Palmatine

Palmatine, C21H23O6N, was first isolated from Jateorhiza palmata by Gadamer (222), who determined the correct formula. Giinzel (160) isolated it subsequently under the name of columbamine, and Feist (159) 

In many of its source plants it is associated with one or two of its 0-desmethyl ethers, namely, jatrorrhizine and columbamine, which form sparingly soluble iodides along with that of palmatine. The mixed iodides are digested with aqueous alkali in which the phenolic compounds dissolve leaving the sparingly soluble palmatine iodide which may be purified by recrystallization from much boiling water. 

Structure. Reduction of palmatine yields di-tetrahydropalmatine, and this can readily be reoxidized to palmatine. It differs from berberine in having four methoxyls, the methylenedioxy group of the latter being replaced by two methoxyls in the former. Since it yields corydaldine and hemipinic acid on oxidation with permanganate Feist and Sandstede (223) suggested structure XXIX, which should be rewritten to conform to the carbinol form analogous to XVII for berberine. Like berberine it forms 

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Berberine is probably the most widely distributed alkaloid. It and the allied alkaloids palmatine, jatrorrhizine, columbamine and coptisine occur somewhat frequently in the Rhcnadales (list, p. 169) as the tetrahydro-derivatives, but, in the botanical families referred to in the distribution list below, the tetrahydro-derivatives are exceptional and the unreduced alkaloids usual. The associated alkaloids include two members of the aporphine group, domesticine and t odomesticine (p. 315), one member of the cryptopine group, y-homochelidonine (p. 294) and two members of the double woquinoline type, viz., berbamine and oxyacanthine (p. 346). 

RANUNCULACEAil. (1) Coptis japonica Mak. Berberine, palmatine, columbamine, coptisine, worenine. 

The following Berberis spp. contain mixtures of alkaloids — B. heteropoda Schrenk. Berberine, palmatine, jatrorrhizine, columbamine, berbamine and oxyacanthine. ... 

B. vulgaris L. Berberine, berberrubine, palmatine, jatrorrhizine, columbamine, berbamine, oxyacanthine and a base C19H22ON2, hydrochloride, m.p. 256°. 

Coscinium blumeanum Miers. Berberine, jatrorrhizine, palmatine. 

Fibraurea chloroleuca Miers F. iinctoria Lour.) Palmatine and jatrorrhizine.2 ... 

It should, however, be noted that though Spath and Kruta were unable to condense tetrahydropapaverines with formaldehyde to the berberine type of alkaloid, they found that tetrahydropapaverolines condensed with formaldehyde in both ways, and examples will be found under corydaline (p. 289) and the constitution of palmatine and the related bases (p. 343). 

Palmatine and Associated Alkaloids. Palmatine, jatrorrhizine (jateorhizine) and columbamine were first isolated from ealumba root (Jateorhiza palmata Lam., Miers) as a result of the work of Giinzel followed by that of Feist, but all three have sinee been found in other genera. All three are quaternary bases, soluble in water, and methods for their isolation have been deseribed by Giinzel, Feist, and Spath and Polgar, usually dependent upon their preeipitation as iodides, or their reduetion to the tertiary tetrahydro-bases. The latter oeeur naturally in the Rhceadales and have been deseribed already (p. 284). A method for the separate estimation of the alkaloids of ealumba root has been described by Neugebauer and Brunner. " ... 

Jatrorrhizine (Jateorhizine). (Items 6, 9, 11, 14, 18, 19, 21, 22 list, p. 329.) The iodide, C20H20O4NI. H2O, crystallises in reddish-yellow needles, m.p. 210-2° the chloride C20H20O4NCI. H2O, forms copper-coloured needles, m.p. 206°, and the nitrate golden-yellow needles, m.p. 225° (dec.). On 0-methylation, jatrorrhizine iodide yields palmatine iodide, and on reduction it is converted into dZ-tetrahydrojatrorrhizine, m.p. 217-8°, the d-form of which is corypalmine and which on 0-methylation yields tetrahydropalmatine (p. 292). ... 

Constitution. Comparison of the empirical formula of the three alkaloids, and the fact that jatrorrhizine and columbamine each stands to palmatine in the relation of a monohydric phenol to its methyl ether, makes it clear that the only difference between jatrorrhizine and columbamine must be in the position of the free hydroxyl group. The method by which this point was settled is described in dealing with the two tetrahydro-derivatives of these alkaloids (p. 291). The constitution of palmatine (XXV R = R = Me) is dealt with under tetrahydropalmatine, but it is still necessary to describe the complete synthesis of this alkaloid via oxypalmatine (XXVII) and tetrahydropalmatine. 

According to Biberfeld, palmatine, calumbamine and jatrorrhizine all paralyse the central nervous system in frogs palmatine also produces this effect in mammals and differs from the other two in stopping respiration, probably by paralysis of the respiratory centre. All three alkaloids lower the blood pressure on intravenous injection, palmatine being the most active. 

Pachycarpine (d-sparteine), 118 Pachycereus marginatits, 161 Paipunine, 767 Palicourea rigida, 781 Palmatine, 328, 329, 342, 345 Palmatine and associated alkaloids, constitution, 342 Palmatine-acetone, 288 Palmatisine, 674 Palustrine, 773... 

Berberis and Related Bases Berberine, Canadine, Palmatine Coptisine, etc.. ... 

Abstract Protoberberine alkaloids and related compounds represent an important class of molecules and have attracted recent attention for their various pharmacological activities. This chapter deals with the physicochemical properties of several isoquinoline alkaloids (berberine, palmatine and coralyne) and many of their derivatives under various environmental conditions. The interaction of these compounds with polymorphic DNA structures (B-form, Z-form, H -form, protonated form, triple helical form and quadruplex form) and polymorphic RNA structures (A-form, protonated form, triple helical form and quadruplex form) reported by several research groups, employing various analytical techniques such as spectrophotometry, spectrofluorimetry, circular dichro-ism, NMR spectroscopy, viscometry as well as molecular modelling and thermodynamic analysis to elucidate their mode and mechanism of action for structure-activity relationships, are also presented. 

Keywords Berberine Palmatine Coralyne Polymorphic nucleic acid structures Alkaloid-nucleic acid interactions... 

Palmatine (Scheme 1) bears the same tetracychc structure as berberine but differs in the nature of the substituents on the benzo ring being methylene dioxy for berberine and dimethoxy for palmatine. In aqueous buffer, the UV-visible spectriun of palmatine shows maxima at 232, 268, 344.5 and 420 nm. Palmatine has a weak fluorescence spectrum in the range 400-650 nm with... 

Fig. 8 Interaction of palmatine with various B-DNAs as obtained from competition dialysis (a), spectrofluorimetric (b), circular dichroism (c) and thermal melting (d) studies. (Reprinted from [176] with permission from Elsevier)...

Table4 Various parameters for the interaction of palmatine with several DNAs [176] (Bhadra et al., unpublished results)...

Table 5 Binding of palmatine to homo and hetero polymer of AT as revealed from isothermal titration calorimetry [176]...

Fig. 12 Representative circular dichroic spectrum of poly(A) treated with various concentrations of berberine (a), palmatine (b) and coralyne (c). a Reprinted from [206], b reprinted from [208] and c reprinted from [187] with permission from Elsevier...

Table 7 Comparative spectrophotometric and thermodynamic parameters for the interaction of berberine, palmatine and coralyne with poly(A) [187,207-209]...

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