OrganoSulfur Compounds

1
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(O2)

2
OrganoSulfur Compounds
Sulfur compounds that have an O analog
without O analog
3
OrganoSulfur Compounds
Nomenclature Thiols CH3SH methane
thiol or methylmercaptan or mercaptomethane
PhSH benzene thiol or
phenylmercaptan or mercapto benzene Sulfoxides
and Sulfones CH3S(O)CH2CH3 methyl ethyl
sulfoxide
CH3S(O2)CH2CH3 methyl ethyl sulfone
4
OrganoSulfur Compounds

• Common and Important Sulfur Compounds

H3NCH(COO-)CH2CH2CONHCH(CH2SH)CONHCH2COO-
or H3NCH(COO-)CH2CH2CO-CYS-GLY
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
OrganoSulfur Compounds

• Common and Important Sulfur Compounds

S-Adenosylmethionine

• Plays a major role in the methyl transfer
  reactions, e.g. onto phenolic groups or DNA

Heparin, Heparan Sulfate, Chondroitin Sulfate

• Glycosaminoglycans have numerous physiological
  roles

6
Heterocycles Containing Sulfur

• Basic Ring Systems

• Examples in Drugs

(Antihistamine)
(Antibiotic)
(Antimalarial)
7
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
OrganoPhosphorus Compounds
Comparison of reactions of P and N

• Similarities

.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 PP- known
  (diazo are known) nor are phosphorus analogs of
  nitriles or amides
• Few unsaturated P compounds known, nearly all
  have PO (double bond with oxygen)
• P does not give stable aromatic compounds, e.g.,
  no phosphorus analog of pyrrole or pyridine is
  known

9
OrganoPhosphorus Compounds
Phosphate buffer
ATP
RNA