80441-61-8 GBTGP Galactopyranosyl 1-thio-beta-D-galactopyranoside Galactopyranosyl-1-thiogalactopyranoside Galactosyl-1-thio-beta-D-galactopyranoside Galactosyl-beta-D-thiogalactosylpyranoside Galsgal Tdg cpd Thiodigalactoside beta-D-Galactopyranoside, D-galactosyl 1-thio-