4.2.3.55 (S)-beta-bisabolene synthase santalene biosynthesis II - 4.2.3.81 exo-alpha-bergamotene synthase santalene biosynthesis II - 4.2.3.82 alpha-santalene synthase santalene biosynthesis II - 4.2.3.83 beta-santalene synthase santalene biosynthesis II -