Enzymatic Synthesis of Anabolic Steroid Glycosides by Glucosyltransferase from Terribacillus sp. PAMC 23288

유은지,Tokutaro Yamaguchi,이주호,임아랑,이준혁,박현,오태진 한국미생물·생명공학회 2020 Journal of microbiology and biotechnology Vol.30 No.4

The application of steroids has steadily increased thanks to their therapeutic effects. However, alternatives are required due their severe side effects; thus, studies on the activities of steroid derivatives are underway. Sugar derivatives of nandrolone, which is used to treat breast cancer, as well as cortisone and prednisone, which reduce inflammation, pain, and edema, are unknown. We linked O-glucose to nandrolone and testosterone using UDP-glucosyltransferase (UGT-1) and, then, tested their bioactivities in vitro. Analysis by NMR showed that the derivatives were 17β-nandrolone β-D-glucose and 17β-testosterone β-D-glucose, respectively. The viability was higher and cytotoxicity was evident in PC12 cells incubated with rotenone and, testosterone derivatives, compared to the controls. SH-SY5Y cells incubated with H2O2 and nandrolone derivatives remained viable and cytotoxicity was attenuated. Both derivatives enhanced neuronal protective effects and increased the amounts of cellular ATP.

구리촉매를 이용한 유기주석화합물 및 유기붕소화합물과 다가 요오드 화합물과의 Cross-Coupling과 Carbonylative Cross-Coupling에 관한 연구

강석구,야마구치토쿠타로,김태현,호필수 성균관대학교 기초과학연구소 1996 論文集 Vol.47 No.2

The copper-catalyzed cross-coupling and carbonylative cross-coupling of organostannanes(aryl-, alkenyl-, alkynyl-, allylstannanes) and anoboranes(aryl-, alkenylboranes)with hypervalent aryl- and alkenyliodonium tetrafluoroborates were achieved at mild conditions.

Pd 촉매하에서 Aryl-과 Alkenyliodonium Salts의 Alkoxycarbonylation에 관한 연구

강석구,야마구치 토쿠타로,호필수,김원엽 성균관대학교 기초과학연구소 1996 論文集 Vol.47 No.1

The palladium-catalyzed carbonylation of diaryliodonium tetrafluoroborates and tosylates in presence of methanol and phenol afforded aromatic esters at room temperature under atmospheric pressure of carbon monoxide. However, carbonylation of diaryliodoniurn triflates and bromides in methanol afforded 4-iodophenyl-substituted methyl esters.

Hypervalent Iodonium Salt와 Organofluorosilane 의 Cross-Coupling과 Carbonylative Cross-Coupling에 관한 연구

강석구,토쿠따로야마구치,김태현,편성재 성균관대학교 기초과학연구소 1996 論文集 Vol.47 No.1

The palladium-catalyzed cross-coupling and carbonylative cross-coupling of aryl-, alkenyl-, and alkynytfluorosilanes promoted by fluoride ion with hypervalent aryl-, alkenyliodonium tetrafluoroborates were achieved at room temperature under an atmospheric pressure of carbon monoxide.

Production, Isolation and Biological Activity of Nargenicin from Nocardia sp. CS682

Sohng, Jae-Kyung,Yamaguchi, Tokutaro,Seong, Chi-Nam,Baik, Keun-Sik,Park, Seong-Chan,Lee, Hyo-Jeong,Jang, So-Young,Simkhada, Jaya Ram,Yoo, Jin-Cheol 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.10

Culture broth of an actinomycete isolate, Nocardia sp. CS682 showed specifically higher antibacterial activity against methicilin resistant Staphylococcus aureus (MRSA). Purified substance from the organism, CS-682, which is active against MRSA and Micrococcus leuteus, is a $C_{28}H_{37}NO_8$ ($M+H^+$, observed: 516.83) and identified as an unusual macrolide antibiotic, nargenicin. The chemical structure of CS-682 was identified by FT-IR, $^1H$-NMR, $^{13}C$-NMR, and ($^1H-^1H$ and $^1H-^{13}H$) COSY. The anti-MRSA activity of CS-682 was stronger than that of oxacillin, vancomycin, monensin, erythromycin, and spiramycin. Phylogenetic analysis showed that strain CS682 is closely related to Nocardia tenerifensis DSM $44704^T$ (98.7% sequence similarity), followed by N. brasiliensis ATCC $19296^T$ (98.4% sequence similarity). The ability of Nocardia sp. CS682 to produce nargenicin was unique.

Lipase 촉매화의 (±)-2-Hydroxymethyl-3,4-dihydro-2H-pyran의 트랜스에스 테르화 반응및 (±)-2-Acetoxymethyl-3,4-dihydro-2H-pyran의 비대칭 가수분해반응의 연구

강석구,전제호,야마구치 도쿠타로,홍융기,고병섭 성균관대학교 기초과학연구소 1994 論文集 Vol.45 No.2

지질 가수 분해 효소인 리파아제를 이용하여 완충 용액하에서 (±)-2-Hydroxymethyl-3,4-dihydro-2H-pyran의 비대칭 가수 분해 및 여러 가지 유기 용매하에서 (±)-2-acetoxymethyl-3,4-dihydro-2H-pyran의 에스테르화 반응을 하여 화학적으로 유용한 synthon을 얻는 연구를 하였다. Porcine pancreas lipase(PPL)-catalyzed acetylation of (±)-2-thdroxymethyl-3,4-dihydro-2H-pyran with vinyl acetate in organic solvent afforded (S)-(+)-2-acetoxymethyl-3,4-dihydro-2H-pyran. Alternatively, (±)-2-acetoxymethyl-3,4-dihydro-2H-pyran was resolved via PPL catalyzed hydrolysis in acetone-phosphate buffer system to afford (S)-(+)-2-hydroxymethyl-3,4-dihydro-2H-pyran with high enantioselectivity.

Photocatalytic Activities of Transition Metal-Doped TiO₂ Nano-Powders by Sonochemical Method and their Physicochemical Properties

Choi, Ah Young,Tokutaro, Yamaguchi,Cho, Sung Hun,Han, Chul Hee Trans Tech Publications, Ltd. 2011 Materials science forum Vol.695 No.-

<P>With respect to metal doping into TiO2, the doping limits for V, Cr, Zr, Nb, Mo, and W are predicted to be higher than other transition metals according to the binding energy calculations in a unit cell model of anatase TiO2, which suggests that Cr and W can be doped into anatase structure more easily than Ag or Pt, for example. Our investigation has twofold research objectives. One is to prepare metal-doped TiO2 nano-powders from these transition metals, and the other is to test photocatalytic activity of each resulting powder. For the former, sonochemical process has been used to produce Cr-doped, W-doped, Ag-doped, and Pt-doped TiO2 nanoparticles. For the latter, we have performed photocatalytic oxidation of methylene blue. The combined results of the morphology and photocatalytic activites have enabled characterization of the physicochemical properties of these transition metal-doped nanoparticles.</P>

Metabolic Engineering of Escherichia coli for Enhanced Production of Naringenin 7-sulfate by Using CRISPRi

Luan LUONG CHU,Jung HYE JIN,Yamaguchi TOKUTARO,Sohng JAE KYUNG 한국생물공학회 2019 한국생물공학회 학술대회 Vol.2019 No.4

In vivo characterization of NcsB3 to establish the complete biosynthesis of the naphthoic acid moiety of the neocarzinostatin chromophore : In vivo characterization of NcsB3

Hang, Vu Thi Thu,Oh, Tae Jin,Yamaguchi, Tokutaro,Sohng, Jae Kyung Oxford University Press 2010 FEMS microbiology letters Vol.311 No.2

<P>Neocarzinostatin (NCS) is an enediyne antibiotic produced by Streptomyces carzinostaticus. The NCS chromophore consists of an enediyne core, a sugar moiety, and a naphthoic acid (NA) moiety. The latter plays a key role in binding the NCS chromophore to its apoprotein to protect and stabilize the bioactive NCS chromophore. In this study, we expressed three genes: ncsB (naphthoic acid synthase), ncsB3 (P450 hydroxylase), and ncsB1 (O-methyltransferase), in Streptomyces lividans TK24. The three genes were sufficient to produce 2-hydroxy-7-methoxy-5-methyl-1-naphthoic acid. Production was analyzed and confirmed by LC-MS and nuclear magnetic resonance. Here, we report the functional characterization of ncsB3 and thereby elucidate the complete biosynthetic pathway of NA moiety of the NCS chromophore.</P>

Characterization and multicolor upconversion emission properties of BaMoO₄: Yb³⁺, Ln³⁺ (Ln = Tm, Ho, Tm/Ho) microcrystals

Ray, Schindra Kumar,Kshetri, Yuwaraj K.,Yamaguchi, Tokutaro,Kim, Tae-Ho,Lee, Soo Wohn Elsevier 2019 Journal of solid state chemistry Vol.272 No.-

<P><B>Abstract</B></P> <P>Hydrothermal process was employed to synthesize the Yb<SUP>3+</SUP>/Tm<SUP>3+</SUP>, Yb<SUP>3+</SUP>/Ho<SUP>3+</SUP> and Yb<SUP>3+</SUP>/Tm<SUP>3+</SUP>/Ho<SUP>3+</SUP> doped BaMoO<SUB>4</SUB> octahedron microcrystals (0.50–5.0 µm). The synthesized phosphors have scheelite tetragonal structure. The elemental mapping suggests the uniform distribution of elements in the samples. The oxidation state of samples were investigated by X-ray photoelectron spectroscopy (XPS) which indicates the existence of Ba<SUP>2+</SUP>, Mo<SUP>6+</SUP>, O, Yb<SUP>3+</SUP>, Tm<SUP>3+</SUP> and Ho<SUP>3+</SUP> in samples. The presence of rare earth ions was also verified by observation of specific absorption peaks in diffuse reflectance spectra (DRS). The tunable multicolor upconversion (UC) emissions were successfully obtained under 980 nm NIR excitation by precisely adjusting the concentration of rare earth ions. The as prepared sample exhibits blue, green and red emission as a result of energy transfer from the Yb<SUP>3+</SUP> to Tm<SUP>3+</SUP> and Ho<SUP>3+</SUP> ions. The power dependent UC emission spectra show the two photonic processes. The energy transfer mechanism from Yb<SUP>3+</SUP> to Tm<SUP>3+</SUP> and Ho<SUP>3+</SUP> was explained <I>via</I> an energy level analysis.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Synthesis of BaMoO<SUB>4</SUB>: Yb<SUP>3+</SUP>, Ln<SUP>3+</SUP> (Ln = Tm, Ho, Tm/Ho) by hydrothermal process. </LI> <LI> Investigation of upconversion luminescence of phosphors under 980 nm excitation. </LI> <LI> Obtaining the multicolor emission by adjusting doped rare-earth ions concentration. </LI> <LI> Explanation of photonic process and energy transfer mechanism. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Multicolor upconversion emission properties of BaMoO<SUB>4</SUB>: Yb<SUP>3+</SUP>, Ln<SUP>3+</SUP> (Ln = Tm, Ho, Tm/Ho) octahedrons</P> <P>[DISPLAY OMISSION]</P>