INTRODUCTION:

Thespesia populnea (Soland) belongs to family Malvaceae is a evergreen tree, bushy when young but thins out with age. It grows to 40 ft (12 m) or more with a spread of 10–20 ft (3–6 m). It has heart-shaped leaves and cup-shaped yellow flowers that are produced intermittently throughout the year in warm climates. Each flower has a maroon eye that ages to purple. This species grows well by the sea ¹.

Nerium odorum (Soland) belongs to family Apocynaceae is an evergreen shrub growing to 4m by 4m. It is hardy to zone 8. It is in leaf all year, in flower from June to October. The scented flowers are hermaphrodite. The leaves and the flowers are cardiotonic, diaphoretic, diuretic, emetic, expectorant and sternutatory ^{2, 3, 4}. A decoction of the leaves has been applied externally in the treatment of scabies ², and to reduce swellings ⁵. This is a very poisonous plant, containing a powerful cardiac toxin ⁵, and should only be used with extreme caution ^2,
3. It is beaten into a paste with water and applied to chancres and ulcers on the penis ⁵. Oil prepared from the root bark is used in the treatment of leprosy and skin diseases of a scaly nature ⁵. The whole plant is said to have anticancer properties ⁴.

Thunbergia alata Bojer popularly known as Black Eyed Susan Vine belongs to family Acanthaceae is nearly neither aggressive nor hardy; the flowers look very striking due to the dark center and will be covered in bloom most of the year, excepting the depths of winter⁶.

Helianthus annus Linn. Belongs to Family: Asteraceae is a coarse tap rooted annual. The stems are rough, branching upwardly often reaching 3 m in height. The leaves are alternate (lowermost may be opposite), with long petioles. The ovate-to-broadly ovate leaf blades are usually toothed along the margin. The inflorescence is a head borne on a long stalk. The involucral bracts are ovate to lanceolate with hairy margins. The ray flowers are bright yellow. The disk flowers are usually reddish to purple, rarely yellow ⁷.

Material and Method:

Fresh flowers of Thespesia populnea Sol., Nerium odorum Sol., Thumbergia alata Bojer, Helianthus annus Linn. were collected from Sangli region and they were authenticated at Dept. of Botany Willingdon College, Sangli (M.S).

The petals of flower were cleaned by distilled water and cut into small pieces and macerated for two hours in 10ml of 90% ethanol. The extract was preserved in tightly closed container and stored away from direct sun light.

Experimental work:

Preparation of extract:

1) Thespesia populnea (Sol.):- 1gm of fresh petals of Thespesia populnea Sol. was macerated for 2 hours in 10 ml of 90% of ethanol.

2) Nerium odorum (Sol.):- 1gm of fresh petals of Nerium odorum Sol. were macerated for 2 hours in 10 ml of 90% of ethanol.

3) Thunbergia alata (Bojer):-1gm of fresh petals of Thunbergia alata Bojer were macerated for 2 hours in 10 ml of 90% of ethanol.

4) Helianthus annus (L.):-1gm of fresh petals of Helianthus annus Linn. were macerated for 2 hours in 10 ml of 90% of ethanol.

Experiment was carried out by using phosphate buffer; place 50.0 ml of the 0.2M potassium di-hydrogen phosphate in a 200ml volumetric flask, add the specified volume of 0.2 M sodium hydroxide and then add water to volume ⁸.

pH	0.2M NaOH (in ml)	pH	0.2M NaOH (in ml)
5.8	3.6	7.0	29.1
6.0	5.6	7.2	34.7
6.2	8.1	7.4	39.1
6.4	11.6	7.6	42.4
6.6	16.4	7.8	44.5
6.8	22.4	8.0	46.1

Standard chart for Phytochemical identification ⁹:

Phytoche micals	Colour with aq. NaOH	Colour with Conc. H₂SO₄	Colour with Mg-HCl
Anthocynins	Blue violet	Yellow orange	Red (fades to pink)
Flavones	Yellow	Yellow to orange	Yellow to red
Flavonols	Yellow to orange	Yellow to orange	Red to magenta
Flavonones	Yellow to orange (cold) Red to purple (hot)	Crimson Orange	Red, magenta, violet, blue
Is flavones	Yellow	Yellow	Yellow
Leucoantho cyanins	Yellow	crimson	Pink

Anthocynins are characterized by two absorption bands

Band I – 475-560 nm (visible region)

Band II – 275-280 nm (UV region)

Band I actual colour depends on number and position of hydroxyl and methoxyl group. When these are fixed. The colour then depends upon the pH and solvent ¹⁰.

RESULTS:

1) Determination of UV absorption of the following plants:

Plant name	UV	Visible
Thespesia populnea Sol.	275 (0.425)	521 (0.039)
Nerium odorum Sol.	329 (0.878)	521 (0.023)
Thunbergia alata Bojer	287 (0.927) (upper part) 260 (0.332) (lower part)	513 (0.319) 518 (0.061)
Helianthus annus Linn.	254.6 (0.709)	-

2) Determination of class, pH and colour change:

Plant name

class

Colour change

Thespesia

populnea Sol.

Leucoanthocyanins

7.4 –

7.8

Pink to yellow

Nerium odorum

Sol.

Flavones

7.0 - 8.6

8.8 - 9.0

Pink to colourless

Fluroscent yellow

to green

Thunbergia

alata Bojer

Anthocynins (upper

part) Flavones

(lower part)

10.0

Pink to green

Helianthus

annus Linn.

Isoflavones

6.6 - 7.0

Faint blue to faint

yellow

ACKNOWLEDGEMENT:

We are thankful to Prof. D.D. Chougule, Principal, Appasaheb Birnale College of Pharmacy, Sangli Mrs. U.S. Yadav, Prof., Dept. of Botany, Willington College, Sangli, as well as teaching and non teaching staff for their kind support.

REFERENCES:

1. Florawww.eeb.uconn.edu/

2. Chiej R. Encyclopaedia of Medicinal Plants. MacDonald, Orbis 1984 ISBN 0-356-10541-5.

3. A Barefoot Doctors Manual. A very readable herbal from China, combining some modern methods with traditional chinese methods. Running Press ISBN 0-914294-92-X.

4. Duke JA and Ayensu ES Medicinal Plants of China. Reference Publications, Inc. 1985.

5. Chopra RN, Nayar SL, and Chopra IC. Glossary of Indian Medicinal Plants (Including the Supplement). Council of Scientific and Industrial Research, New Delhi. 1986.

6. Wagner WL, Herbst DR, and Sohmer SH. Manual of the Flowering Plants of Hawai'i. Vols 2, Bishop Museum Special Publication 83, University of Hawai'i and Bishop Museum Press, Honolulu, 1999.

7. http://explorebiodiversity.com/

8. Indian Pharmacopoeia. Reagent and solutions:buffer solutions, composition of standard buffer solution, phosphate buffer. 1996 pp a-145, appendix 13.1.

9. Agarwal OP. Chemistry of organic natural products. Vol II. Goel publishing house, Krishana prakashan media (p) Ltd, Meerut. p. no 130

10. Agarwal OP. Chemistry of organic natural products. Vol II. Goel publishing house, Krishana prakashan media (p) Ltd, Meerut. p. no 210,213

Received on 06.12.2008 Modified on 18.03.2009

Research J. Pharm. and Tech.2(2): April.-June.2009; Page 421-422