503 research outputs found
The Pharmaceutical Industry in 2016. An Analysis of FDA Drug Approvals from a Perspective of the Molecules
This is an analysis from a chemical point of view of the 22 drugs accepted by the FDA during 2016. The different drugs from the 2016 "harvest" have been classified according to their chemical structure: antibodies; TIDES (oligonucleotides and peptides); amino acids and natural products; drug combination; and small molecules
The Pharmaceutical Industry in 2017. An Analysis of FDA Drug Approvals from the Perspective of Molecules
This is an analysis from a chemical point of view of the 46 drugs (34 New Chemical Entities and 12 Biologics) approved by the FDA during 2017. The drugs included in the 2017 "harvest" have been classified on the basis of their chemical structure: biologics (antibodies and proteins); peptides; amino acids and natural products; drug combinations; and small molecules
Thiopeptide antibiotics: retrospective and recent advances
Thiopeptides, or thiazolyl peptides, are a relatively new family of antibiotics that already counts with more than one hundred different entities. Although they are mainly isolated from soil bacteria, during the last decade, new members have been isolated from marine samples. Far from being limited to their innate antibacterial activity, thiopeptides have been found to possess a wide range of biological properties, including anticancer, antiplasmodial, immunosuppressive, etc. In spite of their ribosomal origin, these highly posttranslationally processed peptides have posed a fascinating synthetic challenge, prompting the development of various methodologies and strategies. Regardless of their limited solubility, intensive investigations are bringing thiopeptide derivatives closer to the clinic, where they are likely to show their veritable therapeutic potential
Intercalative DNA binding of the marine anticancer drug variolin B
Variolin B is a rare marine alkaloid that showed promising anti-cancer activity soon after its isolation. It acts as a cyclin-dependent kinase inhibitor, although the precise mechanism through which it exerts the cytotoxic effects is still unknown. The crystal structure of a variolin B bound to a DNA forming a pseudo-Holliday junction shows that this compound can also contribute, through intercalative binding, to either the formation or stabilization of multi-stranded DNA forms.Peer ReviewedPostprint (published version
Recent advances in lamellarin alkaloids: isolation, synthesis and activity
Lamellarins are a large family of marine alkaloids with potential anticancer activity that have been isolated from diverse marine organisms, mainly ascidians and sponges. All lamellarins feature a 3,4-diarylpyrrole system. Pentacyclic lamellarins, whose polyheterocyclic system has a pyrrole core, are the most active compounds. Some of these alkaloids are potently cytotoxic to various tumor cell lines. To date, Lam-D and Lam-H have been identified as lead compounds for the inhibition of topoisomerase I and HIV-1 integrase, respectively nuclear enzymes which are over-expressed in deregulation disorders. Moreover,these compounds have been reported for their efficacy in treatment of multi-drug resistant (MDR) tumors cells without mediated drug efflux, as well as their immunomodulatory activity and selectivity towards melanoma cell lines. This article is an overview of recent literature on lamellarins, encompassing their isolation, recent synthetic strategies for their total synthesis, the preparation of their analogs, studies on their mechanisms of action, and their structure-activity relationships (SAR)
Amino acid-protecting groups
Synthetic organic chemistry is based on the concourse of reagents and catalysts to achieve the clean formation of new bonds and appropriate protecting groups are required to prevent the formation of undesired bonds and side-reactions. Thus a promising synthetic strategy can be jeopardized if the corresponding protecting groups are not properly chosen
Chemical synthesis of a fully active transcriptional repressor protein
5 pages, 5 figures.-- PMID: 8197204 [PubMed].-- PMCID: PMC43955.Plasmid pLS1-encoded 45-amino acid transcriptional repressor CopG (formerly RepA) has been chemically synthesized. A one-step purification of the synthetic protein has been developed, which yields high levels of pure protein with low or no contamination of truncated products. We have compared some properties of the chemical CopG protein with those of the biologically purified CopG. The two proteins were indistinguishable in (i) their ability to generate specific protein-DNA complexes, (ii) their capacity to protect a restriction site included within the CopG DNA target, and (iii) in their in vitro capacity to specifically repress synthesis of copG mRNA.Research was financed by Comisión Interministerial de Ciencia y Tecnologia, Grant B1091-0691 to (M.E.) and Grant SAL90-0828 (to R.E.). The Special Actions Program of the Consejo Superior de Investigaciones Cientificas stimulated and partially supported this research.Peer reviewe
Highly efficient, multigram and enantiopure synthesis of (S)-2-(2,4′-bithiazol-2-yl)pyrrolidine
(S)-2-(4-Bromo-2,4"-bithiazole)-1-(tert-butoxycarbonyl)pyrrolidine ((S)-1) was obtained as a single enantiomer and in high yield by means of a two-step modified Hantzsch thiazole synthesis reaction when bromoketone 3 and thioamide (S)-4 were used. Further conversion of (S)-1 into trimethyltin derivative (S)-2 broadens the scope for further cross-coupling reactions
Structure, bioactivity and synthesis of natural products with hexahydropyrrolo[2,3-b]indole
Research on natural products containing hexahydropyrrolo[2,3-b]indole (HPI) has dramatically increased during the past few years. Newly discovered natural products with complex structures and important biological activities have recently been isolated and synthesized. This review summarizes the structures, biological activities, and synthetic routes for natural compounds containing HPI, emphasizing the different strategies for assembling this motif. It covers a broad gamut of molecules, from small alkaloids to complex peptides
p-Nitrobenzyloxycarbonyl (pNZ) as Temporary Na-Protecting Group for Mild Solid-Phase Peptide Synthesis. Avoiding Diketopiperazine and Aspartimide Formation
p-Nitrobenzyloxycarbonyl was used as temporary protecting group for the -amino function in solid-phase peptide synthesis. The corresponding derivatives are solids, easy to be synthesized, and perform well in the solid-phase mode. pNZ is removed in practical neutral conditions in the presence of catalytic amounts of acid. They are orthogonal with the most common protecting groups used in peptide chemistry. They are specially useful in combination with Fmoc chemistry to overcome those side reactions associated with the used of the piperidine such DKP and aspartiimide formation. The flexibility of pNZ can be very useful for the preparation of libraries of small organic molecules
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