Benylisoquinoline

From DrugPedia: A Wikipedia for Drug discovery

1-Benzylisoquinoline is the structural backbone of many alkaloids with a wide variety of structures, including papaverine, codeine, morphine, apomorphine, berberine, protopine and tubocurarine.

[edit] Biosynthesis

Plants producing benzylisoquinoline alkaloids have a common biosynthetic pathway, making use of two units of L-tyrosine. One tyrosine molecule is metabolised to dopamine which constitutes the isoquinoline part, while the benzylic part is mostly formed from tyramine, itself the decarboxylation product of tyrosine.

Many benzylisoquinolines have a methylated nitrogen atom as well as functional groups containing oxygen (-OH, -OCH3, -OCH2O-) in positions 6, 7, 3' and 4'. The latter come from the precursors mentioned above, namely tyrosine, dopamine and their derivatives.

[edit] Examples of benzylisoquinoline alkaloids

Papaverine

Apomorphine (one additional ring closure)

Morphine (two additional ring closures)

Berberine (one additional ring closure with incorporated N-methyl)

Protopine (with opened pyridine ring)

Tubocurarine (composed of two benzylisoquinoline units)

[edit] References

Benzylisoquinoline biosynthesis by cultivated plant cells and isolated enzymes