Kharkiv National Medical University Department of Medical and B ioorganic chemistry

1. KharkivNational Medical University Department of Medical and Bioorganic chemistry «Biological and Bioorganic Chemistry» Lecture№ 1 CLASSIFICATION, STRUCTURE AND REACTIVITY OF BIOORGANIC COMPOUNDS Lecturer: As. Professor, Department of Medical and Bioorganic Chemistry,, Ph.D. LukianovaL.V.

2. Bioorganic chemistry is based on Organic chemistry. Organic chemistry is the chemistry of the compounds of carbon. Carbon forms more compounds than any other element.

3. A. M. Butlerov's Theory of Chemical Structure • Atoms of elements, which form molecules, are combined in definite order according to their valence and all valences should be used to combine each other. • 2. Properties of organic compound depend not only on its composition but on its structure as well, i.e. on the order of combining of atoms in a molecule and a character of bonds. • 3. Atoms in a molecule influence each other and especially those, which are directly combined.

4. Isomerism • Isomers have identical qualitative and quantitative composition but different physical and chemical properties. • Compounds that have: • The same molecular formula. • Similar or different types of structural formulas. • Different arrangement of atoms. • Isomerism of organic compounds is explained by the Theory of chemical structure • given by A. M. Butlerovin 1861

5. Types of isomerism

6. Classification of organic compounds

7. Classification of organic compounds • Halogen derivatives • Oxygen-containing: • Alcohols & ethers • Aldehydes & ketones • Carboxylic acids & esters • Nitrogen-containing: • Amines • Nitriles • Mixed: • Aminoacids • Peptides • Nitro compounds

8. C=O - carbonyl O O O O R – C – R R R R R C C C C OH H , NH2 O – R O O O O C C C OH OR NH2 Functional group Name of class General formula Halogen derivatives R – Hal –F, –Cl, –Br - halogens Alcohols, phenols –OH - hydroxyl R – OH Ethers –OR - alkoxy R – O – R R – SH –SH - thiol Thiols R – S – R Thioethers (sulphides) –SR - alkylthiol –SO3 - sulphonic Sulphoacids R – SO3H Amines R – NH2, R2NH, R3N –NH2, =NH2,≡N - amino Nitrocompounds R – NO2 –NO2 - nitro Nitriles R – C ≡N –C≡N - cyano Aldehydes, ketones - carboxyl Carboxylic acids -alkoxycarbonyl Esters Amides - carboxamide

9. 3 2 1 CH3 – CH – COOH OH 2 – hydroxypropanoic acid prefix root secondary suffix primary suffix Nomenclature For a long time, organic compounds were named by common names, generally given after the name of source from which they were obtained (Trivial nomenclature): Citric acid, Lactic acid. Now IUPAC has developed a new system of naming compounds which is known as IUPAC Nomenclature. Lactic acid

10. What makes carbon so special? • It has a “central” role in all living organisms. • It has 4 valence electrons. • It makes 4 covalent bonds. • It can bond with any element, but really loves to bond with other carbon atoms and make long chains

12. 2p 2s 1s 2p 2s 1s Structure of organic compounds Types of hybridization C6 1s22s22p2 Ground state of carbon atom C* Carbon atom in excited state

13. 2p 2s + s p sp3 H sp3-hybridization C* Tetrahedron Methane CH4

14. 2p 2s s p sp2 Ethene C2H4 (CH2=CH2) σ-bond σ-bonds π-bond overlap sp2-hybridization C* 120º

15. Radical substitution - SR

16. CnH2n Cycloalkanes

17. Chemical properties of cycloalkanes Small cycles show some particular properties:

19. Addition to the double bond – AdE reactions Markovnikov rule

20. Structure of alkynes: σ- and π-bonds

21. Carbon forms Rings • Carbon-based molecules also can be shaped like rings. Most carbon rings contain 5 or 6 carbon atoms. • One of the most important carbon rings is benzene. • It has 6 carbons & 6 hydrogens, with alternating double bonds. • All carbon atoms are sp2-hybridized.

22. Carbon forms Rings • Many compounds are based on Benzene. • They often have very strong smells or aromas, so they are called aromatic compounds. • An example of one aromatic compound is a molecule called vanillin.

23. Benzene C6H6 or Aromatic compounds All carbon atoms are sp2-hybridized Kekulé structure