Proanthocyanidins with ( + )-epicatechin units from Byrsonima crassifolia bark

Determinação de enantiômeros em extratos vegetais por cromatografia quiral e dicroísmo circular

“…Additionally, although the use of TFA during chromatography could have induced epimerisation, it was not observed for the standards tested as well. This result is in accordance with the identification of an ent-epicatechin dimer isolated from Byrsonima crassifolia species 23 . (Table IV).…”

“…Byrsonima species have scientifically been proven to present several pharmacological activities such as antiulceroneic 17 , mutagenic 18,19,20 and antimicrobial 21,22 . Phytochemical investigations on Byrsonima species revealed the occurrence of catechin and/or epicatechin derivatives 14,17,19,20,22,23 .…”

NEW DEGRADED QUINONE DITERPENOID FROM THE STEMS OF Byrsonima coccolobifolia Kunth. (Malpighiaceae)

“…Of the compounds isolated from the roots, the triterpenoids α-amyrin, β-amyrin, and oleanolic acid, and the mixture of stigmasterol, β-sitosterol and campesterol have been described before for other species, most of which have been isolated from B. crassifolia [11][12][13][14] and B. verbascifolia, 21,22 except for glochidonol which has not been described in the genus so far.…”

“…The phytochemical investigation of the leaves and stems afforded the flavonoids (+)-catechin, (-)-epicatechin, quercitrin and isoquercitrin, which are frequently found in Byrsonima species including B. basiloba, 6,7 B. bucidaefolia, 8 B. crassa, 9,10 B. crassifolia, [11][12][13][14] B. fagifolia, [15][16][17] B. intermedia, 18 B. microphylla, 19,20 and B. verbascifolia; 21,22 the investigation also afforded the tannins 3,5-di-O-galloylquinic acid, 5-O-galloylquinic acid, 5-O-(3-methylgalloyl)-quinic acid, 3,4,5-tri-O-galloylquinic acid and gallic acid, which have been previously described in B. crassa 9,10 and B. fagifolia. [15][16][17] Among the compounds isolated from the stems of B. coccolobifolia, (+)-syringaresinol and trigonostemone are new in the genus Byrsonima.…”

“…[3][4][5] The compounds most commonly isolated from this genus are flavonoids, terpenes, gallic acids and quinic acid derivatives. 1 Among the constituents, flavonoids (flavanones, bioflavonoids, flavonols and procyanidins), triterpenes (with oleanolic and ursolic skeletons) and modified triterpenoids (steroids) are commonly found in B. basiloba, 6,7 B. bucidaefolia, 8 B. crassa, 9,10 B. crassifolia, [11][12][13][14] B. fagifolia, [15][16][17] B. intermedia, 18 B. microphylla, 19,20 and B. verbascifolia. 21,22 Previous studies on the leaves of B. coccolobifolia revealed the presence of flavonoids, gallic acid and xanthones.…”