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정의길,장다혜,김지혜,백선미,이슬기,도혜진,이애림,한국일,한만덕 순천향대학교 기초과학연구소 2014 순천향자연과학연구 논문집 Vol.20 No.2
This study aimed to investigate antibacterial and antioxidant activities of five different solvent (methanol, n-hexane, chloroform, ethyl acetate, butyl alcohol and water) extracts from Styrax japonicus by in vitro assays. The antibacterial activities of extracts were determined by minimum inhibitory concentrations (MICs), and antioxydative activities were measured by 1,1-diphenyl- 2-picrylhydrazyl (DPPH) and 2,2'-azino-di-2-ethyl-benzthiazoline sulphonate (ABTS·+) radical scavenging activity. Among the six extracts, the ethyl acetate fraction (EAF) from S. japonicus seed showed the highest antimicrobial activities at 51.2 ㎎/㎖ of MIC against Stapylococcus aureus SG511 and Escherichia coli O 78. Total phenolic and total flavonoid contents of EAF were 18.9% and 0.59%, respectively. EC50 of DPPH and ABTS·+ radical scavenging activity of EAF was 2.75 ± 0.05 μg/㎖ and 3.22 ± 0.05 μg/㎖, respectively (p<0.05). The results suggest that EAF of S. japonicus may be useful as potential antioxidant sources. Keywords : Styrax japonicus, Seed extract, Antibacterial agents, Antioxidant, Bioactivity
정의길,한국일,권현정,패트나익,김완종,허강민,남궁우,한만덕 대한약학회 2015 Archives of Pharmacal Research Vol.38 No.6
Sappanchalcone, a bioactive flavonoid isolatedfrom the heartwood of Caesalpinia sappan L. possessesanti-inflammatory effects. We studied the efficacy of sappanchalconein attenuating collagen-induced arthritis(CIA) in a mouse model of rheumatoid arthritis. Sappanchalconewas purified to homogeneity from the chloroformfraction of the methanolic extract of C. sappan, and identifiedusing mass spectrometry and 1H-nuclear magneticresonance spectroscopy. CIA-induced male DBA/1J micewere divided into control, sappanchalcone-treated, andmethotrexate-treated groups (n = 10 per group). Pawswelling, arthritis severity, radiographic and histomorphometricchanges were assessed to measure the protectiverole of sappanchalcone against chronic disease progression. Sappanchalcone administration significantly reducedclinical arthritis and inflammatory edema in paws. Bonemineral density and trabecular structure were maintained inCIA mice administered sappanchalcone. The levels of proinflammatorycytokines (TNF-a, IL-6, and 1L-1b) weresignificantly lower in the serum of sappanchalcone-treatedmice as compared with the control group. Our resultssuggest that sappanchalcone could be used as an antiinflammatoryand bone-protective agent during the treatmentof rheumatoid arthritis.
황정의,곽영우,정재원,길천호,Jung-Ui Hwang,Yong-Woo Kwak,Jae-Won Jung,Chon-Ho Kil 대한화학회 1991 대한화학회지 Vol.35 No.2
수용액 중에서 발린과 노발린의 두 가지 해리상수를 온도와 압력을 변화시키면서 전도도법으로 측정했다. 이들 해리상수로부터 열역학적 성질들을 계산하여 해리반응의 특성을 알아보았다. 아미노산의 종류 즉, 아미노기의 위치나 사슬의 길이, 치환기의 종류에 따라 해리도가 어떤 영향을 받는가 하는 것을 Hammett식을 이용하여 검토했고 이것을 CNDO/2법으로 계산한 분자내 원자의 알짜 전하와 비교 검토하였다. The dissociation constants of valine and norvaline in aqueous solution were measured by conductometric method in various temperatures and pressures. The properties of the dissociation reaction were discussed in term of the thermodynamic properties of reaction. These substituted effects on the dissociation reaction were discussed on the points of Hammett relation and net charge of the O and N-atom calculated from CNDO/2 method respectively.
선체 마운트 지지점에서의 리셉턴스를 고려한 선박용 디젤 엔진의 고체전달음 해석
장성길(Jang, Seong-Gil),정의봉(Jeong, Weui-Bong),홍진숙(Hong, Chin-Suk),배수룡(Bae, Soo-Ryong) 한국소음진동공학회 2011 한국소음진동공학회 논문집 Vol.21 No.2
This paper presents an efficient method to analyze noise and vibration of marine diesel engines mounted on flexible hull structure. The analysis model should in general include the hull structure, leading to lots of computational efforts. To minimize the computational efforts, in this paper, the transfer synthesis utilizing the receptance at the mounting points is proposed. The procedure is then verified by comparing the results with those from the full model calculation. The effects of flexible hull structure on the acoustic power from engine block are finally investigated. It is found that the effect of the hull is significant when the receptance of hull structure is similar to or greater than that of mount or engine block.