ex 5 isolation of eugenol from cloves

SN: Syzygium aromaticum (L.)

FN: Myrtaceae

sci and fam name of cloves

cloves

an evergreen with large leaves and crimson flowers in terminal clusters

cloves

commonly used in food preparation as a spice, usually paired with other spices like cinnamon and peppercorns

volatile oils

cloves commonly contain __

eugenol

cloves

• commonly contain volatile oils

• __ composes almost 90% of the volatile oils extracted

• volatile oils (eugenol)

other components:

• vanillin

• methyl salicylate

• tannins

• triterpenoids

• sesquiterpenes

components of cloves

steam distillation

one of the most common technique in extraction of cloves is __

simple distillation

extraction of cloves

in the exercise, this method was employed

• boiling chips

extraction of cloves

• grounded dried cloves was mixed with water

• finely grounded cloves may promote bumping

• __ are added to prevent this phenomenon

1 drop per 2 seconds

extraction by distillation (cloves)

distillation rate is maintained at __

-

EXTRACTION BY DISTILLATION (CLOVES)

• distillation rate is maintained at 1 drop per 2 seconds

• the distillate may appear as:

• liquid with two layers (oil layer forms on top)

• milky or turbid solution (emulsion)

• if the solution is turbid, distillation can be ceased when it turns clear

separatory funnel

SEPARATION OF THE OIL (CLOVES)

the oil is separated by __

dichloromethane or chloroform

SEPARATION OF THE OIL (CLOVES)

oil is extracted using __ (same nonpolar)

water bath

REMOVING THE SOLVENT (CLOVES)

the dichloromethane or chloroform is removed through __

a test tube is previously weighed and the extract is placed in it

however, the extract is added to the test tube in portions this done to minimize loss of the oil

boiling chip is added to prevent boiling over

• color: colorless or clear pale yellow

• odor: sweet-spicy cooling odor

• appearance: oily liquid

physical test of cloves

ferric chloride

detects presence of phenolic group

phenolic

eugenol is a __ compound

ferric phenoxide

reaction with ferric chloride test

phenols forms complex with the iron ion (__)

purple to reddish brown to green (depends on phenol concentration)

ferric chloride test positive result

bromine water test

detects presence of multiple bonds and phenolic group

eugenol

__ is a phenolic compound with allyl side chain

substitution

bromine water test reaction

phenols undergo __ reaction with bromine water

decolorized solution (HBr) with white precipitate (2,4,6- tribromophenol)

positive result of bromine water test

Baeyer’s test

detects presence of multiple bonds

KMnO4; manganese dioxide

reaction of Baeyer’s test

alkene is oxidized by __ and forms the product __

decolorized solution with brown precipitate

positive result of Baeyer’s test

2-methoxy-4-prop-2-enylphenol

• synonym: 4-allyl-2-methoxyphenol; 4- allylguaiaco

IUPAC name of eugenol

C₁₀H₁₂O₂

molecular formula of eugenol

• physical description: colorless or pale- yellow liquid with warm, spicy odor

• boiling point: 225°C

• melting point: -9.2°C

• molecular weight: 164.20 g/mol

physical properties of eugenol

physical:

BP:

MP:

MW:

eugenol

irritant

chemical safety of eugenol

cloves, cinnamon, bay leaves

sources of eugenol

topical antiseptic, counterirritant, and in dental preparations with zinc oxide for root canal sealing and pain control, found in toothache drops

use of eugenol

guaiacol with allyl chain at para position

structure of eugenol