Phytochemical screening refers to the extraction, screening and identification of the medicinally active substances found in plants. Some of the bioactive substances that can be derived from plants are flavonoids, alkaloids, carotenoids, tannin, antioxidants and phenolic compounds.

1. Bengal School of Technology
TOPIC-PHYTOCHEMICAL CHARACTERIZATION
&
ANTIMICROBIAL ASSAY OF SOME INDDIGENUS
MEDICINAL PLANTS
PRESENTED BY-PRITAM AON
ROLL NO:-19301913049
REG NO:131930210050
Under the supervision of Raja Chakraverty
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2. CONTENTS
Introduction
Literature Survey
Aims and Objectives
Methods
Results
Discussions and Conclusion
Reference
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3. INTRODUCTION
HERBS :Herbs refer to the leafy green or flowering parts of a plant used for food,
flavouring, medicine, or fragrances for their savory or aromatic properties. while
spices are produced from other parts of the plant (usually dried), including seeds,
berries , bark, roots and fruits
HERBAL MEDICINE: Herbal medicine is the oldest and still the most widely used
system of medicine in the world today. Herbal medicine, also called botanical
medicine or phytomedicine, refers to using a plant's seeds, berries, roots, leaves,
bark, or flowers for medicinal purposes
PHYTOCHEMICAL SCREENING: Phytochemical screening refers to the
extraction, screening and identification of the medicinally active substances found
in plants. Some of the bioactive substances that can be derived from plants are
flavonoids, alkaloids, carotenoids, tannin, antioxidants and phenolic compounds.
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4. Ocimum Americanum Linn.
 India has great potential of biodiversity. The genus Ocimum belongs to
Lamiaceae family. Ocimum americanum L.( syn. Ocimum canum sims, is
a traditional medicinal plant distributed all over India mostly on waste
lands, river banks and sides of paddy fields.
. Chemical Constituents:
 Aerial parts yield an essential oil, which contains camphor and linalool
(major constituents), citronellal, methylcinnamate, citronellic acid,
eugenol, citronellol, geraniol, citral
 methylheptenone. On fractionation the oil yields dipentene, terpinolene,
crithmene, limonene, pinene, sabinene, camphene, caryophyllen
Using Information:
 The plant is carminative, diaphoretic and stimulant; used in cold, coughs,
catarrh and bronchitis,
 Leaf juice is used for dysentery and as a mouth-wash for relieving
toothache; poured into nostrils for migraine. Decoction of the leaf is
used for checking nose bleeding and malarial fever. Essential oil of the
leaves and inflorescences possesses strong antifungal and antibacterial
properties. e, traces of phenol and acetic acid.
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Fig:-Ocimum Americanum
Linn.

5. Description of the Plant:
 An Annual, floating in water herb. Colours Leaf- green;
Stems and roots- brown. Odour Characteristic.
Using Information:
 Neptuniaprostrata L. (Synonym: Neptuniaoleracea.
Family: Mimosaceae) is a miniature aquatic herb that
floats by its white spongy structure. It has soft swollen
stem with slenderfibrous roots in flower bearing nodes.
As a medicinal plant it is well-known to the herbal
doctors of Tripura and other states of North-Eastern
region. The tribal people of Tripura cultivate this plant
both as vegetables as well as medicinal plant. They
prepare various tasty dishes with this vegetable. Aqueous
extract of this plant is used in the treatment of jaundice,
sores of tongue, diarrhoea with bleeding, epileptic
convulsions, earache etc.
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Fig:-Neptunia prostrata Linn

6. Literature Survey
Ocimum americanum L. leaf extract mediated synthesis of
silver nano particles: A noval approach towards weed
utilization By Anuradha G.1, B. Syama Sundar*2 and M. V.
Ramana3
Pharmacognostic & Preliminary Phytochemical
Investigations of Neptunia prostrata L. Prashanta Kr. Deb,
Sanjoy Das, Kaushik Nath Bhaumik, Rajat Ghosh, Tarun
Kanti Ghosh, Tejendra Bhakta
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7. AIM:-
The aim of this study was to screen photochemical characterization and antimicrobial assay
of some indigenous medicinal plant.
OBJECTIVES:-
Photochemical Screening of some indigenous medicinal plant
 Antimicrobial Activities of some indigenous medicinal plant
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8. PHYTOCHEMICAL SCREENING: Phytochemical screening refers to the
extraction, screening and identification of the medicinally active substances found
in plants. Some of the bioactive substances that can be derived from plants are
flavonoids, alkaloids, carotenoids, tannin, antioxidants and phenolic compounds.
MICROBIOLOGICAL ASSAY The microbiological assay of an antibiotic is based
upon a comparison of the inhibition of growth of microorganism by measured
concentration of the antibiotics under examination with that produced by known
concentration of a standard preparation of the antibiotics having a known activity.
Two general methods are usually employed, the cylinder plate (or cup plate)
method and the turbidimetric (or tube assay) method.
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9. Detection of alkaloids
 The individual extract is dissolved in dilute hydrochloric
acid and filter.
 The filtrate was further tested with following reagents for
the presence of alkaloids.
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10. 10
• Filtrate was treated with potassium bismuth iodide solution (Dragendroff’s
reagent).
• Formation of orange red precipitate indicated the presence of alkaloids.
Dragendroff’s Test:
• Filtrate was treated with saturated aqueous solution of picric acid (Hager’s
reagent).
• Presence of alkaloids were confirmed by the formation of yellow coloured
precipitate.
Hager’s Test:
• Filtrate was treated with potassium mercuric iodide solution (Mayer’s reagent).
• Formation of a whitish yellow or cream coloured precipitate indicated the presence
of alkaloids.
Mayer’s Test:

11. Detection of flavonoids
• Treat the extract with few drops of sodium
hydroxide solution.
• Formation of intense yellow colour, which
becomes colourless on further addition of dilute
acid, indicated the presence of flavonoids.
Alkaline
Reagent Test
• Treat the extract with few drops of lead acetate
solution.
• Formation of yellow precipitate indicated the
presence of flavonoids.
Lead acetate
Test:
• Add a few drops of ferric chloride solution to the
extract solution.
• Development of intense green colour indicates
the presence of flavonoids.
Ferric chloride
Test:
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12. Detection of cardiac glycosides
Keller-Killani test
Add 1ml of conc.
sulphuric acid,
Appearance of brown ring
at the interface indicate
the deoxysugar
characteristic of
cardenolides
Appearance of a violet ring
below the brown ring & a
greenish ring in the acetic acid
layer confirmed the results.
Treat the extract with 2 ml of
glacial acetic acid containing one
drop of ferric chloride solution.
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13. RESULT
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Fig: Wagner’s Test Fig : Dragendroff’s Test
Result of alkaloidal test of Neptunia Prostrata linn.

14. RESULT OF MICROBIOLOGICAL ASSAY OF
Ocimum americanum Linn
&
Amoxycillin
Organism OA1
Low
dose
100 mg/l
OA 1
High
dose
400
mg/l
Amoxyc
illin
LOW
DOSE
100
mg/l
Amoxyc
illin
HIGH
DOSE
400
mg/l
ZOI ZOI ZOI ZOI
S. aureous 13 mm 25 mm 26 mm 28 mm
S. typhi 15 mm 20 mm 16 mm 28 mm
B. Subtilis 15 mm 17 mm 20mm 30mm
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Ocimum americanum Linn samle 1=OA1
ZOI=ZONE OF INHIBITION
Organism OA3
Low dose
100 mg/l
OA 3
High
dose
400 mg/l
Amoxycillin
LOW DOSE
100 mg/l
Amoxycillin
HIGH DOSE
400 mg/l
ZOI ZOI ZOI ZOI
S.aureous 26 mm 28mm 27 mm 31 mm
S. typhi 16 mm 18mm 14 mm 15 mm
B. subtilis 12 mm 18mm 21mm 25 mm
Ocimum americanum Linn samle 3=OA3
ZOI=ZONE OF INHIBITION

15. pictures OF MICROBIOLOGICAL ASSAY OF
Ocimum americanum Linn(SAMPLE 1) Ocimum americanum Linn(SAMPLE 3)
&
Amoxycillin in LOW &HIGH DOSE
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S. typhi
S. aureous B. subtilis
S. aureous S. typhi B. subtilis

16. discussionThe antimicrobial study using the extracts revealed that the plant definite antimicrobial
activity against the three strains of bacteria and their laboratory cultures as evident from the
Nutrient agar method. IC 50 values may give a clearer picture as to the Minimum Inhibitory
Dose of the plant extract possesses chemical constituents in the extract and has.
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CONCLUSIONFrom the above mentioned study we came to know about the preliminary
phytochemical screening of the extracts of the plant and also the antimicrobial effects
of the plant against bacterial strains.
The pharmacological in-vivo activities of the plant and its toxicity studies as per
OECD guidelines need to be ascertained using a large sample size in animal models of
disease to corroborate the present findings and reaffirm its putative role in
therapeutics.
Antimicrobial studies on other strains of bacteria may be also performed to
understand the spectrum of antimicrobial activity of the plant extracts under study.

17. References
1. Das K, Tiwari RKS, Shrivastava DK. Techniques for evaluation of medicinal plant products as
antimicrobial agent: Current methods and future trends. Journal of Medicinal Plants Research
2010; 4(2): 104-111.
2. Parekh J, Karathia N, Chanda S. Evaluation of antibacterial activity and phytochemical analysis of
Bauhinia variegata L. bark. African Journal of Biomedical Research 2006; 9: 53-56.
3. Eloff JN. Which extractant should be used for the screening and isolation of antimicrobial
components from plants. Journal of Ethnopharmacology 1998; 60: 1–8.
4. Adebolu, T.T. and Oladimeji, S.A. (2005). Antimicrobial activity of leaf extracts of Ocimum
gratissium on selected diarrhoea causing bacteria in southwestern Nigeria. Afr. J. Biotechnol., 4:
682 - 684.
5. Adiguzel, A., Gulluce, M., Sengul, M., Ogutcu, H., Sahin, F. and Karaman, I. (2005). Antimicrobial
effects of Ocimum basilicum (Labiatae) extract. Turk J. Biol., 29: 155 - 160.
6. Ates, D.A. and Erdogrul, O.T. (2003). Antimicrobial activity of various medicinal and commercial
plants extracts. Turk J. Biol., 27: 157 - 162.
7. Burt, S.A. (2004). Essential oils: their antibacterial properties and potential applications in foods-
a review. Int. J. Food Microbiol., 94: 223 - 253.
8. Burt, S.A. and Reinders, R.D. (2003). Antimicrobial activity of selected plant essential oils against
Escherichia coli O157:H7. Lett. Appl. Microbiol., 36: 162 - 167.
9. Chiej, R. (1984). Encyclopaedia of Medicinal Plants. MacDonald. ISBN 0-356-10541-5, Little, Brown.
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