UiJoung Youn

Cholinesterase inhibitory and anti-amnesic activity of alkaloids from Corydalis turtschaninovii.

In the course of screening plants used in Korean folk medicine as memory enhancers, a 70% ethanol extract of tuber from Corydalis turtschaninovii Besser (Papaveraceae) showed significant acetylcholinesterase (AChE) inhibitory activity. Repeated column chromatography led to the isolation of a new aporphine alkaloid, oxoglaucidaline (9), and a new protoberberine, pseudodehydrocorydaline (13) together with 14 known compounds (1-8, 10-12, and 14-16). The chemical structures of isolated compounds were elucidated base on extensive 1D and 2D NMR spectroscopic data. Compounds 1-16 were investigated in vitro for their anti-cholinesterase activity using the mice cortex AChE enzyme. In further study, the anti-amnesic activities of pseudoberberine (16) in mice on the learning and memory impairments induced by scopolamine (1.0 mg/kg, i.p.) were examined. This alkaloid (5.0 mg/kg, p.o.) administration significantly reversed cognitive impairments in mice by passive avoidance test (P<0.05). It also reduced escape latencies in training trials and prolonged swimming times in the target quadrant during the probe trial in the water maze task (P<0.05). These results indicated that Corydalis turtschaninovii due to its alkaloids have anti-cholinesterase activity and pseudoberberine and other alkaloids have anti-amnesic activities that may be useful for cognitive impairment treatment.

Iridoid glycosides from Gardeniae Fructus for treatment of ankle sprain.

The iridoid glycosides, genipin 1-O-beta-D-isomaltoside (1) and genipin 1,10-di-O-beta-D-glucopyranoside (2), together with six known iridoid glycosides, genipin 1-O-beta-D-gentiobioside (3), geniposide (4), scandoside methyl ester (5), deacetylasperulosidic acid methyl ester (6), 6-O-methyldeacetylasperulosidic acid methyl ester (7), and gardenoside (8) were isolated from an EtOH extract of Gardeniae Fructus. The structures and relative stereochemistries of the metabolites were elucidated on the basis of 1D- and 2D-NMR spectroscopic techniques, high-resolution mass spectrometry, and chemical evidence. Geniposide (4), one of the main compounds of Gardeniae Fructus, was tested for treatment of ankle sprain using an ankle sprain model in rats. From the second to fifth day, the geniposide (4) (100mg/ml) treated group exhibited significant differences (p<0.01) with approximately 21-34% reduction in swelling ratio compared with those of the vehicle treated control group. This indicated the potential effect of geniposide (4) for the treatment of disorders such as ankle sprain.

Cytotoxic constituents from angelicae sinensis radix.

Cytotoxic bioassay-guided fractionation of methanol extract of Angelicae Sinensis Radix led to the isolation of a new dimericZ-ligustilide, named neodiligustilide (1), together with three known compounds,Z-ligustilide (2), 11(S),16(R)-dihydroxy-octadeca-9Z, 17-dien-12, 14-diyn-1-yl acetate (3), and 3(R), 8(S)-falcarindiol (4). Among them, 2 showed the strongest cytotoxicity against L1210 and K562 cell lines with IC50 values of 2.27 ± 0.10 and 4.78 ± 0.18 μM, respectively, while 1 showed moderate cytotoxicity with IC50 values of 5.45 ±0.19 and 9.87 ±0.14 μM. Two polyacetylenes, 3 and 4, showed cytotoxicity only against L1210 cell line with IC50 values of 2.60 ± 0.90 and 2.87 ± 0.49 μM, respectively.

Biphenylquinolizidine Alkaloids from Lagerstroemia indica

Two new biphenylquinolizidine alkaloids, 5-epi-dihydrolyfoline (1) and its stereoisomer, dihydrolyfoline (2), along with lagerine (3) were isolated from the aerial parts of Lagerstroemia indica. The structures of compounds 1-3 were elucidated by extensive spectroscopic techniques.

Biphenyl and Biphenyl Ether Quinolizidine N-oxide Alkaloids from Lagerstroemia indica L.

Four new biphenyl and biphenyl ether quinolizidine N-oxide alkaloids, 5- EPI-dihydrolyfoline N-oxide (1), decamine N-oxide (2), lagerstroemine N-oxide (3), and lagerine N-oxide (4), were isolated from the aerial parts of Lagerstroemia indica, and their structures were established by extensive spectroscopic studies. In addition, the inhibitory effects of isolated compounds on rat lens aldose reductase (RLAR) were examined.