Cryptopine

D. chrysaniha Walp. Bicuculline, chrycentrine, cryptocavine, cryptopine, protopine. Base F 25, Ci3Hi40g(NMe), m.p. 230°, phenolic and lactonic. ... 

D. cucullaria (L) Bernh. Bicuculline, corlumine, cryptopine, a-aZZocryptopine, cularidine, cularine, ochotensine, protopine. Manske was unable to confirm from his specimen the presence of cucullarine recorded by Black et al. ... 

Cryptopine type. Protopine, CjoHjgOjN. Cryptopine, C21H23O5N. 

Laudanine, C20H25O4N, was isolated by Hesse. The crude alkaloid is purified by recrj stallisation from dilute alcohol for the removal of small quantities of cryptopine, or it may be dissolved in acetic acid and the solution poured into dilute caustic soda, when this impurity is precipitated and laudanine may be recovered from the filtrate by addition of ammonium chloride. It still contains its isomeride laudanidine, which may be separated by repeated crystallisation of the hydrochlorides, laudanidine accumulating in the aqueous mother liquors. The base crystallises from dilute alcohol, or from a mixture of alcohol and chloroform in rhombic prisms, m.p. 166°, [a]o 0°. It dissolves in solutions of alkali hydroxides, fornung metallic derivatives, which are precipitated by excess of alkali, but is nearly insoluble in solution of ammonia. The salts crystallise well ... 

Haworth, Koepfli and Perkin have shown that, like other alkaloids of the protoherherine series, tetrahydropalmatine is convertible by the general process (p. 302) into an alkaloid of the cryptopine type. The... 

This series of ten alkaloids may appropriately be called the cryptopine sub-group, since the characteristic nuclear structure of the type was first made clear by Perkin s investigation of cryptopine. They are closely related to the profoberberines, with which they are interconvertible by two characteristic reactions, which have been of great value in their investigation. The two alkaloids formerly known as )S- and y-homochelidonines have now been renamed a- and -ofiocryptopines respectively to distin-... 

The formation of (A) and (C) indicates that cryptopine must have in its structure the grouping I, whilst the production of (B) and (D) shows that the alkaloid must also contain the piperonyl ring in the form of grouping II, and from these the structme of anhydrotetrahydromethyl-cryptopine is represented by formula III ... 

On these and other groimds Perkin represented cryptopine, di-hydrocryptopine and uodihydrocryptopine chloride by the following formulae ... 

The reverse change, viz., the conversion of berberine derivatives by iV-methylation into substances constituted similarly to corresponding derivatives of cryptopine, was achieved by the methylation of dihydroanhydroberberine, to the methochloride, which corresponds to tsocrypto-pine chloride and resembles it closely in character and reactions,... 

From this a number of new substances closely resembling the corresponding cryptopine derivatives have been prepared. 

The methochloride of (IX) occurs in two forms, identical with the a-and )S-forms of Modihydrocr3T)topine chloride (X). The two chlorides were converted into the two anhydrodihydrocryptopines A and B (p. 297). Of these the A base was oxidised by perbenzoic acid to the amine oxide (XI), m.p. 135° dec.), and this on heating with acetic and hydrochloric acids passed into cryptopine (XII), m.p. 220-1°, identical in all respects with the natural alkaloid. 

Phosphoryl chloride converts protopine into the quaternary salt isoprotopine chloride, C20H18O4NCI, m.p. 215° (dec.), which on treatment with potassium hydroxide in methyl alcohol yields anhydroprotopine, C2qH4,04N, m.p. 114-5°,1 just as crj ptopine is convertible into iso-cryptopine chloride and this into anliydrocryptopine. Similarly, protopine forms protopine methosulphate, CjoHigOjN. Me2S04, m.p. 252°, which is converted by potassium hydroxide in methyl alcohol, into two methyl-protopines, a-, m.p. 145°, and y-, m.p. 112°, corresponding with the two methyleryptopines, a-, m.p. 153°, and y-, m.p. 110°, respectively. 

This formula was confirmed hy Haworth and Perkin s synthesis of a-flZZocryptopine from herherine, the first application of a process, of which examples have heen given already in the syntheses of cryptopine (p. 298) and protopine (p. 301) hy the same authors. Anhydrotetrahydromethyl-herherine (I cf. hase (a), p. 346) in dry chloroform was added to a solution of perhenzoic acid in ether cooled helow 5°. The amine oxide, C21H23O5N (II), separated as an oil, which after shaking with sodium hydroxide solution, solidified and was crystallised from water in slender prisms, m.p. 135°. It was dissolved in acetic acid, hydrochloric acid added, the mixture heated in boiling water for an hour and the hase precipitated hy addition of potassium hydroxide. The precipitate was dissolved in methyl alcohol, ether added, the alcohol washed out with water and the ethereal... 

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). 

It is of interest in this connection to note that the conversion of tetrahydroberberine into an anhydro-base of type E (p. 337) represents transformation from the berberine to the cryptopine type (p. 295), and that a-canadine methochloride occurs in Zanthoxylum brachyacanihum with its cryptopine analogue, y-homochelidonine ( -aiiocryptopine, p. 301). 

Cryptopine and allied alkaloids, pharmacological action, 305 sub up, alkaloids, 284, 294 a-o/loCryptopine 0-homochelidonine), 169,... 

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