Synthesis of Unnatural Mono- and Oligosaccharides of Farnesol, Geraniol, and (S)-Perillyl Alcohol by Biocatalytic Glycosylations

Farnesol and geraniol were glucosylated to the corresponding unnatural β-glucosides, which were two new biotransformation products, by cultured plant cells of Eucalyptus perriniana, Strophanthus gratus, and Phytolacca americana. Cultured E. perriniana cells glycosylated (S)-perillyl alcohol to two β-glycosides, i.e., β-glucoside and unnatural β-gentiobioside, whereas only perillyl β-glucoside was produced by S. gratus and P. americana. Perillyl β-glucoside was further converted into two unnatural β-maltooligosaccharides, i.e., β-maltoside and β-maltotrioside, by cyclodextrin glucanotransferase.