Problem Set #1

A. Please explain the following terms:


LG-W11-Ameyaw, Condon, Ikonomu, Morgan, Patel, and Tashakor
(1) Pharmacophore and auxophore

Pharmacophore - the molecular framework that carries the essential features responsible for a drug's activity

Auxophore - the rest of the molecule, not required for the drug's activity

LG-W17-Badr, Dean, Judge, George, Quinlan, and Verma
(2) USP and BP

USP = United States Pharmacopeia
BP = British Pharmacopeia

LG-W18-Bagas, Diec, Kahura, Nguyen, Rodrigues, Vu
(3) Monosaccaride, oligosaccharide, and polysaccharides

Monosaccharides are simple sugars. They consist of an aldehyde or ketone with multiple carbon connected to hydroxyl group. They are use as building block for complex sugar. They are classify by the number of carbon atoms in the molecule; trioses have three, tetroses four, pentoses five, hexoses six, and heptoses seven. (examples: glucose, lactose, ribose). Can be linear or cyclic.
Oligosaccharide is a polymer consisting of 3-6 units of monosaccharides linked by glycosidic bonds.
Polysaccharides are made up of chains of monosaccharides which are linked together by glycosidic bonds (examples glycogen, cellulose).


LG-W12-Anderson, Conti, Iromuanya, Morin, Patel, Tchani
(4) Glucuronic acid and gluconic acid
Glucuronic acid is similar to glucose, except the 6th carbon is oxidized to a carboxylic acid. It shouldn't be confused with gluconic acid, which is a linear caboxylic acid with a different carbon atom oxidized.


LG-W19-Balkhi, Dion, Kammermayer, Nguyen, Roth, and Walden
(5) Glycosaminoglycan- long chain unbranched polysaccharide with repeating dissaccharide units. Examples include chondroitin, heparin, keratan.




B. Discuss the possible pharmacological/pharmaceutical consequences when a drug has more than one stereoisomer

Solution #1 by LG-W13-Asal, Danella, Islam, Myzyri, Pereira, and Thomas
One isomer may be active and the other may not.
Different isomers may be needed to bind to specific proteins in the body.
Different isomers can cause different effects in side effects, toxicities etc due to absorption, protein binding, and metabolism changes.

Solution #2 by LG-W14-Asante-Somuah, Dang, Jackson, Nammour, Peters, and Tolpa
Different isomers can have different physiochemical properties, such as melting point, boiling point, and solubility.
Pharmacological action is determined by an isomer's ability to bind to it's specific receptor. No other isomer will fit into the active site of the receptor.

C. If a compound has n chiral carbon atoms, theoretically how many stereo isomers can this compound have?

Work #1 by LG-W15-Aubin, Dauphinais, Jashari, Nayar, Potvin, and Tran
Number of steroisomers in a compound is equal to 2^n where n= the number of structural units capable of sterochemical variation. Structural units include chiral carbons or cis/trans double bonds.

number is reduced to less than 2n if meso forms are possible


Work #2 by LG-W16-Badavas, Davis, Jorgensen, Nelson, Pratt, and Vakil
2^n

D. Is Na
+-K+-ATPase an ion channel, or a receptor, or an enzyme? Please justify your answer.
Work #1 by LG-W17-Badr, Dean, Judge, George, Quinlan, and Verma

The correct answer is all of the above.
Because there are binding sites on the Na+K+ATPase, it is considered a receptor for sodium and potassium. It is considered and enzyme because it can open and close with activation of a phosphate group. Finally, it is considered a receptor because the purpose of the pump is to transport ions across a barrier.

Work #2 by LG-W18-Bagas, Diec, Kahura, Nguyen, Rodrigues, Vu

All of above
Ion Channel -- allow ions to pass through membrane
Receptor - Binding of the K+ and Na+ tp the receptor.
Enzyme - attachment/cleavage of the P open the channel. (allow K+ and Na+ bind/release)



E. Please draw and compare the chemical structures of the following nitrogen-containing groups


LG-W19: Balkhi, Dion, Kammermayer, Nguyen, Roth, and Walden
a. Nitric oxide b. Nitrous oxide c. Nitric acid

nitric oxide
See full size image
See full size image

nitrous oxide
nitric acidexternal image 250px-Nitrous-oxide-2D-VB.png
external image 150px-Nitric_acid_resonance_median.png
- all contain N, O
-differ in their bonding and amount of N, O, H


LG-W20: Basmadjian, Donnelly, Karki, Nwafor, Safo, and Wallace



external image 200px-Nitrous_acid_acsv.svg.png
d. Nitrous acid


File:Nitrite-ester-2D.png
File:Nitrite-ester-2D.png


e. Organic nitrite


external image 200px-Nitrate-ion-2D.png

f. Organic nitrate



g. Thionitrate