TERPINOIDS AND MENTHOL PHARMACOGNOSOY SLIDE 5th sem

1. TERPENOIDS AND METHANOL
BY RISHAV PAUL

2. CONTENTS

 INTRODUCTION
 CLASSIFICATION

 INTRODUCTION
 BIOSYNTHESIS
 MECHANISIM OF ACTION
 APPLICATION

3. INTRODUCTION
 The terpenoids, also known as isoprenoids, are a large and diverse class of naturally occurring organic
chemicals derived from the 5-carbon compound isoprene, and the isoprene polymers called terpenes. While
sometimes used interchangeably with "terpenes", terpenoids contain additional functional groups, usually
containing oxygen.[1] Terpenoids are the largest class of plant secondary metabolites, representing about 60% of
known natural products.[2] Terpenoids are colourless lighter than water with boiling point 150-180 °C. They are
optically active lighter than water but soluble in organic solvents

4. STRUCTURE AND CLASSIFICATION
 Terpenoids are modified terpenes,[5] wherein methyl groups have been moved or removed, or oxygen atoms
added. , The terpenoids can be classified according to the number of isoprene units that comprise the parent
terpene:

5. MENTHOL

6. INTRODUCTION
 Menthol is an organic compound, more specifically a monoterpenoid, made synthetically or
obtained from the oils of corn mint, peppermint, or other mints. It is a waxy, crystalline substance,
clear or white in color, which is solid at room temperature and melts slightly above.
 The main form of menthol occurring in nature is (−)-menthol, which is assigned the
(1R,2S,5R) configuration. Menthol has local anesthetic and counterirritant qualities, and it is widely
used to relieve minor throat irritation. Menthol also acts as a weak κ-opioid receptor agonist.

7. BIOSYNTHESIS
 The biosynthesis of menthol has been investigated in Mentha × piperita and
the enzymes involved in have been identified and characterized.
 It begins with the synthesis of the terpene limonene, followed by hydroxylation,
and then several reduction and isomerization steps.

8. STEPS FOR BIOSYNTHESIS

9. ANALYSIS
 By Gas Chromatography.
 Internal standard solution: A solution of n-ethyl caprylate in ethanol.
 Operating conditions:
 I. Detector: A hydrogen flame ionization detector.
 II. Column: A glass column about 3mm in inside diameter and about 2m in length,
 packed with 25% polyethylene glycol 6000 for GC supported on acid-washed
 180-250micrometer siliceous earth for GC.
 III. Column temperature: 150°C
 IV. Carrier gas: Nitrogen
 V. Flow rate: Adjust flow rate so that retention time of internal standard is about
 10 mins.
 The resolution between the peaks of standard and l-mentho

10. MECHANISIM OF ACTION
 MENTHOL ACTS AS A CALCIUM BLOCKER

11. APPLICATION
 MENTHOL , also called peppermint camphor, terpene alcohol with a strong minty,
cooling odour and taste.
 Menthol is used medicinally in ointments, cough drops, and nasal inhalers.
 It is also used as flavouring in foods, cigarettes, liqueurs, cosmetics, and perfumes.