New bichalcone analogs as NF-κB inhibitors and as cytotoxic agents inducing Fas/CD95-dependent apoptosis.

A series of novel bichalcone analogs were synthesized and evaluated in lipopolysaccharide (LPS)-activated microglial cells as inhibitors of nitric oxide (NO) and for in vitro anticancer activity using a limited panel of four human cancer cell lines. All analogs inhibited NO production. Compounds 4 and 11 exhibited optimal activity with IC(50) values of 0.3 and 0.5 µM, respectively, and were at least 38-fold better than the positive control. A mechanism of action study showed that both compounds significantly blocked the nuclear translocation of NF-κB p65 and up-regulation of iNOS at 1.0 µM. Compound 4 and three other analogs (3, 20, and 23) exerted significant in vitro anticancer activity GI(50) values ranging from 0.70 to 13.10 µM. A mode of action study using HT-29 colon cancer cells showed that 23 acts by inducing apoptosis signaling.

Inhibitory effects of Mannich bases of heterocyclic chalcones on NO production by activated RAW 264.7 macrophages and superoxide anion generation and elastase release by activated human neutrophils.

Some chalcones exert potent anti-inflammatory activities. Mannich bases of heterocyclic chalcones inhibited nitric oxide (NO) production in lipopolysaccharide and interferon-γ stimulated RAW 264.7 macrophages. Also Formyl-Met-Leu-Phe and cytochalasin B induced superoxide anion generation (O2·-) and elastase release in human neutrophils. Mannich bases of heterocyclic chalcone analogs exhibited potent inhibitory effects on NO production with IC(50) values ranges between 10.5 and 0.018 µM, O2·- generation (IC(50) 39.87-0.68 µM) and elastase release (IC(50) 39.74-0.95 µM). Compound 29 (IC(50) 0.055 µM) and 34 (IC(50) 0.018 µM) were showed excellent inhibition on NO production. On the other hand, compounds 2 and 8 showed potent inhibition on O2·- generation and elastase release. Therefore, these four compounds may be new leads for development of anti-inflammatory activities. The structure-activity relationships are also discussed.

Design, synthesis, and biological evaluation of Mannich bases of heterocyclic chalcone analogs as cytotoxic agents.

The chalcone skeleton (1,3-diphenyl-2-propen-1-one) is a unique template that is associated with various biological activities. We synthesized Mannich bases of heterocyclic chalcones (9-47) using a one-step Claisen-Schmidt condensation of heterocyclic aldehydes with Mannich bases of acetophenones, and tested the target compounds for cytotoxicity against three human cancer cell lines (prostate, PC-3; breast, MCF-7; nasopharynx, KB) and a multi-drug resistant subline (KB-VIN). Out of the 39 chalcones synthesized, 31 compounds showed potent activity against at least one cell line with IC(50) values ranging from 0.03 to 3.80 microg/mL. Structure-activity relationships (SAR) are also discussed.

A new naphthoquinone from Ceiba pentandra.

A new naphthoquinone, 2,7-dihydroxy-8-formyl-5-isopropyl-3-methyl-1,4-naphthoquinone (1) together with a known naphthoquinone, 8-formyl-7-hydroxy-5-isopropyl-2-methoxy-3-methyl-1,4-naphthoquinone (2), has been isolated from the heartwood of Ceiba pentandra. The structures of 1 and 2 have been elucidated by extensive 1D and 2D NMR experiments.

Flavonoids from Andrographis lineata.

Three flavonoids, 5,7,2',3',4'-pentamethoxyflavone (1), 2'-hydroxy-2,4',6'-tri methoxychalcone (2) and dihydroskullcapflavone I (3), together with 17,19,20-trihydroxy-5beta, 8alpha H, 9beta H,10alpha-labd-13-en-16,15-olactone (4), a known diterpenoid and six known flavonoids, 5-hydroxy-7,8-dimethoxyflavanone (5), 5-hydroxy-7,8,2',3',4'-pentamethoxyflavone (6), 5,2'-dihydroxy-7-methoxyflavanone (7), 5,2'-dihydroxy-7,8-dimethoxyflavone (8), 5,2'-dihydroxy-7-methoxyflavone (9) and 5,2'-dihydroxy-7-methoxyflavone 2'-O-beta-D-glucopyranoside (10) were isolated from the whole plant of Andrographis lineata. The structures of these compounds were elucidated on the basis of spectral and chemical studies.