• KSBB Journal
• /
• v.23 no.2
• /
• pp.135-141
• /
• 2008

SMB (simulated moving bed) chromatography is a very useful utility for the separation of binary system. We simulated the separation of L-arabinose and L-ribose from the mixture by using lab-scale 4(1-1-1-1)-zone SMB chromatography. Preliminary experiments of PIM (pulse input method) were performed to measure adsorption isotherms of L-ribose and L-arabinose in $NH_2$ HPLC column, and experimental and simulated results from ASPEN chromatography were compared. To find the most suitable separation condition in SMB, we carried out a simulation in $m_2-m_3$ plane base on the triangle theory and calculated operating parameters (flow rate of four zone, switching time and feed concentration and so on) using ASPEN chromatography under the conditions of linear isotherms obtained from PIM.

• KSBB Journal
• /
• v.23 no.1
• /
• pp.31-36
• /
• 2008

The use of L-carbohydrates and their corresponding nucleosides in medicinal application has greatly increased. For example L-ribose has been much in demand as the starting material for curing hepatitis B. High performance liquid chromatography (HPLC) method was studied for the analysis of ribose and arabinose fractions from ion exchange chromatography (IEC). Dowex Monosphere 99 Ca/320 resin was packed in IEC to separate ribose and arabinose under various operating conditions. $NH_{2}$ and sugar HPLC columns were then used to analyze the fractions from the IEC column. Pulse input method (PIM) was also used to measure adsorption isotherms of ribose and arabinose in the Dowex column and HPLC columns. Experimental results and simulations by ASPEN chromatography were compared with fair agreement.

• Journal of Microbiology and Biotechnology
• /
• v.14 no.4
• /
• pp.665-672
• /
• 2004

D-Ribose is a five-carbon sugar used for the commercial synthesis of riboflavin, antiviral agents, and flavor enhancers. Batch fermentations with transketolase-deficient B. subtilis JY1 were carried out to optimize the production of D-ribose from xylose. The best results for the fermentation were obtained with a temperature of $37^{\circ}C$ and an initial pH of 7.0. Among various sugars and sugar alcohols tested, glucose and sucrose were found to be the most effective for both cell growth and D-ribose production. The addition of 15 g/l xylose and 15 g/l glucose improved the fermentation performance, presumably due to the adequate supply of ATP in the xylose metabolism from D-xylulose to D-xylulose-5-phosphate. A batch culture in a 3.7-1 jar fermentor with 14.9 g/l xylose and 13.1 g/l glucose resulted in 10.1 g/l D-ribose concentration with a yield of 0.62 g D-ribose/g sugar consumed, and 0.25 g/l-h of productivity. Furthermore, the sugar utilization profile, indicating the simultaneous consumption of xylose and glucose, and respiratory parameters for the glucose and sucrose media suggested that the transketolase-deficient B. subtilis JY1 lost the glucose-specific enzyme II of the phosphoenolpyruvate transferase system.

• Journal of the Korean Chemical Society
• /
• v.38 no.11
• /
• pp.783-784
• /
• 1994

• Korean Chemical Engineering Research
• /
• v.49 no.5
• /
• pp.628-632
• /
• 2011

L-ribose has recently attracted interest as a starting material for antiviral drug. It could be obtained from L-arabinose by epimerization reaction. Epimerization reaction was carried out with molybdenium oxide or molybdic acid catalyst and methanol/water solution. Reaction temperature, methanol percentage, and catalyst kind were selected to find an optimum reaction condition. Ion exhange chromatography was used for separating epimerization reaction mixture, and then HPLC chromatogram of L-ribose fraction obtained to calculate the yield of the reaction. Shodex ion exchange HPLC column(Model SC1011) and Phenomenex Luna $NH_2$ HPLC column were compared to employ a convenient HPLC analysis. It was found that the usage of 20% methanol, $60^{\circ}C$, and 40 g/L molybdic acid gives the best reaction condition with a yield of 21%.

• Archives of Pharmacal Research
• /
• v.22 no.6
• /
• pp.619-623
• /
• 1999

$2^{l},3^{l}$-dideoxyisoguanosine was synthesized from guanosine via intermediate 6-[(4-methyl-phenyl)thio]-2-oxo-9-($2^{l},3^{l},5^{l}$-tri-O-acetyl-$\beta$-D-ribofuranosyl)-2,3-dihydropurine (4). The 2-oxo, 6-amino and $5^{l}$-hydroxy triprotected isoguanosine derivative was utilized to reduce high polarity and promote poor solubility of intermediates. The protecting groups for oxo and 6-amino were easily removed in reduction of olefin in ribose without additional reaction steps.$2^{l},3^{l}$-Vicinal diol in ribose sugar moiety was transformed to olefin with Bu3SnH by radical reaction via bisxanthate. Removing $5^{l}$-O-TBDMS protecting group gave final product, $2^{l},3^{l}$-dideoxyisoguanosine (12) in a 10% overall yield.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.3
• /
• pp.418-424
• /
• 2018

${\text\tiny{D}}-Allose$ is a potential medical sugar because it has anticancer, antihypertensive, antiinflammatory, antioxidative, and immunosuppressant activities. Allose production from fructose as a cheap substrate was performed by a one-pot reaction using Flavonifractor plautii ${\text\tiny{D}}-allulose$ 3-epimerase (FP-DAE) and Clostridium thermocellum ribose 5-phosphate isomerase (CT-RPI). The optimal reaction conditions for allose production were pH 7.5, $60^{\circ}C$, 0.1 g/l FP-DAE, 12 g/l CT-RPI, and 600 g/l fructose in the presence of 1 mM $Co^{2+}$. Under these optimized conditions, FP-DAE and CT-RPI produced 79 g/l allose for 2 h, with a conversion yield of 13%. This is the first biotransformation of fructose to allose by a two-enzyme system. The production of allose by a one-pot reaction using FP-DAE and CT-RPI was 1.3-fold higher than that by a two-step reaction using the two enzymes.

• Korean Journal of Microbiology
• /
• v.26 no.4
• /
• pp.291-297
• /
• 1988

Three alleles of rbsB gene, rbsB, rbsB103, and rbsB106 from the wild type, the mutant and the revertant strain, respectively, were cloned for overproduction of proteins under the control of lambda $P_{L}$ promoter. Five different species of precursor and mature ribose-binding proteins were purified to homogeneity using DEAE-Sephadex column chromatography, osmotic shock pocedure, CM-Sephadex column chromatography, and Chromatofocusing column chromaography. pI of the precursor proteins and mature proteins were determined and found to be pH 8.0 and 7.5, respectively. The purified proteins were subjected to amino acid sequencing. The results confirmed the amino acid changes deduced from the DNA sequencing.

• Journal of Nutrition and Health
• /
• v.50 no.5
• /
• pp.426-436
• /
• 2017

Purpose: To compare the extent to which three different levels of D-ribose in sugar reduce the glycemic index (GI) and blood glucose response in healthy adults. Methods: Healthy adults (eight male and six female participants, n = 14) fasted for 14~16 h after eating the same dinner. Participants were then randomized to receive glucose, sucrose, sucrose containing 5% D-ribose (RB5), sucrose containing 10% D-ribose (RB10), or sucrose containing 14% D- ribose (RB14) every week on the same day for 10 weeks (repeating the sample twice). Blood samples were collected by finger prick before and 15, 30, 45, 60, 90, and 120 min after starting to eat. Results: We observed a decreased glycemic response to sucrose containing D-ribose. GIs for sucrose, RB5, RB10, and RB14 were 67.39, 67.07, 47.57, and 45.62, respectively. GI values for sucrose and RB5 were similar to those for foods with a medium GI, and GI values for RB10 and RB14 were similar to those for foods with a low GI. The postprandial maximum blood glucose rise (Cmax) with RB14 was the lowest among the test foods. Cmax values for RB10 and RB14 were significantly lower than that for sucrose. Conclusion: The results of this study suggest that sucrose containing D-ribose has an acute suppressive effect on GI and Cmax. In addition, D-ribose active elements in sugar may be effective in preventing blood glucose spikes induced by sucrose intake.

• Korean Journal of Microbiology
• /
• v.26 no.4
• /
• pp.283-290
• /
• 1988

A spontaneous revertant of mutation rbsB103 that is ribose taxis-positive was characterized. This revertant was found to be export-competent in the export of ribose-binding protein shown by the disappearance of accumulated mutant precursor protein and the export of mature ribose-binding protein to the periplasm. The reversional change was shown to be in the region of risB gene that codes for the amino terminal portion of ribose-binding protein. Analysis by high-performance liquid chromatography of peptide patterns of ribose-binding proteins confirmed the relationship between the wild-type and the revertant proteins as shown for the mutant previously (Iida et al., 1985). When the processing rate of presursor proteins from the wild type and the revertant strain in vivo was compared by pulse-chase experiment, it was found that processing is less efficient than normal in the revertant. Purified mature proteins from both wild-type and revertant were subjected to amino acid sequencing. The results confirmed the amino acid changes deduced from the DNA sequencing and showed that processing of the revertant precursor occured in the correct position even though there are two different amino acids present in the signal sequence.