Composition of Peru Balsam

There is some variability in the composition of Peru Balsam exudates Myroxylon pereirae (Royle) Klotzsch (Fam. Fabaceae) [syn. M. balsamum L. (Harms) var. pereirae (Royale) Harms as there is with any natural production but especially with this commodity, since the familiar commercially available item is a result of the combination of materials from three separate processes in fixed ratios (see elsewhere for Peru Balsam's manufacturing details).

The most frequently named constituent of the Peru balsam is arguably cinnamon, which is an older term for the naturally occurring balsamic (i.e. cinnamyl and benzoic) esters.
The British Pharmacopoeia's 2007 monograph on Peru Balsam (equivalent to the European Pharmacopoeia monograph 0754) stipulates that the Balsam should contain from 45% to 70% of such esters. More specifically, the cinnamein esters are largely comprised of benzyl cinnamate (to 40%), benzyl benzoate (to 30%). And cinnamyl cinnamate (to 0.5%. Other constituents include the fragrantly scented vanillin (to 1%), and the sweet-floral scented sesquiterpene alcohol nerolidol (to 7%), the latter constituent being formerly termed peruviol. The resin content is represented by the phenolic peruresinotannol constituent is typically present at 20-40%, and is found combined with both bound and free cinnamic and benzoic acid moieties.

FREE ACIDS
Of the free balsamic acids, trans-cinnamic & benzoic acids (typically to 30% & 11% respectively) are also present in large amounts in the balsam, together with smaller amounts of unesterified alcohols, such as benzyl alcohol (to 2%), cinnamic alcohol (to 0.5%) and some minor content of free coniferyl alcohol.

FURTHER READING
Gao Y., Liu B., Zhu X., Shi L., Chen J., Gong M. & Zhang L. (1999)
Analysis of chemical components of essential oil in Peru balsam balm tree extract by GC/MS Analytical Instrumentation Beijing 3(121), 37-38.
Hausen B.M., Evers P., Stowe H., Konig W.A., & Wollenweber E. (1992)
Propolis allergy IV. Studies with further sensitizers from propolis and constituent's common to propolis, poplar buds and balsam of Peru. Contact Dermatitis 26, 34-44.
Hausen B.M., Simatupang T., Bruhn G., Evers P. & Koenig W.A. (1995).
Identification of new allergenic constituents and proof of evidence for coniferyl benzoate in balsam of Peru. Am J Contact Dermat 6 (4), 199-208.