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Introduction
Schinus terebinthifolius Raddi (Anacardiaceae), known as “Brazilian pepper” is an evergreen tree, native to Brazil and introduced in different parts of the world. It has been used in folk medicine as anti-inflammatory, immunomodulatory, antipyretic, analgesic, detoxifying agent, chemopreventive and in wound healing. In addition, it has been used in treating skin, mucous membranes, genitourinary, respiratory and GIT infections due to its antifungal and antibacterial properties.12345678 Moreover, the ethanolic extract of leaves and stems of S. terebinthifolius inhibits quorumsensing activity in methicillin-resistant Staphylococcus aureus infections and thus inhibits the production of virulence factors.9 The leaves extract exhibits anticancer properties10 and the fruits extract inhibits nitric oxide production and shows antioxidant activity.4 Also, the ethyl acetate fraction of leaves of S. terebinthifolius exhibits anti-allergic properties and inhibits histamine release and edema development in mice.11
Diverse groups of phytochemicals including phenolics and terpenoids have been reported from leaves, barks and fruits of S. terebinthifolius. Several phenolic compounds including mono- and biflavonoids, coumaric acid and gallic acid derivatives have been reported.613141516 A biphenyl compound namely, 4′-ethyl-4-methyl-2,2′,6,6′-tetrahydroxy [1,1′-biphenyl]-4,4′-dicarboxylate, has been also isolated from leaves and stem of S. terebinthifolius.6 However, fewer studies addressed the triterpenoid contents of this plants. For instance, tirucallane-type triterpenes such as masticadienoic acid and schinol have been isolated from the leaves S. terebinthifolius in large amounts.1718 Other triterpenoid groups including ursane-type (α-amyrene, α-amyrenone and ursolic acid), bauerane-type (bauerenone) and adianane-type (simiarenol) triterpenes have been also isolated from this plant.1819
Plant parasites especially root-knot nematode is one of the leading problems in production of vegetables and other essential crops causing serious plant damage. Meloidogyne sp. produced knots that prevent water and nutrients from reaching the leaves and fruits. Meloidogyne incognita, one of the widely distributed species, has been considered the most damaging of ten main genera of plant parasitic nematodes. It causes about 12.3% loss of the annual yield of world's major crops.20 The damage caused by M. incognita to tomato plant is massive and require safe and efficient control.
In the current research, the phenolic content of the methanol extract of the leaves of S. terebinthifolius was investigated. Nine phenolic compounds were isolated and characterized using spectroscopic methods. The isolated phenolic compounds (Fig. 1) 1 – 9 were evaluated for their nematicidal activity against root-knot nematode (M. incognita) infecting tomato plant using in vitro and greenhouse experiments. The in vitro experiments were used to evaluate the number of eggmasses and larvae, while the greenhouse experiments were used to evaluate plant growth parameters including shoot length, shoot and root weight. Additionally, chemical analysis was used to assess carbohydrates, proteins, defense-related proteins such as peroxidase (PO) and polyphenol oxidase (PPO) in both infected and control plants.
Experimental
General experimental procedures
The NMR spectroscopic experiments were performed on a Bruker Avance III 500MHz Spectrometer (Bruker BioSpin Corp., Rheinstetten, Germany). For column chromatography, stationary phases were silica gel G60, 70 - 230 mesh, (Catalogue # 1077345000, Merck, Germany) and Sephadex LH 20 (Catalogue # 17-0090-01, Sigma-Aldrich, USA). For TLC, silica gel plates F254 (Catalogue # 1055540001, Merck, Germany) were used. Vanillin-sulfuric acid was used as a spray reagent. All chromatographic solvents were of reagent grade (El-Nasr Company, Egypt). The HR-MS experiments were conducted with a Bruker MicrOTof-Q (Bruker Daltonics, Bremen, Germany), where analytes were ionized using electrospray ionization (ESI) interface operated in the positive mode.
General methods
Phytochemical isolation of the phenolic compounds from the leaves of Schinus terebinthifolius
The leaves of S. terebinthifolius Raddi were collected from a farm at Damietta city, Egypt in July 2012, shade-dried, powdered and kept for further investigation. The plant was authenticated by Prof. Ibrahim Mashaly, at Ecology and Botany Department, Faculty of Science, Mansoura University. A voucher specimen was deposited at Pharmacognosy Department, Faculty of Pharmacy, Mansoura University (012-Mansoura-3). Powdered leaves of S. terebinthifolius Raddi (4.0 kg) were macerated in a glass jar with methanol (4 × 6 L). The obtained methanol extract was concentrated using rotary evaporator at 45 C° and further dried to obtain a crude extract (817.4 g). The crude methanol extract was then dissolved in a suitable amount of methanol, and an equal amount of dist. H2O and partitioned with n-hexane, CH2Cl2 and EtOAc. The obtained crops, were evaporated and dried to afford n-hexane (n-Hex, 124.7 g), CH2Cl2 (34.7 g) and EtOAc (372 g) extracts. Finally, the left aqueous extract was passed over Diaion®, an ion exchange adsorbent, washed with water, eluted with methanol and evaporated under vacuum at 45 C° to afford a dry aqueous extract (86.0 g). For isolation of the phenolic compounds, only the aqueous and the EtOAc extracts were nominated to proceed an intensive phytochemical isolation using different chromatographic techniques. Fractionation and purification of the components of the aqueous extract afforded six compounds (1 – 6) as demonstrated in Fig. 2. Similarly, the EtOAc extract was also purified to afford three other compounds (7 – 9), in addition to compounds 4 and 6 that were isolated before from the aqueous extract (Fig. 3).
Evaluation of the nematicidal activity of the extracts and the isolated compounds against root-knot nematode (M. incognita)
Preparation of Meloidogyne incognita inocula21
M. incognita eggs inoculum
Eggmasses were collected from the roots of coleus plants, Coleus blumei L., heavily infected with M. incognita grown in horticultural nursery under greenhouse condition and propagated on coleus plants, a susceptible host, for 3 months at Nematological Research Unit (NERU), Faculty of Agriculture, Mansoura University, Mansoura, Egypt. Sodium hypochlorite (NaOCl) extraction method was used in order to collect the eggs of M. incognita. Infected roots were washed and cut into 2 – 3 cm parts and shacked in 200 mL of 1.0% NaOCl solution for 1 – 2 minutes.21 NaOCl solution was quickly filtered through a 60-mesh sieve nested over a 400-mesh sieve to collect freed eggs and quickly placed under a stream of tap water to remove residual NaOCl.
Experimental design
Laboratory Experiments
Impact against eggs of root-knot nematode (M. incognita)23
In order to evaluate the nematicidal properties of the extracts and isolated compounds against the eggs of root-knot nematode, M. incognita, the treatments were tested in Petri dishes, as triplicates at concentrations of 200, 100 and 50 µg/mL. Whereas, solvent and nematodes alone were used as negative control. To each dish, inoculum of 1 mL containing 100 eggs (M. incognita) was added to each treatment. The dishes were left for 10 days then the effect on egg hatching was examined under a microscope and compared to control.
Impact against larva of root-knot nematode (M. incognita)23
In separate experiment, the extracts and the isolated compounds were added in Petri dishes, as triplicates at concentrations of 200, 100 and 50 µg/mL. Solvent and nematodes alone were used as negative control. To each dish, inoculum of 1 mL containing 100 larvae (M. incognita) was added. The dishes were examined after 24, 48 and 72 h using microscope to study the effect of these treatments on the activity of larval second stage of root-knot nematode.
Greenhouse Experiment24
Impact of the extracts and the isolated compounds on tomato plants infected with root-knot nematode (M. incognita)
A greenhouse experiment was conducted using sandy clayey soil in order to evaluate the nematicidal activity of the isolated compounds against the root-knot nematode, M. incognita. The resulting effects on plant growth parameters and on induced resistance (IR) were assayed through chemical composition and enzyme activities. In fifty-seven pots (15 cm in diameter) containing 800 g of sterilized soil, one seedling per pot of tomato plant was placed. Seedlings were then infected with 1000 viable larvae of M. incognita. After one week, infected plants were treated with the isolated compounds and extracts (200, 100 and 50 µg/mL) as soil drench. Three pots were treated with Oxamyl® 10G as a standard nematicide at a concentration of 0.3 g per pot and three other pots were treated with DMSO (10 mL/pot) as a standard solvent. Additionally, three pots were left without nematode infection or any treatment and serve as control (N free). To three other pots nematodes were added alone without any treatment and served as control (N alone). After then, in a greenhouse at 27 ± 3 ℃, pots were settled in three replicates as a random complete block design where they received water as required. After 45 days of nematode inoculation, plants were harvested and washed from adhering soil. Plant growth parameters including weight and length of both fresh or dried shoot and root were recorded. Nematodes were recovered from soil using sieving and modification of the Baermann method.22 Root galling (eggmasses) were ranked according to the number of galls per root system using a scale of 0–5; 0 means “no galls”, 1 means “1 – 2 galls”, 2 means “3 – 10” galls, 3 means “11 – 30” galls, 4 means “31 – 100” galls and finally, 5 means “> 100 galls”.23
Chemical analysis
For each treatment, dried shoot (1 g) was subjected to chemical analysis in order to evaluate crude protein, total carbohydrate and total phenols. For the enzyme assays, enzyme extracts were prepared grinding dried root (0.5 g) of each treatment in 3 mL sod.phosphate buffer (pH 6.8) in a mortar and centrifuge at 1,500 × g 20 min at 6 ℃. The obtained supernatant was used for the evaluation of peroxidase (PO) and polyphenol oxidase (PPO) activities.25
Crude protein
The protein content in supernatant of fresh tomato plant from each treatment was estimated according to the method of Bradford (1976) 26 by using bovine serum albumin as a standard protein. Protein content was adjusted to 2 mg/mL per sample.
Total carbohydrate
Total soluble sugars (reducing and non-reducing) were determined using the spectrophotometeric method described by Thomas and Dutcher, (1924)27 using picric acid at λmax 540 nm.
Total phenols
Total phenols were determined after harvesting of fresh whole plant using Folin-Ciocalteau reagent.28 Total content of phenolic compounds in plant ethanolic extracts was calculated as catechol equivalents by the following equation:
Where, T; Total content of phenolic compounds (mg of catechol/100 g of fresh weight material). C; concentration of catechol established from the calibration curve (mg/mL). V; volume of extract (mL). m; weight of pure plant ethanolic extract (g).
Peroxidase activity (PO)
Peroxidase was evaluated using the spectrophotometric method described by Amako et al. (1994).29 The reaction was started by adding 20 µL of the enzyme solution to a mixture of 1,500 µL phosphate buffer, 480 µL H2O2 and 1,000 µL pyrogallol. Blank was prepared using phosphate buffer instead of the enzyme extract. Absorbance of the solution was measured at λmax 430 nm and compared to blank. One unit of enzyme activity was defined as the amount of the enzyme, which changing the optical density at 430 nm per min. at 25℃ under standard assay conditions. Specific activity was expressed in units by dividing it to mg protein.
Polyphenol oxidase (PPO)
Polyphenol oxidase was evaluated using the spectrophotometric method described by Coseteng and Lee (1987).30 The reaction was started by adding 0.05 mL of the enzyme solution to a mixture of 2.7mL K.phosphate buffer (90.05 M, pH 6.2) and 0.25mL catechol (0.25M). Blank was prepared using phosphate buffer instead of the enzyme extract. Absorbance of the solution was measured at λmax 420 nm and compared to blank. One unit of enzyme activity is defined as the amount of the enzyme that causes an increase of 0.001 absorbance unit per minute at 25℃.
Result and Discussion
Identification of the isolated compounds
Compound 1 was identified based on its spectral data including 1H, 13C NMR, IR and HR-ESIMS and by comparison with previously reported data33 as 1,2,3,4,6-pentagalloyl glucose which has been identified before from S. terebinthifolius.1634 Similarly, characterization of compounds 2 – 9 was established using their 1H and 13C NMR data and by comparison with previously reported data for similar structures. Based on these data, compound 2 was characterized as kaempferol-3-O-α-L-rhamnoside (Afzelin), compound 3 as quercetin-3-O-α-L-rhamnoside (Quercetrin), compound 4 as myricetin and compound 5 as myricetin-3-O-α-L-rhamnoside (Myricetrin),153536 compound 6 methylgallate,123435 compound 7 as protocatechuic acid which is isolated for the first time from S. terebinthifolius,37 compound 8 as quercetin,3436 and finally compound 9 as gallic acid.12
1,2,3,4,6-Penta-O-galloyl-β-D-glucose 1
1H NMR (CD3OD, 500 MHz); δH 6.22 (1H, d, J = 8.3 Hz, H-1), 5.56 (1H, dd, J = 9.7, 8.5 Hz, H-2), 5.88 (1H, t, J = 9.7 Hz, H-3), 5.60 (1H, t, J = 9.6 Hz, H-4), 4.50 (1H, d, J = 10.8 Hz, H-5), 4.36 (2H, m, H-6).13C NMR (CD3OD, 125 MHz); δC 92.4 (C-1), 70.8 (C-2), 72.7 (C-3), 68.4 (C-4), 73.0 (C-5), 62.9 (C-6), Gal-A; 118.3 (C-1′), 109.2 (C-2′/6′), 139.4 (C-3′/5′), 145.2 (C-4′), 164.8 (C-7′), Gal-B; 118.8 (C-1′), 109.0 (C-2′/6′), 139.0 (C-3′/5′), 145.0 (C-4′), 165.6 (C-7′), Gal-C; 118.9 (C-1′), 109.0 (C-2′/6′), 138.8 (C-3′/5′), 144.9 (C-4′), 165.9 (C-7′), Gal-D; 118.8 (C-1′), 109.1 (C-2′/6′), 139.0(C-3′/5′), 145.1 (C-4′), 165.5 (C-7′), Gal-E; 119.6 (C-1′), 108.9 (C-2′/6′), 138.6 (C-3′/5′), 145.0 (C-4′), 166.5 (C-7′); HRMS at m/z 963.1048 [M+Na]+, Calcd. for C41H32NaO26 963.0180.
Kaempferol-3-O-α-L-rhamnoside (Afzelin) 2
1H NMR (CD3OD, 500 MHz); δH 6.16 (1H, brs, H-6), 6.31 (1H, brs, H-8), 6.92 (2H, d, J = 7.6, H-3′/5′), 7.72 (2H, d, J = 7.7 Hz, H-2′/6′), 5.39 (1H, brs, H-1′′), 4.28 (1H, brs, H-2′′), 3.77 (1H, brd, J = 3.0 Hz, H-3′′), 3.37 (1H, brs, H-4′′), 3.33 (1H, brs, H-5′′), 0.95 (3H, brs, H3-6′′). 13C NMR (CD3OD, 125 MHz); δC 158.2 (C-2), 136.2 (C-3), 179.5 (C-4), 163.0 (C-5), 99.9 (C-6), 94.9 (C-8), 159.2 (C-9), 105.9 (C-10), 122.6 (C-1′), 132.0 (C-2′/6′), 116.5 (C-3′/5′), 161.4 (C-4′), 103.5 (C-1′′), 72.0 (C-2′′), 72.1 (C-3′′), 73.3 (C-4′′), 72.0 (C-5′′), 17.7 (C-6′′).
Quercetin-3-O-α-L-rhamnoside (Quercetrin) 3
1H NMR (CD3OD, 500 MHz); δH 6.19 (1H, brs, H-6), 6.34 (1H, brs, H-8), 7.4 (1H, brs, H-2′), 6.92 (1H, d, J = 8.0 Hz, H5′), 7.30 (1H, d, J = 8.0 Hz, H-6′), 5.37 (1H, brs, H-1′′), 4.31 (1H, brs, H-2′′), 3.80 (1H, d, J = 8.8, H-3′′), 3.33 (1H, m, H-4′′), 3.43 (1H, m, H-5′′), 0.97 (3H, d, J = 5.5 Hz, H3-6′′). 13C NMR (CD3OD, 125MHz); δC 159.3 (C-2), 136.3 (C-3), 179.6 (C-4), 163.1 (C-5), 99.9 (C-6), 165.9 (C-7), 94.8 (C-8), 158.4 (C-9), 105.9 (C-10), 123.0 (C-1′), 116.4 (C-2′), 149.7 (C-3′), 146.3 (C-4′), 117.0 (CT-5′), 123.0 (C-6′), 103.5 (C-1′′), 72.1 (C-2′′), 72.1 (C-3′′), 73.3 (C-4′′), 71.9 (C-5′′), 17.7 (C-6′′).
Myricetin 4
1H NMR (CD3OD, 500 MHz); δH 6.20 (1H, brs, H-6), 6.40 (1H, brs, H-8), 7.37 (2H, s, H-2′/6′). 13C NMR (CD3OD, 125 MHz); δC 148.0 (C-2), 136.9 (C-3), 177.2 (C-4), 162.4 (C-5), 99.3 (C-6), 165.5 (C-7), 94.4 (C-8), 158.1 (C-9), 104.5 (C-10), 123.1 (C-1′), 108.6 (C-2′/6′), 146.7 (C-3′/5′), 137.4 (C-4′).
Myricetin-3-O-α-L-rhamnoside (Myricetrin) 5
1H NMR (CD3OD, 500 MHz); δH 6.19 (1H, brs, H-6), 6.34 (1H, brs, H-8), 6.99 (2H, s, H-2′/6′), 5.35 (1H, brs, H-1′′), 4.30 (1H, brs, H-2′′), 3.86 (1H, d, J = 7.1 Hz, H-3′′), 3.18 (1H, m, H-4′′), 3.54 (1H, m, H-5′′), 0.99 (3H, d, J = 5.0 Hz, H3-6′′). 13C NMR (CD3OD, 125 MHz); δC 146.3 (C-2), 136.3 (C-3), 179.6 (C-4), 158.4 (C-5), 100.0 (C-6), 165.7 (C-7), 94.9 (C-8), 158.2 (C-9), 105.8 (C-10), 122.0 (C-1′), 109.9 (C-2′/6′), 146.7 (C-3′/5′), 137.9 (C-4′), 103.5 (C-1′′), 72.1 ′′(C-2′′), 72.1 (C-3′′), 73.4 (C-4′′), 71.9 (C-5′′), 17.8 (C-6′′).
Methylgallate 6
1H NMR (DMSO-d6, 500 MHz); δH 7.00 (2H, s, H-2/6), 3.72 (3H, s, OCH3). 13C NMR (DMSO-d6, 125 MHz); δC 119.4 (C-1), 108.6 (C-2/6), 145.4 (C-3/5), 138.3 (C-4), 166.4 (C-7), 51.3 (OCH3).
Protocatechuic acid 7
1H NMR (DMSO-d6, 500 MHz); δH 6.81 (1H, d, J = 6.9 Hz, H-5), 7.33 (1H, d, J = 6.7 Hz, H-6), 7.38 (1H, brs, H-2), 9.62 (1H, OH). 13C NMR (DMSO-d6, 125 MHz); δC 121.6 (C-1), 116.4 (C-2), 144.7 (C-3), 149.9 (C-4), 115.2 (C-5), 122.1 (C-6), 167.4 (C-7).
Quercetin 8
1H NMR (CD3OD, 500 MHz); δH 6.20 (1H, brs, H-6), 6.40 (1H, brs, H-8), 7.75 (1H, brs, H-2′), 6.89 (1H, d, J = 8.0 Hz, H-5′), 7.64 (1H, d, J = 8.0 Hz, H-6′). 13C NMR (CD3OD, 125 MHz); δC 148.8 (C-2), 137.3 (C-3), 177.3 (C-4), 162.5 (C-5), 99.2 (C-6), 165.6 (C-7), 94.4 (C-8), 158.2 (C-9), 104.5 (C-10), 124.1 (C-1′), 116.0 (C-2′), 146.2 (C-3′), 148.0 (C-4′), 116.2 (C-5′), 121.7 (C-6′).
Gallic acid 9
1H NMR (CD3OD, 500 MHz); δH 7.09 (2H, s, H-2/6). 13C NMR (CD3OD, 125 MHz); δC 122.0 (C-1), 110.4 (C-2/6), 146.4 (C-3/5), 139.6 (C-4), 170.5 (C-7).
Impact against eggs and larva of root-knot nematode (M. incognita)
Data in Table 1 document the impact of screened materials (compounds 1 – 9, EtOA and n-hexane extracts) on in vitro controlling M. incognita. Results revealed that nematode population were significantly suppressed by all tested treatments. Out of the tested materials, compound 1 at the concentration of 200 µg/mL achieved the lowest hatchability in eggs of root-knot nematode (34.0%) followed by EtOAc (40.0%) then compound 7 and 6 (41.0 and 42%, respectively) at the same concentration (Table 1, Fig. 4). Also, compound 1 at the concentration of 200 µg/mL achieved the highest mortality in root-knot nematode population after 72 hr (21.0%) followed by compound 7 and 6 (13.0%, each) at the same concentration after 72 hr of inoculation (Table 1, Fig. 5). Similar trend was noticed at the concentration of 100 and 50 µg/mL for the same treatments. Thus, compound 1, 6, 7, n-hexane and EtOAc extracts were selected for in vivo investigation on plant growth response of tomato plant var. 162 infected with M. incognita.
Impact of the extracts and the isolated compounds on tomato plants infected with root-knot nematode (M. incognita)
M. incognita infection caused a significant reduction in plant growth parameters (shoot and root length, shoot weight). Patel et al.23 reported the effect of several plant extracts on the suppression of the population of M. incognita and M. javanica infecting tomato plants. In this study, compounds 1, 6 and 7, in addition to n-hexane and EtOAc extracts from Schinus terebenthifolius showed remarkable increase in plant growth parameters in terms of shoot length, shoot and root weight with various degrees with all treatments (Table 2). It was evident that compound 1 enhanced plant growth parameters and caused a significant improvement in shoot length (109.1%), plant fresh weight (206.25%) and shoot dry weight (150.0%) at 200 µg/mL (Fig. 6). Also, compound 6 and 7 at 200 µg/mL resulted in a pronounced improvement in plant growth (Table 2). Oxamyl as a standard nematicide showed moderate improvement in pervious criteria of tomato grown with shoot length (68.2%), plant fresh weight (131.25%) and dry shoot weight (16.7%).
Data in Table 3 displays the impact of screened materials on controlling M. incognita infecting tomato var. 162 grown in potted sandy-clayey soil. Results revealed that nematode population within soil and root were significantly suppressed by all tested treatments with reproduction factor ranged from 0.42 to 1.60. Compound 1 exhibited the best suppressed total nematode population (RF = 0.42), root galling (RGI = 3.0) and number of eggmasses (EI = 0.5), respectively at 200 µg/mL (Fig. 7). Also, compound 6 at 200 µg/mL resulted in significant reduction in galling formation (78.9%). On the other hand, total nematode population was suppressed with oxamyl introduced to (RF = 0.33) root galling (RGI = 3.0) and number of eggmasses (EI = 0.5), respectively.
Biochemical activities
Total carbohydrates
Root knot nematode infection cause the formation of typical root galls that affect nutrients uptake and translocation of food materials in plants such as protein and sugar.38 The adverse effect of M. incognita infection on total carbohydrates in leaves of tomato was investigated with percentage of reduction reached (Table 4). However, a detectable induction in total carbohydrates was recorded with all treatments. The greatest % induction in total carbohydrates was recorded for compound 1 (61.4%) at a concentration of 200 µg/mL compared to untreated plants (N alone).
Crude proteins
Untreated tomato infected with M. incognita exhibited significant reduction in total proteins as compared with untreated plants with percentage of reduction reached (Table 4). However, a detectable induction in total proteins was recorded with all treatments. The greatest induction in total proteins was recorded with compound 1 (33.66%) at the concentration of 200 µg/mL compared to untreated plants (N alone).
Defense mechanism against root knot nematode
Plant nematodes, spend most of their life cycles in the roots of the host plant and thus subjected to diverse types of defense responses. Consequently, the root-knot nematode infection increased phenol content, peroxidase activity and polyphenol oxidase activities.39 Thus, total phenols and defense-related proteins including peroxidase and polyphenol oxidase are biochemical markers in infested plants.
Total phenols
The total phenolics increased in infected plants compared to non-infected plants (Table 4). However, all treatments showed a reduction in total phenolics to various extents relative to infected plants. It was observed that pots receiving compound 1 showed reduction in total phenolics comparable to the healthy plant.
Defense-related proteins
Data presented in Table 4 revealed that the least induction of PO and PPO was recorded in tomato plants untreated and inoculated with M. incognita. Oxamyl differed in its ability to stimulate peroxidase (PO) and polyphenol oxidase (PPO) activities in plant inoculated with nematodes. However, increased PO activity was observed for compound 1 followed by the EtOAc, compound 6 then 7 compared to untreated inoculated plants. On the other hand, the increased activity of PPO remained higher in plants treated with compound 6.
Conclusions
Biological control of plant pests including nematodes continues to inspire researchers in this field. Natural products are promising resources for biocontrol agents that are safer, environmentally friendly and cost-effective. In this study, phenolic compounds isolated from the leaves of Schinus terebenthifolius were investigated for their nematicidal activity against the root-knot nematode M. incognita and its infested tomato plant. The isolated compounds from S. terebenthifolius extract showed promising nematicidal activity compared to Oxamyl as a positive control. Compound 1 namely, 1,2,3,4,6-pentagalloyl glucose showed significant nematicidal activity in both in vitro and in vivo studies. It exhibited the best suppressed total nematode population, root galling and number of eggmasses. It also restored total carbohydrates, proteins and phenolics to normal and increased defense-related proteins. Thus, 1,2,3,4,6-pentagalloyl glucose could be a promising nematicidal agent against the root-knot nematode M. incognita.
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