toxicological evaluation of 6'-Sialyllactose sodium salt produced by a novel method.

6'-Sialyllactose (6'-SL) sodium salt is the sodium salt of a naturally occurring trisaccharide found in dairy products and human milk. 6'-SL sodium salt formulations produced by different methods have been the subject of other safety studies and are approved for use in food in the United States and other countries. Because the manufacturing process can influence the toxicological profile of a substance, studies were undertaken to assess the safety of 6'-SL sodium salt produced by a novel manufacturing process.

Evaluation of 6'-Sialyllactose Sodium Salt Supplementation to Formula on Growth and Clinical Parameters in Neonatal Piglets.

Oligosaccharides are complex, non-digestible glycans found in large abundance in human milk. The abundance and the profile of bovine milk oligosaccharides and bovine milk based in infant formula differ from those in human milk. Recently, some human milk oligosaccharides (HMOs) have been supplemented to infant formula, however, not all forms have been available in large scale.

Safety evaluation of 3'-siallylactose sodium salt supplementation on growth and clinical parameters in neonatal piglets.

Sialyllactose (SL) is an abundant oligosaccharide in human milk with health benefits that include intestinal maturation, gut microbiota modulation, and cognitive development. Recent technological advances support large scale production of different forms of sialyllactose, which will enable their use as a food ingredient. The objective of the study was to investigate the dose-dependent effects of novel enzymatically-synthesized 3'-sialyllactose (3'SL) sodium salt supplemented to swine milk replacer on growth, hematological parameters and tissue histology in a pre-clinical neonatal pig model.

Toxicological evaluation of 6'-sialyllactose (6'-SL) sodium salt.

We performed a series of toxicity studies on the safety of 6'-sialyllactose (6'-SL) sodium salt as a food ingredient. 6'-SL sodium salt, up to a maximum dose of 5000 μg/plate, did not increase the number of revertant colonies in five strains of Salmonella typhimurium in the presence or absence of S9 metabolic activation. A chromosomal aberration assay (using Chinese hamster lung cells) found no clastogenic effects at any concentration of 6'-SL sodium salt in the presence or absence of S9 metabolic activation.

Erratum to: Synthesis of Curcumin Glycosides with Enhanced Anticancer Properties Using One-Pot Multienzyme Glycosylation Technique.

This erratum is being published to correct the author's contribution and name of above manuscript by Gurung et al. that was published in Journal of Microbiology and Biotechnology (2017, 27: 1639-1648). The first author (Rit Bahadur Gurung) and the second author (So Youn Gong) contributed equally to this article.

Toxicological evaluation of 3'-sialyllactose sodium salt.

The safety of 3'-sialyllactose (3'-SL) sodium salt was evaluated by testing for gene mutations, in vivo and in vitro clastogenic activity, and animal toxicity in beagle dogs and rats. The results of all mutagenicity and genotoxicity tests were negative, indicating that 3'-SL does not have any mutagenic or clastogenic potential. The mean lethal dose (LD) of 3'-SL sodium salt was well above 20 g/kg body weight (bw) in rats.

Synthesis of Curcumin Glycosides with Enhanced Anticancer Properties Using One-Pot Multienzyme Glycosylation Technique.

Curcumin is a natural polyphenolic compound, widely acclaimed for its antioxidant, antiinflammatory, antibacterial, and anticancerous properties. However, its use has been limited due to its low-aqueous solubility and poor bioavailability, rapid clearance, and low cellular uptake. In order to assess the effect of glycosylation on the pharmacological properties of curcumin, one-pot multienzyme (OPME) chemoenzymatic glycosylation reactions with UDP- α-D-glucose or UDP-α-D-2-deoxyglucose as donor substrate were employed.

Donor specificity of YjiC glycosyltransferase determines the conjugation of cytosolic NDP-sugar in in vivo glycosylation reactions.

Escherichia coli BL21 (DE3) was engineered by blocking glucose-1-phosphate utilizing glucose phosphate isomerase (pgi), glucose-6-phosphate dehydrogenase (zwf) and uridylyltransferase (galU) genes to produce pool of four different rare dTDP-sugars. The cytosolic pool of dTDP-l-rhamnose, dTDP-d-viosamine, dTDP-4-amino 4,6-dideoxy-d-galactose, and dTDP-3-amino 3,6-dideoxy-d-galactose was generated by overexpressing respective dTDP-sugars biosynthesis genes from various microbial sources. A flexible glycosyltransferase YjiC, from Bacillus licheniformis DSM 13 was also overexpressed to transfer sugar moieties to 3-hydroxyl group of 3-hydroxyflavone, a core unit of flavonoids.

Enzymatic synthesis of lactosylated and sialylated derivatives of epothilone A.

Epothilone A is a derivative of 16-membered polyketide natural product, which has comparable chemotherapeutic effect like taxol. Introduction of sialic acids to these chemotherapeutic agents could generate interesting therapeutic glycoconjugates with significant effects in clinical studies. Since, most of the organisms biosynthesize sialic acids in their cell surface, they are key mediators in cellular events (cell-cell recognition, cell-matrix interactions).

Efficient enzymatic systems for synthesis of novel α-mangostin glycosides exhibiting antibacterial activity against Gram-positive bacteria.

Two enzymatic systems were developed for the efficient synthesis of glycoside products of α-mangostin, a natural xanthonoid exhibiting anti-oxidant, antibacterial, anti-inflammatory, and anticancer activities. In these systems, one-pot reactions for the synthesis of UDP-α-D-glucose and UDP-α-D-2-deoxyglucose were modified and combined with a glycosyltransferase (GT) from Bacillus licheniformis DSM-13 to afford C-3 and C-6 position modified glucose and 2-deoxyglucose conjugated novel α-mangostin derivatives. α-Mangostin 3-O-β-D-glucopyranoside, α-mangostin 6-O-β-D-glucopyranoside, α-mangostin 3,6-di-O-β-D-glucopyranoside, α-mangostin 3-O-β-D-2-deoxyglucopyranoside, α-mangostin 6-O-β-D-2-deoxyglucopyranoside, and α-mangostin 3,6-di-O-β-D-2-deoxyglucopyranoside were successfully produced in practical quantities and characterized by high-resolution quadruple time-of-flight electrospray ionization-mass spectrometry (HR-QTOF ESI/MS), (1)H and (13)C NMR analyses.

Assessing acceptor substrate promiscuity of YjiC-mediated glycosylation toward flavonoids.

The acceptor substrate promiscuity of YjiC, a UDP-glycosyltransferase from Bacillus licheniformis, was explored with seven different classes (flavonols, flavanols, flavones, flavanones, chalcone, stilbene, and isoflavonoids) of 23 flavonoid acceptors. For most of the polyphenols used in the reactions, the enzymatic bioconversion was significantly higher with the production of multiple glucosylated derivatives. This study highlights the highly flexible non-regiospecific glycosylation ability of YjiC toward polyphenolic compounds.

Enzymatic synthesis of apigenin glucosides by glucosyltransferase (YjiC) from Bacillus licheniformis DSM 13.

Apigenin, a member of the flavone subclass of flavonoids, has long been considered to have various biological activities. Its glucosides, in particular, have been reported to have higher water solubility, increased chemical stability, and enhanced biological activities. Here, the synthesis of apigenin glucosides by the in vitro glucosylation reaction was successfully performed using a UDP-glucosyltransferase YjiC, from Bacillus licheniformis DSM 13.