Synthesis of lacto-N-neotetraose and lacto-N-tetraose using the dimethylmaleoyl group as amino protective group

Galactose-limited fed-batch cultivation of Escherichia coli for the production of lacto-N-tetraose

“…The synthesis of LNT in milligram-scales has been achieved by chemical as well as enzymatic in vitro approaches [18,[22][23][24]. Recently, we have demonstrated the synthesis of LNT by a Escherichia coli whole-cell biotransformation method that converts lactose by a two-step in vivo glycosylation into LNT using the recombinant ␤1,3-N-acetylglucosaminyltransferase (LgtA) and ␤1,3-galactosyltransferase (WbgO) [25].…”

Synthesis of fucosylated lacto-N-tetraose using whole-cell biotransformation

“…7 Focusing on neutral HMOs, previous studies described chemical, enzymatic or whole-cell syntheses of fucosyllactoses [8][9][10][11][12][13][14] and core structures such as lacto-N-neotetraose (LNnT) and LNT. [15][16][17][18][19] Fucosylated derivatives of the core structure LNnT were synthesized in whole-cell cultivations, 10,11,20 while syntheses of fucosylated LNT structures so far have been only described from in vitro enzymatic conversions. [21][22][23] Enzymatic or whole-cell synthesis requires the availability of fucosyltransferases which can be used either as recombinant human genes, or from bacteria such as Helicobacter pylori.…”

11-Keto-boswellic acid derived amides and monodesmosidic saponins induce apoptosis in breast and cervical cancers cells

“…Thus, KBA was transformed (Scheme 2) into the corresponding benzylester 10 [25,37]. Glycosylation of 10 with 2,3,4,6-tetra-O-acetyl-a-D-glucopyranosyl trichloracetimidate or 2,3,4,6-tetra-O-acetyl-a-D-galactopyranosyl trichloracetimidate [38,39] in the presence of BF 3 $Et 2 O [40] at À25 C gave a 52% yield of 11 and 48% of 12, respectively. Lower yields, however, were achieved with trimethylsilyl trifluormethanesulfonate [40] as a catalyst under various conditions; this parallels our previous findings for the synthesis of glycyrrhetinic acid derived saponins [41].…”

“…The solvents were dried according to usual procedures. Frankincense was obtained from different commercial suppliers in bulk quantities; compounds AKBA and KBA were isolated from frankincense, 2,3,4,6-tetra-O-acetyl-a-Dglucopyranosyl trichloroacetimidate, 2,3,4,6-tetra-O-acetyl-a-Dgalactopyranosyl trichloroacetimidate [38,39] and benzyl (3a) 3-hydroxy-11-oxours-12-en-24-oate (10) [25] were prepared as previously reported. The purity of the compounds were determined by HPLC and found to be >98%.…”