International Research Journal of Plant Science

Pterocarpus santalinus L. f: A study on phytochemical constituents and biological properties of bark and heartwood extracts

S. Nithya Priya, R. Sumathi D, Suresh Babu and N. Senthilkumar^* Chemistry and Bioprospecting Division, Institute of Forest Genetics and Tree Breeding, Coimbatore, Tamilnadu, India
^*Corresponding Author:
N. Senthilkumar, Chemistry and Bioprospecting Division, Institute of Forest Genetics and Tree Breeding, Coimbatore, Tamilnadu, India, Email: senthilnk@icfre.org

Received: 28-Jul-2022, Manuscript No. IRJPS-22-70634; Editor assigned: 30-Jul-2022, Pre QC No. IRJPS-22-70634 (PQ); Reviewed: 13-Aug-2022, QC No. IRJPS-22-70634; Revised: 18-Aug-2022, Manuscript No. IRJPS-22-70634 (R); Published: 25-Aug-2022, DOI: http:/dx.doi.org/10.14303/irjps.2022.026

Introduction

Plants are the source of first medicines and all plant species are considered as potential resource for humanity. The natural plant based remedies are as old as humankind which was evidenced through pre-historic sites and written records. Plant based natural medicines are the most widely used medicines for both acute and chronic health issues. Over the past 100 years, the development and bulk manufacture of chemically synthesized medicines have revolutionized health care in most parts of the word. In developing countries large population still rely on traditional practitioners and herbal medicines for their primary health care. Use of traditional medicine is not only limited to developing countries, during the past two decades public interest in natural therapies has increased greatly in industrialized countries, with expanding use of ethno botanicals.

The history of medicinal plants used for treating diseases and ailments is probably dates back to the beginning of human civilization. World Health Organization predicted that 80 percent of people worldwide rely on herbal medicines and around 21,000 plant species have the potential for being used as medicinal plants (nhp.gov.in). The forest in India has been a rich repository of large quantities of medicinal plants and home to more than 50,000 species of plants. The growing demand towards medicinal plant products has renewed attention in the production of herbal health care formulations, herbal-based cosmetic products, and herbal nutritional supplements. Hence, there is a demand to promote natural products to save the human lives.

There has been an upsurge of interest in the therapeutic potential of medicinal plants as antioxidants because of the worldwide trend toward the use of natural additives in foods, beverages and cosmetics. The increasing demand for plant based antioxidants has increased in recent years due to the growing concern among consumers about these synthetic antioxidants because of their potential toxicological effects (Nunez de Gonzalez et al., 2008). However, antioxidant supplements help the human body from the oxidative damage (Kuhnan, 1976). Oxidative damage plays a significant pathological role in human diseases such as cancer, inflammation arthritis, diabetes and atherosclerosis (Halliwell, 1991).

The alarming increase in the rate of infection by antibiotic resistant microorganism and the microbial infections pose a health problem throughout the world (Davies, 1994). The antimicrobial activity of plants is associated with the defence mechanism against microorganism and plants promise a vital source of natural antimicrobial agents (Jancic et al., 1995). The increasing resistance of most synthetically derived antimicrobial agents is of utmost concern. In recent years, there has been renewed interest in the treatment against different diseases as herbal drugs are generally known to be nontoxic (Rao & Rao, 2001). In general medicinal plants offer polyvalent action through multiple active constituents and are more effective than single compound. (Pullaiah et al., 2019) reported that P. santalinusis one such tree species in which the bioactive compounds present in it accounts for its potential health benefits.

Pterocarpus santalinus L.f (Red Sanders) belongs to the family Fabaceae is endangered globally and endemic to India. In India, the natural range of P. santalinus is limited to 15,540 km in the South eastern Ghats and endemic to Andhra Pradesh (Sarma, 1993), (Raju & Nagaraju, 1999), (Prakash et al., 2006), (Balaraju et al., 2011). The red sandalwood tree is renowned for its exquisite colourand fragrance of heartwood derived from santalinus while the pleasant aroma is caused by the presence of terpenoids (Kumar et al., 1974). It is a precious timber which is highly valued for its pretty and attractive exceptional technical qualitiesmakes it popular in the furniture industry (Prakash et al., 2006), (Arunakumar et al., 2011), (Arunkumar & Joshi 2014), (Azamthulla et al., 2015). P. santalinus is used in traditional herbal medicine and a wide array of biological activities including antioxidative, antidiabetic, antimicrobial, anticancer and anti-inflammatory properties (Arunakumara et al., 2011), (Pullaiah et al., 2019). Stem, bark and leaf extracts of P.santalinus showed maximum antimicrobial activity (Manjunatha, 2006), (Mohandass et al., 2010). Considering its various health benefits, the present study focused on the evaluation of phytochemical constituentsof the bark and heartwood of P.santalinus responsible for its antioxidant and antimicrobial activities. Evaluation of the therapeutic efficacy may pass the development of a health care product.

Materials and Methods

Plant material

The bark and heartwood of Pterocarpus santalinus were collected from Vilar highways of Kollangarai village, Thanjavur district, Tamilnadu situated between 10°41'23.3"N latitude and 79°10'12.3"E longitude. The bark and heartwood samples were brought to the laboratory, washed under running tap water, shade dried at room temperature and ground into fine powder for experimental analysis.

Preparation of the extracts

The powdered plant samples of P.santalinus (20 g) were extracted with 350 ml of methanol and ethanol each using Soxhlet apparatus at 65-80°C for 8-10 h. The solvents of the respective extracts were reduced in rotary vacuum evaporator until complete removal of solvents and stored at 4°C for further use. The stored plant extracts were then dissolved in respective solvents while experimentation to get the solution of 10 mg/10 mL for each extract which has been subjected to in-vitro antioxidant and antimicrobial assays.

Qualitative Phytochemical Analysis

Qualitative phytochemical screening was carried out to identify the presence of various secondary metabolites such as alkaloids, flavonoids, tannins, saponins, sterols, phenols, glycosides, and terpenoids in the methanol and ethanol extracts of bark and heartwood of P. santalinus using standard methods (Harborne, 1967).

Estimation of alkaloid compounds

1 mg of the extract was dissolved in 2N HCl and then filtered. 1 ml of this solution was transferred to separating funnel and washed with 10 ml chloroform. The pH of phosphate buffer solution was adjusted to neutral with 0.1N NaOH. One ml of this solution was transferred to a separating funnel and then 5 ml of bromocresol solution along with 5 ml of phosphate buffer were added. The mixture was shaken and the complex formed was fractioned with chloroform by vigorous shaking. The fractions were collected in 10 ml volumetric flask and diluted to volume with chloroform. The absorbance of the complex in chloroform was measured at 470 nm (Karawya et al., 1971).

Estimation of phenolic compounds

The total phenolic compound present in the bark and heartwood of P.santalinus was estimated Folin-Ciocalteau reagent method described by (Malick & Singh 1980). One gram of bark and heartwood extract of P. santalinus was mixed with each 80 mL of ethanol and incubated overnight at room temperature. Centrifuged the homogenate at 10,000 rpm for 20 min and saved the supernatant. Re-extracted the residue with five times the volume of 80% ethanol, centrifuged and pooled the supernatants. Evaporated the supernatant to dryness and dissolved the residue in a known volume of distilled water (5 ml). For total phenolic content determination, 0.2-2.0 mL of each sample was taken separately and the volume was made up to 3 ml with distilled water and added 0.5ml of Folin-Ciocalteu reagent. After 3 min, added 2 ml of 20% of Na2CO3 solution to each tube and mixed thoroughly. Placed the tube in boiling water bath exactly for 1min, cooled and measured the absorbance at 650 nm. A calibration curve of the standard catechol was constructed and the total phenolics content in the extracts were expressed as mg of catechol equivalent (mg/g extract) by using the standard curve.

Estimation of Tannins compounds

The tannin content was estimated using the procedure described by (Robert, 1971) using vanillin hydrochloride reagent method. 1 ml of the extracts of bark and heartwood of P. santalinus were mixed with 5ml of vanillin hydrochloride reagent. The mixture was incubated for 20 min at room temperature. The tannin content of the supernatant was measured at 500 nm.

Estimation of flavonoids compounds

The flavonoid content of bark and heartwood extracts of P.santalinus was estimated by the method of (Harborne, 1967). An aliquot of the extracts were evaporated to dryness and added 4 ml of vanillin reagent. The solutions were heated for 15 minutes in a boiling water bath. The flavonoids content present in the sample was measured at 415 nm. Concentration of flavonoids was calculated and the values were expressed as μg flavonoids/g sample.

In-vitro antioxidant activities - DPPH radical scavenging activity

The ability of the bark and heartwood methanol and ethanol extracts to scavenge the DPPH free radicals was assessed using the method described by (Sharma et al., 2019). 0.1 mM solution of DPPH (1, 1-Dipheny- 2-Picrylhydrazyl) in ethanol was prepared and 1.0 ml of this solution was added to 3.0 ml of extract solution in water at different concentrations (20-100 mg/ml). The solution was mixed thoroughly and incubated for 30 minutes at room temperature. The absorbance was measured at 517 nm using UV-Vis spectrophotometer. A blank was prepared without adding sample extracts. Ascorbic acid at various concentrations (20 to 100 mg/ml) was used as standard. Lower the absorbance of the reaction mixture indicated higher free radical scavenging activity. The capability to scavenge the DPPH radical was calculated using the following equation:

DPPH Scavenged (%) = [(A control– A test) / A control] × 100

Evaluation of antimicrobial property of P.santalinus bark and heartwood

The antibacterial potency of both bark and heartwood extracts of P.santalinus was evaluated using three bacterial strains infectious to human health. Major bacterial human pathogens that causes a wide variety of clinical manifestations are Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus were used for the antimicrobial assay. All the original culture of the bacterial strains were maintained on Müller-Hinton (MH) agar plates at 4°C and grown at 37°C if required. Antimicrobial susceptibility test was performed for all microbial isolates following Kirby Bauer disc diffusion method. To concentrate the bacteria 20 ml of fresh bacterial culture was centrifuged at 4000 x g for 15 min. 100 μL of bacterial inoculum containing 108 CFU/mL was spread over sterile plates containing Mueller Hinton agar medium. Sterile filter paper discs (6 mm in diameter) impregnated with both bark and heartwood extracts concentration of (10 mg/ml) were placed on the top of Mueller-Hilton agar plates. Filter paper discs loaded with 5μg of Gentamycin was used as positive control. The culture plates were stored at 4°C for 2 h to allow plant extracts diffusion followed by incubation for 24 hrs. at 37°C. The diameters of inhibition zones were measured and considered as indication for antibacterial activity.

Results and Discussion

The processed bark and heartwood samples subjected to hot extraction using polar solvents to separate the therapeutic compounds. The purpose of all extraction is to separate the soluble plant metabolites (Handa et al., 2008). The P.santalinus bark and heartwood showed higher yield in methanol than ethanol and yield was high in bark than heartwood (Table 1). Methanol extracted 39% more than ethanol in both bark (11.71 and 8.41%) and heartwood (11.42 and 8.21%) extracts. (Tchamadeu et al., 2011) reported that the yield of hot extract was high in dried bark materials of Pterocarpus soyauxii.

Table 1. Methanol and ethanol extracts yield of bark and heartwood of P. santalinus.

Qualitative analysis of bark and heartwood of P.santalinus

The phytochemical research approach is considered effective in discovering bioactive profile of plants of therapeutic importance. The ethanol extract of bark and heartwood contains alkaloids, flavonoids, tannins, phenols and terpenoids and the methanol extract of bark and heartwood contains alkaloids, tannins, saponins, phenols and terpenoids. Both bark and heartwood extracts showed the presence of flavonoid in ethanol extract and saponins in methanol extract only (Table 2). (Arunakumar et al., 2011) confirmed the presence of various components, such as carbohydrates, steroids, anthocyanins, saponins, tannins in P. santalinus. The presence of flavonoids, glycosides, and phenols were reported in the bark of P.santalinus (Kondeti et al., 2010) and carbohydrates, flavonoids, terpenoids, phenolic compounds, alkaloids, saponins, tannins, and glycosides were reported in the heartwood of red sanders (Kesari et al. 2004). A variety of plant ingredients with diverse structures are capable of promoting health benefits. These secondary metabolites are widely used in human therapy, veterinary, agriculture, scientific research and in countless other area (Kandukuri et al., 2009).

Table 2. Phytochemical Screening of methanol and ethanol extracts of P.santalinus bark and heart wood.

Quantitative analysis of secondary metabolites of P.santalinus bark and heartwood

Plant produces vast and diverse assortment of organic compounds have shown their nutritional value in the form of flavors, food addition and as biochemicals having industrial application and health benefits. Chemical examination of Pterocarpus woods started more than a century, yet new compounds are still being discovered and variety of compounds were identified some which are unique to the genus (Seshadri, 1971). Quantitative analysis of phytochemicals in methanol and ethanol extracts of the bark for phenol, alkaloid, tannin and flavonoid showed that tannin was quantified more in both the extracts (12.58 mg/g and 12. 41 mg/g) than other phytochemicals (Table 3). In heartwood also tannin was quantified high, but less than bark extracts comparatively. Phenols and alkaloids were estimated more in heartwood (3.60 & 6.62 mg/g) than bark of P. santalinus (Table 3). Tannin and flavonoids were quantified more in bark than heartwood of red sanders which proved its applicability in dying capability. Compared to heartwood, bark have large amount of tannins, phenols, alkaloids and flavonoids as reported (Wang et al., 2014) also reported that tannins are present in many plants which are also considered as a major compound. Most secondary metabolites that are used in skincare or body care products for therapeutic actions are flavonoids that exhibit antioxidant benefits.

Antioxidant activity of P.santalinus bark and heartwood

Table 3. Quantification of secondary metabolites in bark and heartwood of P. santalinus

Free radicals are involved in many disorders like neurodegenerative diseases, cancer and AIDS. Antioxidants through their scavenging power are useful for management of that disease (Pourmorad et al., 2006). DPPH is an easy, rapid and sensitive method for the antioxidant screening of plant extracts. Many plant extracts and their bioactive phytochemicals have shown free radical scavenging properties (Larson, 1988), (Koleva et al., 2002) yet there is a high demand to find out more information regarding antioxidant potentiality of many medicinally important plants. Antioxidant property of red sanders leaves was reported by (Arokyaraj et al., 2008). The scavenging activity of ethanol and methanol extracts of bark and heartwood of P. santalinus showed more than 50% antioxidant activity. When compared with methanol extract, ethanol extract showed high level of antioxidant activity (Shoba et al., 2004). On comparing bark and heartwood, bark extract showed more absorbance activity of antioxidant (Gnanadesigan et al., 2011) molecules. The ethanol bark and heartwood extract of P. santalinus showed significant DPPH radical inhibition of 83.4 and 79% respectively at 1000μg/ml concentration (Table 4). Both methanol and ethanol extracts of bark revealed high scavenging activity than the heartwood which confirmed the potency of red sanders bark as antioxidant source (Chaitanya et al., 2014). High level of total phenol and flavonoid contents showed the best antioxidant activity, may be due presence of hydroxyl groups existing in the phenolic and flavonoid compounds (Siddique et al., 2010). It has been mentioned that antioxidant activity of plants might be due to their phenolic compounds (Cook & Samman, 1996) and flavonoids a group of polyphenolic compounds (Frankel, 1995). The presence of flavonoids, phenols and polyphenolic compounds in bark and heartwood of P.santalinus prompted us to study the free radical scavenging activity which proved that the bark and heartwood of P. santalinus are promising sources of naturally occurring antioxidant for medicinal and commercial uses.

Table 4. Percentage of Antioxidant activity of P.santalinus

Antibacterial activity of Pterocarpus santalinus bark and heartwood

The antibacterial activity of methanol and ethanol extracts of both bark and heartwood of P. santalinus was carried out in human pathogens. Mostly the plant is having medicinal properties and an important source for developing the new chemotherapeutic agents. The first step towards this goal is the in-vitro antibacterial activity assay. Many reports are available on the antiviral, antibacterial, antifungal, antihelmintic, antimolluscal and anti-inflammatory properties of plants. In the present study the ethanol extract of bark and heartwood were subjected to antibacterial study against the human pathogens Staphylococcus aureus, Klebsiella pneumonia and Pseudomonas aeruginosa. The antibiotic (standard) used for the antibacterial study was Amikacin at pH 7. The inhibition rate of Staphylococcus aureus was observed as 14 MM, Klebsiella pneumonia was 11MM and Pseudomonas aeruginosa was 12 MM (Table 5). The ethanol extract of red sanders bark showed antagonistic activity against the pathogens used for the study (Figure 1). The ethanol extract of bark inhibited the growth of bacteria but in heartwood there was no inhibitory activity was observed against the bacteria. (Chandra Sekhar Challa et al., 2018) was also noticed the antagonistic activity in heartwood of P.santalinus. The leaf extract of P.santalinus has antibacterial activity (Manjunatha, 2006). The stem bark extract of red sanders showed maximum activity against Enterobacter aerogenes, Alcaligenes faecalis, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Bacillus cereus, Bacillus subtilis, Staphylococcus aureus (Manjunatha, 2006). The leaf extract showed maximum activity against Escherichia coli, Alcaligenes faecalis, Enterobacter aerogenes and Pseudomonas aeruginosa (Manjunatha, 2006). The bioactive compounds such as phenols, flavonoids and tannins reported in the bark and heartwood may be attributed for antibacterial activity. Flavonoids are found to be effective antimicrobial substances against a wide range of microorganisms (Tsuchiya et al., 1996) and Phenolics and polyphenols present in the plants are known to be toxic to microorganisms (Mason & Wasserman, 1987). The significant antibacterial activity of P.santalinus may be due to the individual or combined action of the active phytochemicals reported upon.

Table 5. Antibacterial activity of ethanol extract of P.santalinus bark.

Conclusion

Pterocarpus santalinus is a multipurpose high value native tree species of India which contains many potent phyochemicals for use in pharmaceuticals and cosmetics industries in addition to its timber and industrial uses. The presence of flavonoids, phenols and polyphenolic compound in bark and heartwood of P. santalinus is promising source of naturally occurring antioxidant for medicinal and commercial uses. The maximum inhibitory activity of P.santalinus against human pathogens suggested that the bark and heartwood of this species is considered as one of the valuable natural source of desirable cosmetic and medicinal values.

Acknowledgement

Authors are thankful to National Biodiversity Authority (NBA), Chennai for funding support through the project No. Tech/ Genl/ 22/149/17/18-19/ 4295 dt. 17.03.2020.

References

Arokiyaraj, S., Radha, R., Martin, S., Perinbam, K. (2008). Phytochemical analysis and anti-diabetic activity of Cadabafuiticosa R. Br. Indian J Scr Technol. 1: 1-4.

Indexed at, Google Scholar, Cross Ref

Arunkumar, A.N., Joshi, G. (2014). Pterocarpus santalinus (red sanders) an endemic, endangered tree of India: current status, improvement and the future. J Trop For Environ. 4: 1–10.

Indexed at, Google Scholar, Cross Ref

Arunkumara, K.K.I.U., Walpola, B.C., Subasinghe, S., Yoon, M-H. (2011). Pterocarpus santalinus Linn. f. (Rathhandun): a review of its botany, uses, phytochemistry and pharmacology. J Korean Soc Appl Biol Chem. 54: 495–500.

Indexed at, Google Scholar, Cross Ref

Azamthulla, M., Balasubramanian, R., Kavimani, S. (2015). A review on Pterocarpus santalinus Linn. World J Pharm  Res. 4:282–292.

Google Scholar

Balaraju, K., Agastian, P., Ignacimuthu, S., Park, K. (2011). A rapid in vitro propagation of red sanders (Pterocarpus santalinus L.) using shoot tip explants. Acta Physiol Plant. 33: 2501–2510.

Indexed at, Google Scholar, Cross Ref

Chaitanya, P.J., Chandra shekar, R., Lakshmi Bhavani, N., Angajala Kishore Kumar., Pochampalli et al., (2014). “Evaluation of Antioxidant nature of methanol extracts from leaf, bark and wood of Pterocarpus santalinus L”. World J Pharm Res. 3: 761-767. Indexed at, Google Scholar

Chandra Sekhar Challa., Saradamma Bulle., Lokesh, T., Devanna Nayakanti., Varadacharyulu Nallanchakravarthula (2018). Identification of bioactive compounds from Pterocarpus santalinus heart wood using high performance liquid chromatography and their antimicrobial activity. World J Pharm Res. 7: 582-590.

Google Scholar

Cook, N. C., Samman, S. (1996). Flavonoids-Chemistry, metabolism, cardio protective effects, and dietary sources. Nutr Biochem. 7: 66-76.

Indexed at, Google Scholar, Cross Ref

Davies, J. (1994). Inactivation of antibiotics and the dissemination of resistance genes.  Science. 264: 375-382.

Indexed at, Google Scholar, Cross Ref

Effect of Pterocarpus santalinus bark, on blood glucose, serum lipids, plasma insulin and hepatic carbohydrate metabolic enzymes in streptozotocin induced diabetic rats. Food Chem Toxicol. 48: 1281–1287.

Frankel, E. (1995). Nutritional benefits of flavonoids. International conference on food factors: Chemistry and Cancer Prevention, Hamamatsu, Japan. Abstracts.C6- 2.

Google Scholar

Gnanadesigan, M., Ravikumar, S., & Inbaneson, S. J. (2011). Hepatoprotective and antioxidant properties of marine halophyte Luminetzera racemosa bark extract in CCL4 induced hepatotoxicity. Asian Pac J Trop Med. 4: 462-465.

Indexed at, Google Scholar, Cross Ref

Halliwell, B. (1991). Reactive oxygen species in living systems: sources, biochemistry and role in human diseases. Am J Med. 91: 14–22.

Indexed at, Google Scholar, Cross Ref

Handa, S.S., Khanuja, S.P.S., Longo, G.  and  Dev  Dutt  Rakesh, Editors  (2008)  Extraction  Technologies  for  Medicinal  and Aromatic Plants Scientific, Published by International Centre for Science  and  High  Technology,  Trieste,  United  Nations Industrial  Development  Organization  and  the  International Centre  for  Science  and  High  Technology  (ICS-UNIDO)  is supported by the Italian Ministry of Foreign Affairs.  23: 30.

Harborne, J.B. (1967). Comparative biochemistry of Flavonoids. Academic press. 25-30.

Jancic, R., Stošić, D., Mimica-Dukić, M., Lakušić, B. (1995). Aromatic plants of Serbia. Belgrade, Gornji Milanovac: NIP Dečje Novine. pp 296.

Kandukuri, V., Vinayasagar, J.G., Suryam, A., Singara Charya, M.A. (2009).  Biomolecular and phytochemical analyses of three aquatic angiosperms.  Afr J Microbiol Res. 3:  418-421.

Indexed at, Google Scholar

Karawya, M.S., Abdel-Wahab, S.M., Zaki, A.Y. (1971). Colorimetric Method for the Estimation of Alkaloids in Lobelia and Its Pharmaceutical Preparations. Journal of Association of Official Analytical Chemists. 54: 1423–1425.

Indexed at, Google Scholar, Cross Ref

Kesari, A.N., Gupta, R.K., Watal, G., (2004). Two aurone glycosides from heartwood of Pterocarpus santalinus. Phytochemistry. 65: 3125–9.

Indexed at, Google Scholar, Cross Ref

Koleva, I.I., Van Beek, T.A., Linssen, J.P.H., de Groot, A., Evstatieva, L.N. (2002).  Screening of plant extracts for antioxidant activity: a comparative study on three testing methods. Phytochem Analysis. 13:  8-17.

Indexed at, Google Scholar, Cross Ref

Kondeti, V.K, Badri, K.R,, Maddirala, D.R,, Thur, S.K.M,, Fatima, S.S et al., (2010).

Kuhnan, J. (1976). The flavonoids: a class of semi-essential food components; their role in human nutrition. World Rev Nutr Diet. 1976; 24: 117–191.

Indexed at, Google Scholar, Cross Ref

Kumar, N., Ravindranath, B, Seshadri, T.R. (1974). Terpenoids of Pterocarpus santalinus heartwood. Phytochemistry. 13: 633–636.

Indexed at, Google Scholar, Cross Ref

Larson, R.A. (1988). The antioxidant of higher plants. Phytochem. 27: 969-78.

Malick, C.P., Singh, M.B. (1980). Estimation of polyphenols, In: CP. Malik, MB. Singh, (Eds). In: Int J Adv Res Bil Sci. 2: 185-189.

Manjunatha, B.K. (2006). Antibacterial activities of Pterocarpus santalinus. Indian J Pharm Sci. 68:  115–116.

Indexed at, Google Scholar, Cross Ref

Mason, T. L., Wasserman, B. P. (1987). Inactivation of red beet beta-glucan synthase by native and oxidized phenolic compounds. Phytochemistry. 26: 2197–2202.

Indexed at, Google Scholar, Cross Ref

Mohandass, G., Suguna Devi, K., Devanesan. (2010). Antifungal activity of Pterocarpus santalinus, an in vitro study. Biomed & Pharmacol J. 3: 107-110.

Indexed at, Google Scholar,

Nunez de Gonzalez, M.T.N., Hafley, B.S., Boleman, R.M., Miller, R.K., Rhee, K.S et al.,  (2008). Antioxidant properties of plum concentrates and powder in precooked roast beef to reduce lipid oxidation. Meat Sci. 80: 997-1004.

Indexed at, Google Scholar, Cross Ref

Pourmorad, L.F., Hosseinimehr, S. J., Shahabimajd, N. (2006). Antioxidant activity, phenol and flavonoid contents of some selected Iranian medicinal plants. Afr J Biotechnol. 5: 1142-1145.

Indexed at, Google Scholar, Cross Ref

Prakash E, Sha Valli Khan PS, Sreenivasa Rao TJV, Meru ES (2006). Micropropagation of red sanders (Pterocarpus santalinus L.) using mature nodal explants. J For Res. 11:329–335.

Indexed at, Google Scholar, Cross Ref

Pullaiah, T., Balasubramanya, S., Anuradha, M. (Eds.). (2019). Red Sanders: Silviculture and Conservation. Springer, Singapore.P.210.

Indexed at, Google Scholar, Cross Ref

Raju, K.K., Nagaraju, A, (1999). Geobotany of red sanders (Pterocarpus santalinus)-a case study from the south eastern portion of Andhra Pradesh. Environ Geol. 37:340–344.

Indexed at, Google Scholar, Cross Ref

Rao, B.K., Rao, C.H. (2001). Hypoglycemic and antihyperglycemic activity of Syzygium alternifolium (Wt.) Walp. Seed extracts in normal and diabetic rats. Phytomedicine. 8: 88-93.

Indexed at, Google Scholar, Cross Ref

Robert, E.B. (1971). Method for estimation of Tannins in grain sorghum. J Agron, 63:511.

Google Scholar

Sarma, C.R. (1993). Study of outturn and value of red sanders. J  Trop. 9:125–131.

Google Scholar

Seshadri, T.R. (1972). Polyphenols of Pterocarpus and Dalbergia woods. Phytochemistry. 11: 881–898.

Indexed at, Google Scholar, Cross Ref

Sharma, P., Manchanda, R., Goswami, R., Chawla, S. (2019). Biodiversity and Therapeutic Potential of Medicinal Plants. Environ Dev Sustain. E. 27–44.

Indexed at, Google Scholar, Cross Ref

Shoba, N., Rethinam, S.D., Vani, G., Chennam, S., Shyamala, D. (2007). Effect of Pterocarpus santalinus extract on the gastric pathology elicited by a hypertensive dru in Wistar Rats Pharm  Biol. 45: 468-474.

Indexed at, Google Scholar, Cross Ref

Siddique, N. A., Mujeeb, M., Najmi, A. K., Khan, H. N., Farooqi, H. (2010). Evaluation of antioxidant activity, quantitative estimation of phenols and flavonoids in different parts of Aegle marmelos. J Saudi Chem Soc. 4: 001-005.

Indexed at, Google Scholar, Cross Ref

Tchamadeu, M. C., Dzeufiet, P. D. D., Nana, P., Kouambou Nouga, C. C., NgueguimTsofack, F., et al.,  (2011). Acute and sub-chronic oral toxicity studies of an aqueous stem bark extract of Pterocarpus soyauxii Taub (Papilionaceae) in rodents. J Ethnopharmacol. 133: 329–335.

Indexed at, Google Scholar, Cross Ref

Tsuchiya, H., Sato, M., Miyazaki, T., Fujiwara, S.,Tanigaki, S., et al., (1996). A prenylated flavanone from roots of Amorpha fruticosa, J Ethnopharmacol. 50: pp27.

Wachtel-Galo, S., Benzie, I. F. F. (2011). Herbal Medicine: An introduction in its history, usage, regulation, current trends and research needs. In (Eds. Iris F. F. Benzie and SissiWachtel-Galo) Herbal Medicine: Biomolecular and Clinical Aspects, Second Edition, CRS Press. 1-9.

Wang, X., Ouyang, Y. Y., and Liu, J. (2014). Flavonoid intake and risk of CVD: a systematic review and meta-analysis of prospective cohort studies. Brit J Nutr.111: 1–11.

Indexed at, Google Scholar, Cross Ref

World Health Organization (WHO) (2005). National Policy on Traditional Medicine and Regulation of Herbal Medicines. Geneva: Report of WHO global survey

Google Scholar

Citation: Senthilkumar N (2022). Pterocarpus santalinus L. f: A study on phytochemical constituents and biological properties of bark and heartwood extracts. IRJPS. 13: 026.