1.Question or problem to be addressed
The aim of this research proposal
is to perform phytochemical screening of a new variety of Syzygium cumini. Syzygium caryophylli folium (family- Myrtaceae) is a
evergreen tropical tree and native to the Indian Subcontinent and was reported
from Chandrapur district of Vidarbha region, Maharashtra. The main objective is
to determine phytochemicals present in S.caryophylli folium leaves through
ethanol extract along with biological activity against gram positive and gram
2.Background to the problem
Medicinal plants are used for
healing and curing of human diseases due to presence of phytochemical
constituents. Phytochemicals are of
two categories; primary and secondary constituents. Primary constituents include
chlorophyll, proteins sugar and amino acids while secondary constituents contain
terpenoids and alkaloids phenolic compounds. Terpenoids exhibit various
pharmacological activities such as anti-malarial, anti-fungal,
anti-inflammatory activities etc. Alkaloids are used as anaesthetic agents.
Phenolic compounds possess biological properties such as anti-ageing,
anti-carcinogen, anti-inflammation, cardiovascular protection and improvement
(Han et al.,2007).
products have been a part of phytomedicines since time immemorial. These can be
derived from any part of the plant like barks, stems, leaves, roots, seeds, etc
(Cragg and David, 2001), i.e., any part of the plant may contain active
compounds which occur naturally. The plants belonging to the family Myrtaceae are
used as anti-inflammatory, antinociceptive, antimicrobial, antioxidant agents.
This species are also used as folk medicines to treat several diseases,
especially gastrointestinal disorders, haemorrhagic and infectious diseases.
to this fact, preliminary phytochemical
screening of plants is in need to discover and develop novel therapeutic drugs
with improved efficacy. Numerous research groups have also reported such
studies throughout the world. Correlation
between the phytoconstituents and the bioactivity of plant is desirable to know
for the synthesis of compounds with specific activities to treat various health
ailments and chronic diseases.
3.Experiment to address the problem
fresh leaves of the plant Syzygium
caryophylli folium should be washed
thoroughly with water, shade dried for about 10 days. The dried plant sample
then should be homogenized into fine powder and stored in air sealed containers
at room temperature before extraction. The components of finely powdered plant
material are to be extracted using Soxhlet apparatus using organic solvent
ethanol. The extract then is concentrated and stored in air tight glass
container for further use. The aqueous extract of leaves sample is analysed for
the presence of the phytochemical constituents present in the plant.
Alkaloid: The ethanolic extract
is to be evaporated to dryness in boiling water bath. Then about 0.2 grams
of residue is dissolved in 2% H2SO4
filtered. A few drops of Dragondroff’s reagent is added. Orange-red
precipitates indicates the presence of alkaloids.
Tannin: A small quantity of extract
is mixed with water and heated on the water bath for several minutes. The
mixture is then filtered, and ferric chloride is added to the filtrate. A
dark green coloured solution indicates the presence of tannins.
Anthraquinones: About 0.5 grams
of the extract is boiled with 10% Hydrochloric acid in water bath for few
minutes. It is filtered and then allowed to cool. Equal quantity of CHCl3
is added to the filtrate and then a few drops of 10% NH3
is added and heated. Formation of rose-pink colour indicates the presence
Glycosides: The extract is
hydrolysed with HCl solution and then neutralized with NaOH solution. A
few drops of Fehling’s A and B solution are added which produces a red
precipitate indicating the presence of glycoside.
Cardiac glycosides: The crude powder of the plant is treated with
1 ml of FeCl3 reagent (mixture of 1 volume of 5% FeCl3
and 99 volumes of glacial acetic acid). To this solution a few drops of
concentrated H2SO4 is added. Appearance of
greenish-blue colour within few minutes indicated the presence of cardiac
glycosides. (Ajaiyeobu, 2002)
Reducing Sugars: The
plant extract is shaken distilled water and then filtered. To the filtrate
Fehling’s solution is added and heated it to boiling for few minutes. An
orange-red precipitate shows a positive result.
Saponins: About 0.2 grams of extract is shaken with 5 ml of
distilled water and heated to boil. Appearance of creamy layer of small
bubbles (frothing) confirms the presence of saponins.
Flavonoids: A small amount of extract is dissolved in dilute NaOH
and then HCl is added. A yellow colour solution turning colourless
indicates the presence of flavonoids.
plant extract is dissolved in distilled water and then filtered. The
filtrate is later boiled with 2% HCl solution forming red precipitate,
which confirms the presence of phlobatannins.
Terpenoids: A small
quantity of plant extract is taken in a test tube, chloroform and
sulphuric acid are added carefully to form a layer. Formation of reddish
brown colour at the interface indicates the presence of terpenoids
4. Expected outcomes and alternative strategy if
following outcome may be anticipated by phytochemical screening of ethanol
extracts of Syzygium caryophylli folium
(Where ‘+’: present, ‘-‘:
expected results of the qualitative analysis of the medicinal plant Syzygium caryophylli folium may show the presence of tannins and saponins in ethanol
extract. It needs further investigation to find out remaining bioactive
constituents. This plant can be seen as a potential source of useful
drugs with astringent properties and can be used for manufacturing chemical and biomedical reagents.
Further solvents used for the
extraction of biomolecules from plants are selected on the basis of polarity of
the solute of interest. A solvent of similar polarity to the solute will
properly dissolve the solute. Multiple solvents can be used sequentially in
order to limit the amount of analogous compounds in the desired yield. The
polarity, from least polar to most polar, of a few common solvents is as
follows: Hexane < Chloroform < Ethyl acetate < Acetone < Ethanol < Water. Using different solvents for screening of various phytochemicals on based on solute-solvent polarity may show the presence of various other bioactive compounds. The phytochemical analysis of the plants is very important commercially and has great interest in pharmaceutical companies to produce the new drugs for curing of various diseases.