Procedure to obtain the 3´,5´-di-O-acetyl-5-formyl- 2´-deoxyuridine

Numerosos tipos de daños al ADN han sido identificados en células expuestas a radiación ionizante y a agentes oxidantes. La 5-formil-2´- desoxiuridina es un compuesto potencialmente mutagénico que ha sido identificado en células expuestas a radiaciones ionizantes y a agentes oxidantes. Este compuesto se emplea para la síntesis de varios derivados de la 2´-desoxiuridina sustituidos en la posición 5. En este trabajo se presenta un método práctico para la conversión de la 2´-desoxitimidina a 3´,5´-di-O-acetil-5-formil-2´-desoxiuridina (4), a través de la halogenación, hidrólisis y oxidación de la 3´,5´-di-O-acetil-2´- desoxitimidina (1). Se realizaron estudios para seleccionar los agentes adecuados para las etapas de bromación, hidrólisis y oxidación. El bromo molecular y la N-bromosuccinimida (NBS) fueron probados en la etapa de halogenación y la NBS permitió obtener el producto deseado, 5-(bromometil)-3´,5´-di-O-acetil-2´- deoxiuridina (2) y trazas del compuesto dibromado. Algunos procedimientos de hidrólisis fueron evaluados para obtener la hidroximetil-3´,5´-di-O-acetil-2´- deoxiuridina (3) a partir de 2 y se seleccionó para esta etapa un procedimiento neutro con agua. En la etapa de oxidación, se llevó a cabo un análisis comparativo entre el óxido de manganeso activo y el reactivo de Jones para establecer las condiciones óptimas para obtener 4. Se utilizó, con buenos resultados, el reactivo de Jones para oxidar el grupo alcohol alílico, del nucleósido, a grupo formilo a través de un método más práctico, fácil y reproducibl

Smart Polymeric Micelles for Anticancer Hydrophobic Drugs

Cancer has become one of the deadliest diseases in our society. Surgery accompanied by subsequent chemotherapy is the treatment most used to prolong or save the patient’s life. Still, it carries secondary risks such as infections and thrombosis and causes cytotoxic effects in healthy tissues. Using nanocarriers such as smart polymer micelles is a promising alternative to avoid or minimize these problems. These nanostructured systems will be able to encapsulate hydrophilic and hydrophobic drugs through modified copolymers with various functional groups such as carboxyls, amines, hydroxyls, etc. The release of the drug occurs due to the structural degradation of these copolymers when they are subjected to endogenous (pH, redox reactions, and enzymatic activity) and exogenous (temperature, ultrasound, light, magnetic and electric field) stimuli. We did a systematic review of the efficacy of smart polymeric micelles as nanocarriers for anticancer drugs (doxorubicin, paclitaxel, docetaxel, lapatinib, cisplatin, adriamycin, and curcumin). For this reason, we evaluate the influence of the synthesis methods and the physicochemical properties of these systems that subsequently allow an effective encapsulation and release of the drug. On the other hand, we demonstrate how computational chemistry will enable us to guide and optimize the design of these micelles to carry out better experimental work

Smart Polymeric Micelles for Anticancer Hydrophobic Drugs

Cancer has become one of the deadliest diseases in our society. Surgery accompanied by subsequent chemotherapy is the treatment most used to prolong or save the patient’s life. Still, it carries secondary risks such as infections and thrombosis and causes cytotoxic effects in healthy tissues. Using nanocarriers such as smart polymer micelles is a promising alternative to avoid or minimize these problems. These nanostructured systems will be able to encapsulate hydrophilic and hydrophobic drugs through modified copolymers with various functional groups such as carboxyls, amines, hydroxyls, etc. The release of the drug occurs due to the structural degradation of these copolymers when they are subjected to endogenous (pH, redox reactions, and enzymatic activity) and exogenous (temperature, ultrasound, light, magnetic and electric field) stimuli. We did a systematic review of the efficacy of smart polymeric micelles as nanocarriers for anticancer drugs (doxorubicin, paclitaxel, docetaxel, lapatinib, cisplatin, adriamycin, and curcumin). For this reason, we evaluate the influence of the synthesis methods and the physicochemical properties of these systems that subsequently allow an effective encapsulation and release of the drug. On the other hand, we demonstrate how computational chemistry will enable us to guide and optimize the design of these micelles to carry out better experimental work

Diabetes Drug Discovery: hIAPP1–37 Polymorphic Amyloid Structures as Novel Therapeutic Targets

Human islet amyloid peptide (hIAPP1–37) aggregation is an early step in Diabetes Mellitus. We aimed to evaluate a family of pharmaco-chaperones to act as modulators that provide dynamic interventions and the multi-target capacity (native state, cytotoxic oligomers, protofilaments and fibrils of hIAPP1–37) required to meet the treatment challenges of diabetes. We used a cross-functional approach that combines in silico and in vitro biochemical and biophysical methods to study the hIAPP1–37 aggregation-oligomerization process as to reveal novel potential anti-diabetic drugs. The family of pharmaco-chaperones are modulators of the oligomerization and fibre formation of hIAPP1–37. When they interact with the amino acid in the amyloid-like steric zipper zone, they inhibit and/or delay the aggregation-oligomerization pathway by binding and stabilizing several amyloid structures of hIAPP1–37. Moreover, they can protect cerebellar granule cells (CGC) from the cytotoxicity produced by the hIAPP1–37 oligomers. The modulation of proteostasis by the family of pharmaco-chaperones A–F is a promising potential approach to limit the onset and progression of diabetes and its comorbidities

Drug Development in Conformational Diseases: A Novel Family of Chemical Chaperones that Bind and Stabilise Several Polymorphic Amyloid Structures

<div><p>The increasing prevalence of conformational diseases, including Alzheimer's disease, type 2 Diabetes Mellitus and Cancer, poses a global challenge at many different levels. It has devastating effects on the sufferers as well as a tremendous economic impact on families and the health system. In this work, we apply a cross-functional approach that combines ideas, concepts and technologies from several disciplines in order to study, <i>in silico</i> and <i>in vitro</i>, the role of a novel chemical chaperones family (NCHCHF) in processes of protein aggregation in conformational diseases. Given that Serum Albumin (SA) is the most abundant protein in the blood of mammals, and Bovine Serum Albumin (BSA) is an off-the-shelf protein available in most labs around the world, we compared the ligandability of BSA:NCHCHF with the interaction sites in the Human Islet Amyloid Polypeptide (hIAPP):NCHCHF, and in the amyloid pharmacophore fragments (Aβ17–42 and Aβ16–21):NCHCHF. We posit that the merging of this interaction sites is a meta-structure of pharmacophore which allows the development of chaperones that can prevent protein aggregation at various states from: stabilizing the native state to destabilizing oligomeric state and protofilament. Furthermore to stabilize fibrillar structures, thus decreasing the amount of toxic oligomers in solution, as is the case with the NCHCHF. The paper demonstrates how a set of NCHCHF can be used for studying and potentially treating the various physiopathological stages of a conformational disease. For instance, when dealing with an acute phase of cytotoxicity, what is needed is the recruitment of cytotoxic oligomers, thus chaperone F, which accelerates fiber formation, would be very useful; whereas in a chronic stage it is better to have chaperones <b>A</b>, <b>B</b>, <b>C</b>, and <b>D</b>, which stabilize the native and fibril structures halting self-catalysis and the creation of cytotoxic oligomers as a consequence of fiber formation. Furthermore, all the chaperones are able to protect and recondition the cerebellar granule cells (CGC) from the cytotoxicity produced by the hIAPP_20–29 fragment or by a low potassium medium, regardless of their capacity for accelerating or inhibiting <i>in vitro</i> formation of fibers. <i>In vivo</i> animal experiments are required to study the impact of chemical chaperones in cognitive and metabolic syndromes.</p></div

Proposal mechanism of chaperone on protein aggregation/disaggregation.

<p>Novel chemical chaperones family can regulate fiber formation processes by binding to the native state, minimizing the formation of amorphous aggregates, as well as cytotoxic oligomers.</p

Cell Apoptosis of CGC exposed to pro-apoptotic stimulus as low potassium concentration (K5) during 4 h and later, the chaperones N-[4-(1-naphthylamino)-4-oxobutanoyl]-β-alanine D; methyl (2-{[4-(1-naphthylamino)-4-oxobutanoyl]amino}ethyl) dithiocarbamate B and C (reference), were inoculated.

<p>In all assays caspase-3 levels were measured by inmunofluorescence.</p

Meta-structure of pharmacophore.

<p>A structural alignment using Pymol, whereby the interaction zones between β-amiloyd_17–42 (Aβ_17–42), IAPP and Eisenberg’s pharmacophore molecules and the chaperons were set in position with the interaction zone between BSA and the chaperons. BSA is shown in white at 70% transparency, the interaction zone between the Aβ_17–42 and the chaperons is shown in red, the one corresponding to the Eisenberg pharmacophore in blue, with IAPP in yellow and with BSA in green.</p

Values of molar ellipticity differences of the BSA fibrilogenesis assays at 70°C, in absence and presence of chaperones A, D, E, B, F and C, calculated from the CD spectra.

<p>*Differences of molar ellipticity at 240 and zero min. of incubation time.</p><p>Values of molar ellipticity differences of the BSA fibrilogenesis assays at 70°C, in absence and presence of chaperones A, D, E, B, F and C, calculated from the CD spectra.</p