Description
A closely-related bisbenzylisoquinoline base found also in Magnolia fuscata, the
alkaloid occurs mainly in the leaves and is obtained in the pure form as a microcrystalline powder from EtOH or C6H6. It may be separated from magnolamine
by virtue of its insolubility in hot C6H6. It is only sparingly soluble in most
organic solvents but dissolves readily in aqueous alkalies. The alkaloid is laevorotatory with [α]
D - 9.6° (pyridine). It furnishes vitreous salts with mineral
acids but yields a crystalline picrate as a yellow microcrystalline powder from
EtOH, m.p. 160-2°C (dec.) and a picrolonate, m.p. 190°C (dec.). Treatment
with CH2N2 gives the trimethyl ether, m.p. 1 09-1 10°C, oxidized by KMn04 in
Me2CO to 2-methoxy-5:4'-dicarboxydiphenyl ether and a lactam, l-keto-6:7-
dimethoxy-2-methyltetrahydroisoquinoline. On the basis of these results, the
alkaloid may be represented by the above structure which makes it a close
relative of dauricine (q.v.). The Ullmann reaction has been used by Kametani
and his colleagues to synthesize the alkaloid.
Definition
ChEBI: Berbamunine is a benzyltetrahydroisoquinoline, a bisbenzylisoquinoline alkaloid and an isoquinolinol. It is a conjugate base of a berbamuninium(2+).
References
Pyman., J. Chern. Soc., 95, 1272 (1909)
Proskurnina, Orekhov., Bull. Soc. Chirn., 5, 1357 (1958)
Proskurnina, Orekhov., J. Gen. Chern. USSR., 10, 707 (1940)
Synthesis:
Kametani, !ida, Sakurai., Chern. Pharrn. Bull. (Tokyo), 16, 1623 (1968)
