Wednesday, November 7, 2012

Useful Concepts for Medicinal Chemist

Useful Numbers, Concepts and Formulae for Medicinal Chemist


Monday, May 28, 2012

Picture of Olympicene

AFM image of Olympicene molecule
Back in 2009, at the IBM Research lab scientists imaged, for the first time, the chemical structure of an individual molecule (pentacene) with unprecedented resolution, using technique they developed called noncontact atomic force microscopy. The same IBM team, has once again come up with an interesting image. This time they've imaged a new organic molecule, Olympicene.

Olympicene, gets its name because its five linked rings resemble the Olympic symbol. The compound is a powder, that is very sensitive to light. In fact, even with brief exposure it changes color. It is only 1.2 nanometers wide, or 100,000 times thinner than a human hair. This AFM technique could become a real structure-determination tool for organic chemist.


Thursday, May 17, 2012

PhD student fellowships


The International Max Planck Research School (IMPRS) "The Exploration of Ecological Interactions with Molecular and Chemical Techniques" in Jena, Germany, invites applications for 6 PhD fellowships beginning in January 2013.

Application deadline is June 29, 2012.
For detailed information about the IMPRS, Projects offered and application requirements, @http://imprs.ice.mpg.de/.

Wednesday, May 16, 2012

Molecule vending machine


 Nano-catalysis is a fast-growing field of chemistry, which involves the use of nanomaterials as catalysts for a variety of selective organic transformations. Nano-catalysis can be considered as a bridge between homogeneous and heterogeneous catalysis. Because of high surface area of nano materials, the contact between reactants and catalyst increases dramatically and they can operate in the same manner as homogeneous catalysts (homogeneous catalysis), at the same time, due to their insolubility in the reaction solvent, they can be separated out easily from the reaction mixture (heterogeneous). Only the molecules of certain sizes and chemical properties are selected and guided to the reaction centers where they are efficiently transformed to the desired products.

 Solid supports have the potential to house more than one metal and, hence, catalyze multiple types of bond constructions. Such “multifunctional” catalysts attained much attention due to several advantages over mono metal catalyst. The high selectivity of the nano catalyst may help reduce the energy consumption required for product separation and waste disposal processes in chemical industries.

Monday, January 23, 2012

Totally drug resistant TB


One of the biggest problems in Tuberculosis (TB) therapy nowadays is that patients have to take antibiotics for up to 9 months. As many patients feel better before this time, they prematurely stop their treatment, leaving pools of the most drug-resistant M. tuberculosis in their lungs. This contributes to the emergence of complete drug resistance in future patients.
In the past few years, strains of drug resistant Mtb have become prevalent. In fact, resistance is so wide spread that it is now being classified as multi-drug resistant (MDR-TB) and extreme-drug resistant (XDR-TB). Two of the world’s most populous countries, India and China, account for more than 50% of the world’s MDR-TB cases.
Recent reports have also confirmed a new strain of existing Mtb which is completely untreatable and has been designated as Totally drug resistance TB (TDR-TB). Indeed, strains of Mtb have even evolved resistance to all major available anti-TB drugs. India (2012) is the third country in which a total drug-resistant form of the TB has emerged, following cases documented in Italy in 2007 and Iran in 2009. There is a need for a more readily available treatment that is effective against both sensitive and drug-resistant strains of M. tuberculosis is evident.

Sunday, January 22, 2012

Nano reactions


Recently, nanoporous materials have emerged as important and efficient heterogeneous catalysts for the organic transformations owing to their excellent textural characteristics including high surface area, large pore volume, and uniform pore size distribution, and its simplicity in workup and recyclability. The pore diameters are chosen to control the access of molecules to the catalytic reaction sites located inside the porous cavities. Only the molecules of certain sizes and chemical properties are selected and guided to the reaction centers where they are efficiently transformed to the desired products.

Friday, January 20, 2012

What's a PhD worth?

Here's another article in the nature that makes some good points about the worth of PhD.

"The number of science doctorates earned each year grew by nearly 40% between 1998 and 2008, to some 34,000, in countries that are members of the Organisation for Economic Co-operation and Development (OECD). The growth shows no sign of slowing: most countries are building up their higher-education systems because they see educated workers as a key to economic growth. But in much of the world, science PhD graduates may never get a chance to take full advantage of their qualifications"

PhD program use to be for science-loving driven people and the world want more innovation from academic science to solve the problems.

Tuesday, January 10, 2012

Mycobacteria and the great wall

Mycobcaterial cell wall is unique, thick waxy and hydrophobic in nature, which ensures its survival inside human macrophages by resisting oxidative damages.The waxy, highly impermeable nature of the wall provides the required defense mechanism against antibiotic agents, and the host organisms. A key component of the cell wall is mycolic acids. Mycolic acid  accounts up to 60% of the dry weight of the organisms which means that most percentage of mycobacteria is a cell wall.  Thorough understanding of the influence of polarity on the drug penetration in to highly impermeable mycobacterial cell wall will guide us to improve permeability.

The permeation ability of a lipophilic molecule is inversely related to the fluidity of the cell wall, which decreases as the length of fatty acids in the mycolic acids layer increases. The permeability barrier presented by this cell envelope is also thought to be a reason why many common antibiotics are ineffective against mycobacteria. Lipophilic drugs, such as fluoroquinolones or rifamycins, pass more easily through the lipid-rich cell wall and thus are more active.
It is clear that, depending on the library screens towards compounds with a particular physicochemical parameter could actually be detrimental and decrease the diversity of finding new anti-TB drugs.