136282-23-0Relevant articles and documents
Catalytic dehydrative peptide synthesis with gem-diboronic acids
Michigami, Kenichi,Sakaguchi, Tatsuhiko,Takemoto, Yoshiji
, p. 683 - 688 (2020/01/02)
Alkane-gem-diboronic acids have emerged as versatile organoboron catalysts for dehydrative amidation of α-Amino acids. A phenol-substituted multiboron catalyst with a B-C-B structure outperformed simple arylboronic acids in the condensation of α-Amino acids with suppressed epimerization of electrophiles. gem-diboronic acid catalysis were compatible with various O, N, and S-functionalized α-Amino acids bearing N-protecting groups including common carbamates used in peptide synthesis (Boc, Cbz, Fmoc). N-Trifluoroacetyl protection enabled an unprecedented catalytic dehydrative peptide synthesis at room temperature. Preliminary mechanistic studies revealed carboxylate-binding nature of gem-diboronic acids, orthogonal to the activation of carboxylic acids by arylboronic acids. The distinctive reactivity of the gem-diboronic acids would open prospects for mild catalytic peptide condensation.
Design, synthesis, and evaluation of cystargolide-based β-lactones as potent proteasome inhibitors
Niroula, Doleshwar,Hallada, Liam P.,Le Chapelain, Camille,Ganegamage, Susantha K.,Dotson, Devon,Rogelj, Snezna,Groll, Michael,Tello-Aburto, Rodolfo
, p. 962 - 977 (2018/09/04)
The peptidic β-lactone proteasome inhibitors (PIs) cystargolides A and B were used to conduct structure-activity relationship (SAR) studies in order to assess their anticancer potential. A total of 24 different analogs were designed, synthesized and evaluated for proteasome inhibition, for cytotoxicity towards several cancer cell lines, and for their ability to enter intact cells. X-ray crystallographic analysis and subunit selectivity was used to determine the specific subunit binding associated with the structural modification of the β-lactone (P1), peptidic core, (Px and Py), and end-cap (Pz) of our scaffold. The cystargolide derivative 5k, structurally unique at both Py and P1, exhibited the most promising inhibitory activity for the β5 subunit of human proteasomes (IC50 = 3.1 nM) and significant cytotoxicity towards MCF-7 (IC50 = 416 nM), MDA-MB-231 (IC50 = 74 nM) and RPMI 8226 (IC50 = 41 nM) cancer cell lines. Cellular infiltration assays revealed that minor structural modifications have significant effects on the ability of our PIs to inhibit intracellular proteasomes, and we identified 5k as a promising candidate for continued therapeutic studies. Our novel drug lead 5k is a more potent proteasome inhibitor than carfilzomib with mid-to-low nanomolar IC50 measurements and it is cytotoxic against multiple cancer cell lines at levels approaching those of carfilzomib.
