styrax benzoin chemical constituents?

Answer 1

The chief constituent of Siam Benzoin is benzoic acid (up to 38%) partly free and partly combined with benzoresinol and siaresinotannol; it also contains vanillin and an oily aromatic liquid.

When quite pure it should be entirely soluble in alcohol and yield only traces of ash.

Sumatra benzoin contains 18 per cent. or more of benzoic acid and about 20 per cent. of cinnamic acid the latter partly free and partly combined with benzoresinol and sumarisinotannol; it also contains 1 per cent. of vanillin, styrol, styracin, phenyl-prophyl cinnamate and benzaldehyde, all of which combine to produce its characteristic odour.

Answer 2

No idea but it does smell wonderful when smouldered on charcoal. I would guess vanillin and other compounds from the smell.