ANSWER THE EXAMINATION OF NATURAL PRODUCT CHEMISTRY

1.  Fats generally are solid while the oil is liquid phase. However both are equally triglyceride. explain why the form of the different triglyceride, and point out important factors that determine the form of fat. why?

Answer:

fatty acids are divided into saturated fatty acids and unsaturated fatty acids. Saturated fatty acids have only single bonds between its constituent carbon atoms, while unsaturated fatty acids having at least one double bond between carbon atoms of the constituent.

Fats and oils can be distinguished by double bonds (saturated and unsaturated). Saturated if it has only one double bond and unsaturated fat if it have two and three double bonds. so the fat is saturated fatty acids, while oils are unsaturated fatty acids.

Saturated fatty acids (fats) are fatty acids containing a single bond in the hydrocarbon chain. Saturated fatty acids have a zig-zig chains that can be matched to each other, so that high vanderwalls gravity, so the usually solid. Whereas unsaturated fatty acids (oils) are fatty acids containing one or more double bonds in the hydrocarbon chain. unsaturated fatty acid structures composed of irregular gravity vanderwalls so low. so it is usually a liquid.

Factors that determine the form of fat:

·         presence of single bonds and double bonds. saturated fatty acids (fats) contain single bonds, while unsaturated fatty acids (oils) contain a double bond.

·         Structure of saturated fatty acids (fats): compact and regularly. While structure of unsaturated fatty acids (oils): not neatly organized and irregularly

·         van der Waals force on saturated fatty acids (fats): High. While van der Waals force on unsaturated fatty acids (oils): low

Example saturated fatty acid (fats):

butirat acid (CH3(CH2)2CO2H)

Example unsaturated fatty acid (oils):

linoleat acid  CH3(CH2)4CH=CHCH2CH=CH(CH2)7CO2H

2.  2. A primary metabolite can be converted into secondary metabolite. What is the basic idea and how the mechanism could be described.

Answer:

A Primary metabolite  can be converted into secondary metabolite from the reaction the fundamental processes of photosynthesis, glycolysis, and the Krebs cycle are tapped off from energy-generating processes to provide biosynthetic intermediates. To make biosynthesis intermediets needs the buillding blocks. 

The building blocks for secondary metabolites are derived from primary metabolism.

The most important building blocks employed in the biosynthesis of secondary metabolites are derived from:

1.              Acetyl coenzyme A (acetyl-CoA)

The form in which acetate is used in most of its important biochemical reactions is acetyl coenzyme A (acetyl-CoA).

Acetyl-CoA is formed by oxidative decarboxylation of the glycolytic pathway product pyruvic acid.

2.              Shikimic acid

Shikimic acid is produced from a combination of phosphoenolpyruvate, a glycolytic pathway intermediate, and erythrose 4-phosphate from the pentose phosphate pathway.

3.              Mevalonic acid

4.              1-deoxyxylulose 5-phosphate

Deoxyxylulose phosphate arises from a combination of two glycolytic pathway intermediates, namely pyruvic acid and glyceraldehyde 3-phosphate.

5.              Amino acids

Deoxyxylulose phosphate arises from a combination of two glycolytic pathway intermediates, namely pyruvic acid and glyceraldehyde 3-phosphate.

3.      3.  Hormone progesterone is essential for the survival of the pregnancy. these hormones are derived from steroid biogenetically. explain the logic of chemical reactions which may occur in the formation of progesterone:

Answer: 
The chemical reactions which may occur in the formation of progesterone:  Before that, Progesterone is a steroid hormone that plays a role in a woman's menstrual cycle, supporting the process of pregnancy, and embryogenesis. Progesterone is the hormone progestogen group belonging, and a progestogen hormone which is widely available in nature.

Biosynthesis of progesterone:

In mammals, progesterone, like all other steroid hormones, is synthesized frompregnenolone (3), which in turn is derived from cholesterol  (see the upper half of the figure to the right).

This reaction is catalyzed by cytochrome P450scc. The conversion of pregnenolone to progesterone takes place in two steps. First, the 3-hydroxyl group is oxidized to a keto group and second, the double bond is moved to C-4, from C-5 through a keto/enol tautomerization reaction.  This reaction is catalyzed by 3beta-hydroxysteroid dehydrogenase/delta-delta isomerase.

Progesterone in turn (see lower half of figure to the right) is the precursor of the mineralocorticoid aldosterone, and after conversion to 17 hydroxyprogesterone (another natural progestogen) of cortisol and androstenedione.  Androstenedione can be converted totestosterone, estrone and estradiol. Pregenolone and progesterone can also be synthesized by yeast.

4.      4.  Many alkaloids are toxic to other organism. They often have pharmacological effects and are used as medications, as recreational drugs, or in entheogenic rituals. Describe in outline the process of biosynthesis of an alkalois compound and describe the functions groups which play an important role in the biological activities.

Answer: 

The process of biosynthesis of an alkaloid compound and the function groups which play an important role in the biological activities:

The morphine is biosynthesized from the tetrahydroisoquinoline reticuline. It is converted into salutaridine, thebaine, and oripavine. The involucrated enzymes in this process are the salutaridine synthase, salutaridine: NADPH 7-oxidoreductase and the codeinone reductase.