Sustainable (-)-Ambrox Production: Chemistry Meets Biocatalysis.

(-)-Ambrox, the most prominent olfactive component of ambergris, is one of the most widely used biodegradable fragrance ingredients. It is traditionally produced from the diterpene sclareol chemically modified and cyclized into (-)-ambrox. The availability of the new feedstock (E)-β-farnesene produced by fermentation opened new routes to (E,E)-homofarnesol as a precursor to (-)-ambrox.

Laccase versus laccase-like multi-copper oxidase: a comparative study of similar enzymes with diverse substrate spectra.

Laccases (EC 1.10.3.

Synthesis and in vitro activity of heterocyclic inhibitors of CYP2A6 and CYP2A13, two cytochrome P450 enzymes present in the respiratory tract.

The synthesis of several heterocyclic compounds (1- or 2-substituted 1H-imidazoles and 2-substituted oxazoles, oxazolines and pyrazines) has been achieved. These compounds were tested as inhibitors of CYP2A6 and CYP2A13--two cytochrome P450 enzymes present in the respiratory tract--with a view to preventing the formation of carcinogenic metabolites of nicotine and inhibiting the metabolism of fragrances. 1-Substituted imidazoles bearing short alkyl chains displayed IC(50) values of around 2 microM for both enzymes, together with high vapour pressures.

Structural determinants of odorant recognition by the human olfactory receptors OR1A1 and OR1A2.

An interaction of odorants with olfactory receptors is thought to be the initial step in odorant detection. However, ligands have been reported for only 6 out of 380 human olfactory receptors, with their structural determinants of odorant recognition just beginning to emerge. Guided by the notion that amino acid positions that interact with specific odorants would be conserved in orthologs, but variable in paralogs, and based on the prediction of a set of 22 of such amino acid positions, we have combined site-directed mutagenesis, rhodopsin-based homology modelling, and functional expression in HeLa/Olf cells of receptors OR1A1 and OR1A2.

Expression of cytochrome p450 and other biotransformation genes in fetal and adult human nasal mucosa.

Despite recent progress in the identification and characterization of numerous nasal biotransformation enzymes in laboratory animals, the expression of biotransformation genes in human nasal mucosa remains difficult to study. Given the potential role of nasal biotransformation enzymes in the metabolism of airborne chemicals, including fragrance compounds and therapeutic agents, as well as the potential interspecies differences between laboratory animals and humans, it would be highly desirable to identify those biotransformation genes that are expressed in human nasal mucosa. In this study, a global gene expression analysis was performed to compare biotransformation enzymes expressed in human fetal and adult nasal mucosa to those expressed in liver.

Olfactory receptor neuron profiling using sandalwood odorants.

The mammalian olfactory system can discriminate between volatile molecules with subtle differences in their molecular structures. Efforts in synthetic chemistry have delivered a myriad of smelling compounds of different qualities as well as many molecules with very similar olfactive properties. One important class of molecules in the fragrance industry are sandalwood odorants.