Module 1.1 - Phytochemical Investigation Flashcards
refers to the extraction, screening, and identification of medicinally active substances found in plants.
Different methods can be conducted to determine the different constituents present in plants
One of the methods of identifying the constituents
PHYTOCHEMICAL INVESTIGATION
A method for use in phytochemical screening should be:
- Simple
- Rapid
- Designed for a minimum of equipment
- Reasonably selective for the class of compounds under study
- Quantitative in so far as having a knowledge of the lower limit of detection is concerned; and if possible
- Should give additional information as to the presence
or absence of specific members of the group being evaluated
Phytochemical Investigation steps
- Authentication and Extraction
- Separation and Isolation of Constituent of interest
- Characterization of the Isolated Compound
- Investigation of the Biosynthetic Pathway
- Quantitative Evaluation
- Pharmacologic Evaluation of the Separated Compound
(COLLECTION OF PLANTS) After vegetative processes are ceased
Roots or Rhizomes
(COLLECTION OF PLANTS) Before vegetative process/After the period of damp weather
Stem or Bark
(COLLECTION OF PLANTS) When they are about to bloom
Flowers
(COLLECTION OF PLANTS) When they are fully matured
Seeds
(COLLECTION OF PLANTS) When photosynthesis is active
Leaves
(COLLECTION OF PLANTS) Unripe/Ripe
Fruits
It is the separation of medicinally active portions of plant/animal tissues using selected solvents through standard procedures
EXTRACTIONS
METHODS OF EXTRACTION
- Plant tissue homogenization
- Serial exhaustive extraction
- Soxhlet extraction
- Sonication
Soaking in a specific solvent for 24-73 hours or as indicated
Maceration
Steeping the sample into a cold or hot water
Infusion
A form of maceration in which gentle heat without boiling for at least 15 minutes
Digestion
The process of a liquid slowly passing through a filter.
Percolation
Used for percolation
Percolator
a method of extraction by boiling herbals or plant to dissolve the chemicals of the material for at least 15 minutes
Decoction
A widely used method for separating the components of liquid mixtures based on the distribution of mixture constituents between the liquid and vapor phase
Distillation
Is typically used for isolating oils from citrus peels. It involves soaking citrus peels in warm water and then hand-squeezing them with a sponge until the oil glands burst
Expression / Cold-press extraction
What are the basic parameters that may influence the quality of extracts?
- plant part used as extracting material
- solvent used for extraction
- extraction procedure
What are the common variations on extraction methods?
- length of the extraction period
- solvent used
- pH of the solvent
- temperature
- particle size
- solvent to sample ratio (1:10)
(SOLVENT USED) fats, fixed oils, waxes, pigments, resins
Petroleum Ether
(SOLVENT USED) alkaloids, resins, glycosides, coumarins, fatty acids
Ether
(SOLVENT USED) same as Ether, terpenoid lactones*
Chloroform
(SOLVENT USED) glycosides, tannins, saponin, resin
95% Alcohol
(SOLVENT USED) hydrophillic and lipophillic components, phenolics, tannins
Acetone
(SOLVENT USED) same as 95% alcohol preferred in phytochemical screening
80% Alcohol
(SOLVENT USED) glycosides, sugar, salt, gum mucin, protein
Water
(SOLVENT USED) alkaloids, salt of veg. acid
1% HCl
(SOLVENT USED) Pentosans and hemicellulose
5% NaOH
(SOLVENT USED) selective extraction of terpenoids
Dichloromethanol
Effect of extracted phytochemicals depends on:
- Nature of plant material
- Its origin
- Degree of processing
- Moisture content
- Particle size
The variations in different extraction methods that will affect quantity and secondary metabolite composition of an extract depends upon:
- Type of extraction
- Time of extraction
- Temperature
- Nature of solvent
- Solvent concentration
- Polarity
water soluble constituents like carbohydrates, amino acids.
Paper Chromatography
lipid soluble constituents like fats, fixed oils, waxes, chlorophyll.
Thin Layer Chromatography
volatile compounds like HC, terpenes, fatty acids
Gas Liquid Chromatography
High Pressure Liquid Chromatography
High Pressure Liquid Chromatography