Available at www.ijcasonline.com ISSN:2349 – 0594 International Journal of Modern Chemistry and Applied Science International Journal of Modern Chemistry and Applied Science 2016, 3(2),402-407 K.Lalitha Jyotsna et al., Page No. 402 Molecular Modelling Of Phentolamine for Cardiovascular Disease 1* K.Lalitha Jyotsna, 2 N .Saritha, Vasudha Bakshi 3 1,3 Department of Biotechnology, Anurag Group of Institutions (Formerly Lalitha College of Pharmacy) Venkatapur (v), Ranga Reddy-500088, Telangana, India.. 2 Department of Chemistry, JNTUA, KALIKIRI, KALIKIRI. Andhra Pradesh. Corresponding author:lalitha.jyotsna@gmail.com ………………………………………………………………………………………………………………. ABSTRACT: Molecular modeling includes wide range of molecular graphics and computational chemistry techniques used to build, display, manipulate, stimulate and analyze molecular structures. By calculating binding affinity the highest binding affinity molecule of new analog of phentolamine is identified. Phentolamine is the active ingredient in the drug Regitime. Its acts as a long lasting adrenergic alpha antagonist, antihypertensive drug which expand blood vessels and reduce blood pressure. Phentolamine blocks alpha adrenergic receptors which lead to muscle relaxation and widening of blood vessels. This widening of blood vessels results in lowering of blood pressure. Phentolamine control episodes of hypertension and sweating that occur with a disease called pheochromocytoma. Phentolamine is used in diagnosis of pheochromocytoma and to control paroxysmal hypertension during pheochromocytomectomy. Key words: phentolamine; binding affinity, alpha adrenergic receptor; pheochromocytoma; blood pressure ………………………...................................................................................................................................................... Introduction Molecular modeling [1-3] is a general term which covers a wide range of molecular graphics and computational chemistry [4] techniques used to build, display, manipulate, simulate, and analyze molecular structures, and to calculate properties of these structures. By calculating binding affinity the highest binding affinity molecule 5 of new analog of phentolamine is identified. Phentolamine is marketed under the trade name Regitine, Regitin and several others is a member of the drug class α-adrenergic blocker used for muscle relaxation and widening of blood vessels. Phentolamine control episodes of hypertension [6 7] and sweating that occur with a disease called pheochromocytoma. It is a long lasting adrenergic, α-receptor blocking agent. Phentolamine produces its therapeutic actions by blocking alpha receptors, leading to muscle relaxation and widening of blood vessels. This widening of blood vessels results in lowering of blood pressure. Currently Phentolamine injections are marketed by Novartis 5mg/vial for injection. The drug acts adrenergic alpha antagonist antihypertensive agent. Its an α adrenergic blocker as a competitive α-adrenergic antagonist, phentolamine binds to α-1 and α-2 receptors resulting in a decrease in peripheral vascular resistance and vasodilatation. This agent also may block 5-hydroxytryptamine (5-HT) receptors and stimulate release of histamine from mast cells. Phentolamine is used in the diagnosis of pheochromocytoma and to control or prevent paroxysmal hypertension [8] immediately during pheochromocytomectomy. Phentolamine lower the risk of death from cardiovascular disorder and has several additional benefits. It s injected to control hypertensive emergencies like pheochromocytoma. Specially phentolamine has diagnostic and therapeutic roles in complex regional pain syndrome. Materials and methods Software: Hyperchem: HyperChem [9] is a versatile molecular modeler and editor and a powerful computational package. It offers many types of molecular and quantum mechanics calculations. For optimization of small molecules in solution and protein complex the intra molecular energies of ligand-solvent and ligand protein will be calculated using molecular mechanics calculations of Hyperchem software enlisted in figure 1. Figure 1. Hyperchem8 HyperChem includes these functions: 1. Drawing molecules from atoms and converting them to three-dimensional (3D) models) 2. Constructing proteins and nucleic acids from standard residues.Using molecules from other sources; for example, Brookhaven Protein Data Bank (PDB) files. 3. Rearranging molecules by, for example, rotating and translating them changing display conditions, including stereo viewing, rendering models, and structural labels