The Contribution of cocoa additive to cigarette smoking addiction

Page 10 of 207 RIVM report 650270002
Theobromine
flammability:
FP = no data available.
FL Limits = no data available.
IT = no data available.
decomposition temperature: no data available.
stability: no data available
vapour pressure/ vapour tension (20 °C): no data available.
vapour pressure (50 °C): no data available.
relative density: no data available.
octanol water partition coefficient, log P, log KOW: log P = -0.8 (4).
conversion factor: not applicable.
Critical assessment
Theobromine is a heterocyclic natural product, occurring in the cacao bean, and it is
classified as an alkaloid. It is a white, bitter tasting, crystalline powder, which readily
sublimates upon heating (direct change from solid into gas). In its structure it is
closely related to caffeine. Its solubility properties indicate a polar compound.
The presence of four nitrogen atoms distributed over two aromatic heterocyclic rings
forms a characteristic feature for purine-derived compounds. In theobromine two of
the nitrogen atoms are methylated, while the remaining two nitrogen atoms have a
quite different character. One of the remaining nitrogen atoms has a pyridine-like
configuration, i.e. it contains a free, unshared pair of electrons, which is known as a
strong feature for interaction possibilities, e.g. the ability to bind a proton, causing the
compound to have basic properties. Complexation interactions are likely to occur as
well (5). The other nitrogen atom is bound to a hydrogen atom that can be released as
a proton, so causing the compound to have acidic properties. Both basic and acidic
properties are weak, resulting in almost neutral solutions when dissolved in water.
Compounds formed upon reaction with bases are more stable than salts obtained with
acids (decompose in water). More general: it has the ability to form complexes with
several compounds.
Except for the purine-like nitrogen, the unshared pairs of electrons of all other
nitrogens participate in the formation of the -clouds, so adding to the aromatic,
stable character of the purine ring system.
Little is known about combustion products. Preliminary pyrolysis data indicate as
products: methane, ethene, ethane, propene, propane, trimethylamine.
Conclusion
Theobromine is a natural product, nitrogen containing, water soluble, with an
amfoteric and complexating character.
FUNCTION IN TOBACCO
No data available.
AMOUNT IN TOBACCO PRODUCTS
Typical concentration of cocoa powder for cigarettes is 1 % (6). Assuming 1.9 %
(w/w) theobromine concentration in cocoa powder (7), a cigarette weighing 1 g,
contains ± 0.19 mg theobromine.