Assessment of total phenolic , flavonoid , tannin content and phytochemical screening of leaf and flower extracts from Peltophorum pterocarpum ( DC . ) Backer ex K . Heyne : a comparative study

Introduction: Total phenolic, flavonoid and tannin content of leaf and flower extract of Peltophorum pterocarpum (DC.) Backer ex K.Heyne was compared. Objective: To explore total phenolic, flavonoid and tannin content of both leaf and flower extracts of Peltophorum pterocarpum(DC) K Heyne. Method: Initially, collected fresh leaves and flower samples were shade dried and extracted with various solvents such as aqueous methanol (1:1), ethyl acetate, ethanol and aqueous. Qualitative analysis was performed for various phytochemical. Thenthe total phenolic content, total flavonoid content and total tannin content was estimated. Results: In preliminary phyto-chemical examination of various solvent extracts of both leaf and flowers of P. pterocarpum revealed that the presence of various phytochemicals such as phlobatannins, terpenoids, alkaloids, saponins, tannin, reducing sugars, phenols and steroids. In phtyochemical evaluation, when compare with all other solvents, Ethanolic extracts shows maximum extractive value. In case of ethyl acetate, it shows very low extractive value in all three phyto-chemicals. In phytochemical evaluation studies, total phenolic content of leaves shows highest in ethanolic extract (33.17 ± 4.72 mg/g) and lowest in ethyl acetate extract from flower (4.71 ± 0.07 mg/g), Similarly, flavonoid content of leaves shows highest in ethanolic extract (1.43 ± 0.01 mg/g) and lowest in aqueous extract of flower (0.23 ± 0.09 mg/g) but in case of tannin content, flower extracts shows higher tannin content in ethanolic extract (844.59 ± 10.38 mg/g) whereas lowest tannin content in leaf ethyl acetate extract (9.54 ± 6.98 mg/g). Conclusion: This is first report of comparative studies on total phenolic, flavonoid and tannin content of various solvent extracts both leaves and flowers from Peltophorum pterocarpum (DC) K Heyne.


INTRODUCTION
Peltophorum pterocarpum (DC).Backer ex K. Heyne (Leguminosae) is commonly referred to as golden flamboyant.It is widely grown in tropical regions of South Eastern Asia, Sri Lanka, Thailand, Indonesia, Malaysia, Philippines and Australia. 1 A handsome tree, up to 24 m. in height, barks grey, smooth; leaves bipinnate: leaflets many, 10-30 pairs of leaflets are present which are oblong.The flowers are bright yellow coloured, nectar producing and shows axillary racemose inflorescence.It is used as astringent to cure intestinal disorder, used as pain relief after child birth, sprains, bruises and edema.It is also used as lotion for eye irritation, muscular pains andsores. 24][5] Its bark is used as medicine for dysentery, as eye lotion, embrocation for pains and sores.7] Similarly, Flowers are used to treat insomnia and to induce good sleep. 8][11][12] Similarly, b-Sitosterol, a mixture of steroidal glycosides, lupeol, bergenin, and naringenin-7-glucoside has been reported from the flowers.  Theraditional healers use the leaves in the form of decoction for treating skin disorders.Stem infusion of Peltophorum pterocarpum Baker ex K. Heyne used in dysentery, for gargles, tooth powder and muscular pain. 18and 19 An antioxidant and cardio tonic activities have also been reported from the flower .10,20Literature reviews indicated that previously, no studies combining the leaf and flowers especially, total phenolic, flavonoid and tannin content of the leaf and flowers of Peltophorum pterocarpum.In the present communication, we qualitatively explore the presence of phytochemicals such as alkaloids, flavonoids, steroids, glycosides, saponins, tannins and many other phyto-chemicals and evaluation of total phenolic, flavonoid content and tannin content of various extracts of both leaf and flowers from Peltophorum pterocarpum (DC.)Backer ex K. Heyne was compared.

Collection and authentication of plant material
Fresh leaves and flowers were collected from healthy P. pterocarpum trees at Kumaraguru College of Technology, Coimbatore, Tamil Nadu, India campus medicinal garden during December 2013.The plant sample was identified to be Peltophorum pterocarpum by Botanical Survey of India, Tamil Nadu Agricultural University (TNAU), Coimbatore, Tamil Nadu, India (Reference no.BSI/SRC/5/23/201 3-14/Tech./1687).The leaf and flower samples were washed thoroughly with running water to remove the dirt from these samples.These samples were blotted dry with tissue papers.

Sample preparation
The collected and cleaned leaf and flower samples were shade dried for 3-4 days till samples were free from moisture.The dried samples were powdered using clean mechanical blender to obtain fine sized leaf and flower samples.Then 5 g of finely powdered leaf and flower samples of P. pterocarpum were extracted with aqueous: methanol (1:1), ethanol and ethyl acetate (150 ml each) separately using soxhlet extractor.Exhaustive extraction was done for 20 cycles in the extractor.The extracts were concentrated using flash evaporator and the concentrated extracts were stored in sealed eppendorf for further studies.

Preliminary phytochemical studies
The leaf and flower extracts of P. pterocarpumwas subjected to qualitative phyto-chemical analysis.Presence of various phytochemicals such as phenols, steroids, glycosides, saponins, flavonoids, phlobatannins, terpenoids, alkaloids and reducing sugars were determined by various phytochemical tests. 21timation of total phenolic contents Total phenolic content was estimated by the following method.Total phenolic content was estimated for aqueous methanol, aqueous, ethanol and ethyl acetate extracts of both leaf and flower extracts of P. pterocarpum.20 µL of the extracts were made up to 1 mL with distilled water.0.5 mL of freshly prepared Folin ciocalteu phenol reagent and 2.5 mL of 20% sodium carbonate were added respectively to each extract.The contents were agitated and left in dark for 40 minutes.The absorbance of the sample was read at 725 nm.Gallic acid was used as the standard.Amount of phenolic content was expressed as mg of Gallic acid per gram of plant tissue (mg GA/g).
Estimation of tannin content 100 µL of each flower and leaf extracts were made upto 7 mL with distilled water.8 mM potassium ferric cyanide and 20 mM ferric chloride prepared in 0.1M hydrochloric acid were added respectively.The contents were mixed and optical density was measured at 700 nm.Tannic acid was used as standard.Tannin content was expressed as mg of tannin per gram of plant tissue (mg TA/g).

Estimation of total flavonoid content
Total flavonoid content was estimated by the method of Sathishkumar et al. 22 using Quercetin as standard.0.1 mL of each flower and leaf extracts were taken and made up to 5 mL with distilled water.0.3 mL of 5% NaNO 2 was added.3 ml of 10% AlCl 3 was added after 5 minutes and were shaken well. 2 mL of 1M NaOH was added after 6 minutes and the absorbance was read at 510 nm.The results were expressed as mg quercetin/g of plant tissue.

Preliminary phytochemical test for extracts of leaves and flowers of Peltophorum pterocarpum.
Preliminary phyto-chemical analysis of various solvent extracts such as aqueous methanol, ethyl acetate, ethanol and aqueousextracts of leaf and flowers of P. pterocarpum revealed that the presence of various phyto-chemicals.It was found that steroids were absent in flowers and phlobatannins were absent in leaves of P. pterocarpum (Table 1 and 2).

Phytochemical evaluation Total phenolic content
The total phenolic content was estimated using Gallic acid as standard.The total phenolic content was expressed as Gallic Acid equivalent (GAE)/g of tissue.Among four different extracts, ethanolic extract shows maximum phenolic content of 33.17 ± 4.72 mg and 24.91 ± 6.82 mg of GAE/g from leaf and flower respectively (Figure 1).Results are expressed as means ± SD (n=3).Aq.l=Aqueous leaf; Aq.f =Aqueousflower; E.a.l=Ethyl acetate leaf; E.a.f=Ethyl acetate flower; E.l=Ethanol leaf; E.f=Ethanol flower; Aq.m.l=Aqueous Methanol leaf; Aq.m.f=Aqueous Methanol flower.

Tannin content
Total tannin content was estimated using tannic acid standard.Figure 2 Shows tannin content of various extracts of Peltophorum pterocarpum and expressed as tannic acid equivalent (mg tannic acid (TAE)/ g tissue).
Total flavonoid content Total flavonoid content of the both flower and leaf extracts of Peltophorum pterocarpum found using quercetin standard.The flavonoid content in various extracts was given in Figure 3.

DISCUSSION
Preliminary phyto-chemical analysis of P. pterocarpum revealed that the presence of various phyto-chemicals such as Phlobatannins, Terpenoids, Alkaloids, Saponins, Reducing sugars and phenols, steroids and glycosides are absent in various solvent extracts of leaf and flowers of P. pterocarpum.In phytochemical evaluation studies, ethyl acetate extract of both leaf and flower extracts shows 7.42 ± 1.50 and 4.71 ± 0.07 mg of phenolic content of GAE/g.Similarly, methanolic extract of Peltophorum pterocarpum (DC) KHeyne showed 242 ± 0.012mg of GAE/g was reported. 23Another report shows total phenolic content (60.53 ± 1.46 mg of GAE/g) of ethyl acetate extract from stem bark of Peltophorum africanum. 24Among four extracts, ethanolic extract of flower showed maximum tannin content of 844 ± 10.38 mg TAE/g.In leaf extracts, aqueous methanolic extracts shows maximum tannin content 776.32 ± 35.01 mg TAE/g.Also, Ethyl acetate, Aqueous and ethanolic extracts showed 9.54 ± 6.97, 395.97 ± 38.62 and 487.36 ± 88.16 mg of tannic acid/g tissue respectively.The flavonoid content was found to be maximum in the leaves of ethanolic extract 1.44 ± 0.01mg quercetin equivalent (QE)/g of plant tissue.Ethyl acetate, Aqueous and aqueous methanolic extracts showed 0.33 ± 0.09mg, 0.53 ± 0.12mg and 0.28 ± 0.12mg of QE/g of plant tissue respectively.Similarly, total flavonoids content of methanolic extract from leaf of Peltophorum pterocarpum 72 mg QE/g was reported. 23Another report shows total flavonoid content (18.37 ± 2.11 mg of QE/g) of ethyl acetate extract from stem bark of Peltophorum africanum. 24

CONCLUSION
The present investigation demonstrates total phenolic, flavonoid and tannin content of both leaf and flower extracts of Peltophorum pterocarpum(DC) K Heyne.In preliminary phyto-chemical analysis of solvent extracts of P. pterocarpum revealed that the presence of various phyto-chemicals such as phlobatannins, terpenoids, alkaloids, saponins, tannin, reducing sugars and phenols, steroids.Among four extracts such as aqueous methanol, ethyl acetate, ethanol and aqueous extracts, ethanolic extracts of Peltophorum pterocarpum shows maximum total phenolic, flavonoid and tannin content.This study, thus, indicates thatthe extracts obtained from the leaves and flowers of Peltophorum pterocarpum (DC) K Heyne can be used for development of clinically important natural drugs.