Biocoordinate Chemistry

Question 1

Bridging Ligand Def.

Answer 1

In atoms with >1 lone pairs the ligand can act as a bridge between 2 different metal ions

Question 2

Example of bidentate ligands

Answer 2

ethylenediamine

Question 3

Chelating Agent

Answer 3

Lewis Base that forms 2 dative bonds with the same metal ion.

Question 4

Chelate Def.

Answer 4

Complex with chelating agent that forms a ring structure

Question 5

What factor contributes to chelate stability

Answer 5

The size of it’s ring. 5 membered (5 sides) are the most stable

Question 6

Oxaliplatin Outline

Answer 6

Colon cancer drug is more stable then cisplatin as it forms 2 5-memberd rings. Increase in stability results in decrease in toxic side effects and increase in drug reaching target site

Question 7

How to improve stability

Answer 7

Get ring members closer to 5 and have atom closer to metal be negative so that positive metal is attracted

Question 8

Example of Hexdante ligands

Answer 8

Ethylenediamine tetraaceticacid (EDTA)

Question 9

How does Ca(EDTA) reduce lead poisoning

Answer 9

EDTA has a higher affinity for lead as lead’s bigger size fits more snuggly then Ca into the complex. Ca is displaced by lead from blood stream. Lead effects are neutralized in complex

Question 10

Disease Chelation Therapy Targets

Answer 10

Coronary Artery Disease and Atherosclerosis

Question 11

Coronary Artery Disease Outline

Answer 11

Build up of plaque within artery walls. Blocks blood flow often resulting in heart attck

Question 12

Atherosclerosis Outline

Answer 12

Calcium compounds/lipids form plaques in coronary arteries resulting in blockage

Question 13

Chelation Therapy Def.

Answer 13

Admin of chelating agents (by IV, IM or oral admin) to mobilize/remove excess metal ions from body

Question 14

Chelating Drugs 3 Areas of Clinical Use

Answer 14

Removal of metal ions present due to genetic disorders, Treatment of heavy metal due to enviormental pollution, removal of Ca containing plaques (prevent blood vessel degeneration)

Question 15

Treatment of atherosclerosis and coronary artery disease

Answer 15

Admin of Mg EDTA complex. Ca2+ ions in blood displace Mg (Ca is bigger and better fits complex). Ca in plaque breaks down to replace Ca2+ ions in blood

Question 16

Thalassemia Def.

Answer 16

Genetic blood disorder caused by variant/missing genes. Effects Alpha + Beta proteins in hemoglobin thus resulting in anemia. Treated by blood transfusion

Question 17

Problem associated with transfusion and solution

Answer 17

May result in iron excess. Excess iron removed by desferal (contains hydroxamic acid groups)