Megastigmane glucosides from Equisetum debile and E. diffusum.
A new megastigmane diglucoside, (3S,5R,6S,7E,9S)-megastigman-7-ene-5,6-epoxy-3,9-diol 3,9-O-beta-D-diglucopyranoside (3), was isolated from the aerial portion of Equisetum debile along with macarangioside D (debiloside A), sammangaoside A, (6R,9S)-3-oxo-alpha-ionol 9-O-beta-D-glucopyranoside, debiloside B, kaempferol 3-O-sophoroside, kaempferol 3,7-O-beta-D-diglucopyranoside, kaempferol 3-O-sophoroside-7-O-beta-D-glucopyranoside, phenylethyl O-beta-D-glucopyranoside, (Z)-3-hexenyl O-beta-D-glucopyranoside, (7S,8R)-dehydrodiconiferyl 4-O-beta-D-glucopyranoside, and L-tryptophan. The absolute configuration at C-6 of the original structure of debilo-side A was revised to 6R-configuration, and was identical with macarangioside D (1). From the aerial portion of E. diffusum, four compounds, sammangaoside A, kaempferol 3-O-sophoroside and L-tryptophan and (3S,5R,6S,7E,9S)-megastigman-7-ene-5,6-epoxy-3,9-diol 3-O-beta-D-glucopyranoside were identified. The spectroscopic data of (3S,5R,6S,7E,9S)-megastigman-7-ene-5,6-epoxy-3,9-diol 3-O-beta-D-glucopyranoside (13) were found to be identical with corchoionoside A (9R-isomeric compound). The structure of corchoionoside A was also discussed. Structure determinations were based on physical data and spectroscopic evidence.
Department of Pharmaceutical Botany and Pharmacognosy, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen, Thailand. trikan@kku.ac.th
Tripetch
T
Kanchanapoom
Hideaki
H
Otsuka
Somsak
S
Ruchirawat
D000596:Amino Acids; D003512:Cyclohexanones / Q000737:chemistry* / Q000302:isolation & purification; D020829:Equisetum / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry; D005960:Glucosides / Q000737:chemistry* / Q000302:isolation & purification; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D000432:Methanol; D045792:Norisoprenoids / Q000737:chemistry* / Q000302:isolation & purification; D012997:Solvents
D000596:Amino Acids; D003512:Cyclohexanones; D005960:Glucosides; D045792:Norisoprenoids; D012997:Solvents; C413264:megastigmane; D005947:Glucose; D000432:Methanol