DPPH FREE RADICAL SCAVENGER ACTIVITY OF FLAVONOID FROM THE LEAVES OF FERN Chingia sakayensis (Zeiller) Holtt

A flavonoid compound in flavonol type namely kaemferol was isolated from the ethyl acetate fraction of the methanol extract of the fern Chingia sakayensis (Zeiller) Holtt's leaves. The DPPH free radical scavenger activity of kaemferol was stronger than buthyl hyroxy toluene (BHT) but it was weaker than ascorbic acid (vitamin C) and -tocopherol (vitamin E).   Keywords: Chingia sakayensis, kaemferol, DPPH free radical scavenger activit

Phenolic Compounds Isolated from The Fern Chingia sakayensis (Zeiller) Holtt

Four known phenolic compounds namely kaemferol, matteucinol, farrerol, and matteucinol-7-O-β-D-glucoside were isolated for the first time from the fern Chingia sakayensis (Zeiller) Holtt’s. All substances were separated by chromatographic techniques, purified by recrystalization, elucidated on the basis of spectroscopic evidence and by comparation with those reported data in literature. These results were very important to study the phytochemicals of the other fern in Chingia genus based on the chemotaxonomic approach

A FLAVONOL COMPOUND FROM <i>Chingia sakayensis</i> (Zeiller) Holtt AND ITS ACTIVITY AS DPPH FREE RADICAL SCAVENGER

It has been separated a flavonol 3,5,7,4'-tetrahydroxy flavone (kaemferol) from the methanol extract partitioned by ethyl acetate of the leaves of the fern Chingia sakayensis (Zeiller) Holtt. This was obtained as yellow crystals with m.p. 271-273oC. Characterization of its molecular structure was carried out by spectroscopic methods (UV, IR, 1H-NMR, HMQC, HMBC, 13C-NMR and FABMS). Kaemferol indicated the DPPH free radical scavenger activity in TLC autography.   Keywords: Chingia sakayensis (Zeiller) Holtt, flavone, kaemferol, DPPH free radical scavenger activit

Cyclizations Producing Hydrindanones with Two Methyl Groups at the Juncture Positions Mediated by Samarium Diiodide and Electrolysis

One-electron reductive intramolecular cyclization of enones with ketones or aldehydes mediated by samarium diiodide and electrolysis to afford cis-trimethyl- hydrindanolones. The reactions gave selectivities ranging from 1:1 to 100:0 depending on the conditions

Terpenoids from Ligularia virgaurea collected in China: the first example of two bakkane derivatives with an anhydride-type ring C and nineteen new chemical constituents

Further chemical investigation of two Ligularia virgaurea samples collected in China resulted in the isolation of 21 new compounds, two of which were bakkane-type sesquiterpenoids bearing an anhydride-type ring C, which was a previously unknown partial structure. These samples belonged to the V-type (the major component was virgaurenone) among the five chemotypes found in this species

Relative Stability of cis- and trans-Hydrindanones

The relative stabilities of several cis- and trans-hydrindanones were compared using both isomerization experiments and MM2 calculations. The generally believed rule that cis-hydrindanones are more stable than trans-isomers is applicable, but is not always true. This review introduces examples, mainly from studies in our laboratory, to explain these facts