• International Journal of Industrial Entomology and Biomaterials
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• v.2 no.2
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• pp.141-147
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• 2001

This study was carried out to find out whether there exists any content variation in 1-deoxynojirimycin (DNJ) among regional and varietal mulberry leaves. HPLC analysis was performed for 22 samples collected from several localities in Korea and Tsushima Islands Japan. The highest content was observed in the Cheongilppong sample collected at Youngchun City, Kyungsangbuk Province (1,882.7 $\mu\textrm{g}$/g DW), whereas lowest content was observed in the Cheongilppong sample collected at Jiniu City, Kyungsangnam Province (395.65 $\mu\textrm{g}$/g DW). In the comparison of regional samples of Kaeryangppong variety, DNJ content was highest in the order of Woniu City (1,460.1) > Boungun (999.85) > Hweongsung-gun (939.12) > Cheongju City (688.78). In case of Cheongilppong, DNJ content was highest in the order of Youngchun City (1.882.8) > Sanchung-gun (1,125.3) > Sunchon City (649.17) > Byunsan-myon (441.54) > Jinju City (395.65). Average content of regional samples was higher in Kaeryangppong (1,021.7 $\mu\textrm{g}$/g DW) than that of Cheongilppong (898.87 $\mu\textrm{g}$/g DW). Average DNJ content of the wild mulberry loaves collected from Cheju Island and Tsushima Island (1,012.9$\mu\textrm{g}$/g DW) was high enough to reach to that of the regional Kaeryangppong samples. In the comparison among varietal samples collected in Suwon, the highest DNJ content was observed in YK209 (768.16 $\mu\textrm{g}$/g DW), amongst overall low DNJ content of the varietal samples. Considering a few pieces of information from our data, DNJ content appears not to be influenced solely by annual temperature of the planted areas.

• Journal of Sericultural and Entomological Science
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• v.51 no.1
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• pp.20-29
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• 2013

Countries of the world are competing for the collection and utilization of genetic resources, which is a resource of value-added industrialization. We are building database of silkworm and mulberry resources with morphological, genetic characteristics data etc. Moreover, recent bioactive compound has been receiving increasing attention. So we analyzed 1-deoxynojirimycin(1-DNJ) content as a this item in addition to the basic information using 363 strains(varieties) of mulberry genetic resources. They were grown under the same environment and conditions. Mulberry leaves were collected and then freeze-dried and powdered for 1-DNJ test. As a result, 1-DNJ mean content of 363 mulberry strains was $0.176{\pm}0.077%$, and the coefficient of variation (CV) was 43.5%. The variation between the strains was greatly severe. Among the tested strains, 'C1D89/29' was showed the highest content of 0.47%, whereas 'Pumbo 24' and 'Turkey E' were showed the lowest content of 0.05% respectively. The content of 1-DNJ of 16 mulberry varieties for silkworm rearing were compared. Average concentration was $0.17{\pm}0.04%$, and the coefficient of variation (CV) was 22.8%. Variation among cultivars was not significant. Finally we selected 1-DNJ high-containing 11 strains. They are as follows. 'C1D89/29', 'Hiihak', 'Jeokasibmunja', 'Gweonchil', 'Botongsibmunja', 'Jeokchuk', 'bulguksang', 'Geunsookgojo', 'Busanggeum', 'Guksang 20' and 'Taekwang' which are more than twice of the overall average content.

• Journal of Microbiology
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• v.45 no.5
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• pp.431-440
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• 2007

A silkworm (Bombyx mori L.) extract known to contain naturally occurring iminosugars, including 1-deoxynojirimycin (1-DNJ) derived from the mulberry tree (Morus alba L.), was evaluated in surrogate HCV and HBV in vitro assays. Antiviral activity of the silkworm extract and one of its purified constituents, 1-DNJ, was demonstrated against bovine viral diarrhea virus (BVDV) and GB virus-B (GBV-B), both members of the Flaviviridae family, and against woodchuck hepatitis virus (WHV) and hepatitis B virus (HBV), both members of the Hepadnaviridae family of viruses. The silkworm extract exhibited a 1,300 fold greater antiviral effect against BVDV in comparison to purified 1-DNJ. Glycoprotein processing of BVDV envelope proteins was disrupted upon treatment with the naturally derived components. The glycosylation of the WHV envelope proteins was affected largely by treatment with the silkworm extract than with purified 1-DNJ as well. The mechanism of action for this therapy may lie in the generation of defective particles that are unable to initiate the next cycle of infection as demonstrated by inhibition of GBV-B in vitro. We postulate that the five constituent iminosugars present in the silkworm extract contribute, in a synergistic manner, toward the antiviral effects observed for the inhibition of intact maturation of hepatitis viral particles and may complement conventional therapies. These results indicate that pre-clinical testing of the natural silkworm extract with regards to the efficacy of treatment against viral hepatitis infections can be evaluated in the respective animal models, in preparation for clinical trials in humans.

• International Journal of Industrial Entomology and Biomaterials
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• v.23 no.1
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• pp.123-128
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• 2011

1-Deoxynojirimycin (DNJ) is an alkaloid that is found at relatively high concentrations in mulberry leaf and tissues of the silkworm, $Bombyx$ $mori$. DNJ is a well known inhibitor of ${\alpha}$-glucosidase, an enzyme that is involved in the early stages of the $N$-linked glycoprotein synthesis pathway. ${\alpha}$-Glucosidase activity in the cell extract from $B.$ $mori$-derived Bm5 cells showed approximately 40-fold less sensitivity to DNJ than ${\alpha}$-glucosidase activity in the cell extract from $Spodoptera$ $frugiperda$-derived Sf9 cells. The replication of $B.$ $mori$ nucleopolyhedrovirus (BmNPV) was not inhibited when it was propagated in BmN cells that were grown in medium containing up to 10 mM DNJ. In contrast, the replication of $Autographa$ $californica$ multiple NPV (AcMNPV) was reduced by 67% when it was propagated in Sf9 cells that were grown in medium containing 10 mM DNJ. The viability of Bm5 and Sf9 cells that were grown in medium containing up to 10 mM DNJ was not affected. Our results suggested that the reduced replication of AcMNPV was the result of the higher sensitivity of ${\alpha}$-glucosidase activity in Sf9 cells to DNJ.

• KSBB Journal
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• v.26 no.6
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• pp.517-522
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• 2011

In our previous study, we isolated and characterized a 1-deoxynojirimycin (DNJ)-producing bacterium, Bacillus subtilis MORI, from chungkookjang, a Korean traditional food. B. subtilis MORI was subjected to ${\gamma}$-irradiation and the resulting bacteria were screened for increased DNJ production. A mutant was identified that produced 7.6 times more DNJ and named B. subtilis MORI 3K-85. In this study, the protein profiles of both strains were compared by one-dimensional and two-dimensional gel electrophoresis (1-DE and 2-DE, respectively) under both native and denaturing conditions. The 1-DE native-PAGE and 1-DE SDS-PAGE analyses identified 5 and 7 bands, respectively, that were found at higher concentrations in B. subtilis MORI 3K-85 than in B. subtilis MORI. Similarly, 2-DE analyses identified 20 protein spots which were found at higher concentrations in B. subtilis MORI 3K-85. The peptide mass profiles of these 20 proteins were analyzed by MALDI-TOF and compared with peptide sequences of B. subtilis and B. amyloliquefaciens in the MASCOT database. This screening suggested that three dehydrogenases, an aldolase, a synthetase, an isomerase, a reductase, and a peroxidase are elevated in B. subtilis MORI 3K-85. Based on this data, one or more of the elevated 8 enzymes might be related to the DNJ biosynthetic pathway.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2001.10a
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• pp.59-59
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• 2001

• Korean Journal of Pharmacognosy
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• v.30 no.2
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• pp.123-129
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• 1999

The hypoglycemic effect of mulberry leaves using alloxan-induced diabetic mice was investigated. The hypoglycemic effect of mulberry leaves was significantly affected with anaerobic incubation up to for 6 hrs. The body weight of mice treated with 20% anaerobic conditioned mulberry leaves was higher than that in the control group. Mulberry leaves which were treated with anaerobic condition significantly decreased blood glucose level in alloxan-induced type I diabetes mice. Furthermore, glucose tolerance was significantly recovered by feeding mulberry leaves anaerobically treated. Pathological analysis revealed that the disappearance of insulin-secreting beta-cells in the islets of Langerhans from the alloxan induced diabetic mice was strongly inhibited in the mulberry leaves feeding group. The content of 1-deoxynojirimycin increased up to 5% in detached mulberry leaves incubated under nitrogen gas for 6 hrs. Nevertheless, it is not clear whether the synthesis of 1-deoxynojirimycin is increased or the degradation of it is decreased. Overall, results obtained from this study indicate that the hypoglycemic effect was increased by the mulberry leaves with anaerobic treatment.

• International Journal of Industrial Entomology and Biomaterials
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• v.33 no.1
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• pp.24-30
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• 2016

1-Deoxynojirimycin (DNJ) have been extensively investigated for their α-glucosidase inhibitor on postprandial hyperglycemia, and applied in nutraceuticals and medicine for preventing or delaying progression of type 2 diabetes. However, the amount of DNJ in mulberry leaves is low (about 0.1%), therefore, more effective extraction method is needed. This study was performed to develop microbial DNJ for biological methods of DNJ as an alternative to the chemical methods. In this study, we obtained evidence for Bacillus subtilis that produce DNJ in large quantities by high performance liquid chromatography. Inhibition of α-glucosidase activity was determined to DNJ production or non-production. Investigation of the effect of mulberry leaves powder concentration (1~5%), using the DNJ high-production bacteria, provided evidence for microbial mass production of DNJ. When the 4% mulberry leaf powder for 9 days was used, the α-glucosidase inhibitory activity was over the 85%. Also, the results presented in this study confirm DNJ yield's increasement in microbes using the various of nutrients and provide insight of ways to improve DNJ yields in microorganisms.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.5
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• pp.1196-1201
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• 2008

A examination of the kinetic properties of UDP-glucose : (1,3)-$\beta$-glucan (callose) synthase from mung bean seedings (Sorbus cortex) shows that these enzymes have a complex interaction with UDP-glucose and various effectors. Deoxynojirimycin increased the inhibitory effect of (1,3)-$\beta$-glucan synthase at the concentration-dependent manner by fluorescence assay. The inhibitory effect of Fr. 2-16 (97.15%) showed higher than that of deoxynojirimycin (80.63%). Fr. 2-3 inhibited the growth of the Candida albicans at 1 mm inhibition zone by disk diffusion method. These results suggest that Sorbus cortex extract can be used as a stable antifungal material.

• International Journal of Industrial Entomology and Biomaterials
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• v.34 no.2
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• pp.38-44
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• 2017

Mulberry leaves containing 1-deoxynojirimycin (DNJ) have been recognized as a potentially important source for prevent or treat hyperglycemia. However, DNJ content of natural mulberry leaf are as low as 0.1%. Thus, the most effective method for increasing ${\alpha}$-glucosidase inhibitory activity with the DNJ high-production is needed. In this study, we investigated the influence of ${\alpha}$-glucosidase inhibitory activity according to different pH values (6-9) and inoculation amounts (0.1-0.5%) when Bacillus subtilis cultured on mulberry leaf powder media. We confirmed that ${\alpha}$-glucosidase inhibitory activity was difference according to culture conditions of different pH values, inoculation amounts, and fermentation times. The results of mulberry leaf fermentation according to pH values and inoculation amounts were shown that the optimal conditions for ${\alpha}$-glucosidase inhibitory activity were defined as pH 7 and 9, inoculation amount 0.4%, and incubation until 2 to 4 days. These results can be provided a basic data for the optimal culture conditions increasing ${\alpha}$-glucosidase inhibitory activity from mulberry leaf fermentation.