1. MEDC 527 Fall 20081 OrganoSulfur Compounds Sulfur (S) S and O :: atomically similar Sulfur also intimately involved in biological processes Sulfur forms two bonds in a manner similar to O But sulfur may form more because of the presence of d-orbitals, e.g., –S(O)– and –S(O 2 )–

2. MEDC 527 Fall 20082 OrganoSulfur Compounds Sulfur compounds that have an O analog … without O analog

3. MEDC 527 Fall 20083 OrganoSulfur Compounds Nomenclature Thiols: CH 3 SH methane thiol or methylmercaptan or mercaptomethane PhSH benzene thiol or phenylmercaptan or mercapto benzene Sulfoxides and Sulfones CH 3 S(O)CH 2 CH 3 methyl ethyl sulfoxide CH 3 S(O 2 )CH 2 CH 3 methyl ethyl sulfone

4. MEDC 527 Fall 20084 OrganoSulfur Compounds + H 3 NCH(COO - )CH 2 CH 2 CONHCH(CH 2 SH)CONHCH 2 COO - or + H 3 NCH(COO - )CH 2 CH 2 CO-CYS-GLY Common and Important Sulfur Compounds — Glutathione Involved in a variety of detoxification, transport and metabolic processes Substrate for peroxidase reactions Maintains balance of sulfhydryl groups (-SH of Cys) in proteins — Coenzyme A Plays a major role in the biosynthesis and metabolism of a number of important molecules, including fatty acids

5. MEDC 527 Fall 20085 OrganoSulfur Compounds Common and Important Sulfur Compounds — S-Adenosylmethionine — Heparin, Heparan Sulfate, Chondroitin Sulfate … Glycosaminoglycans have numerous physiological roles Plays a major role in the methyl transfer reactions, e.g. onto phenolic groups or DNA …

6. MEDC 527 Fall 20086 Heterocycles Containing Sulfur Basic Ring Systems Examples in Drugs (Antihistamine) (Antibiotic) (Antimalarial)

7. MEDC 527 Fall 20087 OrganoPhosphorus Compounds Phosphorus (P) N and P :: atomically similar Phosphorus is an important part of most important biological materials, DNA, RNA, ATP, … Phosphorus forms three bonds like N But P may form more because of d-orbitals

8. MEDC 527 Fall 20088 OrganoPhosphorus Compounds Comparison of reactions of P and N ….in acidification …. in quaternary salt formation ….in oxidation Differences Maximum # bonds with N = 4; it is 5 or 6 with P depending on the number of d- orbitals involved P does not form many unsaturated compounds because of poor p-p overlap, e.g, no – P=P- known (diazo are known); nor are phosphorus analogs of nitriles or amides Few unsaturated P compounds known, nearly all have P=O (double bond with oxygen) P does not give stable aromatic compounds, e.g., no phosphorus analog of pyrrole or pyridine is known Similarities

9. MEDC 527 Fall 20089 OrganoPhosphorus Compounds Phosphate buffer RNA ATP