Glycosides Lecture (8)
49 Questions
2 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the main bitter component found in grapefruit juice?

  • Naringenin
  • Naringin (correct)
  • Liquiritin
  • Neohesperidose

What is the sweetness level of Naringin compared to sucrose?

  • Approximately equal to sucrose
  • 100 times sweeter than sucrose
  • 1000 times sweeter than sucrose (correct)
  • Not sweet at all

Which of the following describes a use of Liquiritin?

  • Boosting immunity
  • Anti-inflammatory and treating gastric ulcers (correct)
  • Treating respiratory infections
  • Weight loss supplement

Which sugar component is part of Naringin?

<p>Glucose (D)</p> Signup and view all the answers

What transformation can Naringin undergo with NaOH and H2/Pd?

<p>Transforming into Naringin chalcone (A)</p> Signup and view all the answers

Which flavonoids are primarily known for their presence in green tea?

<p>Epigallocatechin and its derivatives (C)</p> Signup and view all the answers

What is a primary medicinal use of procyanidins from Crataegus?

<p>Treatment of heart diseases (C)</p> Signup and view all the answers

Which compound found in black tea is a type of flavonoid?

<p>Theaflavins (D)</p> Signup and view all the answers

Which compound is formed when Astilbin is treated with acid?

<p>Taxifolin (A)</p> Signup and view all the answers

What action is epicatechin primarily associated with?

<p>Fat burning and slimming (C)</p> Signup and view all the answers

Which of the following is NOT a characteristic of proanthocyanidins?

<p>They are readily soluble in water (A)</p> Signup and view all the answers

Which type of compound is classified as a dietary phytoestrogen?

<p>Daidzin (D)</p> Signup and view all the answers

What is the significance of the structure of anthocyanidins in relation to pH?

<p>They show color changes between acidic and alkaline conditions. (C)</p> Signup and view all the answers

Which flavonoid derivative is noted for its antiuremic action?

<p>Epicatechin 3-O-gallate (C)</p> Signup and view all the answers

What is one of the pharmacological actions of (+)-Catechin?

<p>Antioxidant properties (C)</p> Signup and view all the answers

Which of the following statements is true about Neoastilbin?

<p>It is derived from Astilbin. (B)</p> Signup and view all the answers

Which of the following glycosides is primarily found in soya beans?

<p>Daidzin (A)</p> Signup and view all the answers

Amentoflavone is primarily found in which plant?

<p>Chrozophora sp. (A)</p> Signup and view all the answers

What is the primary function of anthocyanins?

<p>They serve as antioxidants. (B)</p> Signup and view all the answers

Which of the following compounds is not classified as an isoflavonoid glycoside?

<p>Neoastilbin (D)</p> Signup and view all the answers

What is a common use of isoflavonoid glycosides?

<p>Preventing breast and prostate cancer (C)</p> Signup and view all the answers

What are the principal components of silymarin?

<p>Silybin, Silychristin, and Silydianin (C)</p> Signup and view all the answers

Which of the following is NOT a pharmacological action of silymarin?

<p>Enhancement of digestive enzyme release (B)</p> Signup and view all the answers

What problem does silybin face when taken orally?

<p>Very poor bioavailability (D)</p> Signup and view all the answers

Which enhancement method is NOT mentioned for improving silybin's bioavailability?

<p>Formation of microemulsions (A)</p> Signup and view all the answers

In which of the following conditions is silymarin commonly used?

<p>Chronic degenerative liver conditions (D)</p> Signup and view all the answers

What is a significant benefit of forming complexes with phosphatidyl-choline?

<p>Improved absorption in the gastrointestinal tract (A)</p> Signup and view all the answers

Which of the following components can be found in the fruits of Silybum marianum?

<p>Silybin (C)</p> Signup and view all the answers

Which of the following best describes the pharmacokinetic studies of silybin complexes?

<p>Showed improved bioavailability, up to 10 times (C)</p> Signup and view all the answers

What compound is produced from alliin after crushing garlic?

<p>Allicin (A)</p> Signup and view all the answers

Which of the following describes the structure and function of cyano-glycosides?

<p>O-glycosides that release HCN gas as a chemical defense mechanism (B)</p> Signup and view all the answers

Which compound is associated with both antibacterial and anti-hyperlipidemic properties?

<p>Allicin (A)</p> Signup and view all the answers

Amygdalin is primarily found in which of the following?

<p>Bitter almond seeds (A)</p> Signup and view all the answers

What is the primary effect of dicoumarol in the human body?

<p>Anticoagulant (C)</p> Signup and view all the answers

What enzyme converts alliin to allicin?

<p>Alliinase (B)</p> Signup and view all the answers

Which of the following compounds is known for its hepatotoxic effects?

<p>Aflatoxins (C)</p> Signup and view all the answers

What is released when amygdalin is hydrolyzed by emulsin?

<p>Benzaldehyde and glucose (B)</p> Signup and view all the answers

Which of the following describes the role of glucosinolates?

<p>Flavoring agents and chemical defenses in plants (C)</p> Signup and view all the answers

What is a primary characteristic of non-glycosidic organo-sulfur drugs?

<p>They possess strong aromatic properties. (D)</p> Signup and view all the answers

What does Band I of the UV spectral absorption in flavonoids primarily correspond to?

<p>Cinnamoyl system of ring B (B)</p> Signup and view all the answers

Which carotenoid layout can produce two UV absorption maxima?

<p>Flavonoids (A)</p> Signup and view all the answers

What range of wavelengths corresponds to Band II of flavonoid UV absorption?

<p>220-280 nm (D)</p> Signup and view all the answers

What is a primary chemical characteristic of phenolic hydroxyl (OH) groups in flavonoids?

<p>Increased solubility in water (C)</p> Signup and view all the answers

Which of the following flavonoid types does NOT exhibit a hydroxyl group linked to ring B?

<p>Flavane (A)</p> Signup and view all the answers

Which flavonoid glycoside is associated with increasing venous tone and treating capillary fragility?

<p>Diosmetin (A)</p> Signup and view all the answers

Which of the following mechanisms describes how diosmin affects the body?

<p>Promotes vasodilation (C)</p> Signup and view all the answers

Which is a characteristic structural feature that distinguishes flavonoids from other compounds?

<p>Presence of multiple benzene rings (D)</p> Signup and view all the answers

The UV-Vis absorption patterns are affected by what specific feature of flavonoids?

<p>The substitution pattern on phenolic rings (C)</p> Signup and view all the answers

Which of the following compounds is correctly categorized under the flavonoid class?

<p>Chalcone (C)</p> Signup and view all the answers

Flashcards

Naringin

A bitter compound found in grapefruit peel and juice, responsible for its characteristic flavor. It is a glycoside, linked to the sugar neohesperidose.

Neohesperidose

A type of sugar molecule found in naringin, composed of glucose and rhamnose.

Naringin to Naringin Chalcone

A chemical process that converts naringin into naringin chalcone, a less bitter compound. This is often done to reduce the bitterness of grapefruit juice.

Liquiritin

A naturally occurring compound found in licorice roots. It's a glycoside composed of liquiritigenin and glucose.

Signup and view all the flashcards

DGL (Deglycyrrhizinated Licorice extract)

A type of licorice extract that has been treated to remove glycyrrhizic acid, reducing its mineralocorticoid activity. This helps to avoid side effects and allows for safer use.

Signup and view all the flashcards

Neoastilbin

A type of flavonoid glycoside found in plants like Astilbe and Smilax glabra, known for its sweetness.

Signup and view all the flashcards

Astilbin

A type of flavonoid glycoside found in plants like Astilbe and Smilax glabra. It is not sweet.

Signup and view all the flashcards

Taxifolin

A flavonoid compound produced when Astilbin is broken down by acid.

Signup and view all the flashcards

Neotaxifolin

A flavonoid compound produced when Neoastilbin is broken down by acid.

Signup and view all the flashcards

Daidzin

A type of isoflavonoid glycoside found in soy beans, alfalfa, and other plants. It is known for its potential health benefits.

Signup and view all the flashcards

Genistin

A type of isoflavonoid glycoside found in Genista, lupinus, and Prunus. It is known for its potential health benefits.

Signup and view all the flashcards

Daidzein

A type of isoflavonoid produced when Daidzin is broken down by intestinal bacteria.

Signup and view all the flashcards

Genistein

A type of isoflavonoid produced when Genistin is broken down by intestinal bacteria.

Signup and view all the flashcards

Silymarin

A type of natural compound found in plants, particularly in the fruits of the milk thistle plant (Silybum marianum).

Signup and view all the flashcards

Silybin

The main active component of silymarin, responsible for its protective effects on the liver.

Signup and view all the flashcards

Bioavailability

The degree to which a substance is absorbed into the bloodstream after being taken orally.

Signup and view all the flashcards

Lipophilic

The ability of a substance to pass through cell membranes, particularly the lining of the digestive tract.

Signup and view all the flashcards

Silymarin Phytosome®

A complex formed by combining silybin with a naturally occurring molecule found in soybeans, improving its absorption.

Signup and view all the flashcards

Cyclodextrin

A type of sugar molecule used to improve the absorption of drugs.

Signup and view all the flashcards

Glycoside formation

The process of adding a sugar molecule to a compound, often to improve its properties.

Signup and view all the flashcards

Pharmacokinetic studies

The study of how a drug is absorbed, distributed, metabolized, and eliminated by the body.

Signup and view all the flashcards

UV Absorption Maxima in Flavonoids

UV spectra of flavonoids show two absorption maxima: Band I (220-280 nm) due to the cinnamoyl system of ring B and C4=O, and Band II (300-400 nm) due to the benzoyl system of ring A and C4=O.

Signup and view all the flashcards

Hydroxylation Pattern in Flavonoids

The presence of hydroxyl (OH) groups on the flavonoid structure influences various properties like hydrophilicity, acidity, UV and visible light absorption, and chemical reactivity.

Signup and view all the flashcards

Flavanone

A type of flavonoid with a specific structure characterized by a C2-C3 double bond in ring C. Flavanone is often found in citrus fruits.

Signup and view all the flashcards

Flavanol

A type of flavonoid with a hydroxyl (OH) group at position 3 in ring C. Flavanols, like catechin, are found in tea and grapes.

Signup and view all the flashcards

Flavane

A type of flavonoid with a saturated ring C. Flavanes are often found in tea and cocoa.

Signup and view all the flashcards

Flavone

A type of flavonoid where ring C is linked to ring A via a carbonyl group. Flavones, like apigenin, are found in chamomile and celery.

Signup and view all the flashcards

Flavonol

A type of flavonoid with a hydroxyl (OH) group at position 3 in ring C and ring C is linked to ring A via a carbonyl group. Flavonols, like quercetin, are found in onions and apples.

Signup and view all the flashcards

Isoflavone

A type of flavonoid where ring C is linked to ring A at position 2. Isoflavones, like genistein, are found in soybeans and red clover.

Signup and view all the flashcards

Chalcone

A type of flavonoid with an open ring C, characterized by a double bond between C2 and C3. Chalcones, like chalconaringenin, are found in licorice.

Signup and view all the flashcards

Flavone Glycosides

A type of flavonoid with a glycosidic linkage (sugar molecule) attached to the flavonoid structure. Flavone glycosides often increase the water solubility of the flavonoids.

Signup and view all the flashcards

Anthocyanins

A group of plant pigments responsible for red, purple, and blue colors in flowers, fruits, and leaves. They are derivatives of flavylium cation.

Signup and view all the flashcards

Pelargonidin

A type of anthocyanin with a hydroxyl group at position 3 and various substitutions at other positions, giving rise to diverse colors.

Signup and view all the flashcards

Cyanidin

A type of anthocyanin with a hydroxyl group at position 3 and a hydroxyl group at position 5. It contributes to the red color of many flowers.

Signup and view all the flashcards

Delphinidin

A type of anthocyanin with a hydroxyl group at position 3 and hydroxyl groups at positions 5 and 3', imparting a blue to purple color.

Signup and view all the flashcards

Flavan-3-ols

Flavan-3-ols are a type of flavonoid with a hydroxyl group at position 3. Examples include catechin, epicatechin, and epigallocatechin.

Signup and view all the flashcards

Proanthocyanidins

Proanthocyanidins are polymers of flavan-3-ols, known for their antioxidant and anti-inflammatory properties. They are often found in plants like grapes, apples, and berries.

Signup and view all the flashcards

Biflavones

A group of flavonoids with two flavan units linked together, often found in plants like Ginkgo biloba and Amentotaxus.

Signup and view all the flashcards

Amentoflavone

A specific biflavone found in Amentotaxus, a type of conifer, and some plants like Chrozophora.

Signup and view all the flashcards

What are poisonous coumarins?

Poisonous coumarins are produced by fungi and can cause liver damage (hepatotoxicity) or cancer (carcinogenicity).

Signup and view all the flashcards

What is Dicoumarol?

Dicoumarol is a naturally occurring anticoagulant (blood thinner) found in spoiled sweet clover. It works by inhibiting the production of vitamin K-dependent clotting factors.

Signup and view all the flashcards

What are aflatoxins?

Aflatoxins are a group of potent mycotoxins produced by certain fungi, particularly Aspergillus flavus and Aspergillus parasiticus. They are known to be carcinogenic and can contaminate food products.

Signup and view all the flashcards

What is Alliin?

Alliin is a compound found in fresh garlic that is odorless. When garlic is crushed or chopped, the enzyme alliinase converts alliin into allicin, which gives garlic its pungent odor and flavor.

Signup and view all the flashcards

What is allicin?

Allicin is a potent sulfur-containing compound responsible for the characteristic pungent odor of garlic. It is formed from alliin by the enzyme alliinase when garlic is crushed or chopped.

Signup and view all the flashcards

What are some of the uses of allicin?

Allicin has antibacterial and anti-hyperlipidemic properties, meaning it can fight bacteria and reduce cholesterol levels.

Signup and view all the flashcards

What are cyanogenic glycosides?

Cyanogenic glycosides are plant compounds that, when broken down, release hydrogen cyanide (HCN), a highly toxic gas. These compounds serve as a defense mechanism for plants against herbivores.

Signup and view all the flashcards

What is amygdalin?

Amygdalin is a cyanogenic glycoside found in bitter almond seeds, apricot kernels, peaches, and plums. It is broken down by the enzyme emulsin to produce benzaldehyde, hydrogen cyanide (HCN), and glucose.

Signup and view all the flashcards

What are glucosinolates?

Glucosinolates are a group of sulfur-containing compounds found in plants of the Brassicaceae family (e.g., broccoli, cauliflower, cabbage). They are broken down to produce isothiocyanates, which have anti-cancer properties.

Signup and view all the flashcards

What are isothiocyanates?

Isothiocyanates are compounds produced from the breakdown of glucosinolates in plants. They have anti-cancer properties and are thought to be beneficial for overall health.

Signup and view all the flashcards

Study Notes

Glycosides Lecture (8)

  • Phenolic Glycosides
    • Flavonoid glycosides (E)
    • Coumarin glycosides (F)
  • Non-glycosidic organo-sulfur drugs
  • Cyanogenic Glycosides
  • Glucosinolates

E- Flavonoid Glycosides

  • A diverse group of natural products
  • Found in fruits, vegetables, nuts, seeds, stems, and flowers, as well as tea
  • Important constituents of the human diet
  • Often found free or in glycosidic form, more often in higher plants
  • Common in the seeds of Leguminosae family (isoflavonoids) and Polygonaceae family (flavan-3-ols, anthocyanins)
  • Skeleton: Diphenyl propane derivatives; 15 carbons

Role in Plant Defense and Other Functions

  • Limited role in plant defense mechanisms.
  • Production of phytoalexins (isoflavones or isoflavanones) or other plant phenolics in response to fungal infections or external stimuli.
  • Pigments in flowers attract pollinating birds and insects.
  • Plant growth regulators, inhibiting or activating enzymes.

Pharmacological Activities

  • Binding to enzymes and cell membranes
  • Chelation of heavy metal ions
  • Electron transfer in enzyme systems, e.g., oxidoreductases
  • Free radical scavenging (antioxidant)

Therapeutic Uses

  • Procyanidins in Crateagus sp.: Cardiotonic
  • Catechins in Tea: Anticancer
  • Flavonoids in Licorice: Antiviral
  • Daidzin & Genistin in Soybeans: Anticancer
  • Rutin in Citrus: Prevent capillary fragility
  • Flavonoids in Buchu: Diuretic
  • Tinctormine in Safflower: Treat angina ("Ca antagonist")
  • Astilbin in Smilax: Anti-hepatotoxic
  • Silybin in Silybum marianum: Anti-hepatotoxic

Identification Methods

  • Reaction with AlCl3: Yellow color
  • Shinoda's Test: Orange, red, or violet color using Mg metal/HCl in alcoholic solution
  • Lead Subacetate Test: Yellow precipitate on addition of lead subacetate to an alcoholic solution.
  • UV Spectral Absorption: Flavonoids show two absorption maxima:
    • Band I (220-280nm): Due to cinnamoyl system of ring B + C4=O
    • Band II (300-400nm): Due to benzoyl system of ring A + C4=O
  • Hydroxylation Pattern: Phenolic OH groups affect hydrophilicity, acidity, UV & visible light absorption, and chemical reactivity.

Flavone Glycosides

  • Apiin: In celery and parsley leaves & seeds. Used for veins & hemorrhoids
  • Diosmin: In Buchu and other leaves. MOA treatment of capillary fragility and increase venous tone. Used prophylactially in varicose veins and acute hemorrhoids.

Rutin (Flavonol Glycoside)

  • Hydrolysis: Rutin + 1N H2SO4 → Quercetin + Glc + Rh
  • MOA: Prevents capillary fragility, permeability and bleeding; strengthens capillaries.
  • Uses: Antioxidant, anti-inflammatory; treatment of varicose veins, hemorrhoids, internal bleeding

F- Coumarins

  • Derivatives of benzo-α-pyrone or lactones of o-hydroxycinnamic acid.
  • Some are glycosidic, classified as phenolics
  • Some are toxic (e.g., aflatoxins) or have antibiotic properties (e.g., coumermycin).
  • Some have a strong odor and are bitter. They are soluble in alcohol.

Coumarin Glycosides

  • Aesculin: Aesculus and Fraxinus species.
  • Uses: Treatment of varicose veins and hemorrhoids

Coumarin Derivatives of Pharmaceutical Importance

  • 4-Hydroxycoumarins: (e.g., Bishydroxycoumarin): Anticoagulants.
  • Coumarin Antibiotics: (e.g., Novobiocin): Antibiotic agents.

Poisonous Coumarins

  • Substances produced by fungi (e.g., Aflatoxins)
  • Hepatotoxic or carcinogenic.

Non-glycosidic Organo-sulfur Drugs

  • Alliin: (+)-S-allyl-L-cysteine sulfoxide in fresh garlic.
  • Allicin: Diallyl thiosulfinate formed by alliinase enzyme after crushing garlic; Gives garlic its strong smell
  • Uses: Antimicrobial and anti-hyperlipidemic
  • Allicin+water: Diallyl disulfide, trisulfide, poly…

Cyanogenic Glycosides

  • Plants contain these as flavoring agents; toxic.
  • Considered O-glycosides on H.OH
  • Plants use these compounds as a chemical defense (damaging/feeding)
  • Release HCN; toxic

Amygdalin

  • Found in bitter almond seeds, apricots, peaches, plums
  • H.OH by emulsin → Benzaldehyde + HCN

Glucosinolates

  • (Thioglycosides or Isothiocyanate glycosides) found in mustard family.
  • Sources include mustard seeds, rapeseed, horseradish, and cruciferous vegetables like broccoli and cabbage.
  • Pharmacological Action & Uses: Anticarcinogenic; externally, rubefacients; commercially, condiments.

Isoflavonoid Glycosides

  • Daidzin & Genistin: Dietary phytoestrogens; prevent breast/prostate cancer; aid in osteoporosis treatment.

Anthocyanidins

  • Natural coloured compounds dependent on pH (blue in alkaline, red in acidic).
  • Major examples Include pelargonidin, cyanidin and delphinidin.
  • Sugar part attached to C3.

Flavon-3-ols

  • Catechin, epicatechin, epigallocatechin found in tea, rhubarb, and hawthorn.
  • Proanthocyanidins (flavanoids): Polymers of catechin & epicatechin
  • Uses: Antioxidants, lipid oxidation (slimming), anticancer, antiviral, antibacterial

Biflavones

  • Amentoflavones: Located in Amentotaxus and Chrozophora.
  • Uses: Cardiotonic; prevents cataract formation in diabetic patients

Flavonoid-containing Compounds

  • Silymarin: (Silybin, Silychristin, Silydianin) in milk thistle.
  • Uses: Hepatoprotective; prophylactic against toxins, liver dysfunction, hepatitis, and liver conditions

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Glycosides Lecture Notes (PDF)

Description

Explore the fascinating world of glycosides in this lecture, focusing on phenolic glycosides, their roles in plant defense, and their importance in the human diet. Learn about various types such as flavonoid glycosides and glucosinolates, and discover their pharmacological activities.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser