Proceedings of the UGC sponsored National Workshop on Computational Chemistry –From Theory to Applications (In Silico- 15), July 29-31 2015.

PHYTOCHEMICAL SCREENING OF THE FLOWERS OFTABERNAEMONTANA DIVARICATA

(CREPE JASMINE)USING DIFFERENT SOLVENTS

Dr.Lakshmy.M, Assistant Professor, Department of Chemistry, MSM College ,Kayamkulam, Kerala lakshmymsradha@gmail,com

Medicinal plants have been used for centuries as remedies for diseases. They are enriched withantimicrobial agents which are biologically active chemical molecules. Recently plant derived compounds have become of great interest because of their various applications1. Traditional medicinal system Ayurveda practices drugs derived from plant parts. It has been estimated that 28% of higher plant species are used medicinally and that 74% pharmacologically active plant components were discovered after following up on ethno medicinal use of the plants2. The use of chemical fertilizers and pesticides induces problems to health and environmental hazards in agricultural system. Hence the best biorationalalternative is the natural products of antimicrobialactivity3.Over the last two decades, intensive effort has been made to discover chemically useful antibacterial or antifungal drugs of plant origin4.

The attention of biological scientific community is now focussed on the medicinal plants which are used traditionally. This has involved the isolation and identification of secondary metabolites produced by plants and their use as active components in medicinal preparations5. Plants have endless ability to synthesize aromatic secondary metabolites, most of which are phenols or their oxygen substituted derivatives6. The compounds of phenols, phenolic acid quinones,flavones, flavonoids, flavanols, tannins and coumarinesetc are most commonly present in the extraction of plants. These groups of compounds show anti microbial effect and serves as plant defence mechanism against pathogenic micro organisms. Flavones, flavonoids and flavanols are phenolic structures with one carbonyl group. They are synthesised by plants in response to microbial infection7. Studies reported the antimicrobial activities of flavones8.Astringent properties are shown by tannins. Terpenes which contains essential oils give fragrance to the plants. Essential oils also possess strong antimicrobial properties.

Tabernaemontanadivaricata popularly known as Nandiarvatom in kerala belongs to the family Apocynacea. The plant is an evergreen shrub growing to a height of six feet and found in all parts of the country. The white flowers are soft, silky and sweet smelling. The flowers are widely used for ophthalmic treatment.Apart from this the extracts of these flowerspossessanti inflammatory,analgesic, astringent properties etc.

Materials and methods

Flowers were collected from the plants, washed and dried in shade. The powdered samples were used for the further extraction. The soxhlet extraction method was employed for the pulverized and dried flowers using a sequential method with solvents in the increasing polarity as hexane, chloroform and methanol. The residue was obtained by solvent removal under reduced pressure.

Analytical methods

Phytochemical analysis of various extracts

The phytochemical analysis of the hexane, chloroform and methanol extracts of the flowers for phenols, amino acid,alkaloids, saponins, tannins, reducing sugar, steroids and flavonoids were carried out using the methods described by HarborneSofowara and Trease Evans. The powdered plant material was extracted with the required solvent and the necessary reagent was added to the extract. All observations were recorded and the details of the chemical tests were done as given below

Phenol

Mix1iml of the extract with 1ml Folinciocalteu reagent followed by 3% sodium carbonate. A deep blue colour indicates the presence of Phenols.

Tannins

1ml of the extract is mixed with 2 to 3 drops of 5% FeCl3. Green or black precipitate indicates the presence of tannins and Phenols

Alkaloids

Mix 1ml of the extract with 1ml Mayers reagent. White precipitate indicate the presence of alkaloids.

Saponins

Shake 0.5 ml of the extract vigorously with 5ml distilled water. The presence of saponins is indicated by the formation of persistent froth.

Flavanoids.

A few drops of wagner reagent is added to 0.5ml of the extract. Formation of reddish brown precipitate indicates the presence of flavonoids.

Reducing sugar

1ml of the extract mixed with 1ml of Benedicts reagent is kept in a boiling waterbath for 5 minutes. If the solution appears green , yellow or red reducing sugar is present.

Aminoacids

2ml of the extract and 2ml 5%ninhydrin solution are mixed and heat ina boiling water bath for 10 minutes. Purple or bluish colour indicates the presence of aminoacids

Steroids

To 2ml of extract add 2ml acetic anhydride and chloroform. Add H2SO4 through the sides of the test tube. Green ring at the junction of the three liquids indicate the presence of steroids

Results and discussion

The phytochemical analysis of the flowers ofTabernaemontanadivaricata reveals the presence of secondary metabolites and the results obtained are as below:

+indicates presence and – indicates absence

Extract / Phenols / Tannin / Alkaloids / Saponins / Flavanoids / Reducing sugar / Aminoacids / Steroids
Hexane / + / - / - / + / - / + / + / -
Chloroform / - / + / - / + / - / + / + / -
Cold methanol / + / + / - / + / + / + / + / -

The chemical analysis reveals that alkaloids and steroidsare absent in the extract of the flowers ofTabernaemontanadivaricata.In the hexane extract tannins and flavonoids are absent.Phenols, saponins ,amino acids and reducing sugars are present in all the extracts.

Plant produces various metabolic products for their growth and development. The components which are essential for the growth and survival for the producer plant are known as primary metabolites. Secondary metabolites are plant substances which are derived biosynthetically from primary metabolites .Flavanoids, alkaloids, terpenoids, phenols, tannins, saponins, steroids etc belong to this class. The presence of phenolic group imparts anti oxidant activity to flavonoids, phenols and tannins. Anti oxidant substances can block the action of freeradicals which are responsible for the pathogenesis of various diseases9. Terpenoids act as regulators of metabolism and can also show antimicrobial and antallergic and antiinflammable activity. The qualitative and quantitative phytochemical studies of the aerial parts of the plant reveals the presence of these secondary metabolites10.

Both primary and secondary metabolites are present in the flowers of Tabernaemontanadivaricata. Hence much contribution in the production of new drugs is expected from this plant. This work can be extended to the quantitative analysis of these metabolites and also the detection of other active biochemical components with the help of advanced chromatographic techniques in future.

Acknowledgement

This work was supported by University Grants Commission by providing grant under Minor Research Project.

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