Chiao Ting Yen

Synthesis of chalcone derivatives as potential anti-diabetic agents

Chalcones bearing electron donating or electron withdrawing substitutions were prepared and their glucose uptake activity was evaluated. Chalcone derivatives were synthesized in one step protocol with high purity and yield. Chalcones with chloro, bromo, iodo and hydroxy substitutions at position 2 on A-ring exhibited the highest activity with glucose medium concentration (210 to 236 mg/dl) compared to pioglitazone and rosiglitazone (230 and 263 mg/dl, respectively). Also chalcones with iodo substitution at position 3 on A-ring were comparably active (≤238 mg/dl). The structure-activity relationship of the tested chalcones was studied and the findings were supported statistically.

Antitumor agents. 271: Total synthesis and evaluation of brazilein and analogs as anti-inflammatory and cytotoxic agents

The first total synthesis of the naturally occurring tetracyclic homoisoflavonoid brazilein (1) and 14 new analogs (1a-n) is reported. Target compounds and intermediates were assayed for anti-inflammatory effects on superoxide anion generation and elastase release by human neutrophils in response to fMLP/CB, and for cytotoxic activity against nasopharyngeal (KB), vincristine-resistant nasopharyngeal (KBvin), lung (A549) and prostate (DU-145) human cancer cell lines. The most active compound 1b showed potent effects on superoxide anion generation and elastase release with IC(50) values of 1.2 and 1.9 microM, respectively, and was 65 times more potent than phenylmethylsulfonyl fluoride (PMSF), the positive control, in the latter assay. Additionally, 1b exhibited broad spectrum in vitro anticancer activity with IC(50) values of 6-11 microM against the four tested cancer cell lines.

Bioactive Cembrane Diterpenoids of Anisomeles indica

Five new cembrane-type diterpenoids with a trans-fused alpha-methylene-gamma-lactone (1-5), a new flavonoid glucoside (6), and 17 known compounds were isolated from a methanol extract of Anisomeles indica. The structures of 1-6 were elucidated by spectroscopic analysis, and the absolute configuration of compound 1 was determined using the modified Moshers method. Compound 8 (4,5-epoxovatodiolide) exhibited cytotoxicity against a small panel of human cancer cell lines. Additionally, compounds 4 and 7 (ovatodiolide) exhibited selective antiplatelet aggregation activities toward collagen, while compounds 4, 5, and 8 showed inhibitory effects on antiplatelet aggregation induced by thrombin.

Design and synthesis of new N-(fluorenyl-9-methoxycarbonyl) (Fmoc)-dipeptides as anti-inflammatory agents.

Twenty-four new dipeptide analogs (1-24) of aurantiamide acetate were designed, synthesized, and assayed for effects on superoxide anion generation and elastase release by human neutrophils in response to fMLP/CB. Among them, seven N-(fluorenyl-9-methoxycarbonyl) (Fmoc)-dipeptides (6, 9, 12, 14, 17, 18 and 20) showed potent inhibitory effects. Compounds 9 and 18 showed the most selective effects against human neutrophil elastase release, with IC(50) values of 0.8+/-0.1 and 1.7+/-0.6muM, respectively, and were 130-fold more potent than phenylmethylsulfonyl fluoride (PMSF), the positive control, in this anti-inflammatory assay. These two compounds could be developed as new lead anti-inflammatory agents.

Design and synthesis of gambogic acid analogs as potent cytotoxic and anti-inflammatory agents

Prenyl- and pyrano-xanthones derived from 1,3,6-trihydroxy-9H-xanthen-9-one, a basic backbone of gambogic acid (GA), were synthesized and evaluated for in vitro cytotoxic effects against four human cancer cell lines (KB, KBvin, A549, and DU-145) and anti-inflammatory activity toward superoxide anion generation and elastase release by human neutrophils in response to fMLP/CB. Among them, prenylxanthones 7-13 were generally less active than pyranoxanthones 14-21 in both anticancer and anti-inflammatory assays. Furthermore, two angular 3,3-dimethypyranoxanthones (16 and 20) showed the greatest and selective activity against the KBvin multidrug resistant (MDR) cell line with IC(50) values of 0.9 and 0.8 μg/mL, respectively. An angular 3-methyl-3-prenylpyranoxanthone (17) selectively inhibited elastase release with 200 times more potency than phenylmethylsulfonyl fluoride (PMSF), the positive control.

Cytotoxic N-(fluorenyl-9-methoxycarbonyl) (Fmoc)-dipeptides: Structure–activity relationships and synergistic studies

The synthesis and cytotoxic evaluation of a series of Fmoc-based dipeptides are described. Among the thirty compounds, 4a, 8a, 12a, 2b, 4b, 10b, 3c, 4c and 6c showed potent activity against HepG2, Hep3B, MCF-7, MDA-MB-231, A549 and Ca9-22 human cancer cell lines. The most active compounds (10a and 10c) showed relatively good sensitivity toward HepG2 and Ca9-22 cell lines with IC50 values of 1.0 and 0.4 microM, respectively. Additionally, compound 10c was threefold more potent than doxorubicin, the positive control, against the Ca9-22 cell line. Furthermore, 10c showed a synergistic effect and increased the cytotoxicity of doxorubicin against the MDA-MB-231 cancer cell line. Therefore, 10c could be used as a new lead compound for therapeutic development.

Indiosides G-K: steroidal glycosides with cytotoxic and anti-inflammatory activities from Solanum violaceum.

Five new steroidal glycosides (1-5) and nine known compounds were isolated from Solanum violaceum. Indiosides G (1) and H (2) are spirostene saponins with an iso-type F ring, indioside I (3) is a spirostane saponin, and indiosides J (4) and K (5) are unusual furostanol saponins with a deformed F ring. These structures represent rare naturally occurring steroidal skeletons. The structures of the new compounds were elucidated using 1D and 2D spectroscopic techniques and acid hydrolysis. Compounds 2, 3, and 7-9 exhibited cytotoxic activity against six human cancer cell lines (HepG2, Hep3B, A549, Ca9-22, MDA-MB-231, and MCF-7) with IC(50) values of 1.83-8.04 μg/mL. Steroidal saponins 3, 8, and 9 showed inhibitory effects on superoxide anion generation with IC(50) values of 2.84 ± 0.18, 0.62 ± 0.03, and 1.62 ± 0.59 μg/mL, respectively. Saponins 8 and 9 also inhibited elastase release with IC(50) values of 111.05 ± 7.37 and 4.04 ± 0.51 μg/mL, respectively. Structure-activity relationship correlations of these compounds with respect to cytotoxic and anti-inflammatory effects are discussed.

Anti-neutrophilic inflammatory steroidal glycosides from Solanum torvum

Torvpregnanosides A and B, two pregnane glycosides, and torvoside Q, a 23-keto-spirostanol glycoside, along with twelve known steroidal saponins were isolated from aerial parts of Solanum torvum. Of the latter, four of the 23-hydroxy-spirostanol glycosides, and, a yamogenin glycoside, were in this plant discovered. All structures were identified from spectroscopic data, and all the compounds were tested for in vitro anti-neutrophilic inflammatory activity. Two compounds showed selective inhibition against elastase release and superoxide anion generation, respectively, by human neutrophils with IC50 values of 5.66 and 3.59 μM, while two others inhibited both inflammatory mediators with IC50 values of 0.66-3.49 μM. Structure-activity relationships are discussed.

Spirostanoids with 1,4-dien-3-one or 3β,7α-diol-5,6-ene moieties from Solanum violaceum

Bioassay-guided fractionation of the CHCl3 layer of Solanum violaceum areal parts methanolic extract led to the isolation of four new steroidal sapogenins, indiosides L-O (1-4), along with eight known steroids, one lignin, and a coumarin. Indioside L is a rare spirostanoid possessing a 1,4-dien-3-one moiety in ring A. Moreover, compounds 3 and 4 represent rare examples of spirostene with the 3β,7α-diol-5,6-ene moiety compared to the normal 3β,7β-diol-5,6-ene derivatives. The cytotoxic activity of the isolates (5-14) was evaluated against human hepatoma (HepG2 and Hep3B), human lung carcinoma (A549), and human breast carcinoma (MDA-MB-231 and MCF-7).

Anti-Inflammatory Spirostanol and Furostanol Saponins from Solanum macaonense.

Eight new spirostanol saponins, macaosides A-H (1-8), and 10 new furostanol saponins, macaosides I-R (9-18), together with six known spirostanol compounds (19-24) were isolated from Solanum macaonense. The structures of the new compounds were determined from their spectroscopic data, and the compounds were tested for in vitro antineutrophilic inflammatory activity. It was found that both immediate inflammation responses including superoxide anion generation and elastase release were significantly inhibited by treatment with compounds 20, 21, and 24 (superoxide anion generation: IC50 7.0, 7.6, 4.0 μM; elastase release: IC50 3.7, 4.4, 1.0 μM, respectively). However, compounds 1 and 4 exhibited effects on the inhibition of elastase release only, with IC50 values of 3.2 and 4.2 μM, respectively, while 19 was active against superoxide anion generation only, with an IC50 value of 6.1 μM. Accordingly, spirostanols may be promising lead compounds for further neutrophilic inflammatory disease studies.