This document provides information about Ahmed Metwaly's academic positions and research experience. It then discusses various types of monosaccharides (simple sugars containing five carbon atoms), including ribose, xylose, and arabinose. Examples of each monosaccharide are provided along with their sources and chemical tests.

1. Associate Professor of Pharmacognosy , Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt
•Associate Professor, City of Scientific Research and Technological Applications (SRTA-City), Alexandria,
Egypt
•Senior research fellow, Liaoning University of Traditional Chinese Medicine, China (20118-2019)
•Visiting scholar, School of Pharmacy, University of Mississippi, USA (2012-2014)
Ahmed Metwaly
Monosaccharides

2. ▪ Simple sugars containing five carbon atoms.
▪ Unfermentable by yeast (c.f. from hexoses).
▪ Give furfural when warmed with conc acids.
▪ Rarely present in the free state but generally occur as
pentosans or form the sugar moiety of glycosides.

3. CH
CH2OH
CH
CH
CHO
OH
OH
OH
D-Ribose
CH
CH2OH
CH
CH
CHO
OH
HO
OH
D-Xylose
CH
CH2OH
CH
CH
CHO
HO
HO
OH
L-Arabinose
In all plant and
animal cells as the
carbohydrate part of
Ribonucleic acid
(RNA).
-D-xylose (or wood sugar):
prepared from corncobs,
bran, straw (or any woody
material) by boiling with
acids, fermenting out any
glucose present with yeast,
and crystallizing the d-xylose
from the evaporated solution.
 -L-arabinose (or pectin
sugar): found in gums,
pectic substances,
accompanying
hemicelluloses and forms
the sugar part of several
glycosides
D- apiose (branched sugar):
obtained by hydrolysis of
flavone glycoside (apiin)
present in the leaves and
seeds of parsley

4. Chemical tests
1. Aniline acetate paper: Pentoses give a red stain with a paper moistened with aniline acetate
solution (c.f. Methylpentoses, which give a yellow stain).
2. Bial’s test: Pentoses give a green colour with Bial's reagent (orcinol/HCl).
3. Phloroglucin /HCl: Pentoses give a red colour, which changes to a brownish violet precipitate.

7. ▪ Properties
▪
▪ These contain six carbon atoms.
▪ They are fermentable by yeast.
▪ They give hydroxy- methyl furfural on treatment with conc acids.
▪ They occur free, combined as oligo- and polysaccharides, or forming the sugar part of glycosides.
Examples
▪ Two groups of commonly occurring hexoses are distinguished:
▪ The aldohexoses such as glucose, mannose and galactose.
▪ The ketohexoses such as fructose.

8. D-glucose (dextrose, grape sugar, blood sugar or cornmon sugar)
Preparation
▪ D-Glucose is commercially prepared from starch by:
1. Autoclaving (at 150 0C) an aqueous starch suspension (15-20%) with dilute acid (0.03 N hydrochloric acid) for 30
minutes (complete hydrolysis).
2. The mixture is then neutralized with sodium carbonate to pH 4 to 5.
3. Impurities are skimmed and filtered.
4. The filtrate is decolorized with charcoal, concentrated under reduced pressure and crystallized.
▪ Glucose can also be obtained from honey, which contains a mixture of glucose, fructose and sucrose, or by
▪ Inversion of sucrose.
Properties
▪ D-Glucose is white crystalline, sweet, readily soluble in water.
▪ It reduces Fehling's and Barfoed's solutions.
▪ It gives an osazone that crystallizes on hot (c.f. from the reducing disaccharides, maltose and lactose). Glucosazone
occurs in the form of golden yellow, needle -shaped crystals.

9. ▪Liquid glucose:
▪ Preparation:
It is prepared by partial acid hydrolysis of starch using dilute HCl and heating for 20 minutes
at about 30 pounds pressure.
▪ Composition:
It consists of a mixture of glucose, dextrin, maltose and water.
▪ Uses:
Used as sweetening agent, as substitute for sucrose and as an excipient in massing pills.

11. ▪ Mannose
▪
▪ Mannose is the C-2 epimer of glucose.
▪ It does not occur free in nature, but as constituents of many polysaccharides.
▪ It is prepared from the seeds of date, coffee and from ivory nuts during manufacture of buttons
by acid hydrolysis.
▪ It gives an osazone similar to that of glucose.
▪
▪ Galactose
▪
▪ Galactose is the C-4 epimer of glucose.
▪ It occurs as the sugar part of several glycosides.
▪ It is a constituent of many polysaccharides e.g. agar-agar & linseed mucilage.
▪ It is prepared by acid hydrolysis of agar or linseed mucilages.
▪ Determine liver function test (spillage of galactose in urine, indicate liver dysfunction).
HOW?
40 g of galactose are administered to the patient and urine is collected the next 5 hours, then tested for galactose
(Less < 3 gs Normal ; more > 3gs; some liver damage).

12. FRUCTOSE
▪ Preparation:
▪a) Acid hydrolysis of Inulin.
▪b) Hydrolysis of Sucrose.
Sucrose
Acid or Enzyme
Fructose + Glucose
Ca(OH)2
Ca fructosate
ppt
Ca glucosate
Solution
solution
Hydrolysis

13. ▪Test for ketoses:
▪Fructose + HCl + resorcinol, heat red color
▪Fructose + CaCl2 ppt
▪Uses:
▪ -Infant food.-
▪ -Diabetic food ???? (low glycemic factor) .
▪ - diet control
CH2OH
C
CH
CH
CH
CH2OH
OH
OH
HO
O
D-(-)-Fructose
O OH
CH2OH
HO
OH
HOH2C
-D-(-)-Fructofuranose

14. DEOXY-SUGARS
CHO
CH
CH
CH
CH
CH3
OH
OH
HO
Rhamnose
HO
CHO
CH2
CH
CH
CH
CH3
OH
OH
Digitoxose
OH
CHO
CH2
CH
CH
CH
CH3
OH
OH
Cymarose
OCH3
They are of little occurrence, common in cardiac glycosides and are
formed by removal of oxygen from carbon 2 or 6, or 2 and 6 to
produce 2-deoxy, 6-deoxy or 2,6 deoxy.
N.B. example of -L-deoxy sugar is Rhamnose
6-deoxy sugar 2,6-deseoxy sugar 2,6-deseoxy sugar
cardiac glycosides

15. KELLER KELLIANI TEST:
▪ 2-deoxy sugars gives positive results whether in the free state or in glycosidic combinations:
▪Dissolve sample in glacial acetic acid containing fecl3, add H2SO4 containing fecl3 on the wall of test tube. An intense green color
develops at the interface between the two layers, then spreads into the acetic acid layer (upper layer).
CHO
CH2
CH
CH
CH
CH3
OH
OH
Digitoxose
OH
CHO
CH2
CH
CH
CH
CH3
OH
OH
Cymarose
OCH3

17. ▪
▪is used (by i.v. or orally) for treatment calcium deficiency.
▪These salts are characterized by being more easily absorbed than other Ca
salts.

18. ▪ Hypocalcaemia
▪ Hyperkalaemia
▪ Magnesium sulphate overdose
▪ Hydrofluoric acid burns
The calcium gluconate reacts with hydrofluoric acid to form insoluble, non-toxic
calcium fluoride. In addition to a 2.5% calcium gluconate gel being applied directly to
the chemical burn
▪ nausea, constipation, and upset stomach.
▪ Rapid intravenous injections of calcium gluconate may cause hypercalcaemia, which can result in
vasodilation, cardiac arrhythmias, decreased blood pressure, and bradycardia.

19. FERROUS GLUCONATE
▪
▪ (orally or by i.v.) is used in iron deficiency.
▪ These salts are characterized by being more easily absorbed than other iron salts.

20. ▪Sugar alcohols
▪Preparation:
▪Sorbitol is prepared by reduction of glucose

21. Mechanism of action
Sorbitol exerts its laxative effect by drawing water into the large intestine,
thereby stimulating bowel movements.
Uses:
• mild laxative
• sweetening agent in dietetic food (not absorbed), chewing gum &
tooth pastes.
• Test of kidney function (iv), not metabolized.

22. ▪ Preparation
by reduction of mannose.

23. ▪ Osmotic diuretic
osmotic diuretic that is metabolically inert in humans and occurs naturally in fruits and vegetables
▪ cerebral edema, elevated intracranial pressure, and cerebrospinal fluid
Mannitol elevates blood plasma osmolality, resulting in enhanced flow of water from tissues, including the brain and cerebrospinal fluid,
into interstitial fluid and plasma. As a result, cerebral edema, elevated intracranial pressure, and cerebrospinal fluid volume and
pressure may be reduced.
▪ laxative, and in
▪ tests of kidney function (not metabolized if i.v.)
Toxicity
Mannitol overdose may result in bronchoconstriction and should be counteracted using a short-acting
bronchodilator and other symptomatic and supportive care,

24. GLUCOSAMINE
Source: strong acid hydrolysis of chitin (shells of crustaceae)
Uses : Glucosamine is generally used over the counter in the symptomatic treatment of
osteoarthritis and joint pain, frequently combined with chondroitin sulfate
It is currently not approved as a prescription product by the FDA, but is widely
available over the counter
O
CH2OH
H
H
OH
OH
H
H
NH2
OH
H

25. ▪ Osteoarthritis (OA) is a progressive and degenerative joint disease marked by loss of cartilage, bone
changes, and synovial membrane inflammation.
▪ provides a building block towards the synthesis of glycosaminoglycans (mucopolysaccharides),
slowing the progression of osteoarthritis and relieving symptoms of joint pain.
▪ Glycosaminoglycans or mucopolysaccharides are long, linear polysaccharides consisting of
repeating disaccharide units (uronic sugar and an amino sugar).
hyaluronic acid
(one of the Glycosaminoglycans )

26. ▪ Some in vitro studies show evidence that glucosamine reduces inflammation via inhibition of interferon gamma and Nuclear
factor kappa B.
Toxicity and side effects
The oral LD50 of glucosamine in rats is >5000 mg/kg.Symptoms of an overdose with glucosamine may include
nausea, vomiting, abdominal pain, and diarrhea

27. ASCORBIC ACID
Preparation:
-extraction from citrus fruits
- synthesis from glucose
Uses:
-Cure its deficiency (scurvy), cold, capillary fragility
-Antioxidant in some pharmaceutical preparations
O
HO
OH
HOHC
CH2OH
O

28. 1. In humans, an exogenous source of ascorbic acid is required for collagen formation and tissue repair by acting as
a cofactor in the synthesis of collagens and other proteins.
2. Ascorbic acid is reversibly oxidized to dehydroascorbic acid in the body.These two forms of the vitamin are
believed to be important in oxidation-reduction reactions.
3. The vitamin is involved in
▪ tyrosine metabolism,
▪ conversion of folic acid to folinic acid,
▪ carbohydrate metabolism,
▪ synthesis of lipids and proteins,
▪ iron metabolism,
▪ resistance to infections,
▪ and cellular respiration.