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Six new highly oxygenated lanostane-type triterpenes, called ganoderic acid gamma (1), ganoderic acid delta (2), ganoderic acid epsilon (3), ganoderic acid zeta (4), ganoderic acid eta (5) and ganoderic acid theta (6), were isolated from the spores of Ganoderma lucidum, together with known ganolucidic acid D (7) and ganoderic acid C2 (8). Their structures of the new triterpenes were determined as (23S)-7beta,15alpha,23-trihydroxy-3,11-dioxolanosta-8, 24(E)-diene-26-oic acid (1), (23S)-7alpha,15alpha23-trihydroxy-3,11-dioxolanosta-8, 24(E)-diene-26-oic acid (2), (23S)-3beta3,7beta, 23-trihydroxy-11,15-dioxolanosta-8,24(E)-diene-26-oic acid (3), (23S)-3beta,23-dihydroxy-7,11,15-trioxolanosta-8, 24(E)-diene-26-oic acid (4), (23S)-3beta,7beta,12beta,23-tetrahydroxy-11,15-dioxolanos ta-8,24(E)-diene-26-oic acid (5) and (23S)-3beta,12beta23-trihydroxy-7,11,15-trioxolanosta-8,24(E )-diene-26-oic acid (6), respectively, by chemical and spectroscopic means, which included the determination of a chiral center in the side chain by a modification of Mosher's method. The cytotoxicity of the compounds isolated from the Ganoderma spores was carried out in vitro against Meth-A and LLC tumor cell lines.

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An in vitro bioassay-guide revealed that the methanol (MeOH) extract of the stem bark of Populus davidiana showed considerable inhibitory activity against cyclooxygenase (COX-1, COX-2). Continuous phytochemical study of the MeOH extract of this plant led to the isolation of ten flavonoids; sakuranetin (1), rhamnocitrin (2), 7-O-methylaromadendrin (3), naringenin (4), eriodictyol (5), aromadendrin (6), kaempferol (7), neosakuranin (8), sakuranin (9) and sakurenetin-5,4'-di-beta-D-glucopyranoside (10). Their structures were identified on the basis of their physicochemical and spectroscopic analyses. The isolated compounds, 1-10, were tested for their inhibitory activities against COX-1 and COX-2. Compound 7 was found to have potent inhibitory effect on COX-1 and a moderate effect on COX-2, meanwhile, compounds 1-6 showed moderate inhibition against COX-1 only. Moreover, compounds 5-8 exhibited suppressive effects on xanthine oxidase (XO). These results may explain, in part, the traditional uses of P. davidiana in ethnomedicine.

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As part of our ongoing search of natural sources for therapeutic and preventive agents for diabetic complications, the rat lens aldose reductase (RLAR) inhibitory effect of Coptidis Rhizoma (the rhizome of Coptis chinensis Franch) was evaluated. Its extract and fractions exhibited broad and moderate RLAR inhibitory activities of 38.9 approximately 67.5 microg/mL. In an attempt to identify bioactive components, six quaternary protoberberine-type alkaloids (berberine, palmatine, jateorrhizine, epiberberine, coptisine, and groenlandicine) and one quaternary aporphine-type alkaloid (magnoflorine) were isolated from the most active n-BuOH fraction, and the chemical structures therein were elucidated on the basis of spectroscopic evidence and comparison with published data. The anti-diabetic complications capacities of seven C. chinensis-derived alkaloids were evaluated via RLAR and human recombinant AR (HRAR) inhibitory assays. Although berberine and palmatine were previously reported as prime contributors to AR inhibition, these two major components exhibited no AR inhibitory effects at a higher concentration of 50 microg/ml in the present study. Conversely, epiberberine, coptisine, and groenlandicine exhibited moderate inhibitory effects with IC(50) values of 100.1, 118.4, 140.1 microM for RLAR and 168.1, 187.3, 154.2 microM for HRAR. The results clearly indicated that the presence of the dioxymethylene group in the D ring and the oxidized form of the dioxymethylene group in the A ring were partly responsible for the AR inhibitory activities of protoberberine-type alkaloids. Therefore, Coptidis Rhizoma, and the alkaloids contained therein, would clearly have beneficial uses in the development of therapeutic and preventive agents for diabetic complications and diabetes mellitus.

From the stem-bark of Juglans mandshurica, two new naphthalenyl glucopyranosides, 1,4,8-trihydroxynaphthalene 1-O-[alpha-L-arabinofuranosyl-(1-->6)-beta-D-glucopyranoside] (1) and 1,4,8-trihydroxynaphthalene 1-O-beta-D-[6'-O-(3",5"-dihydroxy-4"-methoxybenzoyl)]glucopyranosi de (4), and two new alpha-tetralonyl glucopyranosides, 4 alpha,5,8-trihydroxy-alpha-tetralone 5-O-beta-D-[6'-O-(3",5"-dihydroxy-4"-methoxybenzoyl)]glucopyranosi de (7) and 4 alpha,5,8-trihydroxy-alpha-tetralone 5-O-beta-D-[6'-O-(3",4",5"-trihydroxybenzoyl)]glucopyranoside (8), were isolated together with three known naphthalenyl glucopyranosides (2, 3 and 5), one alpha-tetralonyl glucopyranoside (6), four flavonoids (9-12), and two galloyl glucopyranosides (13, 14). Amongst the isolated compounds, 1,2,6-trigalloylglucopyranose (13) and 1,2,3,6-tertagalloylglucopyranose (14) exhibited the most potent inhibition of reverse transcriptase (RT) activity with IC50 values of 0.067 and 0.040 microM, respectively, while the latter compound also inhibited ribonuclease H (RNase H) activity with an IC50 of 39 microM, comparable in potency to illimaquinone used as a positive control. 1,4,8-Trihydroxy-naphthalene 1-O-beta-D-glucopyranoside (2), 1,4,8-trihydroxynaphthalene 1-O-beta-D-[6'-O-(4"-hydroxy-3",5"-dimethoxybenzoyl)]glucopyranoside (3) and 8 showed moderate inhibition against both enzyme activities, and inhibitory potency of 2 against RNase H activity (IC50 = 156 microM) was slightly greater than that against the RT activity (IC50 = 290 microM). The inhibitory potencies of 4 alpha,5,8-trihydroxy-alpha-tetralone 5-O-beta-D-[6'-O-(4"-hydroxy-3",5"-dimethoxybenzoyl)] glucopyranoside (6), 7 and 8 against RT activity increased accompanied by an increase in the number of free hydroxyls on the galloyl residues, as represented by the IC50 values of > 500, 330 and 5.8 microM, respectively.