Isolation Identification and analysis of Menthol.pptx

pharmacognosy for pharmacy

1. Isolation Identification and analysis of menthol By: Dr Vineet Mittal 14-09-2020

2. Biological Source  Herb (Peppermint) ‫ It is obtained from the dried leaves and flowering tops of different species of Mentha (Family- Labiatae ) - Mentha piperita Linn. (Peppermint) M. spicata ( spearmint) M. aquatica (water mint), M. longifolia (Horse mint) M. rotundifolia (Apple mint) M. arvensis (Japanese peppermint)

3. Morphological characters Odour : aromatic characteristic Taste: aromatic followed by cooling sensation Stem: - Herbaceous, perennial,Quadrangular,Green to dark purple, Nearly glabrous, with scattered deflected hairs. Leaves: - opposite decussate, petiolate Shape - ovate and lanceolate Color- Light or dark green with purplish tinge upper surface: dark green nearly glabrous lower surface: light green, hairy on the veins Apex: acute Base: acute or rounded Margin: sharply serrate Petiole: long slightly hairy

4. Mentha piperita herb

5. uses G.I.T. - Spasmolytic , Carminative, Digestive, Anti-emetic, Promotion of liver & gall bladder function ( choleretic & cholagogue ) Local anesthetic Anti-parasitic Anti- pruritic Respiratory tract- Decongestant. In Pharmaceutical preparations: Tooth paste, mouth washes & gargles, Soft gelatin capsules, Aromatherapy Also used in pharmaceutical preparations as local antipruritic , counter-irritant and antiseptic

6. Properties Moleular formula- C 10 H 20 O White solid crystalline in nature M.Pt - 41-43˚C Soluble in organic solvents like alcohol, Chloroform, Pet ether, slightly soluble in water

7. Chemical constituents Volatile oil ( 0.7-1.5%) contains free Menthol (78%) Menthol esters (20%) Tannins (6 to 12 %) Flavonoids Menthol

8. Extraction and isolation STEAM DISTILLATION SOLVENT EXTRACTION (when oil is in low amount) Solvents like hexane and ethanol is used Plant material are treated with the solvent to produces a waxy aromatic compound called a “concrete” mixed it with alcohol to release the oil particles Pass it through a condenser to separate out oil

9. MACERATION The plant material is powdered solvent is added and the mixture is kept for 1 week liquid is strained and solid residue is pressed to recover any remaining liquid Strained and expressed liquids are mixed

10. enfleurage The fat is warmed to 500˚C Liquid fat is covered with flower petals and kept for several days until it saturated with essential oils Remove the saturated petals, and the fat is treated with ethanol The alcoholic distillate is then fractionally distilled under reduced pressure to remove the solvent Recently the fat is replaced by coconut charcoal, due to greater stability and higher adsorptive capacity.

11. identification M. Pt- 41-43˚C Chemical test: Positive microchemical test with Sudan III Special chemical test: Menthol crystals + H2SO4 + vanillin orange yellow color violet color Add water

12. Mixed few drops with 5 ml nitric acid & heated on water bath Within 5 min. liquid develops blue color further heating shows cooper color fluorescence After sometime its become yellow.

13. Analysis of Menthol By Physical methods TLC Sample preparation – Dissolved 1mg of menthol in 1ml of methanol Stationary phase - Silica gel G Standard sample - Menthol Mobile phase – Pure Chloroform Detecting agent – 1% vanillin- Sulphuric acid reagent heat the plate 110˚C for 10 minutes RF Value – 0.48 HPLC HPTLC UV-Visible spectrophotometer

14. IR spectrum of Menthol

15. HPLC analysis Column: Luna ® 5 µm C8 Column 150 x 4.6 mm, Dimensions: 150 x 4.6 mm ID Elution Type: Isocratic Elution A: Methanol Elution B: Sodium phosphate buffer pH 2.5 Flow Rate: 0.6  mL /min Coloumn Temp: ambient Detection: UV -Vis Abs.@ 242 nm (22°C) HPTLC GC analysis