Synthesis of isobutyl-C-galactoside (IBCG) as an isopropylthiogalactoside (IPTG) substitute for increased induction of protein expression.

Addition of isopropyl-β-d-thiogalactopyranoside (IPTG) to bacterial cultures is often used to induce expression of plasmid-based genes for the production of recombinant proteins under control of the lac promoter, but a simple method to circumvent the inherent instability of this compound has not been addressed experimentally. Herein we report the first synthesis of isobutyl-C-galactoside (IBCG), the C-glycoside analogue of IPTG, and show that IBCG is superior to IPTG in inducing protein expression over long induction times.