124369-77-3Relevant articles and documents
Effects of Bisphosphonates on the Growth of Entamoeba histolytica and Plasmodium Species in Vitro and in Vivo
Ghosh, Subhash,Chan, Julian M. W.,Lea, Christopher R.,Meints, Gary A.,Lewis, Jared C.,Tovian, Zev S.,Flessner, Ryan M.,Loftus, Timothy C.,Bruchhaus, Iris,Kendrick, Howard,Croft, Simon L.,Kemp, Robert G.,Kobayashi, Seike,Nozaki, Tomoyoshi,Oldfield, Eric
, p. 175 - 187 (2007/10/03)
The effects of a series of 102 bisphosphonates on the inhibition of growth of Entamoeba histolytica and Plasmodium falciparum in vitro have been determined, and selected compounds were further investigated for their in vivo activity. Forty-seven compounds tested were active (IC50 50 ～ 4-9 μM) were nitrogen-containing bisphosphonates with relatively large aromatic side chains. Simple n-alkyl-1-hydroxy-1,1-bisphosphonates, known inhibitors of the enzyme farnesylpyrophosphate (FPP) synthase, were also active, with optimal activity being found with C9-C10 side chains. However, numerous other nitrogen-containing bisphosphonates known to be potent FPP synthase inhibitors, such as risedronate or pamidronate, had little or no activity. Several pyridine-derived bisphosphonates were quite active (IC50 ～ 10-20 μM), and this activity was shown to correlate with the basicity of the aromatic group, with activity decreasing with increasing pKa values. The activities of all compounds were tested versus a human nasopharyngeal carcinoma (KB) cell line to enable an estimate of the therapeutic index (TI). Five bisphosphonates were selected and then screened for their ability to delay the development of amebic liver abscess formation in an E. histolytica infected hamster model. Two compounds were found to decrease liver abscess formation at 10 mg/kg ip with little or no effect on normal liver mass. With P. falciparum, 35 compounds had IC50 values 50 values around 1 μM. Five compounds were again selected for in vivo investigation in a Plasmodium berghei ANKA BALB/c mouse suppressive test. The most active compound, a C9 n-alkyl side chain containing bisphosphonate, caused an 80% reduction in parasitemia with no overt toxicity. Taken together, these results show that bisphosphonates appear to be useful lead compounds for the development of novel antiamebic and antimalarial drugs.
Highly potent geminal bisphosphonates. From pamidronate disodium (Aredia) to zoledronic acid (Zometa)
Widler, Leo,Jaeggi, Knut A.,Glatt, Markus,Müller, Klaus,Bachmann, Rolf,Bisping, Michael,Born, Anne-Ruth,Cortesi, Reto,Guiglia, Gabriela,Jeker, Heidi,Klein, Rémy,Ramseier, Ueli,Schmid, Johann,Schreiber, Gerard,Seltenmeyer, Yves,Green, Jonathan R.
, p. 3721 - 3738 (2007/10/03)
Bisphosphonates (BPs) are pyrophosphate analogues in which the oxygen in P-O-P has been replaced by a carbon, resulting in a metabolically stable P-C-P structure. Pamidronate (1b, Novartis), a second-generation BP, was the starting point for extensive SAR studies. Small changes of the structure of pamidronate lead to marked improvements of the inhibition of osteoclastic resorption potency. Alendronate (1c, MSD), with an extra methylene group in the N-alkyl chain, and olpadronate (1h, Gador), the N,N-dimethyl analogue, are about 10 times more potent than pamidronate. Extending one of the N-methyl groups of olpadronate to a pentyl substituent leads to ibandronate (1k, Roche, Boehringer-Mannheim), which is the most potent close analogue of pamidronate. Even slightly better antiresorptive potency is achieved with derivatives having a phenyl group linked via a short aliphatic tether of three to four atoms to nitrogen, the second substituent being preferentially a methyl group (e.g., 4g, 4j, 5d, or 5r). The most potent BPs are found in the series containing a heteroaromatic moiety (with at least one nitrogen atom), which is linked via a single methylene group to the geminal bisphosphonate unit. Zoledronic acid (6i), the most potent derivative, has an ED50 of 0.07 mg/kg in the TPTX in vivo assay after sc administration. It not only shows by far the highest therapeutic ratio when comparing resorption inhibition with undesired inhibition of bone mineralization but also exhibits superior renal tolerability. Zoledronic acid (6i) has thus been selected for clinical development under the registered trade name Zometa. The results of the clinical trials indicate that low doses are both efficacious and safe for the treatment of tumor-induced hypercalcemia, Paget's disease of bone, osteolytic metastases, and postmenopausal osteoporosis.
