91998-04-8Relevant academic research and scientific papers
Curcuminoid analogs with potent activity against Trypanosoma and Leishmania species
Changtam, Chatchawan,de Koning, Harry P.,Ibrahim, Hasan,Sajid, M. Sohail,Gould, Matthew K.,Suksamrarn, Apichart
experimental part, p. 941 - 956 (2010/04/24)
The natural curcuminoids curcumin (1), demethoxycurcumin (2) and bisdemethoxycurcumin (3) have been chemically modified to give 46 analogs and 8 pairs of 1:1 mixture of curcuminoid analogs and these parent curcuminoids and their analogs were assessed against protozoa of the Trypanosoma and Leishmania species. The parent curcuminoids exhibited low antitrypanosomal activity (EC50 for our drug-sensitive Trypanosoma brucei brucei line (WT) of compounds 1, 2 and 3 are 2.5, 4.6 and 7.7 μM, respectively). Among 43 curcuminoid analogs and 8 pairs of 1:1 mixture of curcuminoid analogs tested, 8 pure analogs and 5 isomeric mixtures of analogs exhibited high antitrypanosomal activity in submicromolar order of magnitude. Among these highly active analogs, 1,7-bis(4-hydroxy-3-methoxyphenyl)hept-4-en-3-one (40) was the most active compound, with an EC50 value of 0.053 ± 0.007 μM; it was about 2-fold more active than the standard veterinary drug diminazene aceturate (EC50 0.12 ± 0.01 μM). Using a previously characterized diminazene-resistant T. b. brucei (TbAT1-KO) and a derived multi-drug resistant line (B48), no cross-resistance of curcuminoids was observed to the diamidine and melaminophenyl arsenical drugs that are the current treatments. Indeed, curcuminoids carrying a conjugated keto (enone) motif, including 40, were significantly more active against T. b. brucei B48. This enone motif was found to contribute to particularly high trypanocidal activity against all Trypanosoma species and strains tested. The parent curcuminoids showed low antileishmanial activity (EC50 values of compounds 1 and 2 for Leishmania mexicana amastigotes are 16 ± 3 and 37 ± 6 μM, respectively) while the control drug, pentamidine, displayed an EC50 of 16 ± 2 μM. Among the active curcuminoid analogs, four compounds exhibited EC50 values of less than 5 μM against Leishmania major promastigotes and four against L. mexicana amastigotes. No significant difference in sensitivity to curcuminoids between L. major promastigotes and L. mexicana amastigotes was observed. The parent curcuminoids and most of their analogs were also tested for their toxicity against human embryonic kidney (HEK) cells. All the curcuminoids exhibited lower toxicity to HEK cells than to T. b. brucei bloodstream forms and only one of the tested compounds showed significantly higher activity against HEK cells than curcumin (1). The selectivity index for T. b. brucei ranged from 3-fold to 1500-fold. The selectivity index for the most active analog, the enone 40, was 453-fold.
Curcuminoids form reactive glucuronides in vitro
Pfeiffer, Erika,Hoehle, Simone I.,Walch, Stephan G.,Riess, Alexander,Solyom, Aniko M.,Metzler, Manfred
, p. 538 - 544 (2008/02/09)
Curcumin is of current interest because of its putative anti-inflammatory, anticarcinogenic, and anti-Alzheimer's activity, but its pharmacokinetic and metabolic fate is poorly understood. The present in vitro study has therefore been conducted on the glucuronidation of curcumin and its major phase I metabolite, hexahydro-curcumin, as well as of various natural and artificial analogs. The predominant glucuronide generated by rat and human liver microsomes from curcumin, hexahydro-curcumin, and other analogs with a phenolic hydroxyl group was a phenolic glucuronide according to LC-MS/MS analysis. However, a second glucuronide carrying the glucuronic acid moiety at the alcoholic hydroxyl group was formed from the same curcuminoids, but not hexahydro-curcuminoids, by human microsomes. Curcuminoids without a phenolic hydroxyl group gave rise to the aliphatic glucuronide only. The phenolic glucuronides of curcuminoids, but not of hexahydro-curcuminoids, were rather lipophilic and, in part, unstable in aqueous solution, their stability depending strongly on the type of aromatic substitution. The phenolic glucuronide of curcumin and of its natural congeners, but not the parent compounds, clearly inhibited the assembly of microtubule proteins under cell-free conditions, implying chemical reactivity of the glucuronides. These novel properties of the major phase II metabolites of curcuminoids deserve further investigation.
Antitumor agents. 250. Design and synthesis of new curcumin analogues as potential anti-prostate cancer agents
Lin, Li,Shi, Qian,Nyarko, Alexander K.,Bastow, Kenneth F.,Wu, Chin-Chung,Su, Ching-Yuan,Shih, Charles C.-Y.,Lee, Kuo-Hsiung
, p. 3963 - 3972 (2007/10/03)
In a continuing study of curcumin analogues as potential drug candidates to treat prostate cancer at both androgen-dependent and androgen-refractory stages, we designed and synthesized over 40 new analogues classified into four series: monophenyl analogues (series A), heterocycle-containing analogues (series B), analogues bearing various substituents on the phenyl rings (series C), and analogues with various linkers (series D). These new compounds were tested for cytotoxicity against two human prostate cancer cell lines, androgen-dependent LNCaP and androgen-independent PC-3. Antiandrogenic activity was also evaluated in LNCaP cells and PC-3 cells transfected with wild-type androgen receptor. Ten compounds possessed potent cytotoxicity against both LNCaP and PC-3 cells, seven only against LNCaP, and one solely against PC-3. This study established an advanced structure-activity relationship (SAR), and these correlations will guide the further design of new curcumin analogues with better anti-prostate cancer activity.
Antitumor agents. 217. Curcumin analogues as novel androgen receptor antagonists with potential as anti-prostate cancer agents
Ohtsu, Hironori,Xiao, Zhiyan,Ishida, Junko,Nagai, Masahiro,Wang, Hui-Kang,Itokawa, Hideji,Su, Ching-Yuan,Shih, Charles,Chiang, Tzuying,Chang, Eugene,Lee, YiFen,Tsai, Meng-Yin,Chang, Chawnshang,Lee, Kuo-Hsiung
, p. 5037 - 5042 (2007/10/03)
A number of curcumin analogues were prepared and evaluated as potential androgen receptor antagonists against two human prostate cancer cell lines, PC-3 and DU-145, in the presence of androgen receptor (AR) and androgen receptor coactivator, ARA70. Compounds 4 [5-hydroxy-1,7-bis(3,4-dimethoxyphenyl)-1,4,6-heptatrien-3-one], 20 [5-hydroxy-1,7-bis[3-methoxy-4-(methoxycarbonylmethoxy)phenyl]-1, 4,6-heptatrien-3-one], 22 [7-(4-hydroxy-3-methoxyphenyl)-4-[3(4-hydroxy-3-methoxyphenyl) acryloyl]-5-oxohepta-4,6-dienoic acid ethyl ester], 23 [7-(4-hydroxy-3-methoxyphenyl)-4-[3-(4-hydroxy-3-methoxyphenyl)acryloyl] 5-oxohepta-4,6-dienoic acid], and 39 [bis(3,4-dimethoxyphenyl)-1,3-propanedione] showed potent antiandrogenic activities and were superior to hydroxyflutamide, which is the currently available antiandrogen for the treatment of prostate cancer. Structure-activity relationship (SAR) studies indicated that the bis(3,4-dimethoxyphenyl) moieties, the conjugated β-diketone moiety, and the intramolecular symmetry of the molecules seem to be important factors related to antiandrogenic activity. The data further suggest that the coplanarity of the β-diketone moiety and the presence of a strong hydrogen bond donor group were also crucial for the antiandrogenic activity, which is consistent with previous SAR results for hydroxyflutamide analogues. When the pharmacophoric elements of dihydrotestosterone (DHT) and compound 4 are superposed, the resulting construct implies that the curcumin analogues may function as a 17α-substituted DHT. Compounds 4, 20, 22, 23, and 39 have been identified as a new class of antiandrogen agents, and these compounds or their new synthetic analogues could be developed into clinical trial candidates to control androgen receptor-mediated prostate cancer growth.
Syntheses of the (+/-)--Gingerols (Pungent Principles of Ginger) and Related Compounds through Regioselective Aldol Condensations: Relative Pungency Assays
Dennif, Phillip,Macleod, Ian,Whiting, Donald A.
, p. 82 - 87 (2007/10/02)
The deprotonation of trimethylsilylzingerone (13) by lithium di-isopropylamide at -78 deg C has been found to be regioselective (92 : 8 in favour of less-substituted enolate): the anion was condensed with alkanals and acyl imidazoles to give convenient syntheses of (+/-)--- and --gingerols (1) and -, -, and -gingerdiones (9).Similary, 3-methoxy-4-trimethylsilyloxybenzylideneacetone (17) gave the (+/-)---dehydrogingerols (8) and -, -, and -dehydrogingerdiones (10).The aldol reaction to -gingerol and methyl -gingerol was also conducted through a vinyloxyborane or through the enol silyl ether (TiCl4 catalysis).Results of organoleptic assays on these compounds are discussed, and the relation between pungency in the gingerols and in capsaicin is commented on.The aldol method was also used to synthesise the natural β-ketols(+/-)-daphneolone (25) and (+/-)-hexahydrocurcumin (4).
