Platonia insignis fruit, popularly known as bacuri, is traditionally used in folk medicine for it... more Platonia insignis fruit, popularly known as bacuri, is traditionally used in folk medicine for its anti-inflammatory and antioxidant properties. Therefore, this study determined the chemical composition and biological activities of the bacuri’s shell and seeds extracts, considered residues from its consumption and industrial uses. Four biflavonoids (GB-2a, GB-1a, morelloflavone, and volkensiflavone) were identified in the extracts by high-performance liquid chromatography-diode array detection (HPLC-DAD), liquid chromatography tandem mass spectrometry (LC-MS/MS), and liquid chromatography-solid phase extraction-nuclear magnetic resonance (LC-SPE-NMR) techniques. Morelloflavone was identified as the main compound in the shell ethyl acetate extract, being responsible for the high in vitro antioxidant (50% effective concentration (EC50) ranging from 8.0-10.5 µg mL−1 in different protocols), anti-glycant (80%), and moderate inhibition of nitric oxide (1.56 µg mL−1 for > 90% cell viab...
Two constituents of Pterogyne nitens leaves, kaempferitrin, a diglycosylated flavonol, and galegi... more Two constituents of Pterogyne nitens leaves, kaempferitrin, a diglycosylated flavonol, and galegin, a guanidine alkaloid, may be considered likely to exert an antidiabetic effect, on the basis of their chemical structures. Thus, experimentally diabetic rats were treated with P. nitens leaf extract, to observe the effects on biochemical and toxicological marker variables. Streptozotocin-diabetic rats (50 mg/kg body weight) were given ethanolic extract of the leaves (76 mg suspended in 0.5 mL of 10% aqueous glycerine per rat) (DP) by gavage, twice a day for 32 days. Diabetic controls were given 0.5 mL of 10% glycerine (DG), insulin (2.5 U in 0.3 mL s. c.) (DI) or 0.5 ml water (DW). Initial glycemia was 537.11 ± 10.35 mg/dL. Each week or fortnight after the treatment glucose, urea and protein contents were determined in the urine and glycemia and alkaline phosphatase activity in the serum. Except for proteinuria, the results for groups DP, DG and DW all differed significantly (p < 0...
Enantiomeric aglycone lignans contained in a mixture were separated from a fraction of the extrac... more Enantiomeric aglycone lignans contained in a mixture were separated from a fraction of the extract of the stems of Alibertia sessilis (Vell.) K. Schum. (Rubiaceae) by preparative high-performance liquid chromatography. An efficient and fast separation can be achieved with methanol-water (30:70, v/v). Their structures were identified as (+)-lyoniresinol 3alpha-O-beta-glucopyranoside and (-)-lyoniresinol 3alpha-O-beta-glucopyranoside, being reported for the first time in Rubiaceae.
The bioassay-guided fractionation of the ethanol extract from Nectandra grandiflora leaves led to... more The bioassay-guided fractionation of the ethanol extract from Nectandra grandiflora leaves led to the isolation of two flavonol glycosides which inhibited the bleaching of beta -carotene on the TLC assay. Both compounds had their molecular structures elucidated by means of extensive use of uni- and bidimensional NMR techniques and were identified as 3-O-beta -rhamnosylkaempferol and 3-O-beta -rhamnosylquercetine.
Platonia insignis fruit, popularly known as bacuri, is traditionally used in folk medicine for it... more Platonia insignis fruit, popularly known as bacuri, is traditionally used in folk medicine for its anti-inflammatory and antioxidant properties. Therefore, this study determined the chemical composition and biological activities of the bacuri’s shell and seeds extracts, considered residues from its consumption and industrial uses. Four biflavonoids (GB-2a, GB-1a, morelloflavone, and volkensiflavone) were identified in the extracts by high-performance liquid chromatography-diode array detection (HPLC-DAD), liquid chromatography tandem mass spectrometry (LC-MS/MS), and liquid chromatography-solid phase extraction-nuclear magnetic resonance (LC-SPE-NMR) techniques. Morelloflavone was identified as the main compound in the shell ethyl acetate extract, being responsible for the high in vitro antioxidant (50% effective concentration (EC50) ranging from 8.0-10.5 µg mL−1 in different protocols), anti-glycant (80%), and moderate inhibition of nitric oxide (1.56 µg mL−1 for > 90% cell viab...
Two constituents of Pterogyne nitens leaves, kaempferitrin, a diglycosylated flavonol, and galegi... more Two constituents of Pterogyne nitens leaves, kaempferitrin, a diglycosylated flavonol, and galegin, a guanidine alkaloid, may be considered likely to exert an antidiabetic effect, on the basis of their chemical structures. Thus, experimentally diabetic rats were treated with P. nitens leaf extract, to observe the effects on biochemical and toxicological marker variables. Streptozotocin-diabetic rats (50 mg/kg body weight) were given ethanolic extract of the leaves (76 mg suspended in 0.5 mL of 10% aqueous glycerine per rat) (DP) by gavage, twice a day for 32 days. Diabetic controls were given 0.5 mL of 10% glycerine (DG), insulin (2.5 U in 0.3 mL s. c.) (DI) or 0.5 ml water (DW). Initial glycemia was 537.11 ± 10.35 mg/dL. Each week or fortnight after the treatment glucose, urea and protein contents were determined in the urine and glycemia and alkaline phosphatase activity in the serum. Except for proteinuria, the results for groups DP, DG and DW all differed significantly (p < 0...
Enantiomeric aglycone lignans contained in a mixture were separated from a fraction of the extrac... more Enantiomeric aglycone lignans contained in a mixture were separated from a fraction of the extract of the stems of Alibertia sessilis (Vell.) K. Schum. (Rubiaceae) by preparative high-performance liquid chromatography. An efficient and fast separation can be achieved with methanol-water (30:70, v/v). Their structures were identified as (+)-lyoniresinol 3alpha-O-beta-glucopyranoside and (-)-lyoniresinol 3alpha-O-beta-glucopyranoside, being reported for the first time in Rubiaceae.
The bioassay-guided fractionation of the ethanol extract from Nectandra grandiflora leaves led to... more The bioassay-guided fractionation of the ethanol extract from Nectandra grandiflora leaves led to the isolation of two flavonol glycosides which inhibited the bleaching of beta -carotene on the TLC assay. Both compounds had their molecular structures elucidated by means of extensive use of uni- and bidimensional NMR techniques and were identified as 3-O-beta -rhamnosylkaempferol and 3-O-beta -rhamnosylquercetine.
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