Two prenylflavanones from Euchresta japonica

Hepatoprotective Compounds of the Roots of Cudrania tricuspidata on Tacrine-Induced Cytotoxicity in Hep G2 Cells

“…The structures of isolated compounds were identified as euchrestaflavanone C (1), 9) gerontoxanthone A (2), 10) cudraxanthone B (3), 11) cudraflavone B (4), 12) gericudranin E (5), 13) cudraxanthone C (7), 11) and cudraxanthone H (8), 14) respectively, by comparing UV, (Table 1), including one carbonyl group, two aromatic rings with six oxygenated carbons, and two C 5 groups, corresponding to a diprenylated and tetrahydroxylated xanthone. The positions of the substituents on the ring system were determined on the basis of HMBC correlations, as shown in Table 1.…”

Isolation, characterization and chemobiological quantification of α-glucosidase enzyme inhibitory and free radical scavenging constituents from Derris scandens Benth

“…Repeated chromatography of the bioactive hexane extract over silica gel led to the isolation of several known compounds which include, 4 -Omethylosajin (1) [13], osajin (2) [14], 4 -O-methylscandinone (3) [15] and 4 , 5 , 7-trihydroxybiprenylisoflavone (4) [8]. On the other hand, extensive chromatography of active chloroform extract led to the isolation of a new naturally occurring isoflavone isoscandinone (5) whose structure was confirmed by X-ray crystallography, two new prenylated isoflavones, scandenin A (6) and scandenin B (7) along with seven known compounds, scandenone (8) [15], scandinone (9) [15], lupalbigenin (10) [16], derrisisoflavone A (11) [7], derrisisoflavone C (12) [7], 4 ,4-Odimethylscandenin (13) [17] and scandenin (14) [18].…”

“…This plant is reported to possess anti-inflammatory, free radical scavenging [1], antibacterial, antihypertensive [2], immunomodulatory and anti-HIV properties [3]. Coumarins, prenylated isoflavones, and isoflavone glycosides have been previously reported from the stem of this plant [4][5][6][7][8][9]. In the course of our ongoing efforts to identify intestinal ␣-glucosidase inhibitors and free-radical scavengers from medicinal plants, we observed that the hexane and chloroform extracts of D. scandens plant powder displayed potent intestinal ␣-glucosidase inhibitory activity.…”

NMR spectral assignments of isoprenylated flavanones from Sophora tonkinensis

“…The proposed structure was confirmed by HSQC and HMBC spectra (Fig. 2) [10] The absolute configuration at C-2 was determined as S from the CD spectrum that showed a positive Cotton effect at λ = 333 nm, and a negative one at λ = 295 nm. [2,3,11] The 1 H NMR data of compounds 6 and 7 reported in 1973 [7] were completed and fully assigned with the aid of a HSQC experiment.…”

“…The absolute configuration at C-2 was determined as S from the circular-dichroism (CD) spectrum that showed a positive Cotton effect at λ = 333 nm, and a negative one at λ = 303 nm. [2,3,11] Tonkinochromane G (3), obtained as a yellow gum, was optically active ([α] and 256 (B 3 + ) [10] suggested that the 2-hydroxy-3-methylbut-3-enyl unit was linked to C-8 position and the two γ ,γ -dimethylallyl groups were attached to the ring C. The proposed structure of 3 was further confirmed by the 13 C NMR data [δ C = 30.1 ppm (C-1 ) and 28.9 ppm (C-11 )], [12] the HSQC and the HMBC spectrum (Fig. 2).…”