Combretastatin-chalcone hybrids: synthesis and cytotoxicity.

A series of all-trans-1-aryl-4-aryl-5-aryl-2,4-pentanediene-1-one (3), a hybridized form of chalcone and combretastatin, was synthesized and evaluated against a panel of cancer cell lines, including B16, murine melanoma; HCT116, colon cancer; A431, human epidermoid carcinoma; and human umbilical venous endothelial cells (HUVEC). Structure-activity relationships analysis of this series revealed that a 2,5-dihydroxyphenyl at position 1 of the 2,4-pentanediene-1-one was essential for cytotoxicity. all-trans-1-(2,5-Dihydroxyphenyl)-5-(4-methoxyphenyl)-4-(3,4,5-trimethoxyphenyl)-2,4-pentanediene-1-one (3a) was the most potent compound from this series.

Antitumor activity of Pulsatilla koreana saponins and their structure-activity relationship.

Seventeen saponins isolated from the root of Pulsatilla koreana were examined for their in vitro cytotoxic activity against the human solid cancer cell lines, A-549, SK-OV-3, SK-MEL-2, and HCT15, using the SRB assay method, and their in vivo antitumor activity using BDF1 mice bearing Lewis lung carcinoma (LLC). The saponins 5-17, with a free acidic functional group at C-28 of aglycon, exhibited moderate to considerable cytotoxic activity, however, the saponins 1-4, esterified with a trisaccharide at C-28 of aglycon, did not exhibit cytotoxic activity (ED50; >300 microM). Among them, oleanolic acid 3-O-alpha-L-rhamnopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->4)]-alpha-L-arabinopyranoside (10) exhibited the most potent cytotoxic activity (ED50; 2.

Triterpenoid saponins from the roots of Pulsatilla koreana.

Six new saponins, five lupanes (1-5) and one oleanane (6), along with 11 known saponins, were isolated from the roots of Pulsatilla koreana. The structures of the new saponins were found to be 23-hydroxy-3beta-[(O-alpha-L-rhamnopyranosyl-(1-->2)-O-[O-beta-D-glucopyranosyl-(1-->4)]-alpha-L-arabinopyranosyl)oxy]lup-20(29)-en-28-oic acid (1), 23-hydroxy-3beta-[(O-beta-D-glucopyranosyl-(1-->3)-O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl)oxy]lup-20(29)-en-28-oic acid (2), 3beta-[(O-alpha-L-rhamnopyranosyl-(1-->2)-O-[O-beta-D-glucopyranosyl-(1-->4)]-alpha-L-arabinopyranosyl)oxy]lup-20(29)-en-28-oic acid (3), 3beta-[(O-beta-D-glucopyranosyl-(1-->3)-O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl)oxy]lup-20(29)-en-28-oic acid (4), 23-hydroxy-3beta-[(O-beta-D-glucopyranosyl-(1-->4)-alpha-L-arabinopyranosyl)oxy]lup-20(29)-en-28-oic acid (5), and hederagenin 3-O-beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranoside (6). Their structures were determined on the basis of 1D and 2D NMR ((13)C NMR, (1)H NMR, (1)H-(1)H COSY, HMQC, and HMBC) methods, FABMS, and hydrolysis.

New constituents from Crinum latifolium with inhibitory effects against tube-like formation of human umbilical venous endothelial cells.

Six compounds (1-6) were isolated from the methanol extract of Crinum latifolium by bioassay-guided separation. Among the six isolates, compounds 2 and 6 were new metabolites. Their structures were established as 4-senecioyloxymethyl-3,4-dimethoxycoumarin (2) and 5,6,3'-trihydroxy-7,8,4'-trimethoxyflavone (6) based on spectroscopic analyses.

Pulsatilla saponin D: the antitumor principle from Pulsatilla koreana.

By bioassay-guided separation, an already known saponin, Pulsatilla saponin D was isolated from the root of Pulsatilla koreana Nakai as a antitumor component when evaluated by in vivo antitumor activity as well as in vitro cytotoxic activity test. It showed potent inhibition rate of tumor growth (IR, 82%) at the dose of 6.4 mg/kg on the BDF1 mice bearing LLC cells.

Synthesis and cytotoxicity of 2,5-dihydroxychalcones and related compounds.

A series of 2, 5-dihydroxychalcones and related compounds were synthesized, and their cytotoxicities against tumor cell lines and human umbilical venous endothelial cells (HUVEC) evaluated. It was found that chalcones, with electron-withdrawing substituents on an A ring, exhibited significant cytotoxicities. Among the synthesized compounds, 2'-chloro-2, 5-dihydroxychalcone (9) was most potent, with an IC50 value as low as 0.

5-Arylidene-2(5H)-furanone derivatives: synthesis and structure-activity relationship for cytotoxicity.

Thirty-eight 5-arylidene-2(5H)-furanone derivatives possessing halo-, methoxy-, oxo-, dioxo-, and thiophenyl groups as well as anthraquinone and naphthquinone moieties were synthesized, and their cytotoxicity was evaluated against various cancer cell lines. The introduction of halogen atoms or nitro group at aromatic ring of 5-arylidene-2(5H)-furanone was shown to increase the cytotoxicity with 5-(3-nitrobenzylidene)-2(5H)-furanone (21) being the most potent. Among anthracenyl or naphthalenyl derivatives, (E)-5-[2-(1,4-dimethoxy-9,10-dioxo) anthracenyl]-2(5H)-furanone (34) showed the most potent cytotoxic activity.

Alkyl and carboxylalkyl esters of 4'-demethyl-4-deoxypodophyllotoxin: synthesis, cytotoxic, and antitumor activity.

Esters of 4'-demethyl-4-deoxypodophyllotoxin (DDPT) with alkanoic acids and alkanedioic acids were prepared and tested for cytotoxic and antitumor activity. Among 19 esters, esters of propanoic acid, tetradecanedioic acid, 13-carboxyundecanoic acid, and hexadecanedioic acid improved the antitumor activity compared with that of the starting compounds, DDPT.

Synthesis and cytotoxic activity of A-ring modified betulinic acid derivatives.

New A-ring modified betulinic acid derivatives having small steric hindrance were prepared and tested for cytotoxic activity on 3 cancer cell lines: 10 compounds showed stronger cytotoxic activity than betulinic acid. Especially, the compounds bearing 1-ene-3-oxo with electron-withdrawing groups at C2 showed strong cytotoxicity.

Antitumor activity of unsaturated fatty acid esters of 4'-demethyldeoxypodophyllotoxin.

Unsaturated fatty acid esters of 4'-demethyldeoxypodophyllotoxin (DDPT) were prepared and tested for antitumor activity. The esters showed increased in vivo antitumor activity despite the lower in vitro activity than DDPT. Especially, the ester (DFE12) of all-cis-11,14-eicosadienoic acid was much better (IR, 83%) than VP-16 (IR, 60%) without loss of body weight.

Inhibitory effect of Adonis amurensis components on tube-like formation of human umbilical venous cells.

Antiangiogenic activity-guided fractionation and isolation carried out on the methanol extract of Adonis amurensis led to the identification of three compounds, namely cymarin, cymarol, and cymarilic acid. Amongst the three compounds, cymarilic acid was isolated from this plant for the first time. This compound showed no significant cytotoxicity against tumor cell lines but was found to be strongly inhibitory toward tube formation induced by human umbilical venous endothelial (HUVE) cells.

Antiangiogenic activity of lupeol from Bombax ceiba.

In the search for antiangiogenic agents from medicinal plants used in Vietnam, a methanol extract of the stem barks of Bombax ceiba was found to exhibit a significant antiangiogenic activity on in vitro tube formation of human umbilical venous endothelial cells (HUVEC). Bioactivity-guided fractionation and isolation carried out on this extract afforded lupeol as an active principle. At 50 and 30 microg/mL lupeol showed a marked inhibitory activity on HUVEC tube formation while it did not affect the growth of tumor cell lines such as SK-MEL-2, A549, and B16-F10 melanoma.

Cytotoxic 2',5'-dihydroxychalcones with unexpected antiangiogenic activity.

A series of 2',5'-dihydroxychalcones were synthesized and evaluated for cytotoxicity against tumor cell lines and human umbilical venous endothelial cells (HUVEC). It was found that chalcones with electron-withdrawing substituents on the B ring exhibited potent cytotoxicity against a variety of tumor cell lines while compounds with electron-releasing groups were less potent in general. Those compounds with B ring replaced by extended or heteroaromatic rings exhibited significant bioactivity.

Water soluble prodrugs of the antitumor agent 3-[(3-amino-4-methoxy)phenyl]-2-(3,4,5-trimethoxyphenyl)cyclopent-2-ene-1-one.

Fourteen prodrugs of the antitumor agent 3-[(3-amino-4-methoxy)phenyl]-2-(3,4,5-trimethoxyphenyl)cyclopent-2-ene-1-one (1) were prepared to improve its water solubility and potency. These prodrugs include alpha-amino acid (1a-1h), aliphatic amino acid (1i-1l), phosphoramidate (1m), and phosphate (1n) derivatives. All of the prodrugs showed improved water solubility.

Inhibitory effects of Vietnamese medicinal plants on tube-like formation of human umbilical venous cells.

Seven of 58 plant materials from Vietnamese medicinal plants showed strong to moderate inhibitory activity on the tube-like formation induced by human umbilical venous endothelial cells in the in vitro angiogenesis assay. These plant materials include the herb of Ephedra sinica, leaves and stem of Ceiba pentandra, seed of Coix lachryma-jobi, rhizome of Drynaria fortunei, fruits and stem of Illicium verum and stem of Bombax ceiba. Of these, the methanol extracts of the herb of Ephedra sinica and stem of -Ceiba pentandra exhibited the strongest activities with inhibition percentages of 89.

Antiinvasive, antiangiogenic and antitumour activity of Ephedra sinica extract.

A water fraction (EW), the remaining water phase from the methanol extract of Ephedra sinica after extraction with ethyl acetate and butanol, has been investigated for its antiangiogenic, antiinvasive and antitumour activities. It was observed that EW, at 30 micro g/mL, a non-cytotoxic concentration, inhibited the tube formation induced by human umbilical venous endothelial cells and the invasion of B16F10 melanoma cells through a matrix membrane by more than 90%. At 30 mg/kg/day, the inhibitory activity of EW on the growth of a tumour mass in BDF1 mice inoculated with B16-F10 murine melanoma cells was comparable to that of adriamycin (ADR) administered at 2 mg/kg/day.

Antiangiogenic activity of Bupleurum longiradiatum on human umbilical venous endothelial cells.

The ethyl acetate fraction of Bupleurum longiradiatum was found to have an inhibitory effect on the tube-like formation of human umbilical venous endothelial (HUVE) cells. The active compounds, isolated from the fraction, were identified as acetylbupleurotoxin (P1) and bupleurotoxin (P2). The compounds P1 and P2 completely inhibited the tube-like formation of HUVE cells at 30 microg/ml, below the cytotoxic concentration.

Synthesis, cytotoxicity and antitumor activity of 2,3-diarylcyclopent-2-ene-1-ones.

Two series of 2,3-diarylcyclopent-2-ene-1-ones including 2-aryl-3-(2,5-dihydroxyphenyl)cyclopent-2-ene-1-ones (2a-2f) and 3-aryl-2-3',4',5'-trimethoxyphenyl)cyclopent-2-ene-1-one (3a-3j) were synthesized and evaluated for the cytotoxicity against three tumor cell lines; B16F10, HCT116 and A431. It was found that the 3,4,5-trimethoxy substituent was optimal for the bioactivity of compounds in series 2. Meanwhile, compounds in series 3 exhibited the most potent cytotoxicity with 3-aryl ring being 4-methoxyphenyl (compound 3f), (3-hydroxy-4-methoxy)phenyl (compound 3e), or (3-amino-4-methoxy)phenyl (compound 3j).

Synthesis and cytotoxicity of some rigid derivatives of methyl 2,5-dihydroxycinnamate.

Eight rigid compounds designed as esterase-stable analogues of methyl 2,5-dihydroxycinnamate (1) were synthesized. These derivatives include 2-(2',5'-dihydroxybenzylidene)cyclopentenone (3a), 2-(2',5'-dihydroxybenzylidene)cyclohexanone (3b), 2,6-bis(2',5'-dihydroxybenzylidene)cyclohexanone (4b), 2,6-bis(2',5'-dihydroxybenzylidene)cyclopentenone (4a), (E)-3-(2',5'-dihydroxybenzylidene)pyrrolidin-2-one (5), (E)-5-(2',5'-dihydroxybenzylidene)-1,2-isothiazolidine-1,1-dioxide (6), 4-(2',5'-dihydroxyphenyl)-5H-furan-2-one (7), and 3-(2',5'-dihydroxyphenyl)cyclopent-2-ene-1-one (8). Among the eight compounds, the furanone 7 and cyclopentenone 8 showed the most potent cytotoxicity with IC50 values of 0.

Prodrugs of 4'-demethyl-4-deoxypodophyllotoxin: synthesis and evaluation of the antitumor activity.

A series of prodrugs of 4'-demethyl-4-deoxypodophyllotoxin (DDPT) including carbamates (3-8), a carbonate (9) and water-soluble amino acid derivatives (10-17) were prepared and tested for their antitumor activity. The carbamate 6 (2-hydroxyethylcarbamoyl-DDPT), carbonate 9 (2-chloroethyloxycarbonyl-DDPT), and most of amino acid prodrugs (12-17) showed enhanced antitumor activity.

Preliminary structure-antiangiogenic activity relationships of 4-senecioyloxymethyl-6,7-dimethoxycoumarin.

Through a systematic modification of the novel angiogenesis inhibitor 4-senecioyloxymethyl-6,7-dimethoxycoumarin (1) we found that a 6,7-dimethoxy moiety is important for bioactivity of 1. Replacement of the lactone functionality in coumarin 1 by an amide decreased its activity. By substitution of the senecioyl chain with various cinnamoyl groups we discovered 6d, bearing a 4-methoxycinnamoyl instead of senecioyl side chain, with inhibitory activity in HUVEC tube formation assay enhanced by one order of magnitude compared to 1.

2,3-dibenzylbutyrolactones and 1,2,3,4-tetrahydro-2-naphthoic acid gamma-lactones: structure and activity relationship in cytotoxic activity.

Dibenzyl-g-butyrolactone and 1,2,3,4-tetrahydro-2-naphthoic acid gamma-lactone (TNL) derivatives were synthesized and evaluated for cytotoxic activity against some cancer cell lines. It was found that TNL derivatives with a shorter distance between C-4 in ring A and C'-2 in ring C were more cytotoxic, while dibenzyl-gamma-butyrolactones with a longer one were nearly inactive. In TNL series, presence of 3,4-dioxy group in ring A and 2-methoxy group in ring C was essential for the enhancement of the activity.

Synthesis and anti-tumor activity of novel combretastatins: combretocyclopentenones and related analogues.

A series of 2-(3,4,5-trimethoxyphenyl)-3-arylcyclopent-2-ene-1-ones (8a-8e) and their related analogues, including pentenone 9a, pentenol 10a, pentene 12a, and furane 15, were synthesized and evaluated for cytotoxicity against murine and human tumor cell lines. Compounds 8a-c, 8e and 9a showed strong cytotoxicity with IC(50) values in the range of 8-34ng/mL. Compound 8e exhibited significant anti-tumor activity in BDF1 mice bearing Lewis lung carcinoma cells with an inhibition ratio of 59%.

Deoxypodophyllotoxin; the cytotoxic and antiangiogenic component from Pulsatilla koreana.

The petroleum ether fraction of Pulsatilla koreana (Ranunculaceae) was found to have an inhibitory effect on the tube-like formation of human umbilical venous endothelial (HUVE) cells and strong cytotoxic activity against five tumor cell lines. The active component isolated from the fraction was deoxypodophyllotoxin (DPT). The cytotoxic activity against the tumor cells comprising the A549, SK-OV-3, SK-MEL-2, HCT15, and B16F10 cell lines, expressed as ED50, ranged from 6 to 18 ng/ml.

Synthesis and cytotoxicity of 3,4-diaryl-2(5H)-furanones.

A series of 3,4-diaryl-2(5H)-furanone derivatives were synthesized and evaluated for their cytotoxicity in a small panel of cancer cell lines. Four out of 10 compounds in this series, for example 3-(3,4,5-trimethoxyphenyl)-4-(4-methoxyphenyl)-, 3-(3,4,5-trimethoxyphenyl)-4-(3-hydroxy-4-methoxyphenyl)-, 3-(3,4,5-trimethoxyphenyl)-4-(3-amino-4-methoxyphenyl)-, and 3-(3,4,5-trimethoxyphenyl)-4-(2-naphthyl)-2(5H)-furanones, were found to have potent cytotoxic activities with ED50 values of less than 20 nM in most of the cell lines tested.