Sandalwood Fragrance Pathway and Its Engineering for Sustainable Production of High-Value Santalols

Abstract

AbstractThe essential oil extracted from the Santalum genus, known as sandalwood oil is one of the most valuable plant-derived secondary metabolites. It is obtained from the steam distillation of the heartwood of the sandalwood tree. The high value of this oil mainly stems from the limited supply, caused by difficulties in the cultivation of the plant and other socio-economic conditions. All species of the Santalum genus, including the highest oil-producing Santalum album (east Indian sandalwood), are very slow-growing that takes about 15–20 years to form heartwood from which oil is distilled. Combined with the loss of cultivatable land and poaching of wild trees make sandalwood oil very valuable. This oil has seen various applications in the aroma, perfume, cosmetic, flavor, and pharmaceutical industries. Though the essential oil of sandalwood constitutes several terpenes and terpene alcohols, the main fragrance-defining constituents of the oil are sesquiterpene alcohols (Z)-α-santalol, (Z)-β-santalol, (Z)-epi-β-santalol, and (Z)-α-exo-bergamotol, which are derived from their corresponding sesquiterpenes. In this chapter, we summarise the biosynthetic pathways involved in the formation of terpenoids and genes involved in the formation of key constituents of sandalwood essential oil. We cover different studies carried out toward the complete understanding of the pathway involved in sandalwood oil formation. We also take a look at how the deciphering of the sandalwood oil pathway has enabled bio-engineering approaches for enhanced and sustainable production using various biotechnological strategies.KeywordsSandalwoodEssential oilSesquiterpenesSantalolsBiosynthesisPathwayEngineering