Pharmacognosy: Shikimic Acid and Coumarins

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Questions and Answers

What is the primary focus of the Shikimic acid pathway?

Formation of aromatic amino acids (correct)

Production of flavonoids

Synthesis of alkaloids

Metabolism of lipids

Which compounds are derived from the Shikimic acid pathway?

Saponins and glycosides

Terpenes and steroids

Phenolic acids and tannins

Coumarins and furanocoumarins (correct)

What is a key characteristic of furanocoumarins?

They are known for their antibiotic properties.

They often exhibit bioactive properties. (correct)

They are primarily aromatic hydrocarbons.

They are exclusively found in synthetic compounds.

Chromones are classified as which type of compound?

Condensed phenolic compounds Signup and view all the answers

Which of the following pathways is indirectly related to the production of secondary metabolites in plants?

Shikimic acid pathway Signup and view all the answers

What is the primary function of shikimic acid in relation to oseltamivir synthesis?

It is the starting material for synthesizing oseltamivir. Signup and view all the answers

What type of inhibitor is oseltamivir phosphate (Tamiflu)?

Neuraminidase inhibitor Signup and view all the answers

Which plant is known as the source of shikimic acid used in Tamiflu production?

Star anise Signup and view all the answers

What is one of the roles of shikimic acid in plants?

Protection against microorganisms Signup and view all the answers

For what specific diseases is oseltamivir phosphate intended for treatment?

Influenza viruses A and B Signup and view all the answers

What is shikimic acid derived from?

Fermentation of genetically engineered E. coli Signup and view all the answers

Which gene is deficient in the genetically engineered E. coli used for shikimic acid production?

Shikimate kinase gene Signup and view all the answers

What role does shikimate kinase play in E. coli?

It is involved in the biosynthesis of amino acids Signup and view all the answers

Why are genetically engineered E. coli strains used in shikimic acid production?

To increase the yield of shikimic acid Signup and view all the answers

What is a potential application of shikimic acid obtained from E. coli?

Synthesis of antiviral medications Signup and view all the answers

What type of toxins are aflatoxins classified as?

Hepatotoxins and carcinogens Signup and view all the answers

From which fungus are aflatoxins produced?

Aspergillus Signup and view all the answers

Which structural component is common to all aflatoxins?

Coumarin ring Signup and view all the answers

What type of health issues can aflatoxins cause?

Liver damage and cancer Signup and view all the answers

In which of the following conditions would you expect aflatoxins to be a concern?

High humidity and temperature in food storage Signup and view all the answers

Which furanocoumarin is NOT mentioned as being found in grapefruits?

Psoralen Signup and view all the answers

What is the primary effect of grapefruit juice on drug metabolism?

It inhibits CYP3A4-mediated drug metabolism. Signup and view all the answers

What role do furanocoumarins play in the interaction between grapefruit and drug metabolism?

They interfere with liver and intestinal enzyme CYP3A4. Signup and view all the answers

Which of the following statements about CYP3A4 is accurate?

CYP3A4 is an enzyme involved in drug metabolism. Signup and view all the answers

Which statement correctly describes the relation between grapefruit juice and drug interactions?

Grapefruit juice can increase the effects of certain medications. Signup and view all the answers

What methods does Roche currently use to obtain shikimic acid?

Both extraction and fermentation methods Signup and view all the answers

What is the primary characteristic of free coumarins?

Organic solvents-soluble Signup and view all the answers

Which of the following is a coumarin glucoside found in horse chestnut?

Aesculin Signup and view all the answers

What chemical is used in the conversion process from shikimic acid?

Chorismic acid Signup and view all the answers

What is the effect of coumarins in medicinal applications?

Anti-inflammatory effects Signup and view all the answers

Which plant is a significant source of aescin?

Aesculus hippocastanum Signup and view all the answers

What possible health risk is associated with high consumption of Cassia cinnamon?

Liver toxicity Signup and view all the answers

Which of the following is NOT a common family where coumarins are found?

Solanaceae Signup and view all the answers

What is the main structural characteristic that differentiates derivatives of coumarins?

Substituents on the benzene ring Signup and view all the answers

Which of the following compounds is involved in the synthesis of alkaloids from tyrosine?

Anthranilic acid Signup and view all the answers

Study Notes

Pharmacognosy and Phytochemistry (Coumarins/furanocoumarins/chromones)

Shikimic acid is isolated from plants of Illicium species (Japanese "shikimi," Japanese star anise)
The shikimic acid pathway is important for aromatic compounds
It's a precursor of aromatic amino acids (Phe, Tyr, Try) biosynthesis in bacteria, fungi, and higher plants
It's a building block for other compounds: alkaloids, coumarins, phenyl propanes, and volatile oils
It's a starting point for tannins in all plants
It provides protection of plants against microorganisms
Oseltamivir phosphate (Tamiflu) is an orally active neuraminidase inhibitor, developed for treating and preventing influenza viruses A and B
The starting material for the synthesis of oseltamivir is (-)-shikimic acid
Shikimic acid is currently in demand as the raw material for the synthesis of oseltamivir (Tamiflu), for defense against avian influenza (bird flu)
Illicium verum (star anise) contains large amounts of shikimic acid
The drug manufacturer Roche currently relies on both extraction and fermentation to obtain shikimic acid

Coumarins

Coumarin is a derivative of Benzo-α-pyrone
It has a vanilla-like flavor
It's an oxygen heterocycle
Coumarin can be free or combined with glucose (coumarin glycoside)
Coumarins are organic solvents-soluble
Derivatives differ in benzene ring substitutions (OH, OCH₃, CH₃)
Coumarins are common in Apiaceae, Fabaceae, and Rutaceae families
Umbelliferone: R₁ = H, R₂ = OH
Aesculetin: R₁ = R₂ = OH
Scopoletin: R₁ = OCH₂, R₂ = OH
Coumarins are hepatotoxic in high doses
Coumarin and several derivatives have various therapeutic and pharmacological potentials.

Furanocoumarins (Photosensitizers)

Often known as psoralens
Plants containing psoralens are used internally and externally to promote skin pigmentation and suntanning
Psoralen absorbs near UV light and stimulates melanin pigment formation
Furan ring is derived from isopentyl pyrophosphate (mevalonic acid pathway)

Aflatoxins

Aflatoxins are mycotoxins produced by the fungus Aspergilus
Aflatoxins are potent hepatotoxins and carcinogens in the liver
All aflatoxins contain a coumarin ring and an unsaturated lactone moiety

Bleeding

Dicoumarol is present in sweet clover ( Melilotus officinalis)
Dicoumarol interferes with the effects of vitamin K in blood coagulation.
The blood loses its ability to clot, and minor injuries can lead to severe internal bleeding

Medical Value of Coumarins / Furanocoumarins

Aesculin/Aescin from Aesculus hippocastanum reduces inflammation, and is used as an anti-inflammatory agent, and also for treating cutaneous capillary fragility
Psoralens and derivatives used in PUVA photochemotherapy for vitiligo and psoriasis repigmentation.
Methoxsalen (also known as xanthotoxin), commonly found in the fruits of Ammi majus is used for skin repigmentation.

Grapefruits

Grapefruit juice inhibits CYP3A4-mediated drug metabolism
Major furanocoumarins in grapefruits include bergamottin and 6',7'-dihydroxybergamottin

Other Details

Warfarin, a coumarin derivative, is used as an anticoagulant
Warfarin's discovery was linked to an outbreak of hemorrhaging in cattle consuming moldy sweet clover
The 14th Dalai Lama's quote on happiness

Ammi visnaga

Ammi visnaga contains furochromones, used traditionally as an antispasmodic and for angina pectoris treatment
Khellin, extracted from Ammi visnaga, is a coronary vasodilator and spasmolytic agent
Khellin and its analogs (e.g., amiodarone, cromolyn sodium) are also used in current medical practice

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Description

Explore the fascinating world of pharmacognosy and phytochemistry focusing on shikimic acid, its role in the biosynthesis of aromatic compounds, and its application in synthesizing oseltamivir for influenza treatment. This quiz covers important plant-derived compounds and their significance in both nature and medicine.