TAILIEUCHUNG - Flavonoid glucosides from the leaves of Croton tonkinensis Gagnep., Euphorbiaceae

The structures of 1, 2 and 3 were determined on the basis of ESIMS, 1D and 2D NMR spectroscopic data. Although the flavonoid glucosides found exclusively in the ethyl acetate and n-butanol soluble fractions are reported for antioxidative and antiinflammatory activities their contribution to the medicinal properties of C. tonkinensis is demonstrated to be less than the lipid soluble entkaurene diterpenoid constituents of this plant. | Journal of Chemistry, Vol. 42 (1), P. 125 - 128, 2004 FLAVONOID GLUCOSIDES FROM THE LEAVES OF CROTON TONKINENSIS GAGNEP., EUPHORBIACEAE Received 14-7-2003 Phan Minh Giang1, Jung Joon Lee2, Phan Tong Son1 1 Faculty of Chemistry, College of Natural Science, Vietnam National University Anticancer Agent Research Laboratory, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea 2 Summary Two flavone C-glucosides vitexin (1) and isovitexin (2) were isolated as the major constituents with the total content of of the methanol extract of the Croton tonkinensis leaves along with an minor acylated flavonol O-glucoside kaempferol 3-O- D-(6’’-O-coumaroyl)glucopyranoside (tiliroside, 3) (). The structures of 1, 2 and 3 were determined on the basis of ESIMS, 1D and 2D NMR spectroscopic data. Although the flavonoid glucosides found exclusively in the ethyl acetate and n-butanol soluble fractions are reported for antioxidative and antiinflammatory activities their contribution to the medicinal properties of C. tonkinensis is demonstrated to be less than the lipid soluble entkaurene diterpenoid constituents of this plant. In our past studies on the medicinal plant Croton tonkinensis Gagnep. (Euphorbiaceae) [1], the phytosterols, the long chain alkyl alcohols and the ent-kaurene-type diterpenoids [2] were isolated from the non-polar parts (n-hexane and CH2 Cl 2 soluble fractions) of the methanol extract of the dried leaves of C. tonkinensis [3]. The investigation of the methanol extract by reserved-phase high performance liquid chromatography (RP HPLC) coupled with a photodiode array (PDA) detector [4] revealed the presence of two major classes of components: ent-kaurene diterpenoids and flavonoid gluco-sides. Of the flavonoids two were quantified as the major (total ) and one as the minor constituents () of the methanol extract which were found to be localized in the polar ethyl acetate and n-butanol soluble fractions. When the ethyl acetate

• Hoá học
• Journal of Chemistry
• Flavonoid glucosides from the leaves
• Croton tonkinensis Gagnep
• Two flavone C glucosides vitexin
• The basis of ESIMS
• DMSO d6 revealed
• Journal of technology and science education
• Innovative chemistry learning model
• Improving the critical thinking skill
• Self efficacy of pre service chemistry teachers
• Pre service chemistry teachers
• SCT learning model syntax covers
• The Chemistry and Antimicrobial Activity of Psychotria reevesii Wall
• The Chemistry and Antimicrobial Activity
• Psychotria reevesii Wall
• The polar fractions against Staphylococcus aureus
• The relationship between teacher related factors
• Students attitudes towards secondary school chemistry subject
• Bureti district Kenya
• Secondary school chemistry subject
• Click chemistry
• Poly(ethylene glycol)
• Poly(epsilon caprolactone)
• Azide functionalized molecules
• Azide montmorillonite clay
• Block copolymer
• Ketene chemistry
• Telechelic polymers
• Controlled radical polymerization (CRP)
• C60 fullerene
• Metallosupramolecular chemistry
• Host–guest complexes
• Supramolecular chemistry
• Donor–acceptor (D–A)
• Ring opening polymerization
• Thiol benzoxazine reaction
• Catechol based benzoxazine copolymer
• Antibacterial coatings
• Benzoxazine chemistry
• Green chemistry
• Heavy metals
• Cetylpyridinium chloride
• Analytical chemistry
• Journal of Science and Technology
• Green organic synthesis of N methylpyrrolidine
• Gas Chromatography Mass spectroscopy
• The green chemistry process
• Via the green chemistry process
• Journal of medical research
• Production of liophilized quality control samples
• Liophilized quality control samples
• Several clinical chemistry test
• Statistical quality control
• Perspectives on blended learning
• The on line platform
• LabLessons for Chemistry
• Hydrogen and Titration
• College mentors alongside
• Contextualizing technology in the classroom via remote access
• Using space exploration themes
• Scanning electron microscopy
• Tools to promote engagement
• Multidisciplinary geology chemistry experiments
• The service of learning chemistry in Industrial Engineering
• Degrees in Industrial Engineering
• Chemical Engineering and Materials Engineering
• The feed back
• Assessment of achievement in problem solving skills
• General Chemistry course
• Problem based learning
• Measure problem solving skills
• Use of chemistry software to teach
• Assess model based reaction and equation knowledge
• Assess model based reaction
• Two advanced placement
• Public suburban high school
• Collaborative activities for solving multi step problems
• Solving multi step problems in general chemistry
• Solving multi step problems
• The relatve partcipaton of instructor students
• Antioxidant activity
• Bioinorganic chemistry
• Cytotoxic activity
• DNA binding and cleavage activity
• Topoisomerase inhibitor
• Transition metal compounds
• Analytical methods
• Electroanalytical chemistry
• Ionic liquids
• Penicillin allergic patients
• Capillary electrophoresis
• Carbamate SCC interactions
• Fluorescence quenching
• Quantum chemistry calculation
• Inhibition chemiluminescence
• Piperazine chemistry
• Structural features
• Anticancer activity
• Anticancer drugs
• D cyclin dependent kinase
• 3 Amino 9 ethylcarbazole
• Multicomponent reaction
• Arylation reactions
• Cyclization reactions
• Pyrrolo[2 3 c]carbazole
• Prido[3 2 b]carbazole
• Ionic liquid
• Organic phase change materials
• Thermal energy storage
• Solvent free medium
• Silicon chemistry
• Reaction mechanism
• Density functional theory (DFT)
• Homogeneous transitionmetal catalysis
• Silicon analogues
• Medicinal chemistry
• Antiproliferative agents
• Protect endangered tissue
• Anti inflammatory cytokines
• Persistent inflammatory reaction
• Formic acid decomposition
• Renewable feedstock
• Energy feedstocks
• High surface area materials