ABSTRACT
A phytochemical investigation on the aerial parts of Lindelofia stylosa has resulted in the isolation of seven phenyl propanoids. This includes three analogs of lithospermic acid, along with rosmarinic acid and its ester derivatives. Compound 1 was identified as a new natural product. These compounds were studied for their antioxidant properties.
Subject(s)
Antioxidants/chemistry , Benzofurans/chemistry , Boraginaceae/chemistry , Heterocyclic Compounds, 4 or More Rings/chemistry , Antioxidants/isolation & purification , Benzofurans/isolation & purification , Biphenyl Compounds , Chemical Phenomena , Chemistry, Physical , Chromatography, High Pressure Liquid , Free Radical Scavengers/chemistry , Free Radical Scavengers/isolation & purification , Heterocyclic Compounds, 4 or More Rings/isolation & purification , Iron Chelating Agents/chemistry , Magnetic Resonance Spectroscopy , Picrates/chemistry , Spectrometry, Mass, Fast Atom Bombardment , Spectrophotometry, Ultraviolet , Superoxides/chemistryABSTRACT
Two xanthones, bangangxanthone A (1) [1,5,8-trihydroxy-6'-methyl-6'-(4-methylpent-3-enyl)- pyrano[2',3':3,4]xanthone] and B (2) [1,4,8-trihydroxy-2-prenylxanthone], along with two known xanthones, 1,5-dihydroxyxanthone, 2-hydroxy-1,7-dimethoxyxanthone and the pentacyclic triterpenoids, friedelin, oleanolic acid and lupeol were isolated from the chloroform extract of the stem bark of Garcinia polyantha. The structures of these compounds were assigned by spectroscopic analysis. Compounds 1-4 showed antioxidant DPPH radical scavenging activities.
Subject(s)
Free Radical Scavengers/isolation & purification , Garcinia/chemistry , Xanthones/isolation & purification , Biphenyl Compounds/chemistry , Free Radical Scavengers/chemistry , Free Radical Scavengers/pharmacology , Hydrazines/chemistry , Magnetic Resonance Spectroscopy , Molecular Structure , Picrates , Plant Bark/chemistry , Plant Stems/chemistry , Xanthones/chemistry , Xanthones/pharmacologyABSTRACT
Two new prenylated anthronoids, harunmadagascarins A and B, were isolated from the stem bark of Harungana madagascariensis along with six known compounds including two anthronoids: harunganol B and harungin anthrone, one benzophenone: methyl 3-formyl-2,4-dihydroxy-6-methyl benzoate and three pentacyclic triterpenes: friedelin, lupeol and betulinic acid. Harunmadagascarins A and B were characterized as 8,9-dihydroxy-4,4-bis-(3,3-dimethylallyl)-6-methyl-2,3-(2,2-dimethylpyrano)anthrone and 8,9-dihydroxy-4,4,5-tris-(3,3-dimethylallyl)-6-methyl-2,3-(2,2-dimethylpyrano)anthrone, respectively. The structures of these secondary metabolites were determined by spectroscopic means and comparison with the published data. Methyl 3-formyl-2,4-dihydroxy-6-methyl benzoate was isolated for the first time from a plant. Harunmadagascarins A and B, harunganol B and harungin anthrone exhibited significant antioxidant activity.
Subject(s)
Anthracenes/chemistry , Antioxidants/chemistry , Clusiaceae/chemistry , Plant Bark/chemistry , Free Radical Scavengers/chemistry , Molecular Structure , Plant Stems/chemistryABSTRACT
Fungal transformation of (E)-guggulsterone (= (17E)-pregna-4,17-diene-3,16-dione; 1) by Rhizopus stolonifer, Fusarium lini, Cunninghamella elegans, or Gibberella fujikuroi afforded ten hydroxylated metabolites (2-11; Scheme), which were fully characterized. Compounds 4-11 have not been described yet. Some of these novel hydroxylated metabolites, as well as acetylated derivatives thereof, exhibited significant antibacterial and radical-scavenging activities (Table 3).
