• Journal of Photoscience
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• v.9 no.2
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• pp.174-177
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• 2002

Sugar-linked porphyrin and chlorin compounds have been synthesized. Phototoxicity of these compounds against the HeLa cell line was also examined. For the porphyrin derivatives, the higher activity was observed for a derivative having four OH-protected sugar moieties. For the chlorin derivatives, OH-unprotected free-base derivatives were generally effective. Singlet oxygen producing ability were examined to evaluate the activity on photodynamic therapy of the compounds.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4227-4232
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• 2011

A number of new 2,5-disubstituted 1,3,4-thiadiazole and their S- or N-substituted derivatives as well as the corresponding sugar hydrazone derivatives were synthesized and tested for their antimicrobial activity against Bacillus subtilis (Gram-positive), Pseudomonas aeruginosa (Gram-negative), and Streptomyces species (Actinomycetes). The synthesized compounds displayed different degrees of antimicrobial activities or inhibitory actions.

• Biomolecules & Therapeutics
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• v.12 no.2
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• pp.74-78
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• 2004

Paecilomyces tenuipes, a caterpillar fungus, contains many health-promoting ingredients. Recent reports indicate that consumption of P. tenuipes helps reducing blood sugar content for diabetes. Mechanism for reduction in the circulatory sugar content, however, still remains least understood. Methanolic extraction of P. tenuipes (MPT) was prepared and acetoxyscirpendiol (ASD) was subsequently purified limn MPT. Glucose transporter-1 (GLUT-1) was expressed in the Xenopus oocytes and the effect of MPT or ASD on the expressed GLUT-1 was analyzed according to the uptake of 2-dideoxy-D-glucose (2-DOG). MPT was shown to inhibit GLUT-1 activity significant1y compared to the non-treated control. In the presence of ASD and its derivatives, GLUT-1 activity was greatly inhibited in a dose-dependent manner. Among ASD and its derivatives, AS-1 showed most significant inhibition. Taken together, these results strongly indicate that ASD in P. tenuipes may serve as a functional substance in lowering blood sugar in the circulatory system. ASD and its derivatives can be utilized as inhibitors of GLUT-1.

• BMB Reports
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• v.38 no.2
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• pp.211-217
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• 2005

Cordyceps, an entomopathogenic fungus, contains many health-promoting ingredients. Recent reports indicate that the consumption of cordyceps helps reduce blood-sugar content in diabetics. However, the mechanism underlying this reduction in circulatory sugar content is not fully understood. Methanolic extracts were prepared from the fruiting bodies of Paecilomyces tenuipes, and 4-beta acetoxyscirpendiol (4-ASD) was eventually isolated and purified. $Na^+$/Glucose transporter-1 (SGLT-1) was expressed in Xenopus oocytes, and the effect of 4-ASD on SGLT-1 was analyzed utilizing a voltage clamp and by performing 2-deoxy-D-glucose (2-DOG) uptake studies. 4-ASD was shown to significantly inhibit SGLT-1 activity compared to the non-treated control in a dose-dependent manner. In the presence of the derivatives of 4-ASD (diacetoxyscirpenol or 15-acetoxyscirpendiol), SGLT-1 activity was greatly inhibited in an 4-ASD-like manner. Of these derivatives, 15-acetoxyscirepenol inhibited SGLT-1 as well as 4-ASD, whereas diacetoxyscirpenol was slightly less effective. Taken together, these results strongly indicate that 4-ASD in P. tenuipes may lower blood sugar levels in the circulatory system. We conclude that 4-ASD and its derivatives are effective SGLT-1 inhibitors.

• Journal of Microbiology and Biotechnology
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• v.30 no.1
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• pp.11-20
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• 2020

Quercetin and its derivatives are important metabolites that belong to the flavonol class of flavonoids. Quercetin and some of the conjugates have been approved by the FDA for human use. They are widely distributed among plants and have various biological activities, such as being anticancer, antiviral, and antioxidant. Hence, the biosynthesis of novel derivatives is an important field of research. Glycosylation and methylation are two important modification strategies that have long been used and have resulted in many novel metabolites that are not present in natural sources. A strategy for modifying quercetin in E. coli by means of glycosylation, for example, involves overexpressing respective glycosyltransferases (GTs) in the host and metabolic engineering for increasing nucleoside diphosphate sugar (NDP-sugar). Still others have used microorganisms other than E. coli, such as Streptomyces sp., for the biotransformation process. The overall study of the structural activity relationship has revealed that modification of some residues in quercetin decreased one activity but increased others. This review summarizes all of the information mentioned above.

• Analytical Science and Technology
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• v.8 no.4
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• pp.859-864
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• 1995

Mono- and oligosaccharides are derivatized with p-aminobenzoic ethyl ester (ABEE), strongly absorbs UV light at 254 nm, in the presence of sodium cyanoborohydride. C18-bonded silica column is used for the separation of sugar-ABEE derivatives in an isocratic mode. RP-HPLC conditions are optimized by using ternary mixture as mobile phase and $45^{\circ}C$ as a column temperature. Sugar-ABEE derivatives are separated well within a short run time (ca. 25 min) by reverse-phase partition chromatographic mode. The ($1{\rightarrow}6$) linkage type of dihexose-ABEE derivatives has shorter retention time than ($1{\rightarrow}4$)-linkage type. After acid hydrolysis of glycoproteins with 2M trifluoroacetic acid, monosaccharide composition and contents are determined. This procedure is very useful for the simultaneous analysis of neutral and amino sugars in a single chromatographic step using RP-HPLC without reacetylation of deacetylated amino sugars, which are produced by acid hydrolysis.

• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.52-56
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• 1991

The browning reaction of sugar derivatives, fructo-oligosaccharide, high maltose syrup(HMS), sorbitol and maltitol, and their effect on the appearance of jam and candy were investigated. The spectrophotometrie scanning of the absorbance between 230 nm and 700 nm could demonstrate the heat induced browning of the sugar derivatives. Fructo-oligosaccharide and HMS showed sharp increase in absorbance at 270-330 nm range by heating at $100{\sim}120^{\circ}C$ for 1 hr but sorbitol and maltitol did not show the increase in absorbance. When the pH was lowered red from neutral to 2.0, the absorbance of HMS and sucrose increased sharply, showing that these substances are relatively unstable in acidic heating compared to fructo-oligosaccharide. The addition of glycine enhanced the browing reaction of fructo-oligosaccharide and HMS, whereas little change was observed with sucrose, sorbitol and maltitol. These browning characterisitcs of sugar derivatives were reflected to the color development of apple jam and candy where they were used. Both fructo-oligosaccharide and HMS increased the yellowness of these products, while sugar alcohols reduced the yellowness compared to sugar.

• Journal of Microbiology and Biotechnology
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• v.28 no.2
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• pp.298-304
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• 2018

The single-vessel multienzyme UDP-${\alpha}$-$\text\tiny{D}$-glucose recycling system was coupled with a forward glucosylation reaction to produce novel glucose moiety-conjugated derivatives of different tetracycline antibiotic analogs. Among five tetracycline analogs used for the reaction, four molecules (chlorotetracycline, doxytetracycline, meclotetracycline, and minotetracycline) were accepted by a glycosyltransferase enzyme, YjiC, from Bacillus licheniformis to produce glucoside derivatives. However, the enzyme was unable to conjugate sugar units to rolitetracycline. All glucosides of tetracycline derivatives were characterized by ultraviolet absorbance maxima, ultra-pressure liquid chromatography coupled with photodiode array, and high-resolution quadruple time-of-flight electrospray mass spectrometry analyses. These synthesized glucosides are novel tetracycline derivatives.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.325-333
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• 1996

This study was conducted to develop neural networks of predicting the sugar content of fruits based on the optical densities obtained from a spectrophotometer. Pear, apple and peach were used in investigating the feasbility of the developed neural networks as a nondestructive measurement. A spectrophotometer was used to measure the optical densities of test fruits. The neural networks suggested in this study consisted of multi-layers having one hidden layer and one output layer. The correlation coefficients between the predicted and the measured sugar content for most fruits were high. The neural networks using 2nd derivatives of optical density spectrum produced a better results in predicting the sugar content of fruits. This study contributed to develop a method for nondestructively predicting the sugar content of fruits.

• Korean Journal of Food Science and Technology
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• v.22 no.7
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• pp.852-857
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• 1990

The rheological properties and food functionality of the novel sugar derivatives, fructo-oligosaccharide, high maltose syrup(HMS), maltitol and sorbitol were examined and compared to those of sucrose. All samples tested showed Newtonian fluid property at the concentration range of 10% to the original concentrated products containing $69{\sim}81%w/w$ solid. HMS showed the highest viscosity. The viscosity increased(r=0.8038) as the average molecular weight of sugar derivatives were increased. The viscosity increased exponentially as the concentration increased, and sugar alcohols had lower value of the exponent compared to HMS and fructo-oligosaccharide. The viscosity of sugar derivatives solutions decreased by the increasing temperature following the Arrhenius equation. The flow activation energies of sorbitol and HMS were higer than that of sucrose. Substitution of sucrose with fructo-oligosaccharide in apple jam processing did not change the textural characteristics, but in redbean jelly(yanggaeng) it reduced the hardness, adhesiveness, springiness and cohesiveness. When sucrose was 100% replaced by HMS, the texture of apple jam and redbean jelly was not changed, but by mixing sucrose and HMS 1 : 1 ratio, the hardness decreased substantially The sugar alcohols reduced the hardness, adhesiveness, springiness of apple jam and redbean jelly significantly. Addition of fructo-oligosaccharide and HMS to sucrose did not influence the solidifying rate of candy, but sorbitol, even at 10% addition, retarded the candy moulding.