Unit I herbs as raw materials, biodynamic agriculture.ppt
PHYTOCHEMISTRY MCQS
1. CHAP 1 CARDIAC GLYCOSIDES
1. describe the chemical structure of cardiac glycosides
2. T/F aglycones are of cardiac glycoside are cardenolide and bufadienolide where
bufadienolide is more occurred in nature
3. T/F Aglycone of the cardiac glycosides are derived from mevalonic acid but the
final molecules arise from a condensation of a C21 steroid with a C2 unit (the
source of C-22 and C-23).
4. T/F Bufadienolides are condensation products of a C21 steroid and a C3 unit
5. T/F common to all the aglycones is the presence of two hydroxyl groups: one is
a 3 primary alcohol, the other is a 14 secondary alcohol
6. T/F The A, B, C and D rings normally have a trans-trans-cis configuration and
or less often, a cis-trans-cis configuration
7. T/F Conversion to A/B trans system leads to a marked drop in activity
8. T/F The activity is maximized when the A, B, C and D rings are in the cis,
trans, cis configuration AND The C and D rings must be TRANS fused
9. T/F Aglycone lactone ring with C24 is know as cardenolide
10.T/F in cardica glycoside The sugar moiety is generally linked to the aglycone
through the hydroxyl group at C-3
11.T/F The sugars cannot affect the activity of the glycosides.
2. 12.T/F The cardiac activity is linked to both the aglycone and glycone molecules
13.T/F The glycone participate directly in the activity by modifying the polarity of
the compound.
14.T/F The lactone is at C-17 may be in the configuration
15.T/F The saturated 17-lactone plays an important role in receptor binding and
unSaturation of the lactone ring dramatically reduced the biological activity.
16.T/F the substituents. The inversion of the configuration at C-3 diminishes the
activity, but 3-deoxy compounds are not completely inactive.
17.T/F A skeleton without 14b-OH group but retaining the C/D cis ring fusion was
found to loose activity.
18.T/F Comparison of digitoxin and digoxin structures reveals that they differ only
by an extra OH group in digoxin at C-14, yet their partition coefficients differ by
as much as 15 % points
19.T/F Lactones alone, when not attached to the steroid skeleton, are less active,
thus the activity I shared with steroid glycone and aglycone.
20.What are the solvent used in cardiac glycoside extraction
21.What is importance of the lead acetate in extraction process
22.What solvent /reagent will help in obtain glycoside for further characterisation
23.T/F The chloroform is helpful to precipitate the impurity during extraction of
the glycoside
24.T/F What is the best solvent for extraction of glycoside
25.T/F Characterisation depends only on the aglycone
26.T/F Reagent used in Raymond's test is methanolic alkali and Violet color
confirms the presence of cardiac glycosides
27.T/F In large doses they are toxic and bring about cardiac arrest in systole, but
in lower doses they are important drugs in the treatment of congestive heart
failure.
3. 28.T/F Digoxin is indicated for edema ,heart failure and hypotension
29.T/F Cardiac glycosides inhibit the membrane bound proton pump responsible.
30.Describe The Action Mechanism Of Digitalis
31.T/F The glycosides are thought to act at the membrane level, by inhibition of
the ATPase, which would result in an increase of the intracellular calcium ion
concentration
32.T/F you can manage digitalis intoxication by calcium administration
33.T/F Rifampin decrease the digoxin concentration
34.T/F Itraconazole which slows down the metabolism of digoxin
35. T/F Quinidine increase concentration of digitalis by inhibition of P-glycoprotein
36.T/F 5 g of powdered leaf of purple foxglove in 100 ml of water are used as
infusion
37.T/F Purple foxglove is indicated for the skin ulcer and scar wound
38.T/F Digitoxin is most widely used of the cardiotonic glycosides obtained from D.
purpurea, D. lanata WHILE Digoxin is a cardiotonic glycoside obtained from the
leaves of D. lanata.
39.T/F Digoxin is the most lipid-soluble of the cardiac glycosides used in
therapeutics while Digitoxin is a highly potent drug and should be handled with
exceptional care
40.T/F The major pharmacokinetic parameters for digitoxin include incomplete
oral absorption about 8o% hile digoxin is completely aborbed and quickly
eliminated
41.TF Digoxin may be indicated in patients with impaired renal function while
Digitoxin should cause harms
42.T/F Digoxin is indicated when the risk of digitalis intoxication is great, since it
is relatively short-acting and rapidly eliminated when compared with Digitoxin
43.T/F Bufadienolides are therapeutically much valued even though therapeutic
index is low and produce more side effect and it is widely used in the treatment
of cough.
4. CHAP 2: SAPONIN GLUCOSIDES
1. T/F Saponins constitute a vast group of organic compounds that form
persistent froth when shaken with water
2. T/F Saponins cause hemolysis of white blood cells, it means that injection into
the blood stream are more or less toxic.
3. T/F Saponins are very harmful when taken orally and more or less toxic as IV
injection
4. Briefly describe the classification of Saponins
5. List 10 properties of Saponins
6. What is the suitable solvent for Saponins extraction= water, alcohol methanol,
ethanol or hydroalcoholic
7. Why free drying is not much applicable in Saponins extraction=cause
hydrolysis of bidesmonsides
8. How the fat are separated from saponin =by use petroleum ether
9. What is the importance of treatment of the sample by HCl= to neutralize
esterase enzyme
10.What is the most useful alcohol in separation of water soluble compound and
Saponins = N-butanol
5. 11.How the saponin will be obtained= precipitate it by organic solvent then
conduct filtration to get precipitates
12.Pentacyclic Triterpenoid Saponins contain 30 carbons
13.Pentacyclic Triterpenoid are rare in dicots and common in monocots
14.Strophanthus and Digitalis contain both steroidal Saponins and cardiac
glycosides
15.Steroidal Saponins are both in monocots and dicots
16.Steroidal Formed via the mevalonic acid pathway.
17.Therapeutic properties of saponin , discuss
18.What is the cause of hemolysis of RBC by saponin = detergent properties
CHAP 3: QUINONES
O
O
O
O
OH
HHH
OH
O
O
H
10
Antraquinone
Reduction
Oxidation
Oxanthrone
Anthrone Anthranol
Dimerisation
dianthrone
Reduction
Oxidation
Reduction
Oxidation
1. T/F Simple benzoquinones are specific to Arthropoda and rarely found in high
plants.
6. 2. T/F Biosynthesis of quinones is done by different metabolic pathways from a
limited number of precursor’s acetate, mevalonate and phenylalanine
3. T/F Quinones with one aromatic ring is known as benzoquinones
4. T/F The quinones with two aromatic rings are known as anthraquinones
5. Discuss the properties of qunonoes
6. T/F Anthranol is a mediator of dianthrone and anthraquinone
7. T/F Oxidation of the anthraquinone yield oxanthrone
8. T/F Actually natural benzoquinones have therapeutics application and they occur
as glycoside some of them like arbutin possesses strong urinary antiseptic
activities
9. T/F Glycosides of anthranols and anthrones have a more drastic action than
anthraquinone glycosides
10.T/F as laxatives, cathartics, anti-inflammatory, antibacterial, antifungal & natural
dyes
11.T/F Some quinones serve as electron acceptors in electron transport chains such
as those in photosynthesis (plastoquinone, phylloquinone), and aerobic respiration
(ubiquinone). Phylloquinone is also known as Vitamin D1 as it is used by animals
to help form certain proteins, which are involved in blood coagulation, bone
formation, and other processes
CHAP 4: ANTHRAQUINONE GLYCOSIDE
7. 1. T/F Anthraquinone are characterized by presence of phenolic and glycosidic
compounds, derived from anthracene and have various degree of oxidation.
2. T/F They have in common a double oxidation at C1 & C8.
3. T/F Anthraquinone glycosides upon hydrolysis yield aglycone, which are di, tri
or tetra hydroxy anthraquinone or derivative of these compound
4. T/F o-succinylbenzoic acid (OSB) (the most common pathway in higher plants ,
OSB arise from the reaction of isochorismic acid with α-ketoglutaric acid in the
presence of thiamine pyrophosphate (TPP).
5. T/F Anthranonls and Anthrones are educed anthraquinone derivatives that
Occur only as glycosides.
6. T/F Anthranol is pale yellow, non-soluble in alkali, non-fluorescent while
Anthrone is brown-yellow, soluble in alkali, strongly fluorescent
7. T/F Anthronols and anthrone are the isomers of each other
8. T/F The quantification of free forms of quinones is useful as they have
significant therapeutic activity.
9. T/F Combined form and free form of the quinones are separated from each
other using the non-polar organic solvent where the free form are occurred in
aqueous phase and combined form occur in non-polar organic solvent.
10.T/F Herbal anthraquinones are possibly the most important herbal factors that
exert an action of irritation over your gastrointestinal system
11.T/F anthraquinone laxative herbs possess qualities of “sacral irritants” and
hence contraindicated in pregnancy, Senna has been shown to be very safe in
pregnancy and lactation
12.T/F The long term use of the anthraquinone glycoside induce the constipation
13.Stimulant laxative should not be done to patient suffering from spastic colon.
14.Aloe gel has laxative effect and is used in cosmetic, and topical products
15.Aloe gel has, interesting effects in treatment of asthma, peptic ulcers, hairloss,
as spermicide and as a cancer chemo-preventive agent
16.Aloe gel components inhibit the pain & promote wound healing also stimulates
fibroblast and connective tissue formation
8. 17.T/F Senna is manly used to treat constipation by stimulating of intestinal
peristalsis, flushing out the toxins from the body
18.T/F Senna laxative effect is attributed mainly to “the anthraquinone
glycosides, especially sennoside A and B
19.T/F The metabolism of the anthraquinone glycosides in the digestive tract can
occur in SINGLE ways.
REAGARDING SENNA MECHANISM
20.T/F The glycosides are not absorbed in the upper gut but are converted by the
microflora of the large intestine into active aglycones, principally Rhein
anthrone, which exerts a laxative effect on the colon
21.T/F Alternatively, in the presence of bile and the sugar, the free aglycone can be
absorbed into the blood stream and secreted later into the colon.
22.T/F The final result is stimulation of the Auerbach plexus (myenteric) resulting
in increased intestinal muscle contraction, Moreover, its mucilage content
decreases absorption of fluid leading to an enhancement of the final laxative
action.
23.T/F Pregnant, nursing or menstruating women should use Senna, but it is not
appropriate for children under twelve years of age
24.T/F Long time use of Senna are responsible of severe constipation and can
provoque heart failure
9. 26.T/F Rhubarb at the doses of 1g is used as laxative
27.T/F Rhubarb at doses of 3g is used as purgative
28.T/F Rumex abyssinicus, In Rwanda, the leaf of the plant is traditionally used to
treat malaria, gonorrhoea, constipation, poisoning, hepatitis, constipation and
sciatic neuralgia.
29.T/F Rumex abyssinicus , in Rwanda The root is used to treat coughs and
gastric ulcers
CHAP 5: CYANOGENIC GLYCOSIDE
1. T/F The cyanogenic or cyanogenetic glycosides may be defined chemically as
glycosides of beta hydroxynitriles and belong to the secondary metabolites of
plants
2. T/F All cyanogens are amino acid-derived plant constituents and are always
glycosides of 2-hydroxynitriles
3. T/F The combination of cyanogenic and cyanidrins is the means by which
cyanogenic plants are protected against predators.
4. T/F Upon consumption of a cyanogenic plant, β-glycosidase (a part of bacterial
microflora in GIT of mammals) will be released during digestion and remain
active until deactivated by the low pH of the stomach thus enzyme will
10. hydrolyse the cyanogenic glycoside and release at least part of the potential
hydrogen cyanide content of the plant.
5. T/F cyanogenic plants are characterised by free HCN in normaal plant tissues
6. T/F The plant injuries like mechanical damage should be the sources of release
of cyanide due cyanogen’s and hydrolytic enzymes contact.
7. T/F Beans and sorghum should be ones of cyanogen sources
8. T/F The biosynthetic precursors of the cyanogenic glycosides are different D-
amino acids, which are hydroxylated, then the N-hydroxylamino acids are
converted to aldoximes and these are converted into nitriles and hydroxylated
to α-hydroxynitriles and then glycosylated to cyanogenic glycosides
9. T/F All known cyanogenic glycosides are ALPHA-linked, mostly with D-glucose
10.T/F Aglycones are formed by α-hydroxynitriles, which are stabilised by glucosyl
bound to hydroxyl group of a sugar.
11.T/F The sugar residue is almost always D-glucose joined by an 0-beta-D-
glucosyl linkage
REGARDING THE MECHANISM OF ACTION OF CYANOGENIC GLYCOSIDE
12.T/F Hydrogen cyanide inactivates the enzyme cytochrome oxidase in the
mitochondria of cells by binding to the Fe3+ /Fe2+ contained in the enzyme then
provoque a decrease in the utilization of oxygen in the tissues.
11. 13.T/F Cyanide causes a decrease in blood glucose and lactic acid levels and a
decrease in the ATP/ADP ratio indicating a shift from aerobic to anaerobic
metabolism.
14.T/F Cyanide activates glycogenolysis and shunts glucose to the pentose
phosphate pathway decreasing the rate of glycolysis and inhibiting the
tricarboxylic acid cycle
15.T/F Hydrogen cyanide will reduce the energy availability in all cells, but its
effect will not affect the respiratory system and heart
16.T/F In blood hydrogen cyanide binds to iron in both haemoglobin and
methaemoglobin and forms cyanmethaemoglobin and cyanhaemoglobin
respectively
17.T/F The affinity of hydrogen cyanide to haemoglobin is used for treatment
18.T/F Cyanides and cyanic acid act as neurotoxins and they also bind to several
proteins damaging enzyme systems
19.T/F In chronic poisoning we can see increased respiration due to
“chemoreceptors” and respiration centre damage
Regarding cyanide biotransformation
20.T/F The major defence of the body to counter the toxic effects of cyanide is its
conversion to thiocyanate mediated by the enzyme rhodaminase
21.T/F limiting factor for the conversion of cyanide is thiosulphate
22.T/F dietary sulphur amino acids such as methionine and cysteine are
important in detoxification of cyanides
23.T/F cyanide may combine with niacin (vitamin B6) in detoxification to enhance
the of cyanide via urine and bile
24.T/F cysteine may react indirectly with the cyanide to form 2-imino-thiazolidine-
4-carboxylic acid, which is excreted in the feces and urine
25. T/F A minor amount may be converted into formic acid, which may be
excreted in urine.
12. 26.T/F methaemoglobin effectively competes with cytochrome oxidase for cyanide,
and its formation from haemoglobin, effected by sodium nitrile or amylnitrite, is
exploited in the treatment of cyanide intoxication
27.Briefly describe the mechanisms of dissociation of cyanide from cyanogenic
glycosides.
28.T/F Administration of nitrites – formation of methaemoglobin, which binds
cyanides – formation of cyanmethaemoglobin – administration of thiosulphates
– cyanides released from methaemoglobin react with them and form
thiocyanates
29.Lethal dose for humans is 0.5 – 3.5 mg/kg HCN
30.Plants detoxify HCN by conversion into Asparagine and beta-cyanoalanine
31.T/F Garification”, a process whereby fermented and dried cassava mash is
simultaneously cooked and dried in a shallow wok, resulted in a 90-93%
reduction in total cyanogen content .
32.T/F Overall, traditional African processes typically decrease the cyanogen
content of cassava by 97-99%.
33.T/F Plants with 20 mg HCN /100 g fresh weight are considered as toxic and few
cultivator exceed this value
34.T/F A part of ingested linamarin in cassava products has been found to pass
through the human body unchanged and it is excreted in the urine within 24
hours in both humans and rodent
35.T/F Less than one-half of orally ingested linamarin is converted to cyanide and
hence thiocyanate, about one-quarter is excreted unchanged and another
quarter is metabolized into an as yet unknown compound.
36.T/F Apricot pits are rich in amygdalin, ground up for preparation of laetrile, a
controversial cancer treatment
37.T/F Eating fruits and vegetables that contain beta-glucosidase (such as celery,
peaches, bean sprouts, and carrots) may increase the risk of cyanide poisoning
Traditionally, the steps of bamboo shoots preparation are:
fresh bamboo shoots are cut in half lengthwise;
the outer leaves are peeled away and any fibrous tissue at the base is trimmed;
the bamboo shoot is thinly sliced into strips;
the shoots are boiled in lightly salted water for 8-10 minutes.
13. 38.T/F Bamboo shoots may contain as much as 1000 mg/kg hydrogen cyanide,
significantly higher than the amounts detected in cassava tubers, however, the
cyanide content is reported to decrease substantially following harvesting
39.T/F The concentration of cyanide in the immature shoot tip of
bamboo is approximately 8000 mg/kg of hydrogen cyanide and in the apical
part of bamboo shoots may contain as much as 1000 mg/kg of hydrogen
cyanide.
40.Briefly and traditionally , discuss the step of bamboo shoot preparation
41.T/F Konzo is an upper motor neuron disease that causes reversible paralysis of
the legs mainly in children and young women,1,2 due to consumption of large
amounts of cyanogens from poorly processed cassava, the staple food of tropical
Africa
42.T/F Tropical Ataxic Neuropathy affects males and females in all age groups
equally
Chap 6 thiocyanate glycosides
43.T/F Thiocyanate is toxic to many microorganisms at relatively low cyanide
concentrations
44.T/F Self-plant damaging should occur once the glucosinolates are in contact
with myrosinase enzyme
45.T/F Glucosinolates are classified into 3 class which are Aliphatic glucosinolates
,aromatic glucosinolates and indole glucosinolates
46.T/F After myrosinase activity, the remaining molecule then quickly converts to
a thiocyanate, an isothiocyanate or a nitrile; these are the active substances
that serve as defense for the plant
14. 47.T/F Isothiocyanates are irritating to mucous membranes and not readily
consumed in sufficient quantities to be toxicity but they can have powerful
antithyroid effects and interfere with the synthesis of necessary thyroid
hormones.
48.T/F Oxazolidine-2-thiones depress growth and increase the incidence of goiters.
They inhibit thyroid function by blocking the incorporation of iodine into
thyroxine precursors and by suppressing thyroxine secretion from the thyroid.
49.T/F Nitriles: depress growth, cause liver and kidney lesions, and in severe cases
leading to liver necrosis, bile duct hyperplasia, and megalocytosis of tubular
epithelium in the kidney.
50.T/F Thiocyanates: inhibit iodine uptake by the thyroid leading to reduced
iodination of tyrosine, resulting in decreased production of the important
thyroid hormone thyroxine
51.T/F Glucosinolates are destroyed by hydrolytic enzymes called myrosinase and
is not always present in plants containing glucosinolates
52.T/F In normal conditions, thiocyanates and Isothiocyanates are formed; under
pH 7, nitriles and elementary sulphur are established
53.T/F Glucosinolates are heat-stable, so cooking is less important in food
processing for reducing glucosinolates
54.T/F Goitrin, a breakdown product of glucosinolates, interferes with iodine
uptake in to thyroid gland (blocks it), it is so called strumigen
15. 55.T/F Decrease intake of glucosinolates leads to increased activity of thyroid
gland, which has to catch iodine more carefully, cells of its epithelium grow and
hypertrophy follows Struma is formed.
56.T/F About 120 different glucosinolates are known to occur naturally in plants
57.T/F The species in which glucosinolates occur that are important for animal or
human feeding belong to the family Brassicaceae
58.T/F Isothiocyanates and oxazolidine-2-thiones have been shown to have effects
on the thyroid gland in animals and these effects occur even if iodine is
sufficient.
59.T/F Isothiocyanates, nitriles and indole products can all be further degraded to
produce the thiocyanate ion. This compound is able to cause goitre in humans
when dietary iodine is insufficient
60.T/F there is no evidence to support a causative role for dietary glucosinolates in
human goitre
61.T/F have been shown to induce the activity of the phase II detoxification
enzymes and inhibit phase I (activating) enzymes, exerting an anticancer
effect
62.Cooking of glucosinolates by boiling will reduce exposure through leaching of
glucosinolates into water and inactivation of myrosinase
CHAP 7 ALKALOID