Isoboldine

Papaveraceae Papaver somniferum Morphine Codeine Thebaine Papaverine Narco tine Narceine Isoboldine... 

A minor constituent of P. somniferum is the aporphine alkaloid isoboldine (Figure 6.58). Other species of poppy, e.g. Papaver orientale and P. pseudoorientale, are known to synthesize aporphine alkaloids as principal constituents rather than morphinan structures. (Aj-Isoboldinc is readily appreciated to be the product of oxidative coupling of (5)-reticuline, coupling ortho to the phenol group in the tetrahydroisoquinoline, and para to the phenol of the benzyl substituent... 

Neolitsea aureo-sericea Kosterm. (stem bark) Lauraceae Bisnorargemonine (50) Isoboldine (50) Norcinnamolaurine (50) ( + )-Reticuline (50)... 

The tested isoquinolines were observed to display a selective inhibition against PI-3 as seen in Table 4, except for (-t-)-isoboldine, (-)-stylopine, and ( )-corydalidzine, that were totally ineffective against both viruses. Protopine, b-allocryptopine, chelidimerine, fumarophycine, a-hydrastine, (-t-)-bulbocapnine, (+)-isoboldine, (-)-sinactine, palmatine, dehydrocoryda-... 

Oxidation of (+ )-reticuline perchlorate with cuprous chloride and oxygen in pyridine produced (+ )-corytuberine (36) in 28% yield, and (+)-isoboldine (37) in 8% yield. Oxidation with cuprous chloride, therefore, favours ortho-ortho over ortho-para coupling.28... 

Full experimental details have appeared on the synthesis of bracteoline, isoboldine, N-methyl-laurotetanine, and related aporphines, through oxidation with... 

Photolytic syntheses of norisoboldine,33 isoboldine,34 and norglaucine34 have appeared. 

Reticuline has been biotransformed into the morphinandienone pallidine, the aporphine isoboldine, and the protoberberines coreximine and scoulerine by rat liver enzyme 37 and the use of isolated enzymes in the formation of natural products, including aporphines, has been reviewed.38... 

Alkaloids of Aconitum karakolicum Rapes.—Workers at Tashkent have completed the elucidation of the structure of aconitine (C34H47N012 m.pt 195—197 °C),28 isolated from the tubers and aerial parts of plants collected in the Terskei Ala-Tau mountain range. Aconitine (55), napelline (70), songorine (71), and the aporphine alkaloid isoboldine were also isolated from the tubers. Aconitine was assigned structure (72) from chemical and H and 13C n.m.r. and mass-spectral analyses. Alkaline hydrolysis of (72) afforded benzoic acid and the amino-alcohol aconifidine... 

Methylating only one phenol on each ring of norreticuline leaves the other one free for radical coupling. Reticuline is oxidized in the plant to isoboldine by a radical cyclization with the formation of a new C-C bond. 

We mentioned isoboldine a while back, so there must be a boldine as well. This alkaloid is also formed from norlaudanosoline by a different methylation sequence and oxidative radical coupling. Looking at the structure of boldine you may see what appears to be a mistake on someone s part. 

Corunnine, Nandazurine, ( )-Caaverine, ( )-Isoboldine, ( )-Thalicmi-dine, and ( )-Domesticine. Relative to the aporphine synthesis by enamide photocyclization, Kupchan and O Brien (141) have developed the oxidative photochemical synthesis of aporphine alkaloids. 

The Reissert compound 289 was condensed with the 1 -iodobenzaldehyde 290 to give the 1-benzyl compounds 291, which were then irradiated. The photocyclized products 292 were the oxoaporphines, which were then converted to the respective alkaloid corunnine, nandazurine, ( )-caaver-ine, ( )-isoboldine, ( )-thalicmidine, and ( )-domesticine in good yields (Scheme 109). 

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