초록

Abstract ▼

영문제목(Title) Screening and Identification of Bioactive Compounds from Hibiscus syriacus 영문요약 (Summary) The genus Hibiscus belongs to the family Malvaceae and is widely distributed in eastern and southern Asia. The dried flowers and root bark of H. syriacus L. have been used as an antipyretic

영문제목(Title) Screening and Identification of Bioactive Compounds from Hibiscus syriacus 영문요약 (Summary) The genus Hibiscus belongs to the family Malvaceae and is widely distributed in eastern and southern Asia. The dried flowers and root bark of H. syriacus L. have been used as an antipyretic, anthelmintic, and antifungal agents in the Orient. Saponarin, polyphenol compounds, betulin, canthin-6-one, carotenoids, and anthocyanins were previously isolated from the stem bark and root bark of H. syriacus. We have screened for biologically active principles and chemically novel constituents from methanolic extract of the higher plant H. syriacus, which was collected at Yusong, Chungnam Province, Korea, in 1995 to 1996 and identified by staff at the Korea Research Institute of Bioscience and Biotechnology (KRIBB), Korea. The biological activity of the isolated compounds was estimated by the lipid peroxidation inhibitory activity for antioxidants, cytotoxic effect on various cancer cell lines for anticancer agents, and antimicrobial activity. The results are as follows: 1) The dried root bark and stem bark of H. syriacus were extracted twice with methanol for 2 days at room temperature and then the extracts were partitioned between hexane, chloroform, ethyl acetate, butanol and water. The biological activity of each solvent-soluble fraction was evaluated by the lipid peroxidation inhibitory activity, cytotoxic effects, and antimicrobial activity. Among them, chloroform, ethyl acetate, and butanol extracts of the root bark showed strong antioxidative effect and cytotoxicity. 2) The chloroform, ethyl acetate, and butanol extracts of the root bark of H. syriacus showing strong antioxidative effect and cytotoxicity were purified with various column chromatographies including silica gel column, Sephadex LH-20 column, and ODS column, preparative silica gel TLC, ODS-TLC, and HPLC. In result, chloroform-soluble portion afforded compounds 1-28 and ethyl acetate-soluble one gave compounds 29-40. Also, several compounds including a new antioxidative compound, hibiscuside, were obtained from the butanol fraction. 3) The chemical structures of about 40 compounds isolated from the root bark of H. syriacus were assigned by the physico-chemical properties and various NMR spectroscopic analyses such as 1H, 13C, DEPT, NOE difference, DQF-COSY, HMQC, HMBC, and NOESY. The names of the identified compounds are described below. Names of Novel Compounds Syriacusin A (Compd 1), Syriacusin B (Compd 4), Syriacusin C (Compd 3), Syriacusin D (Compd 2), Hibispeptin A (Compd 22), Hibispeptin B (Compd 23), Compound A (Compd 8), Compound B (Compd 9), Hibiscuside (Butanol 층에서 분리) Hydroxyhibiscone A (Compd 10), Norneolignan glucoside (Compd 24), Coumarinolignan (Compd 25) Names of Known Compounds Syringaresinol (Compd 6), Feruloyltyramines (Compd 7), Cleomiscosin A (Compd 12), Cleomiscosin C (Compd 13), Cleomiscosin D (Compd 14), Scopoletin (Compd 26), Hexamethoxyflavone (Compd 18), Isosinensetin (Compd 19), Puerarin (Compd 27), Hesperetin 배당체 (Compd 28), Tricin, (Compd 29), Liquiritigenin (Compd 30), Diadzein (Compd 32), 2'-Hydroxydiadzein (Compd 33), Naringenin 배당체 (Compd 34), 6"-O-Acetyldaidzin (Compd 37), 6"-O-Acetylgenistein (Compd 39), Ononin (Compd 38), Hibiscone D (Compd 5), α-Dimorphecolic acid (Compd 11), Uracil (Compd 35), Methyl gallate (Compd 36) Among them, 12 compounds were isolated for the first time from natural sources and the others were previously reported by other groups. Hibispeptins A and B, new peptides isolated from the chloroform-soluble fraction of the root bark, were structurally unique cyclic peptides composed of L-proline, L-leucine, L-phenylalanine, L-pyroglutanine, and an unusual amino acid, Ahabpa (2-amino-3-(2-hydroxy-5-aminoacetylbenzyl)pentanoic acid). Also, highly substituted three new naphthalene compounds, syriacusins A, B, and C, were isolated from the chloroform-soluble fraction and their structure were assigned as 2,7-dihydroxy-6-methyl-8-methoxy-1-naphthalenecarbaldehyde, 2-hydroxy-6-hydroxy methyl-7,8-dimethoxy-1-naphthalenecarbaldehyde, and 1-carboxy-2,8-dihydroxy-6-m- ethyl-7-methoxynaphthalenecarbolactone(1→8), respectively. In addition, two new triterpene caffeates, compounds A and B, a new family of hibiscone, hydroxyhibiscone A, a new norneolignan glucoside, and a new coumarinolignan were isolated from the chloroform-soluble fraction of the root bark of H. syriacus. In addition to these compounds, 13 known compounds including syringaresinol, cleomiscosins A-D, and scopoletin were isolated from the chloroform-soluble fraction. The ethyl acetate-soluble fraction afforded 13 compounds, which were identified as nine flavonoids including tricin, liquiritigenin, and ononin, and some phenolic compounds. Also, a new antioxident lignan, hibiscuside, was isolated from the butanol-soluble fraction of the root bark of H. syriacus. 4. The detailed biological activity of structurally unique novel constituents and some known compounds were investigated. New naphthalenes, syriacusins A, B, and C inhibited lipid peroxidation in rat liver microsomes with IC50 values of 0.54, 5.90, and 1.02 ㎍/㎖, respectively. Syriacusin A was ca three times as active as vitamin E which was used as a control. Also, the cytotoxicity of the major component A against several human tumor cell lines was examined. Syriacusin A was the most effective against melanoma (UACC62), renal (ACHN), colon (SW620), and central nervous system (SF539), but none of them were as effective as adriamycin used as a control. Unique cyclic peptide, hibispeptin A, inhibited lipid peroxidation with an IC50 value of 9.2 ㎍/㎖, but hibispeptin B did not show even at the concentration of 30 ㎍/㎖. Some cyclic peptides were also reported to have tyrosinase inhibitory activity but hibispeptins did not exhibit this activity up to the concentration of 50 ㎍/㎖. In addition, antimicrobial activity and cytotoxicity were not detected. Two new triterpene caffeates, compounds A and B, showed the lipid peroxidation inhibitory activity with IC50 values of 2.3 and 1.1 ㎍/㎖, respectively and showed cytotoxic effects to renal and colon cancer cell lines. New lignan glycoside hibiscuside exhibited moderate inhibitory activity against lipid peroxidation with an IC50 value of 18.9 ㎍/㎖. Of known compounds, hibiscone D showed highly specific antifungal activity against human pathogenic fungus Trichophyton mentagrophytes and also, E-N-feruloyltyramine and Z-N-feruloyltyramine showed weakly antifungal activity against same pathogenic fungus.

목차 Contents

• Summary...7
• I. 서 언...11
• II. 연 구 사...13
• III. 재료 및 방법...15
• 1. 실험재료...15
• 2. 분석기기...15
• 가. 선광도...15
• 나. 자외선 스펙트럼 (UV spectrum)...15
• 다. 적외선 스펙트럼 (IR spectrum)...15
• 라. 질량분석 스펙트럼 (mass spectrum)...15
• 마. 핵자기공명 스펙트럼 (NMR spectrum)...16
• 3. 기타시약...16
• 4. 무궁화로부터 활성물질의 추출 및 분리...16
• 5. 지질과산화 억제 활성...17
• 가. Microsome의 분리...17
• 나. 지질과산화 억제 활성의 측정...17
• 6. 세포독성 측정...20
• 가. 암세포주의 배양...20
• 나. 세포독성의 측정...20
• 7. 항균활성...20
• IV. 결과 및 고찰...21
• 1. 무궁화로부터 생리활성물질의 추출 및 분리...21
• 가. 무궁화나무의 추출...21
• 나. 무궁화나무 추출물로부터 생리활성물질의 분리 및 정제...21
• 2. 신규 항산화활성물질 syriacusin A, B, C 및 D...26
• 가. Syriacusin A, B, C 및 D의 분리, 정제...26
• 나. Syriacusin A, B, C 및 D의 물리화학적 특성...26
• 다. Syriacusin A, B 및 C의 화학구조...30
• 라. Syriacusin A, B 및 C의 생물활성...37
• 3. 신규 cyclic peptide 화합물 hibispeptin A 및 B...38
• 가. Hibispeptin A 및 B의 분리, 정제...38
• 나. Hibispeptin A 및 B의 물리화학적 특성...38
• 다. Hibispeptin A 및 B의 화학구조...42
• 라. Hibispeptin A 및 B의 입체화학...48
• 마. Hibispeptin A 및 B의 생물활성...54
• 4. 신규 triterpene 화합물 compound A 및 B...55
• 가. Compound A 및 B의 분리, 정제...55
• 나. Compound A 및 B의 물리화학적 특성...55
• 다. Compound A 및 B의 화학구조...59
• 라. Compound A 및 B의 생물활성...64
• 5. 신규 항산화 활성물질 hibiscuside...65
• 가. Hibiscuside의 분리, 정제...65
• 나. Hibiscuside의 물리화학적 특성...65
• 다. Hibiscuside의 화학구조...66
• 라. Hibiscuside의 생물활성...68
• 6. 신규 furan 화합물 hydroxyhibiscone A...69
• 가. Hydroxyhibiscone A의 분리, 정제...69
• 나. Hydroxyhibiscone A의 물리화학적 특성...69
• 다. Hydroxyhibiscone A의 화학구조...70
• 7. 신규 norneolignan glucoside 화합물...74
• 가. Norneolignan glucoside의 분리, 정제...74
• 나. Norneolignan glucoside의 물리화학적 특성...74
• 다. Norneolignan glucoside의 화학구조...75
• 8. 신규 coumarinolignan 화합물...80
• 가. Coumarinolignan의 분리, 정제...80
• 나. Coumarinolignan의 물리화학적 특성...80
• 다. Coumarinolignan의 화학구조...81
• 9. 기타 화합물...85
• 가. 페놀성 화합물...85
• (1) Syringaresinol...85
• (2) E-N-Feruloyltyramine 및 Z-N-feruloyltyramine...86
• (3) Cleomiscosin A, C 및 D...90
• (4) Scopoletin...93
• (5) 기타 페놀성 화합물...95
• 나. Flavonoid 화합물...96
• (1) 3,3',4',5,7,8-Hexamethoxyflavone...96
• (2) Isosinensetin...97
• (3) Puerarin...98
• (4) Hesperetin-7-O-neohesperidoside...99
• (5) Tricin...100
• (6) Liquiritigenin...101
• (7) Diadzein...102
• (8) 2'-Hydroxydiadzein...103
• (9) Naringenin-7-O-neohesperidoside...104
• (10) 6...105
• (11) 6...106
• (12) Ononin...107
• (13) 기타 flavonoid 화합물...108
• 다. 기타 화합물들...109
• (1) Hibiscone D...109
• (2) α-Dimorphecolic acid...113
• (3) Uracil...116
• (4) 기타...117
• V. 적 요...118
• VI. 인 용 문 헌...121