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严小军, Li Zheng, Haimin Chen, Xiaotian Han, Wei Lin and Xiaojun Yan, *
World Journal of Microbiology & Biotechnology 2005 21: 201-206,-0001,():
-1年11月30日
Twenty-nine marine bacterial strains were isolated from the sponge Hymeniacidon perleve at Nanji island, and antimicrobial screening showed that eight strains inhibited the growth of terrestrial microorganisms. The strain NJ6-3-1 with wide antimicrobial spectrum was identified as Pseudoalteromonas piscicida based on its 16S Rrna sequence analysis. The major antimicrobial metabolite, isolated through bioassay-guide fractionation of TLC bioautography overlay assay, was identified as norharman (a beta-carboline alkaloid) by EI-MS and NMR.
Antimicrobial activity,, beta-carboline,, marine bacteria,, sponge
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严小军, Hai-Min Chena, b, Li Zheng a, Wei Lin a, Xiao-Jun Yan c, ∗
Talanta 64(2004)773-777,-0001,():
-1年11月30日
Since the discovery of multiple bioactivities for agarobiose oligomers, a quantitative method has been in great need to monitor the agarobiose oligomers. This report demonstrates that agarobiose oligomers can be separated with high resolution in HPLC after introducing α-naphthylamine into compounds. Agarobiose oligomers ranged from biose to decaose were isolated by Sephadex column. HPLC analysis indicated that each oligomer could be quantified with good linearity and a low detection limit of 0.1-4µg/ml. The chromatographic profiles of agaro-oligosaccharides with different hydrolysis modes (hydrochloride, citric acid, solid acid, and hydroxyl radical degradation) showed that agarobiose could be obtained more than 57.8% using solid acid mediated hydrolysis, while hydrochloride acid could degrade agar into a series of agaro-oligosaccharides from biose to decaose. The yield of oligosaccharides was low if hydrolyzed by citric acid. The Fenton degradation can increase the speed of hydrolysis, but the product was complex.
Agarobiose oligomers, HPLC, α-Naphthylamine, Agaro-oligosaccharides
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【期刊论文】A New Method for Screening a-Glucosidase Inhibitors and Application to Marine Microorganisms
严小军, Haimin Chen, Xiaojun Yan, Wei Lin, Li Zheng and Weiwei Zhang
Pharmaceutical Biology 2004, Vol. 42, No.6, pp. 416-421,-0001,():
-1年11月30日
A new enzyme assay method for screening a-glucosidase inhibitors with rapidity and simplicity was developed. The enzyme-substituted a-glucosidases for this assay was glucoamylase. Samples were spotted or developed on the silica gel plate. The agar solution containing substrate was poured on the plate, and paper impregnated with enzyme was layered on the agar. After incubation, an inhibitory circle would appear around the inhibitor. By using this method, more than 200 strains of marine microorganisms were screened. Among them, three active strains were found to secrete inhibitors in the culture medium.
Enzyme assay,, a-glucosidase inhibitor,, marine microorganism.,
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【期刊论文】Extraction and Identification of Antioxidants in the Roots of Yacon (Smallanthus sonchifolius)
严小军, Xiaojun Yan, †, Masahiro Suzuki, Mayumi Ohnishi-Kameyama, *, Yasutoshi Sada, ‡, Tateo Nakanishi, §, and Tadahiro Nagata†
J. Agric. Food Chem. 1999, 47, 4711-4713,-0001,():
-1年11月30日
Yacon, Smallanthus sonchifolius (Poepp. & Endl.) H. Robinson, Asteraceae, an important economic species grown for its juicy tuberous root, is potentially beneficial in the diet to diabetics. The antioxidative activity of yacon root was studied by 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Antioxidants were extracted by methanol and isolated and purified by gel permeation chromatography and preparative reverse-phase HPLC. Two of the major antioxidants were identified as chlorogenic acid and tryptophan by NMR and mass spectrometry.
Yacon, Smallanthus sonchifolius, antioxidant, chlorogenic acid, tryptophan, Asteraceae
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【期刊论文】Determination of Synthetic Hydroxytyrosol in Rat Plasma by GC-MS
严小军, Chen Bai, †, Xiaojun Yan, Makiko Takenaka, Keizo Sekiya, ‡, and Tadahiro Nagata*
J. Agric. Food Chem. 1998, 46, 3998-4001,-0001,():
-1年11月30日
2-(3,4-Dihydroxyphenyl)ethanol (DPE), the major phenolic compound in olive oil, may contribute the antioxidative activities and other beneficial effects to olive oil. However, the lack of commercial available DPE and procedures sensitive enough to quantitatively determine DPE in body fluids have limited the bioavailability and metabolism studies on this phenolic compound. In the present study, DPE was synthesized with high yield and high purity and administered orally to rats. DPE concentration in rat plasma, after absorption, was measured using a sensitive GC-MS-SIM method. The results indicated that the highest level of DPE in plasma was detected at 5-10 min after administration. During this period, the concentration of DPE fluctuated widely with the individual.
Hydroxytyrosol, dihydroxyphenylethanol (, DPE), , plasma, GC-MS, metabolism
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