Tigliane

Structure of Tigliane:General Characteristics:
It has almost same system as that of daphnanes i.e. tricyclo tetradecane ring system. It has additional gem-dimethyl cyclopropane appended to the 6-membered ring. (Its most) famous (part) is Phorbol, which was named in about 25 BC by King Juba II of Mauritania. Wender, on one hand, and Cha, on the other hand, has completed its synthesis.

Action:
It primarily acts on protein kinase C (PKC, which is important for regulating cellular growth and differentiation).

Isolation of tiglianes:
It has been isolated from Euphorbia and Thymelaceae as esters.

Therapeutic uses:
It was primarily used for tumors, parasites, migraines, venereal diseases and as purgatives.
It has been found that C12 deoxy derivative blocks formation of the tumor.

Adverse effects:
Its most important tumor promoting example is Tetradodecanoyl phorbol acetate.

Further reading:
Naturally Occurring Phorbol Esters by Evans

Dissociation

It is a process in which there is separation of ionic compounds into smaller parts (molecules or ions).

It is usually a reversible process.

It is the opposite of association and recombination.

pKa

pKa is an acid dissociation constant.

Definition:
It is the negative logarithm of the acid dissociation constant i.e., Ka

Equation:
Its equation is:
pKa = -log10 Ka

Importance:
1. It shows the extent of dissociation. As the value of pKa increases, the extent of dissociation will decrease.
2. It has the ability of telling the acidic or basic properties of a substance.

Mass analyzer

Mass analyzer is a technique used for the separation of the ions according to mass/charge ratio.

Equation for the Mass analyzer:

1. Lorentz force law:
F=Q(E+v*B)

Where
F = force applied to the ion
Q = ion charge
E = electric field
v*B = the vector cross product of the ion velocity and the magnetic field

2. Newton's second law of motion:
F=ma

Where
F = force applied to the ion
m = mass of the ion
a = acceleration

By combining the above two equations, we get:

Q(E+v*B) = ma

=> E+v*B = a(m/Q)

where m/Q denotes mass to charge ratio.

Types of mass analyzers:

There are various types of mass analyzers:

1. Scanning Mass Analyzers

2. TOF - Mass Analyzers

3. Trapped Ion Mass Analyzers

Ion Source

It is a type of an electro-magnetic instrument, primarily used to create charged particles.

It is used in ion implanters, ione engines, mass spectrometersand particle accelerators.

Carbomer

Carbomer is a type of molecule which is usually obtained by the insertion of Carbon units in a certain molecule. It is a polymer of acrylic acid crosslinked with a polyfunctional molecule or compound such alkyl ethers of sucrose and/or pentaerythritol. [1]

It is also referred to as polyacrylic or polyacrylate.

Types of Carbomers:
In the National Formulary, there are six types of carbomers' monographs:
1. Carbomers 910
2. Carbomers 934
3. Carbomers 934P (The suffix "P" shows that this is a highly purified product and can be used orally). [2]
4. Carbomers 940
5. Carbomers 941
6. Carbomers 1342 [1]

Properties of Carbomers:[2]
1. White powder (Fluffy)
2. Hygroscopic
3. Soluble in water
4. pH of 1% aquous dispersion is 2.5 to 3.0
5. Incompatible with phenol and resorcinol
6. Products of Carbomers are sensitive to light

Uses:
It is mostly used as a suspending agent in Pharmaceutical industry. They are also used as gelling agents at the concentration of 0.5 to 2.0 % in water. [1]

References:
[1]Page # 2444, Encyclopedia of Pharmaceutical Technology by James Swarbrick.

[2] 18.18, Part 4 Pharmaceutical necessities, A Practical Guide to Contemporary Pharmacy Practice by Judith E. Thompson and Lawrence Davidow.

Further Reading:
A Practical Guide to Contemporary Pharmacy Practice by Judith E. Thompson and Lawrence Davidow

The National Formulary X : Tenth Edition

Martindale: The Complete Drug Reference, 35th Edition: Book and CD-ROM Package

Remington: The Science and Practice of Pharmacy

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5-fluorouracil

Mechanism of action:

5-FU is a cytostatic drug that causes the inhibition of the formation of DNA through the inhibition of Thymidylate synthesis. [1]

Uses of 5-Fluorouracil (5-FU):

It is used as an anti-cancer agent and anti-scarring agent. [1]

References:

[1] New concept in glaucoma treatment by Faezah Sarfarazi. United States Patent, 5304561.

Further Reading:

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Nuclear Magnetic Resonance (NMR)

Nuclear magnetic resonance (NMR) is a technique depending on the basis that nucleus within atoms have spinning properties and this spinning properties is used to determine the absorption and emmission of energy, moreover, this property can be used to determine the electromagnetic properties of nuclei. (Resonance is the vibrational frequency of a moving or rotating object. Magnetic Resonance is a technique, where computer is used for analyzing the response of atoms of hydrogen or any other element to a generated magnetic field. So by this response the electronic images of the atoms or molecular structures of solids can be obtained).

This is used for determining the chemical structure of materials and more properly for organic materials.

Proton NMR (represented by 1H NMR) is the type of NMR spectroscopy in which protons within a molecule or hydrogen atoms are under study for determination of structure. (J Urenjak et al.) It is a non-invasive technique. It has many important uses. (J. D. Otvos et al.) One of the application of 1H NMR is for quantifying plasma lipoproteins.

Carbon NMR is the type of NMR spectroscopy in which carbon atoms are under study for determination of the structure. (L. P. Lindeman et al.) Carbon-13 form is mostly used for this purpose and this is one of the great tools for structure analysis because it is naturally abundant. For molecules with few polar functional groups, like hydrocarbons, the fully proton decoupled carbon-13 NMR spectra are usually much better resolved than the proton NMR spectra.

Zero field NMR (A. Bielecki et al.)has been used when there is no predefined direction in space. In this case, all crystallites contribute equivalently and resolved dipolar splittings can be judged by internuclear distances. The importance of this is in molecular structure determination without the need for single crystals or oriented samples.

References:
A. Bielecki, D. Zax, K. Zilm, and A. Pines, Zero-Field Nuclear Magnetic Resonance. Physical Review letters, 50, Pages 1807 - 1810 (1983).
(Physical Review Letters - 14 March 2008 - American Physical Society Periodical/Physical Review Letters October - December 1980 /Physical Review Letters July-September 20 1965 Bound Volume by American Physical Society )

J. D. Otvos, E.J. Jeyarajah, D.W. Bennett, Quantification of plasma lipoproteins by proton nuclear magnetic resonance spectroscopy. Clinical Chemistry, 1991 Mar;37(3):Pages 377-86.

J Urenjak, SR Williams, DG Gadian and M Noble, Proton nuclear magnetic resonance spectroscopy unambiguously identifies different neural cell types. Journal of Neuroscience, Vol 13, Pages 981-989.

L. P. Lindeman, J. Q. Adams, Chemical Shifts for the Paraffins through C9,
Analytical Chemistry, Volume 43, No. 10, August 1971. Page 1245.

Further Reading:
Nuclear Magnetic Resonance by P. J. Hore

Nuclear Magnetic Resonance Spectroscopy: An Introduction to Principles, Applications, and Experimental Methods by Joseph B. Lambert , Eugene P. Mazzola

Principles of Nuclear Magnetic Resonance in One and Two Dimensions by Richard R. Ernst , Geoffrey Bodenhausen and Alexander Wokaun

Nuclear Magnetic Resonance: Concepts and Methods by Daniel Canet

Encyclopedia of Nuclear Magnetic Resonance by David M. Grant and Robin Harris

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Calorimetry

Calorimetry is the study of heat reading in chemical changes or physical changes. It is a thermoanalytical method that measure changes in enthalpy or heat during when the reaction is in progress. [1]

Types of Calorimetry:
There are two main types related to calorimetry:

1. Constant pressure calorimetry.
This measures heat at constant pressure, and represented by "qp" or delta H.

2. Constant Volume calorimetry.
This measures heat at constant volume and represented by "qv" or delta E. [2]

Other types are as follows:

Scanning calorimetry:
(Julian M. Sturtevant) In this calorimeter, there is the measurement of the specific heat of the system as the function of the temperature. Differential scanning Calorimetry is the measurement of the change of the difference in the heat flow rate to the sample and to a reference sample while they are subjected to a controlled temperature program. [3]

Indirect calorimetry:
(D. C. Simonson et al.)Indirect calorimetry is the net rate of disappearence of a substrate (It is not importantly the metabolic changings that the substrate may undergo before its removal from its metabolic pool.)

References:
[1] Handbook of Thermal Analysis and Calorimetry by Michael E. Brown, Patrick K. Gallagher. Elsevier Publishing, 2003.

[2] Chemistry and Chemical Reactivity by John C. Kotz, Paul M. Treichel, Gabriela C. Weaver
Published by Thomson Brooks/Cole, 2005.

[3] Differential Scanning Calorimetry By G.W.H. Höhne, W.F. Hemminger, H.-J. Flammersheim, Published by Springer, 2003

D. C. Simonson, R. A. DeFronzo , Indirect calorimetry: methodological and interpretative problems. American journal of Physiology, Endocrinology and Metabolism 258: Pages E399-E412, 1990.

Julian M. Sturtevant, Biochemical applications of differential scanning calorimetry. Annual Review of Physical ChemistryVol. 38: 463-488. 1987.

Further Reading:
Principles of Thermal Analysis and Calorimetry by P.J. Haines

Comprehensive Handbook of Calorimetry and Thermal Analysis by The Japan Society of Calorimetry and Thermal Analysis

Journal of Thermal Analysis and Calorimetry

Calorimetry and Thermal Analysis

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