Methodical Instruction for Students of the 1 Course Medical Faculty
LESSON № 4 (PRACTICAL – 6 HOURS)
Themes: 1. Heterocyclic compounds. Structure, composition and properties of biological-active heterocyclic compounds. Structure, composition, properties and biological role of alkaloids.
2. Nucleic acids. Structure and properties nucleic acids.
Aim: to be able to study structure and properties biological-active heterocyclic compounds; structure and properties nucleic acids. To determine heterocyclic compounds by qualitative tests; component of nucleotides by qualitative test in solutions.
Professional orientation of students:
The most of heterocyclic compounds are biological active natural compounds. Knowledge structure and properties of heterocyclic compounds have been necessary for understanding processes of a metabolism in an organism. Some of them are structural component of proteins, enzymes, vitamins, nucleic acids and other compounds are formed in an organism. Some alkaloids are natural nitrogen-contain heterocyclic compounds, derivates, which have been used as drugs. A lot of heterocyclic compounds are medicine. For example amidopyrinum, furacilinum, fnalginum.
Knowledge of structure and properties heterocyclic compounds; to be able to determine they by qualitatively test in solutions are necessary for investigation them in pharmacology, biological chemistry, therapy, surgery.
The nucleic acids play the main role in preservation and transfer genetic information, in which synthesis specific proteins was depended. Therefore knowledge of a structure and properties of nucleic acids important for understanding of processes of habitability and originating of pathologies, parentage of genetic molecular diseases, which one will be studied in a course of physiology, biological chemistry.
Methodology of Practical Class (900-1200).
Investigation of structure, physical and chemical properties of heterocyclic compound, alkaloids and Nucleic acids. Mechanism of nucleophilic addition reactions and nucleophilic substitution reactions.
I. Heterocyclic compounds. Structure, composition and properties of biological-active heterocyclic compounds. Structure, composition, properties and biological role of alkaloids.
Work 1. To determine antipyrinum and amidopyrinum by iron chloride.
Materials. 0,1 mol/l iron chloride solution, crystalline antipyrinum and amidopyrinum solution.
Protocol. Take two tubes:
In one of them add: some crystalline of antipyrinum;
5-7 drops water (antipyrinum can dissolve);
1 drop iron chloride solution FeCl3. (Orange-red colour solution can be)
In other add: some crystalline of amidopyrinum;
5-7 drops water (amidopyrinum can dissolve);
1 drop iron chloride solution FeCl3. (violet colour solution can be, which change to white after some time, because add 3 drops iron chloride solution FeCl3).
This reacting will be used for definition of antipyrinum and amidopyrinum in solutions.
Work 2. To determine antipyrinum and amidopyrinum by nitrous acid.
Materials. 0,5 mol/l sodium nitrite solution NaNO2, 2 mol/l sulfuric acid solution H2SO4, crystalline antipyrinum and amidopyrinum solution.
Protocol. Take two tubes:
In one of them add: some crystalline of antipyrinum;
4 drops water (antipyrinum can dissolve);
2 drops sulfuric acid solution H2SO4;
2 drops sodium nitrite solution NaNO2;
Emerald -green colour solution can be, which change to white after some time.
In other add: some crystalline of amidopyrinum;
4 drops water (antipyrinum can dissolve);
2 drops sulfuric acid solution H2SO4;
2 drops sodium nitrite solution NaNO2;
Violet colour solution can be, which change to white after some time.
This reacting will be used for definition of antipyrinum and amidopyrinum in solutions.
Work 3. To investigate dissolubility of uric acid and sodium urate in water.
Materials. ammonia chloride solution, sodium hydroxide solution, crystalline uric acid
Protocol. Add in the tube:
some crystalline of uric acid and 5-7 drops water (The cloudy solution of uric acid has been formed).
10 drops of sodium hydroxide solution (precipitate can dissolve, because formed middle sodium salt of uric acid)
Work 4. Reduction properties of uric acid.
Materials. uric acid solution, which made in last experiment, 2 mol/l ammonia chloride solution, 0,2 mol/l silver nitrate solution
Protocol. Add in the tube:
1 drop silver nitrate solution;
3-4 drops of ammonia chloride solution;
1 drop uric acid solution, which made in last experiment.
This mixture are warmed. The black colour precipitate silver is formed.
Work 5. To determine uric acid by Murexide test.
Materials. strong nitric acid solution HNO3, 0,5 mol/l potassium hydroxide solution, sodium urine solution, which you made in last experiment.
Protocol. Add in the microscope slide:
1 drop sodium urine solution, which you made in last experiment
1 drop of strong nitric acid solution HNO3;
Glass heated to solution was evaporated and red colour solid is formed. After cooling microscope slide add 1drop potassium hydroxide solution. Red violet colour compounds have been farmed.
This reacting will use for definition uric acid and its salts, urinary rockss, and also for determine a coffeine, theobrominum and other purine bases.
Work 6. Common reactions on alkaloids.
Materials. 1 % quinine hydrochloride solution, 0,1 % iodine solution, 0,5 % tanninum solution, picric acid saturated solution.
Protocol. Add in the tube:
1 drop of 1 % solution of quinine hydrochloride
6 drops water
3 drops this solution put by the pipette on microscope slide (The drops should beat on some spacing interval one from other)
Near one of drops put on 1 drop of iodine solution, near second put on 1 drop tanninum solution, and near third put on 1 drip of picric acid saturated solution. Precipitations are derived, if alkaloids are in solution.
Work 7. Influencing of solvents on salt of alkaloids.
Materials. 1 % quinine hydrochloride solution, 2 mol/l sodium hydroxide solution, 2 mol/l sulfuric acid solution, picric acid saturated solution, chloroform.
Protocol. Add in the tube:
1 drop of 1 % solution of quinine hydrochloride
6 drops water
2 drops sodium hydroxide solution
White colour precipitation is derived. It is frees quinine, which is base, and was not dissolved in water.
In this tube add 8 drops of chloroform and mixed. Two phases are formed: water and chloroform phases.
1 drop of water solution put by the pipette on microscope slide and 1 drip of picric acid saturated solution.
Precipitation was not formed, because quinine has not in water solution.
In same tuber add 2 drops sulfuric acid solution, 1 drop of water solution put by the pipette on microscope slide and 1 drip of picric acid saturated solution. Precipitation was formed, because quinine has in water solution. It solved in acid water solution.
Work 8. Reacting of quinine with bromine water and ammonia.
Materials. 1 % quinine hydrochloride solution, 2 mol/l ammonia hydroxide solution, saturated bromine solution.
Protocol. Add in the tube:
1 drop of 1 % solution of quinine hydrochloride
6 drops water;
2 drops bromine solution;
2 drops ammonia hydroxide solution.
After that solution is green colour.
II. Nucleic acids. Structure and properties nucleic acids.
Work 9. "Argentine" test on the purine bases.
Materials. 0,5 % solution of a nucleic acids hydrolysate, 2 mol/l ammonia hydroxide solution, 0,2 mol/l silver nitrate solution
Protocol. Add in the tube:
1 drops silver nitrate solution;
3-4 drops of ammonia hydroxide solution;
5 drop of a nucleic acids hydrolyzed solution.
The gray color precipitate silver is deposed.
Work 10. To determine pentoses by Molich’s reaction.
Materials. 0,5 % solution of a nucleic acids hydrolysate, solution of sulfuric acid, alcohol solution of thymol
Protocol. Add in the tube:
5 drops 0,5 % solution of a nucleic acids hydrolysate
10 drops of solution of sulfuric acid
some crystalline of thymol
This mixture are warmed, the solution has been red color
Work 11. To determine phosphoric acid by molybdenum reagent.
If in solution present phosphoric acid, so after added to this solution molybdenic reagent liquid yellow color have been formed.
Materials. 0,5 % solution of a nucleic acids hydrolysate, molybdenic reagent (mixture, which contain solution of ammonium molybdate and nitrate acid)
Protocol. Add in the tube:
5 drops 0,5 % solution of a nucleic acids hydrolysate
10 drops of solution of molybdenic reagent
This mixture are warmed, the solution has been yellow color
Individual Students Program.
I. Heterocyclic compounds. Structure, composition and properties of biological-active heterocyclic compounds. Structure, composition, properties and biological role of alkaloids.
1. Heterocyclic compounds. Classification.
2. Five-ring heterocyclic compounds. Their properties and structure. Properties of pyrole, imidazole, thiazole.
3. Six-ring and seven-ring heterocyclic compounds. Their properties and structure. Properties of pyridine, diazines.
4. Bicyclic heterocyclic compounds, their biological role (purine, and its derivative).
5. Alkaloids. Biological functions of alkaloids.
6. Classes of alkaloids.
II. Nucleic acids. Structure and properties nucleic acids.
1. Nucleic acids Types of nucleic acids.
2. Nucleic acids composition.
3. Chergaff’s rules.
4. Primary structure of nucleic acids.
5. Secondary structure of DNA: double helix.
6. Levels of structural organization RNA. Biological functions.
7. Biosynthesis of proteins.
8. Use of synthetic nucleic acid bases in medicine. Biological role ATP (adenosine triphosphate), NAD (nicotinamide adenine dinucleotide).
Seminar discussion of theoretical issues (1200 – 1400 hour).
Test evaluation and situational tasks.
1. What from complementary pairs of nitrogen bases are characteristic for DNA, and for RNA
a) A -T, G - C;
b) A – U, G – C.
2. Hydrolysate of nucleic acids is in two tubes: if added to one of tubes thymol, so formed red color solution. And if added to another tube added molybdenum reagent, so formed yellow color solution. Which component of nucleic acids is in those tubes?
3. The formula of which from the medicinal matters contains imidasole?
A. Analgin;
B. Histamine;
C. Antipyrine;
D. Amidopyrinum;
E. Furacyline.
4. Guanine is nitric basis, which is in molecule of nucleotides. Guanine is derivative of such heterocyclic compound:
A. Pyridine;
B. Pyrimidine;
C. Pyrrole;
D. Purane;
E. Pyrasol
Correct answers of test evaluations and situational tasks:
1. A -T, G – C in DNA; A – U, G – C in RNA.
2. In first tube is pentose (ribose or desoxyribose), in second is phosphatic acid.
3. d; 4. d.
Individual student work (1415-1500 hour) are checked by solving situational tasks for each topic, answers in test evaluations and constructive questions (the instructor has tests & situational tasks).
Students must know:
- The biological role and chemical properties of heterocyclic compounds;
- Structure of heterocyclic compounds;
- Properties of heterocyclic compounds;
- the biological role and chemical properties of alkaloids;
- chemical properties of alkaloids methods;
- The biological role and chemical properties of nucleic aced;
- Structure of nucleic aced;
- Properties of nucleic aced.
Students should be able to:
- Determine the heterocyclic compounds in solution by qualitative test;
- determine the alkaloids in solution by qualitative test;
- Determine the nucleic aced components in hydrolysate solution by qualitative test.
References:
Basic:
1. Andrew
Streltwieser, Jr. Clayton H. Hcathcocr. Introduction to Organic Chemistry. -
2. David Gutsche C., Baniel
J. Pasto. Fundamentals of Organic Chemistry. -
3. Lewis D.E. Organic chemistry. A modern perspective. – Copyright, 2006. 1138 p.
4. http://intranet.tdmu.edu.ua/data/kafedra/internal/zag_him/classes_stud/biological and bioorganic chemistry/medical/1 course/lesson 4. Heterocycles. Nucleotides. Nucleic acids
Additional:
1. Andrew Streltwieser, Jr. Clayton
H. Hcathcocr. Introduction to Organic
Chemistry. -
2. Lewis D. E. Organic chemistry. A modern perspective. – Copyright, 2006. P. 25 – 95
The methodical instruction has been worked out by: Associate Prof. Dmukhulska Ye. B.
Methodical instruction was discussed and adopted at the Department sitting
25.06.2013. Minutes N 11
Methodical instruction was adopted and reviewed at the Department sitting
27.08.2013. Minutes N 1