnos toxifera = Caracurine metho salt Alkaloid B from Cissampelos pareira = Cycleanine C-Alkaloid K = Dihydrotoxiferine C-Alkaloid Q == Macusine B (Hesse [257])... 

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