Dong-Geol Lee

Asinibacterium lactis gen. nov., sp. nov., a member of the family Chitinophagaceae, isolated from donkey (Equus asinus) milk.

A novel bacterial strain, designated LCJ02(T), was isolated on R2A agar from donkey (Equus asinus) milk powder and subjected to a taxonomic study using a polyphasic approach. Strain LCJ02(T) showed a Gram-negative reaction, was non-motile, non-spore-forming and possessed rod-shaped cells and yellow-pigmented colonies. Phylogenetic analysis based on 16S rRNA gene sequences showed that the novel isolate formed a cluster with several uncultured bacterial clones and with cultured members of the genera Hydrotalea, Sediminibacterium and Lacibacter (family Chitinophagaceae, phylum Bacteroidetes). The gene sequence similarities with respect to the type strains of recognized species from the above genera and other phylogenetic neighbours ranged from 89.3 to 92.9%. The G+C content of the genomic DNA was 49.2 mol%, the only isoprenoid quinone was MK-7 and the major fatty acids were iso-C(15:0), iso-C(17:0) 3-OH, iso-C(15:1) G and summed feature 3 (C(16:1)ω7c and/or iso-C(15:0) 2-OH). The major polar lipids of strain LCJ02(T) were phosphatidylethanolamine, two unidentified aminophospholipids, one unidentified aminolipid and five unidentified lipids. The results of physiological and biochemical tests allowed phenotypic differentiation of strain LCJ02(T) from its closest phylogenetic neighbours. On the basis of the evidence of this polyphasic study, isolate LCJ02(T) represents a novel genus and species in the family Chitinophagaceae for which the name Asinibacterium lactis gen. nov., sp. nov. is proposed. The type strain is LCJ02(T) ( =KCCM 90108(T) =JCM 18484(T)).

Hepatoprotective and neuroprotective tocopherol analogues isolated from the peels of Citrus unshiu Marcovich

Three tocopherol analogues methoxytocopherol (1), α-tocopherol (2) and γ-tocopherol (3) were isolated from the peels of Citrus unshiu Marcovich. The protective effects of the isolated compounds against tert-butyl hydroperoxide-induced hepatotoxicity in human liver-derived HepG2 cells and glutamate-induced oxidative stress in HT22-immortalised hippocampal cells were evaluated. Compounds 1–3 were significantly protective in HepG2 cells with EC50 values of 21.22 ± 2.01, 25.21 ± 2.11 and 25.25 ± 1.21 μM, respectively, and in HT22 cells, compounds 1–3 had EC50 values of 20.62 ± 1.36, 6.44 ± 1.65 and 9.52 ± 1.54 μM, respectively.

Inhibition effect of phenyl compounds from the Oryza sativa roots on melanin production in murine B16-F10 melanoma cells

Five phenyl compounds, vanillin (1), methyl trans-ferulate (2), trans-p-coumaric acid methyl ester (3), N-benzoyltryptamine (4), and N-(trans-cinnamoyl)tryptamine (5), were isolated from the roots of Oryza sativa L. and identified on the basis of spectroscopic data. Compounds 3 and 5 showed strong inhibition effect on melanin production in murine B16-F10 melanoma cells and tyrosinase activity. Also, the quantitative analysis of the compounds was carried out using LC/MS/MS experiment. Compounds 3 and 5 could be used as skin-whitening agents.

Phenylethanoid Glycosides from the Fruits of Magnolia obovata

Chromatographic methods such as silica gel, ODS, and Sephadex LH-20 column chromatographic techniques were used to identify three new phenylethanoid glycosides along with three known ones, 2-(3,4-dihydroxyphenyl)ethyl o-α-L-rhamnopyranosyl-(1→2)-β-D-allopyranoside (1), magnoloside D (2), and magnoloside A (3), from the fruits of Magnolia obovata. Using the spectroscopic data, including NMR, MS, and IR, the new phenylethanoid glycosides were identified and named magnoloside F (4), magnoloside G (5), and magnoloside H (6).

Jeotgalibaca dankookensis gen. nov., sp. nov., a member of the family Carnobacteriaceae, isolated from seujeot (Korean traditional food).

A novel, Gram-stain-positive bacterium, designated strain EX-07T, was isolated from seujeot (Korean traditional food). The strain was aerobic, halotolerant and non-motile; it formed cocci that grouped into tetrads and sarcinae or formed irregular conglomerates. Growth occurred at pH 7-9, at 10-37 °C and with up to 9% NaCl. Isolate EX-07T was catalase- and oxidase-negative and used sugars and organic acids as carbon sources. The 16S rRNA gene sequence of the novel strain showed 94.2-94.5% similarity with the type strains of Trichococcus pasteurii, Trichococcus patagoniensis, Trichococcus collinsii, Trichococcus flocculiformis and Trichococcus palustris and only 92.2% with representatives of the genera Bavariicoccus, Carnobacterium and Granulicatella. Sequence similarities based on the groEL gene ranged from 81.3 to 82.8% between the novel isolate and the type strains of all species of the genus Trichococcus, and only 74.2 and 75.3% with type strains of members of the genera Bavariicoccus and Granulicatella, respectively. The G+C content of the genomic DNA was 39.6 mol%. The predominant fatty acids were C16:1ω9c, C18:1ω9c, C16:0 and C14:0. The polar lipid profile was very complex and included phosphatidylethanolamine and several unidentified aminolipids, glycolipids and phospholipids. Based on the genotypic and phenotypic results obtained in this study, it is proposed that isolate EX-07T represents a novel species of a new genus in the family Carnobacteriaceae for which the name Jeotgalibaca dankookensis gen. nov., sp. nov. is proposed. The type strain of Jeotgalibaca dankookensis is EX-07T (=KCCM 90229T=JCM 19215T).

New tocopherol analogue with radical-scavenging activity from the peels of Citrus unshiu Marcovich

One new tocopherol analogue, methoxytocopherol (1), and two known analogues, α-tocopherol (2) and γ-tocopherol (3), were isolated from the peels of Citrus unshiu Marcovich. The chemical structures of compounds 1–3 were determined by interpretation of spectroscopic data. All isolated compounds were evaluated for radical-scavenging capacity using 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt, 1,1-diphenyl-2-picrylhydrazyl, and oxygen radical absorbance capacity assays.

Diterpenes from the roots of Oryza sativa L. and their inhibition activity on NO production in LPS-stimulated RAW264.7 macrophages.

Two new pimarane diterpenoids, momilactone D (3) and momilactone E (5), along with three known diterpenoids, momilactone A (1), sandaracopimaradien‐3‐one (2), and oryzalexin A (4) were isolated from Oryza sativa roots. The chemical structures of the compounds were determined by spectroscopic data analysis. The isolated diterpenoids were evaluated for their ability to inhibit NO production and iNOS mRNA and protein expression in LPS‐stimulated RAW264.7 macrophages. Compound 4 showed strong inhibition activity on NO production, and compounds 1 and 4 decreased the expression of iNOS mRNA and protein levels.

Oleanolic acid from Fragaria ananassa calyx leads to inhibition of α-MSH-induced melanogenesis in B16-F10 melanoma cells

Natural products with non-toxic and environmentally friendly properties are good sources for skin-whitening and brightening cosmetic agents. Strawberries (Fragaria ananassa), and their parts are used as cosmetic agents, because they contain high levels of bioactive substances. We isolated and identified compounds from F. ananassa calyx. Oleanolic acid has multiple biological activities, including anti-tumor, anti-angiogenic, antiinflammatory, anti-oxidant, and pro-apoptotic effects. However, no study has investigated the influence of oleanolic acid on melanin synthesis in B16-F10 melanoma cells. In the present study, we investigated the effect of oleanolic acid on melanin biosynthesis in B16-F10 melanoma cells stimulated with α-melanocyte stimulating hormone (α-MSH). Oleanolic acid-mediated melanogenesis inhibition was studied by measuring intracellular and secreted melanin levels and by using Western blot and semiquantitative reverse transcriptase-polymerase chain reaction analyses. Oleanolic acid suppressed melanin release and expression, resulting in a significant dose-dependent decrease in secreted and intracellular melanin levels and cellular tyrosinase activity. Furthermore, it inhibited the expression of melanogenesis-associated factors, including tyrosinase, tyrosinase-related proteins-1 and -2, and microphthalmia-associated transcription factor, in α-MSH-stimulated B16-F10 melanoma cells. The results of the present study can contribute to the development of cosmetic agents utilizing the skin whitening and brightening effect of oleanolic acid, which will likely have a wide range of applications in the cosmetic industry and/or clinical practice in the future.

Pseudogulbenkiania gefcensis sp. nov., isolated from soil.

A novel strain, yH16, was isolated on nutrient agar from soil samples collected at KyungHee University, Suwon City, Republic of Korea. Cells of strain yH16(T) were short rods, Gram-negative-staining, motile and non-spore-forming, with a polar flagellum. Biochemical and molecular characterization revealed that this strain was most similar to Pseudogulbenkiania subflava BP-5(T). Further 16S rRNA gene sequencing studies revealed that the new strain clustered with Pseudogulbenkiania subflava BP-5(T) (95.9 % similarity), Paludibacterium yongneupense 5YN8-15(T) (95.2 % similarity), Gulbenkiania mobilis E4FC31-5(T) (94.6 % similarity) and Chromobacterium aquaticum CC-SE-YA-1(T) (93.9 % similarity). The isolate was able to grow at 25-40 °C, 0.3-2 % NaCl and pH 5.5-7. The DNA G+C content was 65.9 ± 1.0 mol%. The predominant fatty acids were summed feature 3 (C(16 : 1)ω7c and/or iso-C(15 : 0) 2-OH) and C(16:0). Ubiquinone 8 was the major respiratory quinone. It was evident from the data obtained that the strain should be classified as a novel species of the genus Pseudogulbenkiania. The name proposed for this taxon is Pseudogulbenkiania gefcensis sp. nov., and the type strain is yH16(T) (=KCCM 90100(T) = JCM 17850(T)).

Epidermidibacterium keratini gen. nov., sp. nov., a member of the family Sporichthyaceae, isolated from keratin epidermis

A novel actinobacterial strain, designated EPI-7T, was isolated on R2A agar from human skin (keratinocytes) and subjected to a taxonomic study using a polyphasic approach. Strain EPI-7T showed a Gram-positive reaction, was non-motile, non-spore-forming, and cells had a rod-shape. Colonies were round, convex and pale yellow. Phylogenetic analysis based on 16S rRNA gene sequences showed that the novel isolate formed a cluster with several uncultured bacterial clones and with cultured members of the genera Modestobacter and Sporichthya. The 16S rRNA gene sequence similarities with respect to the type strains of recognized species from the above genera and other phylogenetic neighbours ranged from 92.6 to 93.4 %. The G+C content of the genomic DNA was 68.9 mol%. The only isoprenoid quinone was MK-9(H4), and the major fatty acids detected were C17 : 1ω8c, C16 : 0, iso-C15 : 0 and summed feature 3. The major polar lipids were found to be phosphatidylethanolamine, phosphatidylinositol, three unidentified phospholipids, phosphatidylglycerol, phosphatidylcholine, two unidentified amino lipids and three unidentified lipids. The cell-wall peptidoglycan contained meso-diaminopimelic acid, glutamic acid and alanine. Whole-cell sugars present included rhamnose, glucose and galactose. The combination of the genotypic and phenotypic data allowed differentiation of strain EPI-7T from its closest phylogenetic neighbours and provided evidence that strain EPI-7T represents a novel genus and species in the family Sporichthyaceae. The name Epidermidibacterium keratini gen. nov., sp. nov. is proposed with the type strain being EPI-7T (=KCCM 90264T=JCM 31644T).