Phytochemistry, Pharmacological Potential, and Future Prospects of Abietane-Type Diterpenoids From Salvia rosmarinus

Salvia rosmarinus, formerly known as Rosmarinus officinalis, is a medicinal plant known as one of the sources of abietane-type diterpenoids. The largest family of chemical constituents from the Salvia genus is abietanes and rearranged abietanes. Since 1976, 365 of the 545 known diterpenoids have been recognized as abietane diterpenoids. Carnosic acid, carnosol, rosmanol, epirosmanol, and their derivatives are among the bioactive abietanes that have gained much attention because of the wide spectrum of pharmacological activities. This review presents information on the distribution, isolation, biosynthesis, structural variation, degradation, semi-synthetic strategies, pharmacokinetics, and bioactivities of abietane-type diterpenoids from S. rosmarinus. Recent developments in eco-friendly extraction techniques, namely, supercritical fluid extraction, microwave-assisted extraction, ultrasound-assisted extraction, and pressurized liquid extraction, are also described in this review. The biosynthetic pathway from geranylgeranyl diphosphate to main diterpenoids, such as carnosic acid and carnosol, is also presented. Moreover, newly isolated compounds, structure-activity relationships, and antioxidant, antimicrobial, anti-inflammatory, neuroprotective, and anticancer activities are included. Moreover, the pharmacokinetics of abietane diterpenoids isolated from S. rosmarinus and their medicinal applications are also covered in this review.