PHA6117 LAB: Extraction + Qualitative Tests

Medicinal plants

are the richest bioresource of drugs for traditional systems of medicine, modern medicines, nutraceuticals, food supplements, folk medicines, pharmaceutical intermediates and chemical entities for synthetic drugs.

Nutraceuticals

different natural sources of drugs based with their pharmacologic condition

Cacao

flavonoids, antioxidant

Tea

catechin components

Polyphenol

grapes

Resveratrol

obtained from red grapes, berries

Extraction

• is the process of separating a substance (soluble) or constituent from a matrix which is usually derived from natural sources like plants or animals.

Extraction

It utilizes solvent systems of different polarities to isolate compounds.

extractives

The main product of extraction

Marc

solid residue obtain after extraction

Menstruum

solvent used for extraction

complex mixtures

The products obtained from plants are relatively _ of metabolites, in liquid or semisolid state or (after removing the solvent) in dry powder form, and are intended for oral or external use.

pillular

semisolid extracts

galenicals

These include classes of preparations known as decoctions, infusions, fluid extracts, tinctures, pillular (semisolid) extracts or powdered extracts.

Vincristine and Vinblastine

extracted from Vinca Rosea or Catharanthus roseus

Hyoscyamine

extracted from deadly nightshade (Atropa belladonna) and from Jimsonweed

Pilocarpine

extracted from Jaborandi plant (Pilocarpus microphyllus)

Forskolin

found in the root of Coleus plant, which belongs to the mint (Lamiaceae) family

Codeine

•  an opioid analgesic extracted from opium poppy (Papaver somniferum)

Dry extract

Belladona extract

Soft extract

Glycyrrhiza extract

Liquid

Tincture

STEPS INVOLVED IN EXTRACTION

Size reduction

Extraction

Filtration

Concentration

Drying

SIZE REDUCTION

to rupture its organ, tissue and cell structures so that its medicinal ingredients are exposed to the extraction solvent.

SIZE REDUCTION

maximizes the surface area, which in turn enhances the mass transfer of active principle from plant material to the solvent.

GENERAL METHODS OF EXTRACTION

Maceration

Infusion

Decoction

Digestion

Percolation

Continuous hot extraction

Supercritical fluid extraction

MACERATION

• The whole or coarsely powdered crude drug is placed in a stoppered container with the solvent and allowed to stand at room temperature for a period of at least 3 days with frequent agitation until the soluble matter has dissolved. The mixture then is strained, the marc (the damp solid material) is pressed, and the combined liquids are clarified by filtration or decantation after standing.

macerare

Latin: _ – “to soak”

INFUSION

Fresh infusions are prepared by macerating the crude drug for a short period of time with cold or boiling water. These are dilute solutions of the readily soluble constituents of crude drugs

DECOCTION

The crude drug is boiled in a specified volume for a defined time; it is then cooled and strained or filtered

DECOCTION

This method is suitable for extracting water-soluble, heat stable constituents.

DECOCTION

are solutions representing the water-soluble constituents of the plant drugs prepared by boiling the drug in water.

DIGESTION

This is a form of maceration in which gentle heat is used during the process of extraction.

DIGESTION

It is used when moderately elevated temperature is not objectionable. The solvent efficiency of the menstruum is thereby increased.

per

Latin: – “through”

colare

Latin for to strain

PERCOLATION

Process in which a comminuted drug is extracted of its soluble constituents by the slow passage of a suitable solvent through a column drug

Percolator

 is the special type of column used in percolation.

Percolate

is the collected material after percolation.

Menstruum

Top most layer of percolator

Washed sand

2nd layer of a percolator

Filter paper

3rd layer of a percolator

Drug

fourth layer of a percolator

glass wool or marble

bottom most layer of percolator

Size reduction

The drug to be extracted is subjected to a suitable degree of size reduction, usually from coarse powder to fine powder.

Imbibition

 During imbibition the powdered drug is moistened with a suitable amount of menstruum and allowed to stand for four hours in a well closed container.

Packing

After imbibition the moistened drug is evenly packed into the percolator.

Maceration

After packing sufficient menstruum is added to saturate the material. The percolator is allowed to stand for 24 hours to macerate the drug.

Percolation

The lower tap is opened, and liquid collected therein is allowed to drip slowly at a controlled rate until 3/4th volume of the finished product is obtained

Porous cup

CONTINOUS EXTRACTION

Boiling solvent vapors rise through the larger side-arm. Condensed drops of solvent fall into the _, dissolving out the desired component from a solid mixture.

siphoning action

CONTINOUS EXTRACTION

When the smaller side-arm fills to overflowing, it initiates a _.

porous cup

CONTINOUS EXTRACTION

The solvent, containing the dissolved component, is siphoned into the boiler below residual solvent then drains out of the _, as fresh solvent drops continue to fall into the porous cup.

Siphon arm

is responsible for the suction

condenser

occurs the repeating process of extraction cycle

Supercritical fluid extraction

is an alternative sample preparation method with general goals of reduced use of organic solvents and increased sample throughput.

Supercritical fluid extraction

The factors to consider include temperature, pressure, sample volume, analyte collection, modifier (cosolvent) addition, flow and pressure control, and restrictors.

Advantage of SFE

The extraction of constituents at low temperature, which strictly avoids damage from heat and some organic solvents.

Advantage of SFE

No solvent residues.

Advantage of SFE

Environmentally friendly extraction procedure.

WATER

• Anthocyanins

• Starches

• Tannins

• Saponins

• Terpenoids

• Polypeptides

• Lectins

ETHANOL

• Tannins

• Polyphenols

• Polyacetylenes

• Flavonol

• Terpenoids

• Sterols

• Alkaloids

METHANOL

• Anthocyanins

• Terpenoids

• Saponins

• Tannins

• Xantoxyllines

• Totarol

• Quassinoids

• Lactones

• Flavones

• Phenones

• Polyphenols

CHLOROFORM

• Terpenoids

• Flavonoids

ETHER

• Alkaloids

• Terpenoids

• Coumarins

• Fatty acids

ACETONE

• Phenols

• Flavonols

FILTRATION

The extract so obtained is separated out from the marc to remove fine or colloidal particles from the extract.

CONCENTRATION

The extract so obtained is concentration thru different means to eliminate the solvents that was used during the extraction process

SOLVENT PARTITIONING

• is a process used to separate compounds based on their solubility or affinity to the two immiscible liquids, usually an organic solvent and water.

Methanol

First solvent in extraction

Hexane

First fraction in extraction

Dicholoromethane

Second fraction in extraction

Ethyl Acetate

Third fraction in extraction

Aqueous

Fourth fraction in extraction

Sequential extraction

a common analytical method used to identify elements associated with solid phases in environmental media based on their reactivity with specific solutions.

Extraction

is essential for isolation of different chemical constituent from crude drug material

Extraction

depends on properties of material to be extracted; hence, necessary to study extraction methods in detail.

Aldehydes and ketones

_  derivatives of polyhydric alcohols

Glucose

 most important carbohydrate

The major source of metabolic fuel of mammals

Precursor for synthesis of all other carbohydrates in the body

Trioses

contains 3 carbon atoms

glycerose

Pentoses

contains 5 carbon atoms

ribose

Hexoses

contains 6 carbon atoms

glucose

Aldoses

contain terminal aldehyde group

glucose

Ketoses

contain nonterminal ketone group

fructose

Monosaccharides

contain a single  sugar unit

glucose, galactose, fructose

Disaccharides

made up of two monosaccharide units linked together

sucrose, lactose, maltose

Polysaccharides

made up of many monosaccharides' units linked together

starch, cellulose, glycogen

Glycan

is the generic term for polysaccharide and in the systematic nomenclature the latter is assigned a suffix “-an”

Homoglycan

The polysaccharide is termed as homoglycan when it contains only one type of monosaccharide unit.

Heteroglycan

The polysaccharide is known as heteroglycan when it involves more than one kind of monosaccharide unit

Pentosans

Pentoses, Arabinose, Xylose, Ribose

Hexosans

Hexoses, Glucose, Fructose

Fructan

Inulin that results Fructose

Glucan

Starch that gives Glucose

MOLISCH TEST

General test for all carbohydrates

conc. sulfuric acid

MOLISCH TEST
Carbohydrates when treated with _, they undergo dehydration to give furfural derivatives.

alpha-napthol

MOLISCH TEST

These compounds condensed with _ to form colored products.

pentoses; hexoses

xx yield furfural while xx yield 5-hydroxy methyl furfurals.

MOLISCH TEST

• Take 0.5 ml of carbohydrate solution in a clean and dry microcentrifuge tube. 

• Add 5 drops of ethanolic Alpha Naphthol (Molisch reagent) and mix.

• Incline the test tube and add carefully 1 ml of concentrated sulfuric acid along the side of the test tube to form 2 layers.

MOLISCH TEST

This is a sensitive but non-specific test and is given positive by all types of carbohydrates. If the oligosaccharides or polysaccharides are present, they are hydrolyzed to monosaccharides which are then dehydrated to give test positive

MOLISCH TEST

An appearance of reddish violet or purple colored ring at the junction of two liquids is observed in a positive Molisch test.