Synthesis, Cytotoxic Activity and In Silico Study of Novel Dihydropyridine Carboxylic Acids Derivatives.

To aid the possible prevention of multidrug resistance in tumors and cause lower toxicity, a set of sixteen novel dihydropyridine carboxylic acids derivatives 3a-p were produced; thus, the activation of various ynones with triflic anhydride was performed, involving a nucleophilic addition of several bis(trimethylsilyl) ketene acetals, achieving good yields requiring easy workup. The target molecules were unequivocally characterized by common spectroscopic methods. In addition, two of the tested compounds (3a, and 3b) were selected to perform in silico studies due to the highest cytotoxic activity towards the HCT-15 cell line (7.94 ± 1.6 µM and 9.24 ± 0.9 µM, respectively). Employing theoretical calculations with density functional theory (DFT) using the B3LYP/6-311++G(d,p) showed that the molecular parameters correlate adequately with the experimental results. In contrast, predictions employing Osiris Property Explorer showed that compounds 3a and 3b present physicochemical characteristics that would likely make it an orally active drug. Moreover, the performance of Docking studies with proteins related to the apoptosis pathway allowed a proposal of which compounds could interact with PARP-1 protein. Pondering the obtained results (synthesis, in silico, and cytotoxic activity) of the target compounds, they can be judged as suitable antineoplastic agent candidates.

Experimental data on synthesis and characterization of chiral dinuclear manganese (II-II) compounds as biomimetic models of the active center of catalase.

Dinuclear manganese (II- III) compounds, which are potential models of the active center of catalase, were synthetized. This type of metalloenzymes presents biological importance due to three factors: they are redox catalyst centres, they are able to carry out hydrolytic reactions and they participate in activated processes via Lewis acids. Structurally, their active centre is composed by dinuclear manganese compounds, linked to nitrogen and oxygen donor atoms. An octahedral geometry around the metal ions were found, with acetate, hydroxy and aquo ligands; which can work as molecule bridges between them. The acid medium favours the electronic transfer between Mn3+ - Mn2+ as redox centre at 1.559 V and the consequent oxidation of hydrogen peroxide or organic molecules. The work also reports the data of two chiral novel compounds, [Mn2(S,S(+)Hcpse)4(NaClO4)2(NaOH)(CH4O)]n·[(C2H6O)2]n·[(CH4O)2]n and its respective enantioisomer, in which µ-oxo being as bridge metal centre. The X-ray structural was obtained as well as the optical and magnetic properties using Circular Dichroism, Electronic Paramagnetic Resonance, Magnetic Susceptibility and X-ray photoelectron spectroscopy.

Stereochemistry of a Second Riolozane and Other Diterpenoids from Jatropha dioica.

The dichloromethane extract of the roots of Jatropha dioica afforded riolozatrione (1) and a C-6 epimer of riolozatrione, 6-epi-riolozatrione (2), as a new structure and only the second reported riolozane diterpenoid. The two known diterpenoids jatrophatrione (3) and citlalitrione (4) were also isolated and characterized. Both epimers 1 and 2 are genuine plant constituents, with 2 likely being the biosynthesis precursor of 1 due to the tendency for the quantitative transformation of 2 into 1 under base catalysis. The structural characterization and distinction of the stereoisomers utilized 1H iterative full-spin analysis, yielding complete J-correlation maps that were represented as quantum interaction and linkage tables. The absolute configuration of compounds 1-4 was established by means of vibrational circular dichroism and via X-ray diffraction analysis for 1, 2, and 4. Additionally, the cytotoxic and antiherpetic in vitro activities of the isolates were evaluated.

Hydroxyclerodanes from Salvia shannoni.

Six new hydroxyclerodanes (1-6), named sepulturins A-F, and four known diterpenes were isolated from the leaves of Salvia shannoni. The structures of these compounds were established by extensive analysis of their NMR and MS spectroscopic data. The relative configurations of compounds 1 and 2 were determined by NOESY experiments and were confirmed by single-crystal X-ray diffraction studies. All of the isolated diterpenes possess tertiary OH groups. The structure of infuscatin (7), a clerodane previously isolated from S. infuscata, was revised. Cytotoxic, antiprotozoal, and anti-inflammatory activities of these compounds were evaluated.

On the mechanism of iron(III)-dependent oxidative dehydrogenation of amines.

Kinetic and structural data are presented for the iron-promoted dehydrogenation of the amine, [Fe(III)L3]3+ (1), L3 = 1,9-bis(2'-pyridyl)-5-[(ethoxy-2''-pyridyl)methyl]-2,5,8-triazanonane. Spectroscopic and electrochemical experiments under the exclusion of dioxygen helped to identify reaction intermediates and the final product, the Fe(II)-monoimine complex [Fe(II)L4]2+ (2), L4 = 1,9-bis(2'-pyridyl)-5-[(ethoxy-2''-pyridyl)methyl]-2,5,8-triazanon-1-ene. 2 is formed by disproportionation of the starting complex 1 by a three-step reaction mechanism, most likely via ligand-centered radical intermediates. The rate law can be described by the second-order rate equation, -d[(Fe(III)L3)3+]/dt = k(EtO)- [(Fe(III)L3)3+][EtO-], with k(EtO)- = 4.92 +/- 0.01 x 104 M(-1) s(-1) (60 degrees C, mu = 0.01 M). The detection of general base catalysis and a primary kinetic isotope effect (k(EtO)-(H)/k(EtO)-(D) = 1.73) represents the first kinetic demonstration that the deprotonation becomes rate determining followed by electron transfer in the oxidative dehydrogenation mechanism. We also isolated the Fe(II)-monoimine complex 2 and determined its structure in solution (NMR) and in the solid state (X-ray).

Crystal structure of trans-dibromobis(triphenylphosphine)platinum(II).

Crystal structure of trans-dibromobis(triphenylphosphine)platinum(II) was determined by X-ray-crystallography. The complex crystallizes on an inversion center in distorted square planar coordination around platinum with triphenylphosphine ligands in trans positions to each other and with two molecules of dichloromethane as solvate.

Sarcomas de cabeza y cuello: estudio clinicopatológico de 29 casos / Head and neck sarcomas: clinical pathological study of 29 cases

Los sarcomas originados en la cabeza y cuello representan menos del 1 por ciento de las neoplasias malignas de esa región. En este estudio se analizaron 29 casos atendidos en el Hospital General de México, recopilados en un periodo de cinco años. Se presentaron más frecuentemente en el sexo femenino en una proporción de 2:1. La edad promedio fue de 35 años. El tiempo promedio de evolución desde el inicio de los síntomas hasta su diagnóstico fue de 30.5 meses. Los síntomas más frecuentes fueron: tumor palpable, dolor y disfagia. En el 38 por ciento se efectuó el diagnóstico clínico de sarcoma, el 20 por ciento se diagnosticó como tumor, el 7 por ciento como linfoma, carcinoma y pólipo nasal, respectivamente. Todos fueron tratados quirúrgicamente; en el 27 por ciento además se aplicó radioterapia y en el 10 por ciento quimioterapia. Histopatológicamente, el 27.5 por ciento correspondieron a sarcoma neurogénico, 13.7 por ciento a osteosarcoma, 10.3 por ciento a leiomiosarcoma, 10.3 por ciento a rabdomiosarcoma, 6.8 por ciento, respectivamente, a sarcoma de Kaposi, angiosarcoma y condrosarcoma, y el 3.4 por ciento correspondió a un caso de tumor rabdoide, uno de fibrosarcoma, uno de sarcoma alveolar de partes blandas, uno de dermatofibrosarcoma protuberans y uno de sarcoma sinovial monofásico. En esta serie, a diferencia de otras, los sarcomas de cabeza y cuello fueron más frecuentes en mujeres jóvenes y el tipo histológico más común resultó el sarcoma neurogénico