A new flavone glycoside from the aerial part of Peganum nigellastrum

Abstract

Keywords: Peganum nigellastrum, diosmetin 7-O-E-D-glucopyranosyl(1o2)-E-D-glucopyranosyl(1o2)-[D-Lrhamnopyranosyl(1o6)]-E-D-glucopyranoside, flavone glycoside. Peganum nigellastrum Bge. (Zygophyllaceae) is distributed over Asia and commonly found in the northwest region of China. The plant has been used as a Chinese traditional medicine for rheumatism, abscess, inflammation, and so on [1].Various compounds have been reported in this plant, including alkaloids, phenylpropanoids, triterpenes, and so on [2-6]. We have studied the chemical constituents of the ethanol extract of the aerial part and obtained a novel flavone glycoside with a tetrasaccharide. Its structure was determined as diosmetin 7The ethanol extract of the aerial part of P. nigellastrum was fractionated on silica gel with petroleum, ethyl acetate, and methanol. Isolation and purification were achieved using a combination of TLC, MCI, and Sephadex LH-20.Compound 1 was a pale yellow powder. The 13 C NMR showed the characteristic signals of flavonoid at G 181.9 (C=O), 164.1 (C-2), and 103.8 (C-3). The signals of H at G 6.50 (1H, d, J = 2.05 Hz, H-6) and 6.81 (1H, d, J = 2.05 Hz, H-8) were meta-coupled with each other, and the signals of C-6 (G 99.5) and C-8 (G 94.8) moved to higher field, confirming that the ring A was substituted by O at C-5 and C-7.

Flavone Tetraglycosides and Benzyl Alcohol Glycosides from the Mongolian Medicinal Plant Dracocephalum ruyschiana

“…2 Herein, we report the isolation of five new flavone tetraglycosides (1−5) and five new benzyl alcohol glycosides (7−9, 12, and 13) from D. ruyschiana. Similar tetraglycosides comprising a rhamnopyranosyl and three glucopyranosyl units were identified in Peganum harmala, 3 P. nigellastrum, 4 and Coptis japonica var. dissecta.…”

“…From an extract of D. ruyschiana, 29 compounds (1−29) were isolated. Known compounds were identified from spectroscopic data as diosmetin 7-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→6)]-β-D-glucopyranoside (6), 4 benzyl-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (10), 12 benzyl-O-β-D-glucopyranoside (11), 13 kaempferol 3-O-β-D-glucopyranoside ( 14), 14 quercetin 3-O-β-D-glucopyranoside (15), 14 quercetin 3-O-β-D-glucuronide (16), 15 chlorogenic acid (17), 16 3,5-dicaffeoylquinic acid (18), 17 3,4-dicaffeoylquinic acid (19), 17 3-p-(E)-coumaroyl-5-(E)-caffeoylquinic acid (20), 16,17 (7S,8R)-dihydrodehydrodiconiferyl alcohol-9′-O-β-D-glucopyranoside (21), 18 (7S,8R)-urolignoside (22), 18 citrusin C (23), 19 trans-p-coumaric acid (24), 20 methyl trans-p-coumaric acid (25), 21 trans-ferulic acid (26), 20 cis-p-coumaric acid (27), 20 p-hydroxybenzaldehyde (28), 22 and 4,4′-dihydroxydiphenylmethane (29). 23 Compounds 1−5 were isolated as amorphous solids.…”

“…Similar tetraglycosides comprising a rhamnopyranosyl and three glucopyranosyl units were identified in Peganum harmala , P . nigellastrum , and Coptis japonica var. dissecta .…”