Salicylaldehyde be prepared from the corresponding phenol by the Duff reaction, or by treatment with paraformaldehyde in the presence of magnesium chloride and a base. Salicylaldehyde was identified as a characteristic aroma component of buckwheat. It is also one of the components of castoreum, the exudate from the castor sacs of the mature North American beaver ("Castor canadensis") and the European beaver ("Castor fiber"), used in perfumery. Furthermore, salicylaldehyde occurs in the larval defensive secretions of several leaf beetle species that belong the subtribe Chrysomelina. An example for a leaf beetle species that produces salicylaldehyde is the red poplar leaf beetle
Resinoid (perfumery) Resinoid (perfumery) Resinoids are extracts of resinous plant exudates (balsams, oleo gum resins, and natural oleoresins). Resinous plant exudates (balsams, oleo gum resins, and natural oleoresins) and animal secretions (ambergris, castoreum, musk, and civet) are extracted with solvents such as methanol, ethanol, toluene, or acetone. Yields range from 50 to 95 %. The products mainly consist of nonvolatile, resinous compounds. They are usually highly viscous and are sometimes diluted (e.g., with phthalates or benzyl benzoate) to improve their flow and processing properties. Resinoids are mainly used as perfume fixatives. The resinoids described above should be distinguished from prepared oleoresins (e.g.,