Lactose 1-thio

Four years later, Nelson and Stoddart designed di- and tetra-valent lactosylated dendrons according to a convergent pathway and under mild and chemoselective conditions (Scheme 46).320 The strategy was based on the photochemical addition of hepta-0-acetyl-l-thio-/j-lactose (448) onto bisallyl trisaccharide 449 to form divalent adduct 450. Two nearly quantitative deprotection steps consisting in standard... 

Sasaki, M. and Keenan, T. W. 1978. Membranes of mammary gland XV. 5-thio-D-glucose decreases lactose content and inhibits secretory vesicle maturation in lactating rat mammary gland. Exp. Cell Res. Ill, 413-425. 

Tsuruta O, Shinohara G, Yuasa H et al (1997) UDP-N-acetyl-5-thio-galactosamine is a substrate of lactose synthase. Bioorg Med Chem Lett 7 2523-2526... 

The activity of [i-galactosidasc (P-Gal) was studied on a quartz chip using a static micromixer to mix the enzyme and substrate on the ms time scale. Inhibition by phenylethyl-P-D-thio-galactoside was also studied [1048]. In another report, the enzyme P-Gal was assayed on a chip in which P-Gal would convert a substrate, resoruhn-P-D-galactopyranoside (RBG), to resoruhn to be detected fluorescently [1049]. By varying the substrate concentrations and monitoring the amount of resoruhn by LIF, Michaelis-Menten constants could be determined. In addition, the inhibition constants of phenylethyl-P-D-thiogalactoside, lactose, and p-hydroxymercuribenzoic acid to the enzyme P-Gal were determined [1049]. 

HEK-293 hGH High-Five hsp70 HSV IPTG IRES kb Lac LCR LoxP LUC MCS human embryonic kidney cells human growth hormone TM BTI-TN-5B1-4 (cell line derived from the insect Trichoplusia ni) heat shock protein 70 herpes simplex virus isopropyl 1 -thio-fi-D-galactopyranoside internal ribosomal entry site kilobases lactose operon/repressor locus control region locus of crossover of PI luciferase isolated from firefly multiple cloning site... 

Tsuruta, O, Shinohara, G, Yuasa, H, Hashimoto, H, UDP-A-acetyl-5-thio-galactosamine is a substrate of lactose S3mthase, Bioorg. Med. Chem. Lett., 1, 2523-2526, 1997. 

Benzyl 1-thio-lactoside and ethyl lactoside, prepared from lactose dibenzyl dithioacetal116 by the preceding methods, are necessarily pyranosides (owing to the substitution on 0-4). Stevens and coworkers310 prepared ethyl 2,3 4,5-di-0-isopropylidene-l-thio-/3-D-glucoseptanoside by partial demercaptalation of 2,3 4,5-di-O-isopropylidene-D-glucose diethyl dithioacetal. 

UDP-A-acetyl-5-thio-D-galactosamine (UDP-5.SGalNAc) was active as a donor substrate of lactose synthase, the complex of galactosyltransferase (EC 2.4.1.38) and lactalbumin. By tliis method the disaccharide /9-5SGalNAc/9(1 4)GlcNAc was prepared. UDP-5.S GalNAc was synthesized from an A -acetyIgalactosaininc... 

Preparation of phenyl hepta-O-acetyl-l-thio-p-D-lactoside (2) from acetobromo-lactose (1) [22]. 

Peracylated 1,2-thio-orthoesters derived from a-n-glucopyranose [e.g. (121)], methyl o-glucopyranuronate, and a-lactose gave the l,2-(ethyl or isopropyl orthoester) derivatives when treated with Raney nickel in ethanol or propan-2-ol, respectively, although complex alcohols e.g. t-butanol) failed to yield ortho-... 

In this example, the same starting trisaccharide 38, which has been developed by Turnbull et al. was used for botb reactions. For the photoaddition, the alkene groups were introduced to 38 by allylation under acidic conditions to give 39. Then, this compound was irradiated in the presence of hepta-O-acetyl-l-thio-p-lactose 40 and was easily deprotected to give the compound 41 in very good yields (73%) (Scheme 10). 

Thio-D-glucose has been demonstrated to be a substrate for lactose synthetase which converts it into 5-thio-lactose. The reaction of r/c-epoxides with thiourea to yield y/c-epithio-compounds has been used to synthesize 2-acetamido-2-deoxy-5-thio-D-glucopyranose as portrayed in Scheme 5. Two further papers on the reaction of epimines with sulphur-containing compounds have appeared (see Vol. 11, p. 97). Reactions leading to... 

Azido-2-nitrophenyl- l-thio-jS-D-galdcto- pyranoside Lactose transport system in E. coli Analog is transported, competitive with lactose, irradiation inactivates in presence of D-lactate 96... 

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