1-Deoxynojirimycin Content and Alfa-Glucosidase Inhibitory Activity and Heat Stability of 1-Deoxynojirimycin in Silkworm Powder

Silkworm powder containing 1-deoxynojirimycin (DNJ) has α-glucosidase inhibitory activity and is promising as a complementary and alternative medicine (CAM) agent in Japan. Silkworm powder produced in Korea was extracted with 75% ethanol. The extract was derivatized with 9-fluorenylmethyl chloroformate (FMOC-Cl), and DNJ-FMOC content was measured by HPLC. Then, alfa-glucosidase inhibition by silkworm and mulberry powder in pig liver crude enzyme was assayed using 4-nitrophenyl-alfa-D-glucopyranoside as a substrate. Silkworm powder DNJ content (0.39 to 0.58%) was higher than that in mulberry powder (0.08 to 0.12%). The alfa-glucosidase inhibitory activity of silkworm powder was more potent than that of mulberry leaves and green tea. Silkworm powder DNJ was stable upon heating to 121?C for up to 15 min.

Metabolic engineering of Bacillus amyloliquefaciens for efficient production ofα-glucosidase inhibitor1-deoxynojirimycin

Owing to the feature of strongα-glucosidase inhibitory activity,1-deoxynojirimycin(1-DNJ)has broad application prospects in areas of functional food,biomedicine,etc.,and this research wants to construct an efficient strain for 1-DNJ production,basing on Bacillus amyloliquefaciens HZ-12.Firstly,using the temperature-sensitive shuttle plasmid T2(2)-Ori,gene ptsG in phosphotransferase system(PTS)was weakened by homologous recombination,and non-PTS pathway was strengthened by deleting its repressor gene iolR,and 1-DNJ yield of resultant strain HZ-S2 was increased by 4.27-fold,reached 110.72 mg/L.Then,to increase precursor fructose-6-phosphate(F-6-P)supply,phosphofructokinase was weaken,fructose phosphatase GlpX and 6-phosphate glucose isomerase Pgi were strengthened by promoter replacement,moreover,regulator gene nanR was deleted,1-DNJ yield was further increased to 267.37 mg/L by 2.41-fold.Subsequently,promoter of 1-DNJ synthetase cluster was optimized,as well as 5′-UTRs of downstream genes in synthetase cluster,and 1-DNJ produced by the final strain reached 478.62 mg/L.Last but not the least,1-DNJ yield of 1632.50 mg/L was attained in 3 L fermenter,which was the highest yield of 1-DNJ reported to date.Taken together,our results demonstrated that metabolic engineering was an effective strategy for 1-DNJ synthesis,this research laid a foundation for industrialization of functional food and drugs based on 1-DNJ.

Scheme of Nitrogen Reasonable Fertilization in Mulberry Gardens of Sichuan Hilly Areas

Abstract In the research, five test groups were set, including urea at O, 120, 240, 360 and 480 kg/hm^2, respectively, and analysis was conducted on mulberry leaf yield and some characters of the quality in order to establish utility functions of ap-plied N in mulberry gardens with different production purposes and to provide schemes of rational N fertilization. The results indicated that yield of mulberry leaf and content and yield of active nutritional substances in the leaves would be reduced either by insufficient or excessive N quantity. In addition, 240 kg/hm^2 of applied N significantly improved active nutritional substances in leaf and 360 kg/hm^2 of applied N significantly improved yields of mulberry leaf and active nutritional sub-stances. Therefore, utility functions of applied N quantity with leaf yield, DNJ content and yield were established accordingly. The optimal N quantity in mulberry gardens for sericulture is recommended 360 kg/hm^2 and the optimal N quantities in mulberry gardens for increase of yield and content of DNJ are 299.56 and 294.72 kg/hm^2, respectively.

Accumulation of 1-deoxynojirimycin in silkworm,Bombyx mori L.

1-deoxynojirimycin (1-DNJ) contents in the silkworm,Bombyx mori,at different developmental stages and tissues were investigated by using reverse-phase high-performance liquid chromatography. The 1-DNJ contents of silkworm larvae change significantly with their developmental stages. The male larvae showed higher accumulation efficiency of 1-DNJ than the females and also a significant variation was observed among the silkworm strains. The present results show that tissue distribution of 1-DNJ was significantly higher in blood,digestive juice,and alimentary canal,but no 1-DNJ was observed in the silkgland. Moreover,1-DNJ was not found in silkworms fed with artificial diet that does not contain mulberry leaf powder. This proves that silkworms obtain 1-DNJ from mulberry leaves; they could not synthesize 1-DNJ by themselves. The accumulation and excretion of 1-DNJ change periodically during the larval stage. There was no 1-DNJ in the newly-hatched larvae and 1-DNJ was mainly accumulated during the early and middle stages of every instar,while excreted at later stages of larval development. Further,it is possible to extract 1-DNJ from the larval feces and it is optimal to develop the 1-DNJ related products for diabetic auxiliary therapy.

The Mulberry Silkworm--A New Source of Bioactive Proteins

Beyond the commonly known proteins built silk fibres--fibroin and sericin, there are almost 300 bioactive proteins in the silkworm haemolymph. The aim of this work was to present bioactive compounds obtained from the silk fibre and isolated from the body of this insect, which may be used in medical and pharmacological applications. The most important are bioactive proteins. However, the juvenile stages of mulberry silkworm possess other very valuable active substances.

拉米夫定与N-壬基-1-脱氧野尻霉素联合应用抗-HBV的体外研究

目的体外观察拉米夫定(3TC)与N-壬基-1-脱氧野尻霉素(NN-DNJ)联合应用的抗HBV作用。方法以HepG2,2,15细胞为靶细胞,以试验药物单用或联合培养细胞,在第6天和第10天应用时间分辨免疫荧光分析法和实时荧光定量PCR法检测培养上清液中HBsAg、HBeAg和HBV DNA,同时应用MTT法检测药物对细胞的毒性。结果125.0μg/ml的NN-DNJ、5.0μg/ml的3TC及上述浓度的两者联合应用,均能显著减少细胞培养上清液中HBsAg、HBeAg、HBV DNA的分泌。联合应用后,上清液中HBsAg、HBeAg,HBV DNA含量与阴性对照组及单用相同浓度的3TC、NN-DNJ组相比,差异均有统计学意义(P<0.05)。结论3TC与NN-DNJ联合应用对HBV的抑制作用明显增强。

Biotransformation Effect of Bombyx Mori L. May Play An Important Role in Treating Diabetic Nephropathy

Compared with herbal drugs, medicine processed from animals(animal medicine) was thought to have more bioactive substances and higher activities. Biotransformation effect often plays an important role in their effect. However, researches about effect of animal medicine on diabetic nephropathy and applying animal medicine as natural bio-transformer were seldom reported. The purpose of this paper was to reveal the use of Bombyx Mori L. on diabetic nephropathy from ancient to modern times. The classical literature indicated that Saosi Decoction(缫丝汤), which contains Bombyx Mori L. or silkworm cocoon, was applied to treat disorders congruent with modern disease diabetic nephropathy from the Ming to Qing Dynasty in ancient China. Modern studies showed that Bombyx Mori L. contains four main active constituents. Among these, 1-deoxynojirimycin(1-DNJ) and quercetin showed promising potential to be new agents in diabetic nephropathy treatment. The concentrations of 1-DNJ and the activities of quercetin in Bombyx Mori L. are higher than in mulberry leaves, because of the biotransformation in the Bombyx Mori L. body. However, these specific components need further human and mechanistic studies to determine their therapeutic potential for this challenging condition.

A New Alkaloid from Bombycis Feculae and Its α-Glucosidase Inhibitory Activity

Objective To study the chemical constituents of Bombycis Feculae.Methods Chemical constituents were isolated by HPLC-ELSD.The structures of the isolated compounds were determined by spectral means.Results Two compounds were isolated and identified as 1-deoxynojirimycin(1)and(2R,3R,5R)-2-(hydroxymethyl) piperidine-3,5-diol,named as 1,3-dideoxygalatonojirimycin(2).Conclusion Compound 2 is a new alkaloid.The extract of Bombycis Feculae,compound 1 and compound 2 show inhibitory activities againstα-glucosidase.