Antipyretics

Antipyretics are substances that reduce fever.

Antipyretics cause the hypothalamus to override a prostaglandin-induced increase in temperature. The body then works to lower the temperature, which results in a reduction in fever.

 Ibuprofen and aspirin, which are non-steroidal anti-inflammatory drugs (NSAIDs) used primarily as analgesics , and antipyretic .

Example:

1.Paracetamol (C8H9NO2)

It is also known as acetaminophen and APAP, is a medication used to treat pain and fever. It is typically used for mild to moderate pain relief.

It  is also used for severe pain, such as cancer pain and pain after surgery.

It is typically used either by mouth or rectally, but is also available by injection into a vein.Effects last between 2 to 4 hours.

It is generally safe at recommended doses.

The recommended maximum daily dose for an adult is 3 or 4 grams.

 Higher doses may lead to toxicity, including liver failure, serious skin rashes may rarely occur.

It appears to be safe during pregnancy and when breastfeeding.

 In those with liver disease, it may still be used, but in lower doses. It is classified as a mild analgesic.

It does not have significant anti-inflammatory activity.

 

(structure)

Medicinal uses:

It  is used for reducing fever in people of all ages.

It is  used to treat fever in children only if their temperature is higher than 38.5 °C

It  is used for the relief of mild to moderate pain.

It is used  for people with arthritis pain of the hip, hand and dental pain.

Adverse Effect:

Liver damages, asthma, diarrhea, vomiting and abdominal pain.

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Source: Wikipedia

Ruby Laser - Seminar prearation

Ruby Laser

Ruby laser definition
A ruby laser is a solid-state laser that uses the synthetic ruby crystal as its laser medium. Ruby laser is the first successful laser developed by Maiman in 1960.
Ruby laser is one of the few solid-state lasers that produce visible light. It emits deep red light of wavelength 694.3 nm.
Construction of ruby laser
A ruby laser consists of three important elements: laser medium, the pump source, and the optical resonator.
Laser medium or gain medium in ruby laser
In a ruby laser, a single crystal of ruby (Al2O3 : Cr3+) in the form of cylinder acts as a laser medium or active medium. The laser medium (ruby) in the ruby laser is made of the host of sapphire (Al2O3) which is doped with small amounts of chromium ions (Cr3+). The ruby has good thermal properties.

Pump source or energy source in ruby laser
The pump source is the element of a ruby laser system that provides energy to the laser medium. In a ruby laser, population inversion is required to achieve laser emission. Population inversion is the process of achieving the greater population of higher energy state than the lower energy state. In order to achieve population inversion, we need to supply energy to the laser medium (ruby).
In a ruby laser, we use flashtube as the energy source or pump source. The flashtube supplies energy to the laser medium (ruby). When lower energy state electrons in the laser medium gain sufficient energy from the flashtube, they jump into the higher energy state or excited state.
Optical resonator
The ends of the cylindrical ruby rod are flat and parallel. The cylindrical ruby rod is placed between two mirrors. The optical coating is applied to both the mirrors.The process of depositing thin layers of metals on glass substrates to make mirror surfaces is called silvering. Each mirror is coated or silvered differently.
At one end of the rod, the mirror is fully silvered whereas, at another end, the mirror is partially silvered.
The fully silvered mirror will completely reflect the light whereas the partially silvered mirror will reflect most part of the light but allows a small portion of light through it to produce output laser light.
Working of ruby laser
The ruby laser is a three level solid-state laser. In a ruby laser, optical pumping technique is used to supply energy to the laser medium. Optical pumping is a technique in which light is used as energy source to raise electrons from lower energy level to the higher energy level.
Consider a ruby laser medium consisting of three energy levels E1, E2, E3 with N number of electrons.

We assume that the energy levels will be E1 < E2 < E3. The energy level E1 is known as ground state or lower energy state, the energy level E2 is known as metastable state, and the energy level E3 is known as pump state.
Let us assume that initially most of the electrons are in the lower energy state (E1) and only a tiny number of electrons are in the excited states (E2 and E3)

When light energy is supplied to the laser medium (ruby), the electrons in the lower energy state or ground state (E1) gains enough energy and jumps into the pump state (E3).
The lifetime of pump state E3 is very small (10-8 sec) so the electrons in the pump state do not stay for long period. After a short period, they fall into the metastable state E2 by releasing radiationless energy. The lifetime of metastable state E2 is 10-3 sec which is much greater than the lifetime of pump state E3. Therefore, the electrons reach E2 much faster than they leave E2. This results in an increase in the number of electrons in the metastable state E2 and hence population inversion is achieved.
After some period, the electrons in the metastable state E2 falls into the lower energy state E1 by releasing energy in the form of photons. This is called spontaneous emission of radiation.
When the emitted photon interacts with the electron in the metastable state, it forcefully makes that electron fall into the  ground state E1. As a result, two photons are emitted. This is called stimulated emission of radiation.
When these emitted photons again interacted with the metastable state electrons, then 4 photons are produced. Because of this continuous interaction with the electrons, millions of photons are produced.
In an active medium (ruby), a process called spontaneous emission produces light. The light produced within the laser medium will bounce back and forth between the two mirrors. This stimulates other electrons to fall into the ground state by releasing light energy. This is called stimulated emission. Likewise, millions of electrons are stimulated to emit light. Thus, the light gain is achieved.
The amplified light escapes through the partially reflecting mirror to produce laser light.




Source:www.physics-and-radio-electronics.com

The Ionic bond -Study notes Prearation

An ionic bond results from the transfer of an electron from a metal atom to a non-metal atom.
Ionic bonds are formed between cations and anions.
A cation is formed when a metal ion loses a valence electron while an anion is formed when a non-metal gains a valence electron. They both achieve a more stable electronic configuration through this exchange.
Ionic solids form crystalline lattices, or repeating patterns of atoms, with high melting points, and are typically soluble in water.
Cations and Anions

Ionic bonds involve a cation and an anion. The bond is formed when an atom, typically a metal, loses an electron or electrons, and becomes a positive ion, or cation. Another atom, typically a non-metal, is able to acquire the electron(s) to become a negative ion, or anion.
One example of an ionic bond is the formation of sodium fluoride, NaF, from a sodium atom and a fluorine atom. In this reaction, the sodium atom loses its single valence electron to the fluorine atom, which has just enough space to accept it. The ions produced are oppositely charged and are attracted to one another due to electrostatic forces.

At the macroscopic scale, ionic compounds form lattices, are crystalline solids under normal conditions, and have high melting points. Most of these solids are soluble in H2O and conduct electricity when dissolved. The ability to conduct electricity in solution is why these substances are called electrolytes. Table salt, NaCl, is a good example of this type of compound.
Ionic bonds differ from covalent bonds. Both types result in the stable electronic states associated with the noble gases. However, in covalent bonds, the electrons are shared between the two atoms. All ionic bonds have some covalent character, but the larger the difference in electronegativity between the two atoms, the greater the ionic character of the interaction.


Ionic Compounds
An ionic bond is formed through the transfer of one or more valence electrons, typically from a metal to a non-metal, which produces a cation and an anion that are bound together by an attractive electrostatic force. On a macroscopic scale, ionic compounds, such as sodium chloride (NaCl), form a crystalline lattice and are solids at normal temperatures and pressures.
Crystalline Lattice: Sodium chloride crystal lattice

The charge on the cations and anions is determined by the number of electrons required to achieve stable noble gas electronic configurations. The ionic composition is then defined by the requirement that the resulting compound be electrically neutral overall.
For example, to combine magnesium (Mg) and bromine (Br) to get an ionic compound, we first note the electronic configurations of these atoms (valence level in indicated in italics):

Mg: 1s22s22p63s2
Br: 1s22s22p63s23p63d104s24p5
In order to achieve noble gas configurations, the magnesium atom needs to lose its two valence electrons, while the bromine atom, which has 7 valence electrons, requires one additional electron to fill its outer shell. Therefore, for the resulting compound to be neutral, two bromine anions must combine with one magnesium cation to form magnesium bromide (MgBr2). In addition, though any ratio of 2 bromine atoms to 1 magnesium atom will satisfy the two requirements above, the formula for ionic compounds is typically presented as the empirical formula, or the simplest whole-number ratio of atoms with positive integers.
Note that the cation always precedes the anion both in written form and in formulas. In the written form, while the cation name is generally the same as the element, the suffix of single-atom anions is changed to –ide, as in the case of sodium chloride. If the anion is a polyatomic ion, its suffix can vary, but is typically either –ate or –ite,as in the cases of sodium phosphate and calcium nitrite, depending on the identity of the ion.
More examples:
lithium fluoride: Li+ and F– combine to form LiF,calcium chloride: Ca2+ and Cl– combine to form CaCl2

Electronegativity

Electronegativity is a property that describes the tendency of an atom to attract electrons  toward itself. An atom’s electronegativity is affected by both its atomic number and the size of the atom. The higher its electronegativity, the more an element attracts electrons. The opposite of electronegativity is electronaffinity. which is a measure of an element’s ability to donate electrons.Electronegativity is not directly measured, but is instead calculated based on experimental measurements of other atomic or molecular properties. Several methods of calculation have been proposed, and although there may be small differences in the numerical values of the calculated electronegativity values.

Electronegativity, as it is usually calculated, is not strictly a property of an atom, but rather a property of an atom in a molecule. Properties of a free atom include ionization energy and electron affinity. It is expected that the electronegativity of an element will vary with its chemical environment, but it is usually considered to be a transferable property; that is to say, similar values will be valid in a variety of situations.

On the most basic level, electronegativity is determined by factors such as the nuclear charge and the number/location of other electrons present in the atomic shells. The nuclear charge is important because the more protons an atom has, the more “pull” it will have on negative electrons. Where electrons are in space is a contributing factor because the more electrons an atom has, the farther from the nucleus the valence electrons will be, and as a result they will experience less positive charge; this is due to their increased distance from the nucleus, and because the other electrons in the lower-energy core orbitals will act to shield the valence electrons from the positively charged nucleus.

The most commonly used method of calculation for electronegativity was proposed by Linus Pauling. This method yields a dimensionless quantity, commonly referred to as the Pauling scale, with a range from 0.7 to 4. If we look at the periodic table without the inert gases, electronegativity is greatest in the upper right and lowest at the bottom left.

Fluorine (F) is the most electronegative of the elements, while francium (Fr) is the least electronegative.

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Cinnarizine

It is predominantly used to treat nausea and vomiting associated with motion sickness,vertigo.

Cinnarizine’s mechanism of action is that it intercepts the signal between the middle ear and the hypothalamus, reducing the impulse to vomit.

Dosage will depend on your age, gender and medical condition.

For balance disorders, the average dose is around 25mg three times a day.The typical dosage for children five to seven years old is 6mg three times a day, and children eight to 12, 12.5mg, three times a day.

Special precautions:

Make sure to tell your doctor or Clicks pharmacist if you are allergic to cinnarizine.

Avoid alcohol while taking cinnarizine as it can increase the sedative effect of the medication.

During pregnancy or breastfeeding, it is best to avoid the use of cinnarizine as it could adversely impact your unborn child and your infant, unless your doctor determines that the benefits outweigh the risks.

Avoid driving or operating heavy machinery as cinnarizine could impair your functioning.

Cinnarizine should be avoided if you have the following conditions:

Cinnarizine should be used with caution if you suffer from hypotension (low blood pressure) or are elderly.

To avoid adverse drug interactions, always inform your doctor or Clicks pharmacist what prescription and non-prescription medications, vitamins, nutritional supplements and herbal products you are taking or planning to take.

Side effects:

Drowsiness,Dry mouth,Headache,Indigestion,Depression,Skin rashes,Excess saliva,Restlessness,Weight gain,Facial twitches,Extreme sleepiness,Vomiting.

Anticancer

Anticancer

Dactinomycin:

Dactinomycin (or) actinomycin D

*It is a chemotherapy medication used to treat a cancer.

*This includes tumor, rhabdomyosarcoma, Ewing's sarcoma, trophoblastic neoplasm, testicular cancer, and certain types of ovarian cancer.

*Most people develop side effects.

* Common side effects include bone marrow suppression, vomiting, mouth ulcers, hair loss, liver problems, infections, and muscle pains.

*Other serious side effects include future cancers, allergic reactions, and tissue death at the site of injection.

*Use in pregnancy may harm the baby.

*It is a clear, yellow liquid.

Side effects

Common adverse drug reaction includes bone marrow suppression, fatigue, hair loss, mouth ulcer, loss of appetite and diarrhea.

Today's notes preparation..,
Source: Wikiedia

Edited : periodic table

Analgesics (Medicinal Chemistry)- Seminar preparation:

Analgesics:

An analgesic is a medicine that relieves pain.

The medicines are commonly used to treat pain due to arthritis, surgery, injury, toothache, headache, menstrual cramps, sore muscles, or other causes.

Types of anasthetics:

Opioids (narcotics):

 such as morphine, oxycodone

Non-steroidal anti-inflammatory drugs (NSAIDs):

 such as Advil (ibuprofen), Aleve (naproxen), Celebrex (celecoxib).

Analgesic Side Effects:

Constipation, Upset stomach ,Ringing in your ears, Skin itching or rash ,Dry mouth.

Some examples:

1.Ibuprofen:

Ibuprofen is a medication in the non steroidal anti-inflammatory drug (NSAID) class that is used for treating pain, fever, and inflammation.

It typically begins working within an hour.

Common side effects

 * heartburn and a rash.

 It increases the risk of heart failure, kidney failure, and liver failure.

it appears to be harmful in later pregnancy and therefore is not recommended.

Medical uses:

Ibuprofen is used primarily to treat fever mild to moderate pain (including pain relief after surgery), painful menstruation, dental pain, headaches, and pain from kidney stones. 

It is used for inflammatory diseases such as juvenile idiopathic arthritis and rheumatoid arthritis.

Adverse effects:

Adverse effects include nausea, dyspepsia, diarrhea, constipation, gastrointestinal ulceration/bleeding, headache, dizziness, rash, salt and fluid retention, and high blood pressure.

Infrequent adverse effects include esophageal ulceration, heart failure.

Stereochemistry:

It is an optically active compound with both S and R-isomers, of which the S (dextrorotatory) isomer is the more biologically active.

Ketoprofen:

(RS)-2-(3-benzoylphenyl)-propionic acid (chemical formula C16H14O3) is one of the propionic acid class of nonsteroidal anti-inflammatory drugs (NSAID) with analgesic and antipyretic effects.

It acts by inhibiting the body's production of prostaglandin.

Medical uses:

Ketoprofen is generally prescribed for arthritis-related inflammatory pains or severe toothaches.

It is used for treatment of musculoskeletal pain.

Ketoprofen can also be used for treatment of some pain, especially nerve pain such as sciatica, postherpetic neuralgia.

Side effect:

upset stomach, heartburn, stomach pain, unusual tiredness, constipation, diarrhea, headache, skin itching or rash, dry mouth, increased sweating,

Nefopam

It sold under the brand names nefopam medisol among others, is a painkilling medication. It is primarily used to treat moderate to severe, acute or chronic pain.

It is believed to work in the brain and spinal cord to relieve pain.

Medical uses

Nefopam has additional action in the prevention of shivering, which may be a side effect of other drugs used in surgery.

 Nefopam was significantly more effective than aspirin as an analgesic in one clinical trial,[6] although with a greater incidence of side effects such as sweating, dizziness and nausea, especially at higher doses.

Side effects

Common side effects include nausea, nervousness, dry mouth, light-headedness and urinary retention.

Less common side effects include vomiting, blurred vision, drowsiness, sweating, insomnia, headache, confusion, hallucinations, tachycardia, aggravation of angina and rarely a temporary and benign pink discolouration of the skin .



Source: Wikipedia

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Carbonic Anhydrase (Bio-Inorganic Chemistry)

Carbonic Anhydrase

*It is a zinc enzyme that catalyses the hydration of co2 and dehydration of HCO3-.
* The enzyme can hydrate 10^6 molecules of co2 per second at 30 degree celsius .
Which is 10^7 times faster than the uncatalysed rate of hydration of co2.
Carbonic anhydrase with a molar mass of about 30000 occurs in animals as well as plants.

(His- Histidine Unit)

*Epo enzyme binded with metal ion

*The zinc ion lies in a deep pocket created by coiled enzyme and is coordinated with three nitrogen atom of three imidazole ring of histidine groups of the epoenzyme.

*The 4th coordination site is perhaps occupied by a water molecule  when the enzyme is at rest.

*The stereochmistry of zinc in the enzyme is tetrahedral.

*The lewis acidity of zn2+ ion in carbonic unhydrate polarizes the coordinated H2O molecule to the point of loss of H+ ion to form coordinated OH group.

(Probable mechanism for reversible hydration of Co2)

*It is a hydroxy form of enzyme. which is believed to reversibly hydrate Co2 to HCO3-

*Catalyst reversible hydration of Co2 is a close loop.

*The clockwise cycle shows a Co2 to HCO3- and the anticlock wise cycle shows the relese of Co2 from HCO3-.

Preparation of cris(Thio-urea) - Cu(II) Sulphate dihydrate

Chemicals required:
cu-sulphate pentahydrate -2g
Thi-urea-2g

Procedure:
       *2 g of thiourea crystals dissolved in 20 ml of hotwater in a round bottom flask and cooled to flask at room temperature.
*Solution of cu-sulphate is prepared by dissolving of 2g in 20ml water the flask is stoppered well and thoroughly aftereach addition of copper sulphate.
when the addition of copper sulphate solution is completely dissolved.
The flask is again shaken well for 20 minutes. At this stage cris complex will begin to appear.


The content of the flasks are heated for 5to 20 minutes .The flask is cooled to room temperature under ta water.

The another liquid is decamped off . The oily liquid of crystal formed at side of the flask are thoroughly with 2:1 of thiourea solution.
When white crystal is formed ,  Now the crystals are filtered at the pump, washed with distilled water and dry. the yield is recorded.

Myoglobin and Hemoglobin (Bio-Inorganic Chemistry)

Myoglobin and Hemoglobin 

*Both myoglobin and hemoglobin are metal porphyrins . Which contains the haemo group in their structure.

*The haemo group consist of an iron atom which is coordinated to four nitrogen atoms of  Porphyrins  rings.

*In myoglobin , haemo group  is embedded in a crevice formed by the coiling of its polypeptide chain containing 150 to 160 amino acid residues.

*The molar mass of myoglobin is about 17000.

*Myoglobin which has not taken u oxygen is called deoxymyoglobin.

* Haemoglobin which has a mass of about 64500,consist of 4 myoglobin like sub units.

*Each sub unit of haemoglobin contains a polypeptide chain and a haemo group coordinated through the N atom of the histidine group of its polypeptide chain.

* The 4 sub units of haemoglobin are linked with one another through salt bridges present between the 4 polypeptide chain.

* The oxygenated haemoglobin is called oxyhaemoglobin 

The haemoglobin which is not taken up oxygen is called deoxyhaemoglobin.

*The 5 coordinated Fe (II) present  in myoglobin and haemoglobin 

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Sommelet–Hauser rearrangement

The Sommelet–Hauser rearrangement is a rearrangement reaction of certain benzyl quaternary ammonium salts. The reagent is sodium amide or another alkali metal amide and the reaction product a N,N-dialkylbenzylamine with a new alkyl group in the aromatic ortho position.

Reaction mechanism:

The Stevens rearrangement is a competing reaction.

Stevens rearrangement

The Stevens rearrangement is a  reaction converting quaternary ammonium salts and sulfonium salts to the corresponding amines or sulfides in presence of a strong base in a 1,2-rearrangement.

Example:

Reaction mechanism: