Oscar Mario Saavedra

Discovery of a novel and potent series of thieno[3,2-b]pyridine-based inhibitors of c-Met and VEGFR2 tyrosine kinases

A series of thieno[3,2-b]pyridine-based inhibitors of c-Met and VEGFR2 tyrosine kinases is described. The compounds demonstrated potency with IC(50) values in the low nanomolar range in vitro while the lead compound also showed in vivo activity against various human tumor xenograft models in mice. Further exploration of this class of compounds is underway.

N-(4-(6,7-Disubstituted-quinolin-4-yloxy)-3-fluorophenyl)-2-oxo-3-phenylimidazolidine-1-carboxamides: A novel series of dual c-Met/VEGFR2 receptor tyrosine kinase inhibitors

A series of N-(4-(6,7-disubstituted-quinolin-4-yloxy)-3-fluorophenyl)-2-oxo-3-phenylimidazolidine-1-carboxamides targeting c-Met and VEGFR2 tyrosine kinases was designed and synthesized. The compounds were potent against these two enzymes with IC(50) values in the low nanomolar range in vitro, possessed favorable pharmacokinetic profiles and showed high efficacy in vivo in several human tumor xenograft models in mice.

Constrained (l-)-S-adenosyl-l-homocysteine (SAH) analogues as DNA methyltransferase inhibitors

Potent SAH analogues with constrained homocysteine units have been designed and synthesized as inhibitors of human DNMT enzymes. The five membered (2S,4S)-4-mercaptopyrrolidine-2-carboxylic acid, in 1a, was a good replacement for homocysteine, while the corresponding six-member counterpart was less active. Further optimization of 1a, changed the selectivity profile of these inhibitors. A Chloro substituent at the 2-position of 1a, compound 1d, retained potency against DNMT1, while N(6) alkylation, compound 7a, conserved DNMT3b2 activity. The concomitant substitutions of 1a at both 2- and N(6) positions reduced activity against both enzymes.

SAR around (l)-S-adenosyl-l-homocysteine, an inhibitor of human DNA methyltransferase (DNMT) enzymes

The inhibitory activity of base-modified SAH analogues and the specificity of inhibiting human DNMT1 and DNMT3b2 enzymes was explored. The 6-amino group was essential while the 7-N of the adenine ring of SAH could be replaced by CH- without loss of activity against both enzymes. The introduction of small groups at the 2-position of the adenine moiety favors DNMT1 over DNMT3b2 inhibition whereas alkylation of the N(6)-amino moiety favors the inhibition of DNMT3b2 enzyme.

N-(3-fluoro-4-(2-arylthieno[3,2-b]pyridin-7-yloxy)phenyl)-2-oxo-3-phenylimidazolidine-1-carboxamides: a novel series of dual c-Met/VEGFR2 receptor tyrosine kinase inhibitors.

A series of N-(3-fluoro-4-(2-arylthieno[3,2-b]pyridin-7-yloxy)phenyl)-2-oxo-3-phenylimidazolidine-1-carboxamides targeting c-Met and VEGFR2 tyrosine kinases was designed and synthesized. The compounds were potent against these two enzymes with IC(50) values in the low nanomolar range in vitro, possessed favorable pharmacokinetic profiles and showed high efficacy in vivo in several human tumor xenograft models in mice.

Practical syntheses of B disaccharide and linear B type 2 trisaccharide—non-primate epitope markers recognized by human anti-α-Gal antibodies causing hyperacute rejection of xenotransplants

Abstract Synthetic protocols are presented for the elaboration of Galα1→3GalOR and Galα1→3Galβ1→4GlcNAcOR di- and trisaccharides that use a common Gal donor/acceptor unit, and are potentially adaptable to scale-up.

N3-Arylmalonamides: A new series of thieno[3,2-b]pyridine based inhibitors of c-Met and VEGFR2 tyrosine kinases

A family of thieno[3,2-b]pyridine based small molecule inhibitors of c-Met and VEGFR2 were designed based on lead structure 2. These compounds were shown to have IC(50) values in the low nanomolar range in vitro and were efficacious in human tumor xenograft models in mice in vivo.

Identification of a novel series of potent RON receptor tyrosine kinase inhibitors

A novel series of N-(3-fluoro-4-(2-substituted-thieno[3,2-b]pyridin-7-yloxy)phenyl)-1-phenyl-5-(trifluoromethyl)-1H-pyrazole-4-carboxamides targeting RON receptor tyrosine kinase was designed and synthesized. SAR study of the series allowed us to identify compounds possessing either inhibitory activity of RON kinase enzyme in the low nanomolar range with low residual activity against the closely related c-Met or potent dual inhibitory activity against RON and c-Met, with no significant activity against VEGFR2 in both cases.

Design and synthesis of functionalized glycomers as non-peptidic ligands for SH2 binding and as inhibitors of A-431 human epidermoid and HT-29 colon carcinoma cell lines

A set of O-substituted aryl beta-D-glucopyranosides were prepared and found to have inhibitory activity on the growth of two carcinoma cell lines.

Synthesis, broad spectrum antibacterial activity, and X-ray co-crystal structure of the decoding bacterial ribosomal A-site with 4′-deoxy-4′-fluoro neomycin analogs

This study reports the synthesis, antibacterial evaluation and nature of fluorine–rRNA contacts revealed by an X-ray co-crystal structure of a series of 4′-deoxy-4′-fluoro B-neomycin analogs. 4′-Deoxyfluorination improves the inhibition profile towards resistant enzymes and renders equally potent antibiotics compared to the parent neomycin B. The 4′-deoxy-4′-fluoro-4′-epi neomycin analogs showed a preferential inhibition over the 4′-deoxy-4′-fluoro neomycin counterpart against the strains of P. aeruginosa carrying a chromosomal APH(3′)-IIb enzyme, known to inactivate the parent aminoglycoside. To the best of our knowledge, this is the first example of a neighboring-group aminoglycoside-modifying enzyme evasion by fluorine substitution. A unique F-G1491 stacking was observed in a co-crystal structure of 4′-deoxy-4′-fluoro-4′-epi neomycin with a bacterial ribosomal RNA A-site.