A whole-cell biocatalytic system for the production of cadaverine from L-lysine has been developed. Among the investigated lysine decarboxylases from different microorganisms, Escherichia coli LdcC showed the best performance on cadaverine synthesis when E. coli XL1-Blue was used as the host strain. Six different strains of E. coli expressing E. coli LdcC were investigated and recombinant E. coli XL1-Blue, BL21(DE3) and W were chosen for further investigation since they showed higher conversion yield of lysine into cadaverine. The effects of substrate pH, substrate concentrations, buffering conditions, and biocatalyst concentrations have been investigated. Finally, recombinant E. coli XL1-Blue concentrated to an OD(600) of 50, converted 192.6 g/L (1317 mM) of crude lysine solution, obtained from an actual lysine manufacturing process, to 133.7 g/L (1308 mM) of cadaverine with a molar yield of 99.90 %. The whole-cell biocatalytic system described herein is expected to be applicable to the development of industrial bionylon production process.
Activity-guided isolation of 80% acetone extract of Cornus alba, which is traditionally used as an anti-inflammatory, hemostatic and diuretic in Korea, yielded one novel compound, tentatively designated cornusiin H (13), together with 12 known compounds. The known compounds included four flavonoids (catechin (1), quercetin- (4)) and eight hydrolysable tannins (gallic acid (5) (9), cornusiin B (10), cornusiin A (11) and camptothin B (12)). All compounds exhibited potent 1,1-diphenyl-2-picrylhydrazyl (DPPH)-free radical scavenging activity. Especially, the radical scavenging activities of 6 and 9-13 were higher than that of vitamin C. Compounds 9, 11, 12 and 13 inhibited the production of nitric oxide (NO) in lipopolysaccharide-stimulated RAW264.7 cells to the same degree as N G -Monomethyl-L-arginine (L-NMMA). When the antiproliferative effects of the isolated compounds were assessed in prostate cancer cells, the dimeric ellagitannins (11-13) selectively inhibited LNCaP hormone-dependent prostate cancer cells. Flow cytometry analysis indicated that the dimeric ellagitannins induced apoptosis and S-phase arrest. These results suggest that dimeric ellagitannins from Cornus alba can be developed as functional materials or herbal medicines for prostate tumors such as benign prostate hyperplasia and early-stage prostate cancer.
Two new phenolic compounds, 4-O-glucopyranosyl-5-O-caffeoylshikimic acid (1) and 2,3-digalloyl oregonin (2), were isolated along with eight known phenolic compounds (3–10) from an 80% acetone extract of Alnus sibirica leaves. The chemical structures of these compounds were elucidated using 1D/2D nuclear magnetic resonance and high resolution-MS. The anti-oxidative activities of these compounds were determined by assaying their 1,1-diphenyl-2-picrylhydrazyl radical and nitroblue tetrazolium superoxide anion scavenging activity. All of the isolated phenolic compounds (1–10) exhibited potent anti-oxidative activities. In particular, 2 and 4, which are diarylheptanoids, and 10 which is ellagitannin exhibited excellent anti-oxidative activities with almost the same potency as that of the positive controls L-ascorbic acid and allopurinol.
− Alnus sibirica (AS) geographically distributes in Korea, Japan, Northeast China and Russia. The bark of this plant had been used for antipyretic, expectorant, anti-phlogistic, antitussive, anti-asthmatic and as a health tea for alcoholism. Recently, we studied various biological activities of AS and the isolated diarylheptanoid. In present study, we conducted fermentation of AS (FAS) and isolated two diarylheptanoid (hirsutenone and muricarpone B). Moreover, we established the validation and contents determinations of the two compounds by HPLC on FAS.
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