Vanadium complexes with polypyridyl ligands: Speciation, structure and potential medicinal activity.

This review focuses on the interaction between the essential element­vanadium with 1,10-phenanthroline and polypyridyl ligands. It starts with a summary of the prior work on speciation studies for the binary systems vanadium-phenanthroline alongside several hydrolytic studies of the metal ion. It also includes a complete overview on the different X-ray structures known to date with discussions on the potential cytotoxic activity of several vanadium-polypyridyl complexes.

Identification and evaluation of (3Z, 6Z, 8E)-dodeca-3, 6, 8-trien-1-ol as the trail following pheromone on Microcerotermes exiguous (Isoptera:Termitidae) / Identificación y evaluación de (3Z, 6Z ,8E)-dodeca-3, 6, 8-trien-1-ol como feromona de camino de Microcerotermes exiguus (Isoptera:Termitidae)

Abstract Trail-following pheromone is one of the most important semiochemical in termites. This pheromone is responsible for the recruitment of individuals from the colony to perform different tasks. The aim of this work was to isolate and identify the trail-following pheromone of Microcerotermes exiguus (Isoptera: Termitidae), a typical termite from the Neotropic, that is considered pest in some crops. Subterranean nest of M. exiguus were collected with a shovel in Caracas, Venezuela in 2010. Different chemical micro-reactions combined with chromatographic analysis of solvent extracts, as well as solid phase microextraction analyses (SPME) were applied to termite sternal glands; besides, some behavioral biossays were undertaken. A peak in the chromatograms from extracts (retention index: 1 483), presented a fragmentation pattern with m/z ions: 41; 55; 67; 79; 91; 105; 119; 135; 142; 180, this result alongside behavioral assays allowed us to conclude that (3Z,6Z,8E)-dodeca-3, 6, 8-trien-1-ol (DTOH) acts as the main component of the trail following pheromone. The estimated optimum concentration for termite recruitment and orientation was around 1 pg/cm, being statistically comparable to the value on trails marked with whole body extracts at concentration of 1 worker/cm. The period of time that this compound takes to recruit other colony members is 13.67 ± 5.76 s and lasts up to two hours. Both analytical and behavioral results provided better understanding on the chemical communication of M. exiguus. This information could be used for the future development of newer pest control methods. Rev. Biol. Trop. 66(1): 303-311. Epub 2018 March 01.

Resumen La feromona de camino es uno de los semioquímicos más importantes en las termitas. Esta feromona es responsable del reclutamiento de individuos de la colonia para realizar diversas tareas. El objetivo de este trabajo fue aislar e identificar la feromona de camino de Microcerotermes exiguus (Isoptera: Termitidae), que es una termita típica del Neotrópico, considerada como plaga en algunos cultivos. Nidos subterráneos de M. exiguus fueron recolectados en Caracas, Venezuela en el 2010. Se realizaron diferentes micro-reacciones químicas combinadas con el análisis cromatográfico de los extractos en solventes, así como el de la microextracción en fase sólida (SPME) de las glándulas esternales de las termitas; además de algunos bioensayos de comportamiento. Un pico en los cromatogramas de los extractos (índice de retención:1 483), presentó un patrón de fragmentación con los iones m/z: 41; 55; 67; 79; 91; 105; 119; 135; 142; 180, este resultado junto con los ensayos comportamentales, nos permitieron concluir que el (3Z,6Z,8E)-dodeca-3, 6, 8-trien-1-ol (DTOH) es el compuesto principal de la feromona de camino. La concentración óptima estimada para el reclutamiento y la orientación se encuentra alrededor de 1 pg/cm, siendo estadísticamente comparable al valor en los caminos trazados con extractos de cuerpo entero de 1 obrera /cm. El tiempo que toma este compuesto para reclutar a otros miembros de la colonia es de aproximadamente 13.67 ± 5.76 s y se mantiene hasta por dos horas. Los resultados analíticos y de comportamiento proporcionan una mejor comprensión de la comunicación química de M. exiguus, y dicha información podría ser utilizada para el desarrollo de nuevos métodos de control de plagas.

GC-MS based metabolomics used for the identification of cancer volatile organic compounds as biomarkers.

A biomarker can be a metabolite, coming from a metabolic pathway or cell process, which might be employed in the diagnostic of diseases, predict patient response towards chemical therapies and/or monitor disease recurrences. Biomarkers, e.g. aldehydes or hydrocarbons, are often identified from different body fluids such as blood, urine, serum, saliva or from various tissues samples, and their concentration can vary from one sample to the other. However, the detection and the action of these biomarkers for diseases is a complicated process. Cancer is one of the main cause of death worldwide. The main characteristic of cancerous tumor is the uncontrolled growing of cells inside the organism. Likely, these uncontrolled growths are as consequence changes in the metabolism that could be analytically monitored. Depending on where the cancer cells are located, they provide different characteristics profiles. These profiles as fingerprints are used for differentiation in a comparison to normal cells. This critical study aimed at highlighting the latest progress in this area, especially in the employment of gas chromatography for the monitoring of volatile organic compounds (VOCs) and the identification of possible molecules used as biomarkers for cancer therapy.

Vanadium: History, chemistry, interactions with α-amino acids and potential therapeutic applications.

In the last 30 years, since the discovery that vanadium is a cofactor found in certain enzymes of tunicates and possibly in mammals, different vanadium-based drugs have been developed targeting to treat different pathologies. So far, the in vitro studies of the insulin mimetic, antitumor and antiparasitic activity of certain compounds of vanadium have resulted in a great boom of its inorganic and bioinorganic chemistry. Chemical speciation studies of vanadium with amino acids under controlled conditions or, even in blood plasma, are essential for the understanding of the biotransformation of e.g. vanadium antidiabetic complexes at the physiological level, providing clues of their mechanism of action. The present article carries out a bibliographical research emphaticizing the chemical speciation of the vanadium with different amino acids and reviewing also some other important aspects such as its chemistry and therapeutical applications of several vanadium complexes.

Analysis of Volatile Compounds by Advanced Analytical Techniques and Multivariate Chemometrics.

Smelling is one of the five senses, which plays an important role in our everyday lives. Volatile compounds are, for example, characteristics of food where some of them can be perceivable by humans because of their aroma. They have a great influence on the decision making of consumers when they choose to use a product or not. In the case where a product has an offensive and strong aroma, many consumers might not appreciate it. On the contrary, soft and fresh natural aromas definitely increase the acceptance of a given product. These properties can drastically influence the economy; thus, it has been of great importance to manufacturers that the aroma of their food product is characterized by analytical means to provide a basis for further optimization processes. A lot of research has been devoted to this domain in order to link the quality of, e.g., a food to its aroma. By knowing the aromatic profile of a food, one can understand the nature of a given product leading to developing new products, which are more acceptable by consumers. There are two ways to analyze volatiles: one is to use human senses and/or sensory instruments, and the other is based on advanced analytical techniques. This work focuses on the latter. Although requirements are simple, low-cost technology is an attractive research target in this domain; most of the data are generated with very high-resolution analytical instruments. Such data gathered based on different analytical instruments normally have broad, overlapping sensitivity profiles and require substantial data analysis. In this review, we have addressed not only the question of the application of chemometrics for aroma analysis but also of the use of different analytical instruments in this field, highlighting the research needed for future focus.