Absolute Configurations of (±)-Glabridin Enantiomers

Mihyang Kim,Soo-Un Kim,Yong-ung Kim,한재홍 대한화학회 2009 Bulletin of the Korean Chemical Society Vol.30 No.2

Concerned with ambiguous stereochemistry assignment of natural (+)-glabridin, absolute configurations of (±)-glabridin enantiomers were studied with synthetic glabridin. Synthetic glabridin enantiomers were separated by semi-preparative Sumi-chiral column chromatography, and characterized by UV-Vis and NMR spectroscopy. Three-dimensional molecular structure of glabridin was obtained as equatorial Ph-3 half chair chroman ring from semi-empirical PM3 calculation, and refined by coupling constants in 1H NMR spectrum. Finally, absolute configurations of two enantiomers were determined by circular dichroism spectroscopy based on the empirical helicity rules. Absolute configuration of natural (+)-glabridin was confirmed as (R)-glabridin, as known.

Antioxidant Effect of Peanut (Arachishypogaea L.) Hull Extracts in Oxidative-damaged HepG2 Cells

Mihyang Kim,Min Yung Kim,Yu-Young Lee,Hyun-Joo Kim,Jin Young Lee,Moon Seok Kang,Dong-Jae Won 한국식품영양과학회 2021 한국식품영양과학회 학술대회발표집 Vol.2021 No.10

This study was performed to examine the antioxidant effect of peanut (Arachishypogaea L.) hull extracts in oxidative- damaged human hepatocellular carcinoma (HepG2) cells. The cultivars used as materials were Sinpalkwang, Pungan, and K-Ol and they were pretreated under three conditions (HP, high pressure (1.2 MPa); HTPW, high temperature and pressure (121℃, 120kPa) with water; HTPA, high temperature and pressure (121℃, 120kPa) with acetic acid) prior to extraction. The HepG2 cells viabilities were over 90% at the concentration of 100 μg/ml, 50 μg/ml, 25 μg/ml, 12.5 μg/ml of each extracts. Accordingly, the intracellular reactive oxygen species (ROS) level of HepG2 cells on peanut hull extracts was analyzed at those non-cytotoxic concentrations to investigate the antioxidant effect. The ROS level was the lowest (81.4%) at the 100 μg/ml of no pretreated Pungan extract. The highest was 199.1% at the 12.5 μg/ml of HTPA pretreated Pungan extract. And the differences in ROS level between cultivars, pretreatments and concentrations were significant (p<0.05). These results can be used as basic data to utilize peanut byproducts.

Stereospecific Biotransformation of Dihydrodaidzein into (3S)-Equol by the Human Intestinal Bacterium Eggerthella Strain Julong 732

Kim, Mihyang,Kim, Su-Il,Han, Jaehong,Wang, Xiu-Ling,Song, Dae-Geun,Kim, Soo-Un American Society for Microbiology 2009 Applied and environmental microbiology Vol.75 No.10

<B>ABSTRACT</B><P>Stereochemical course of isoflavanone dihydrodaidzein (DHD) reduction into the isoflavan (3<I>S</I>)-equol via tetrahydrodaidzein (THD) by the human intestinal anaerobic bacterium <I>Eggerthella</I> strain Julong 732 was studied. THD was synthesized by catalytic hydrogenation, and each stereoisomer was separated by chiral high-performance liquid chromatography. Circular dichroism spectroscopy was used to elucidate the absolute configurations of four synthetic THD stereoisomers. Rapid racemization of DHD catalyzed by Julong 732 prevented the substrate stereospecificity in the conversion of DHD into THD from being confirmed. The absolute configuration of THD, prepared by reduction of DHD in the cell-free incubation, was assigned as (3<I>R</I>,4<I>S</I>) via comparison of the retention time to that of the authentic THD by chiral chromatography. Dehydroequol (DE) was unable to produce the (3<I>S</I>)-equol both in the cell-free reaction and in the bacterial transformation, negating the possible intermediacy of DE. Finally, the intermediate (3<I>R</I>,4<I>S</I>)-THD was reduced into (3<I>S</I>)-equol by the whole cell, indicating the inversion of stereochemistry at C-3 during the reduction. A possible mechanism accounting for the racemization of DHD and the inversion of configuration of THD during reduction into (3<I>S</I>)-equol is proposed.</P>

한약재 추출물의 에스트로겐 유사활성 및 조골세포 증식과 분화에 미치는 영향

김미향(Mihyang Kim),김보경(Bokyung Kim),김재덕(Jae-Deog Kim),강아람(A-Ram Kang),이창은(Chang-Eun Lee),서정민(Jungmin Seo),이동근(Dong-Geun Lee),조정권(Jung-Kwon Jo),김육용(Yuck Yong Kim),유기환(Ki Hwan Yu),이상현(Sang-Hyeon Lee) 한국생명과학회 2017 생명과학회지 Vol.27 No.4

본 연구는 3종의 한약재(감초(Glycyrrhizae radix), 황기(Astragali radix) 및 산약(Dioscorea rhizome)) 추출물의 에스트로겐 유사활성 및 조골세포 증식과 분화에 미치는 영향을 검토하고자 실험을 진행하였다. 에스트로겐 유사활성측정을 위하여 인체 유방암 세포주인 MCF7 세포를 luciferase 유전자를 리포터로 사용하는 에스트로겐 반응성 리포터 시스템을 가지는 세포로 형질전환하여 사용하였다. 상기 세포를 이용하여 추출물의 에스트로겐 유사활성을 측정한 결과, 한약재 추출물이 음성대조군과 비교하여 1.11배~5.73배 높은 에스트로겐 유사활성을 나타내었다. 그 중 감초 추출물이 가장 높은 에스트로겐 유사활성을 보였다. 감초 추출물의 에스트로겐 유사활성은 추출물의 농도가 50 μg/ml 및 500 μg/ml 일 때 각각 10<SUP>-8</SUP> M 및 10<SUP>-7</SUP> M 17β-estradiol과 거의 유사한 활성을 나타내었다. 조골세포주인 MC3T3-E1 세포를 이용한 실험에서는 감초 추출물의 농도가 1~1,000 μg/ml 범위일 때 독성을 나타내지 않았다. 황기 추출물은 조골세포에 있어서 유의적인 세포 증식률을 보이지 않았다. 그러나, 감초 및 산약추출물은 각각 148% 및 133%의 최대 증식률을 보였다. 또한, 감초 추출물은 대조군과 비교하여 alkaline phosphatase (ALP) 활성이 증가하였으며, 추출물의 농도가 100 μg/ml 일 때 최대 122%의 ALP 활성을 나타내었다. 또한, Alizarin red S 염색법을 이용한 석회화 형성능 측정에서도 대조군과 비교하여 석회화가 증가하였다. 이러한 결과로 미루어 보아 감초 추출물이 골 형성 및 골다공증 예방 효과가 우수한 식품 소재인 것으로 사료된다. The purpose of this study was to investigate the effect of 3 types of medicinal herbs (Glycyrrhizae radix, Astragali radix and Dioscorea rhizoma) extracts on estrogen-like activities, proliferation and differentiation in osteoblast. Human breast cancer cell line MCF7 was transfected using an estrogen responsive luciferase reporter plasmid for measure the estrogen-like activity. Estrogen-like activities of extracts were in the range of 1.11~5.73 fold to that of negative control. The extract of G. radix showed the strongest estrogen-like activities. The estrogen-like activities of 50 and 500 μg/ml extracts of G. radix were similar to that of 10<SUP>-8</SUP> and 10<SUP>-7</SUP> M standard solution (17β-estradiol), respectively. G. radix extract showed no cytotoxicity against osteoblast MC3T3-E1 cells at 1~1,000 μg/ml. The extract of A. radix showed no significant proliferation of osteoblast. However, the extract of G. radix and D. rhizome showed maximum 148% and 133% proliferation effects. The extract of G. radix also increased alkaline phosphatase activity and the maximum was 122% at 100 μg/ml compared to that of control. The nodule formation by the method of the Alizarin red S staining increased compared to control. These results suggest that G. radix is able to perform the bone formation and prevent osteoporosis.

곰피 추출물이 난소를 절제한 흰쥐의 혈액 유동성 및 혈중 지질함량에 미치는 영향

Young Kyoung Kim(김영경),Min Hee Jeon(전민희),Yong Soo Park(박용수),Hyun Jung Hwang(황현정),Sang-Hyeon Lee(이상현),Sung Gu Kim(김성구),Yuck Young Kim(김육용),Mihyang Kim(김미향) 한국생명과학회 2010 생명과학회지 Vol.20 No.12

갱년기의 여성에는 여러 폐경 증후들이 나타나는데, 특히 estrogen의 감소로 인한 혈중 지질 조성의 변화 등으로 심혈관계 질환의 발병율이 높아지게 된다. 본 연구에서는 실험동물로써 흰쥐를 이용하여 인위적으로 갱년기를 유도한 후 갈조류인 곰피 추출물의 영향을 혈중지질 농도, 혈소판 응집력 및 혈액 유동성을 통하여 그 효과를 검토하고자 하였다. 그 결과 갱년기유도로 인하여 증가된 혈청 중 중성지방 및 총콜레스테롤 함량은 곰피 추출물 투여에 의해 저하되었으며, 특히 곰피 추출물 200 ㎎/㎏ bw/day 투여는 중성지방 함량을 유의적으로 감소시키는 결과를 나타내었다. Ldl-콜레스테롤, 동맥경화지수(AI) 및 심혈관위험지수(CRF) 또한 곰피 추출물 투여에 의해 저하되었다 한편 Hdl-콜레스테롤 농도는 난소절제에 의해 감소하였으나, 곰피 추출물을 투여에 의해 증가되었다. 혈액의 유동성에 곰피 추출물의 효과를 실험한 결과 난소 절제에 의해 혈액의 점도가 증가하여 유동성이 저하되었으나, 곰피 추출물 투여로 인해 유동성이 향상됨을 알 수 있었다. 또한 난소 절제에 의해 혈소판 응집능이 증가하였으나, 곰피 추출물 투여로 인해 완화되는 효과를 볼 수 있었다. 이상의 결과로부터 갱년기에 나타날 수 있는 혈중 지질 변화에 대하여 곰피 추출물이 지질 및 혈행 개선 효과를 나타내었으며, 특히 곰피 추출물 200 ㎎/㎏ bw/day 투여는 모든 항목에서 유의성 있는 결과를 나타내어 곰피가 심혈관 관련성 질환 예방에 도움을 줄 것으로 기대된다. Estrogen deficiency in peri- and postmenopausal women results in variety of neurovegetative, psychic and somatic symptoms, and may contribute to severe diseases within the aged female population. Ecklonia stolonifera (ES) is an edible brown algae traditionally used in fishery towns in Far East Asia. This study was performed to investigate the effects of ES extracts on blood flow and serum lipid concentration in ovariectomized rats. Weight-matched female Sprague-Dawley strain rats were assigned to four groups. Three groups were surgically ovariectomized (OVX). The fourth group was sham operated. Rats were randomly assigned to the following groups: sham-operated rats (Sham), ovariectomized control rats (OVX-CON), ovariectomized rats supplemented with ES extract at 50 ㎎/㎏ bw/day (OVX-ES50) and ovariectomized rats supplemented with ES extract at 200 ㎎/㎏ bw/day (OVX-ES200). Serum total cholesterol and triglyceride contents decreased in the sham group compared to the OVX-CON group. Six weeks feeding of ES extract resulted in a significant (p<0.05) lowering of serum triglyceride and a lowering tendency of total cholesterol level. The level of Hdl-cholesterol in serum increased by supplementation of ES extracts at 50 ㎎/㎏ and 200 ㎎/㎏ bw/day (p<0.05). Blood passage time of the ES extracts-supplemented group was higher than the OVX-CON group. The ability of platelet aggregation of groups treated with ES extracts was less than that of the OVX-CON group. These results suggest that the beneficial effects of ES extract may be used to possibly improve on the metabolic syndrome of menopausal women.

Comparison of lipid components in wheat bran by supercritical carbon dioxide extraction conditions

Hyun-Joo Kim,Kyeong-Hoon Kim,Jin Hee Park,Byung-Soo Chun,You-Geun Oh,Hong-Sik Kim,Mihyang Kim,Yu-Young Lee,Jin Young Lee,Moon Seok Kang 한국식품영양과학회 2022 한국식품영양과학회 학술대회발표집 Vol.2022 No.10

Metabolism of <i>Kaempferia parviflora</i> Polymethoxyflavones by Human Intestinal Bacterium <i>Bautia</i> sp. MRG-PMF1

Kim, Mihyang,Kim, Nayoung,Han, Jaehong American Chemical Society 2014 Journal of agricultural and food chemistry Vol.62 No.51

<P>Poylmethoxyflavones (PMFs) are major bioactive flavonoids, which exhibit various biological activities, such as anticancer effects. The biotransformation of PMFs and characterization of a PMF-metabolizing human intestinal bacterium were studied herein for the first time. Hydrolysis of aryl methyl ether functional groups by human fecal samples was observed from the bioconversion of various PMFs. Activity-guided screening for PMF-metabolizing intestinal bacteria under anaerobic conditions resulted in the isolation of a strict anaerobic bacterium, which was identified as <I>Blautia</I> sp. MRG-PMF1. The isolated MRG-PMF1 was able to metabolize various PMFs to the corresponding demethylated flavones. The microbial conversion of bioactive 5,7-dimethoxyflavone (5,7-DMF) and 5,7,4′-trimethoxyflavone (5,7,4′-TMF) was studied in detail. 5,7-DMF and 5,7,4′-TMF were completely metabolized to 5,7-dihydroxyflavone (chrysin) and 5,7,4′-trihydroxyflavone (apigenin), respectively. From a kinetics study, the methoxy group on the flavone C-7 position was found to be preferentially hydrolyzed. 5-Methoxychrysin, the intermediate of 5,7-DMF metabolism by <I>Blautia</I> sp. MRG-PMF1, was isolated and characterized by nuclear magnetic resonance spectroscopy. Apigenin was produced from the sequential demethylation of 5,7,4′-TMF, via 5,4′-dimethoxy-7-hydroxyflavone and 7,4′-dihydroxy-5-methoxyflavone (thevetiaflavone). Not only demethylation activity but also deglycosylation activity was exhibited by <I>Blautia</I> sp. MRG-PMF1, and various flavonoids, including isoflavones, flavones, and flavanones, were found to be metabolized to the corresponding aglycones. The unprecedented PMF demethylation activity of <I>Blautia</I> sp. MRG-PMF1 will expand our understanding of flavonoid metabolism in the human intestine and lead to novel bioactive compounds.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jafcau/2014/jafcau.2014.62.issue-51/jf504074n/production/images/medium/jf-2014-04074n_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jf504074n'>ACS Electronic Supporting Info</A></P>

Deglycosylation of isoflavone <i>C</i>‐glycosides by newly isolated human intestinal bacteria

Kim, Mihyang,Lee, Jaekwan,Han, Jaehong John Wiley Sons, Ltd 2015 Journal of the Science of Food and Agriculture Vol.95 No.9

<P><B>Abstract</B></P><P><B>BACKGROUND</B></P><P>Plant isoflavones are mostly present in the glycoside form. Isoflavone aglycones produced by intestinal microflora are reported to be more bioactive than the glycoside form. However, the deglycosylation of isoflavone <I>C</I>‐glycosides is known to be rare, and is less studied.</P><P><B>RESULTS</B></P><P>Three new bacteria were isolated from human faecal samples, two of which hydrolysed the <I>C</I>‐glycosidic bond of puerarin, daidzein‐8‐<I>C</I>‐glucoside. They were identified as two <I>Lactococcus</I> species, herein designated as MRG‐IFC‐1 and MRG‐IFC‐3, and an <I>Enterococcus</I> species, herein designated MRG‐IFC‐2, based on their 16S rDNA sequences. From a reactivity study, it was found that <I>Lactococcus</I> sp. MRG‐IFC‐1 and <I>Enterococcus</I> sp. MRG‐IFC‐2 hydrolysed isoflavone <I>C</I>‐ and <I>O</I>‐glycosides, as well as the flavone <I>O</I>‐glycoside apigetrin, but could not hydrolyse the flavone <I>C</I>‐glycosidic bond of vitexin. The other <I>Lactococcus</I> sp., MRG‐IF‐3, could not hydrolyse the <I>C</I>‐glycosidic linkage of puerarin, while it showed a broad substrate spectrum of <I>O</I>‐glycosidase activity similar to the other two bacteria. Puerarin was completely converted to daidzein within 100 min by <I>Lactococcus</I> sp. MRG‐IFC‐1 and <I>Enterococcus</I> sp. MRG‐IFC‐2, which is the fastest conversion among the reported human intestinal bacteria.</P><P><B>CONCLUSION</B></P><P>Two new puerarin‐metabolising human intestinal bacteria were isolated and identified, and the deglycosylation activity for various flavonoid glycosides was investigated. The results could facilitate the study of <I>C</I>‐glycosidase reaction mechanisms, as well as the pharmacokinetics of bioactive <I>C</I>‐glycoside natural products. © 2014 Society of Chemical Industry</P>

Bacillus Licheniformis CP6 Fermented Abelmoschus Manihot Jinhuakui Ameliorates Bone Loss in Ovariectomized Rats and Promotes Osteoblast Differentiation Through BMP Signaling Pathway

Mihyang Kim,Sang-Jae Lee,Mi Hwa Park 한국식품영양과학회 2022 한국식품영양과학회 학술대회발표집 Vol.2022 No.10

<i>Ishige sinicola</i> extract stimulates osteoblast proliferation and differentiation via the bone morphogenetic protein 2/runt-related gene 2 signalling pathway

Kim, Mihyang,Kang, Jeong Hyeon,Oh, Geun Hye,Park, Mi Hwa De Gruyter 2019 Zeitschrift für Naturforschung. C, A journal Vol.74 No.7

<P><B>Abstract</B></P><P>Osteoporosis is one of the most common bone diseases, occurring due to an imbalance between bone formation and bone resorption. The aim of this study was to investigate the effects of<I>Ishige sinicola</I>, a brown alga, on osteoblast differentiation through the activation of the bone morphogenetic protein 2 (BMP-2)/runt-related transcription factor 2 (Runx2) signalling pathway in MC3T3-E1 cells. A cell proliferation assay, alkaline phosphatase (ALP) activity assay, alizarin red staining, and expression analysis of osteoblastic genes were carried out to assess MC3T3-E1 cell proliferation and osteoblastic differentiation. We found that<I>I. sinicola</I>extract (ISE) increased cell proliferation in a dose-dependent manner.<I>Ishige sinicola</I>extract markedly promoted ALP activity and mineralization. Alizarin red S staining demonstrated that ISE treatment tended to increase extracellular matrix calcium accumulation. Moreover, ISE up-regulated the osteoprotegerin/receptor activator of nuclear factor κB ligand ratio.<I>Ishige sinicola</I>extract also increased the protein expression levels of type 1 collagen, ALP, osteocalcin, osterix, BMP-2, and Runx2. Therefore, ISE showed potential in stimulating osteoblastic bone formation, and it might be useful for the prevention and treatment of osteoporosis.</P>