Medicinal chemistry

Role of cytochrome P450 in microsomal oxidataions

 Ø   The key component in  these reaction is cytochromes P450 Labeled because in can unit with carbon monoxide as well as with atmospheric oxygen give a complex with an absorption peak at 450.

Ø   Cytochrome P450 is present almost all tissues in the body like lungs, Kindly, skin, Brain, Liver.


Ø   But it is not found in these tissues the Microsomal Oxidations do not take place ,because of substrate specificity is very low.


Ø   Cytochrome P450 is described as Oxygen carvers.


Ø   Cytochrome p450 transfers atmospheric O2 to the  substance.

structure

 






 Ø   Only reduced form of cytochrome P450 can carry O2 for this way but in the case of it activity it is oxidized to the Fe 3+ form.

Ø   The transfers of electrons necessary to effect it change back to the reduced form and so maintain metabolic activity it requires the NICODINMI ADENINE DINUCLEOSIDE PHOSPHATE (NADP/NADPH2) system.

Ø   The drug forms a complex with oxidized [FE37] cytochrome p450.

silicon (si)

                                                     SILICON

Silicon Image

 Atomic Number: 14

Symbol: Si

Atomic Weight: 28.0855

Discovery: Jons Jacob Berzelius 1824 (Sweden)

Electron Configuration: [Ne]3s²3p²

Word Origin: Latin: silicis, silex: flint

Element Classification: Semimetallic

Density (g/cc): 2.33

Melting Point (K): 1683

Boiling Point (K): 2628

Appearance: Amorphous form is brown powder; crystalline form has a gray

Atomic Radius (pm): 132

Atomic Volume (cc/mol): 12.1

Covalent Radius (pm): 111

Ionic Radius: 42 (+4e) 271 (-4e)

Specific Heat (@20°C J/g mol): 0.703

Fusion Heat (kJ/mol): 50.6

Evaporation Heat (kJ/mol): 383

Debye Temperature (K): 625.00

Pauling Negativity Number: 1.90

First Ionizing Energy (kJ/mol): 786.0

Oxidation States: 4, -4

Lattice Structure: Diagonal

Lattice Constant (Å): 5.430

Preparation: Silicon may be prepared by heating silica and carbon in an electric furnace, using carbon electrodes. Amorphous silicon may be prepared as a brown powder, which can then be melted or vaporized. The Czochralski process is used to produce single crystals of silicon for solid-state and semiconductor devices. Hyperpure silicon may be prepared by a vacuum float zone process and by thermal decompositions of ultra-pure trichlorosilane in an atmosphere of hydrogen.

Properties: The melting point of silicon is 1410°C, boiling point is 2355°C, specific gravity is 2.33 (25°C), with a valence of 4. Crystalline silicon has a metallic grayish color. Silicon is relatively inert, but it is attacked by dilute alkali and by halogens. Silicon transmits over 95% of all infrared wavelengths (1.3-6.7 mm).

Uses: Silicon is one of the most widely used elements. Silicon is important to plant and animal life. Diatoms extract silica from water to build their cell walls. Silica is found in plant ashes and in the human skeleton. Silicon is an important ingredient in steel. Silicon carbide is an important abrasive and is used in lasers to produce coherent light at 456.0 nm. Silicon doped with gallium, arsenic, boron, etc. is used to produce transistors, solar cells, rectifiers, and other important solid-state electronic devices. Silicones range from liquids to hard solids and have many useful properties, including use as adhesives, sealants, and insulators. Sand and clay are used to make building materials. Silica is used to make glass, which has many useful mechanical, electrical, optical, and thermal properties.

Sources: Silicon makes up 25.7% of the earth's crust, by weight, making it the second most abundant element (exceeded by oxygen). Silicon is found in the sun and stars. It is a principal component of the class of meteorites known as aerolites. Silicon is also a component of tektites, a natural glass of uncertain origin. Silicon is not found free in nature. It commonly occurs as the oxide and silicates, including sand, quartz, amethyst, agate, flint, jasper, opal, and citrine. Silicate minerals include granite, hornblende, feldspar, mica, clay, and asbestos.

Aluminium (Al)

                                             AIUMINUM OR ALUMINIUM

Aluminum or Aluminium Image

Atomic Number: 13

Symbol: Al

Atomic Weight: 26.981539

Discovery: Hans Christian Oersted (1825, Denmark), Wohler (1827)

Electron Configuration: [Ne] 3s2 3p1

Word Origin: Latin alumen: alum, an astringent and dyeing mordant

Note on Naming: Sir Humphry Davy proposed the name aluminum for the metal, however, the name aluminium was adopted to conform with the "ium" ending of most elements. This spelling is in use in most countries. Aluminium was also the spelling in the U.S. until 1925, when the American Chemical Society officially decided to use the name aluminum instead.

Element Classification: Metal

Density (g/cc): 2.6989

Appearance: soft, lightweight, silvery-white metal

Atomic Radius (pm): 143

Atomic Volume (cc/mol): 10.0

Covalent Radius (pm): 118

Ionic Radius: 51 (+3e)

Specific Heat (@20°C J/g mol): 0.900

Fusion Heat (kJ/mol): 10.75

Evaporation Heat (kJ/mol): 284.1

Debye Temperature (K): 394.00

Pauling Negativity Number: 1.61

First Ionizing Energy (kJ/mol): 577.2

Oxidation States: 3

Lattice Structure: Face-Centered Cubic

Lattice Constant (Å): 4.050

Properties: Aluminum has a melting point of 660.37°C, boiling point of 2467°C, specific gravity of 2.6989 (20°C), and valence of 3. Pure aluminum is a silvery-white metal. It is soft, light, relatively nontoxic, with a high thermal conductivity, and high corrosion resistance. It can be easily formed, machined, or cast. Aluminum is nonmagnetic and nonsparking. It is second among metals in terms of malleability and sixth in ductility. Aluminum coatings are highly reflective of both visible and radiant heat. The coatings form a thin layer of protective oxide and do not deteriorate like silver coatings.

Uses: Ancient Greeks and Romans used alum as an astringent, for medicinal purposes, and as a mordant in dyeing. It is used in kitchen utensils, exterior decorations, and thousands of industrial applications. Although the electrical conductivity of aluminum is only about 60% that of copper per area of cross section, aluminum is used in electrical transmission lines because of its light weight. The alloys of aluminum are used in the construction of aircraft and rockets. Reflective aluminum coatings are used for telescope mirrors, making decorative paper, packaging, and many other uses. Alumina is used in glassmaking and refractories. Synthetic ruby and sapphire have applications in producing coherent light for lasers.

Sources: Aluminum is the most abundant metal in the Earth's crust (8.1%), although it is not found free in nature. In 1886, Hall in the United States and Heroult in France discovered how to obtain aluminum metal from electrolysis of alumina dissolved in cryolite. Cryolite is an aluminum ore, although it is has been replaced for commercial aluminum purification by an artificial mixture of sodium, aluminum, and calcium fluorides. The Bayer process is commonly used to refine the impure hydrated oxide ore, bauxite, for use in the Hall-Heroult refining process. Aluminum also can be produced from clay, although this is not the most economically feasible method at present. In addition to cryolite and bauxite, aluminum is found in feldspars, granite, and many other common minerals. The oxide, alumina, occurs naturally as ruby, sapphire, emery, and corundum.

Magnesium (Mg)

                                            MAGNESIUM (Mg)

Magnesium Image

   

Magnesium

Atomic Number: 12

Symbol: Mg

Atomic Weight: 24.305

Discovery: Recognized as an element by Black 1775; Isolated by Sir Humphrey Davy 1808 (England)

Electron Configuration: [Ne] 3s²

Word Origin: Magnesia, a district in Thessaly, Greece

Atomic Weight: 24.305

Element Classification: alkaline earth metal

Density (g/cc): 1.738

Appearance: lightweight, malleable, silvery-white metal

Atomic Radius (pm): 160

Atomic Volume (cc/mol): 14.0

Covalent Radius (pm): 136

Ionic Radius: 66 (+2e)

Specific Heat (@20°C J/g mol): 1.025

Fusion Heat (kJ/mol): 9.20

Evaporation Heat (kJ/mol): 131.8

Debye Temperature (K): 318.00

Pauling Negativity Number: 1.31

First Ionizing Energy (kJ/mol): 737.3

Oxidation States: 2

Lattice Structure:Hexagonal

Lattice Constant (Å): 3.210

Lattice C/A Ratio: 1.624

Properties: Magnesium has a melting point of 648.8°C, boiling point of 1090°C, specific gravity of 1.738 (20°C), and valence of 2. Magnesium metal is light (one-third lighter than aluminum), silvery-white, and relatively tough. The metal tarnishes slightly in air. Finely divided magnesium ignites upon heating in air, burning with a bright white flame.

Uses: Magnesium is used in pyrotechnic and incendiary devices. It is alloyed with other metals to make them lighter and more easily welded, with applications in the aerospace industry. Magnesium is added to many propellents. It is used as a reducing agent in the preparation of uranium and other metals that are purified from their salts. Magnesite is used in refactories. Magnesium hydroxide (milk of magnesia), sulfate (Epsom salts), chloride, and citrate are used in medicine. Organic magnesium compounds have many uses. Magnesium is essential for plant and animal nutrition. Chlorophyll is a magnesium-centered porphyrin.

Sources: Magnesium is the 8th most  abundant element in the earth's crust. While it is not found free it nature, it is available in minerals including magnesite and dolomite. The metal may be obtained by electrolysis of fused magnesium chloride derived from brines and seawater.

References: Los Alamos National Laboratory (2001), Crescent Chemical Company (2001), Lange's Handbook of Chemistry (1952), CRC Handbook of Chemistry & Physics (18th Ed.)

                        

Sodium (Na)

                                                         SODIUM

         Sodium Image

Sodium Atomic Number: 11
Sodium Symbol: Na
Sodium Atomic Weight: 22.989768
Electron Configuration: [Ne]3s¹
Sodium Word Origin: English soda and Medieval Latin sodanum: headache remedy; Latin natrium: sodium carbonate
Isotopes: Seven isotopes of sodium are known.
Element Classification: Alkali Metal
Discoverer: Sir Humphrey Davy
Discovery Date: 1807 (England)
Density (g/cc): 0.971
Appearance: soft, silvery-white metal
Atomic Radius (pm): 190
Atomic Volume (cc/mol): 23.7
Covalent Radius (pm): 154
Ionic Radius: 97 (+1e)
Specific Heat (@20°C J/g mol): 1.222
Fusion Heat (kJ/mol): 2.64
Evaporation Heat (kJ/mol): 97.9
Debye Temperature (K): 150.00
Pauling Negativity Number: 0.93
First Ionizing Energy (kJ/mol): 495.6
Oxidation States: 1 Lattice Structure: Body-Centered Cubic
Lattice Constant (Å): 4.230

Properties: Sodium has a melting point of 97.81 +/- 0.03°C, boiling point of 882.9°C, specific gravity of 0.971 (20°C), and a valence of 1. Sodium is a bright, silvery metal. It is soft and highly reactive. Sodium floats on water, which decomposes it to evolve hydrogen and form the hydroxide. Sodium may ignite spontaneously on water. It does not usually ignite in air at temperatures below 115°C.
Uses: Sodium chloride is important for animal nutrition. Sodium compounds are used in the glass, soap, paper, textile, chemical, petroleum, and metal industries. Metallic sodium is used in manufacturing of sodium peroxide, sodium cyanide, sodamide, and sodium hydride. Sodium is used in preparing tetraethyl lead. It is used in the reduction of organic esters and preparation of organic compounds. Sodium metal may be used to improve the structure of some alloys, to descale metal, and to purify molten metals. Sodium, as well as NaK, an alloy of sodium with potassium, are important heat transfer agents.
Sources: Sodium is relatively abundant in the sun and other stars. The D lines of sodium are prominent in the solar spectrum. Sodium is the sixth most abundant element on earth. It comprises approximately 2.6% of the earth's crust. Sodium is the most abundant of the alkali metals. The most common sodium compound is sodium chloride (salt). Sodium occurs in many minerals, such as cryolite, soda niter, zeolite, amphibole, and sodalite. Sodium is not found free in nature. It is obtained commercially by the electrolysis of dry fused sodium chloride.

References: Los Alamos National Laboratory (2001), Crescent Chemical Company (2001), Lange's Handbook of Chemistry (1952)