J. Biodivers. Conservation 10(2): 144-151 – 2026
ISSN: 2457-0761 (online)
Alok Ranjan Sahu1, Samir Halder2 and Brajesh Kumar Sahu3*
1Department of Botany, Vikash Degree College, Bargarh, Odisha, India
2Department of Botany, Taki Government College, Taki, North 24 Parganas, West Bengal, India
3Department of Botany, P.M. College of Excellence, Government College Vidisha, Madhya Pradesh, India
*Email-Id: bksahubotany@gmail.com; ORCID: 0000-0002-3729-6170
DOI: https://doi.org/10.5281/zenodo.20603937
Article Details: Received: 2026-04-16| Accepted: 2026-06-08 | Available online: 2026-06-09
Licensed under a Creative Commons Attribution 4.0 International License
Abstract: The present study aimed to evaluate the phytochemical composition and in vitro antioxidant potential of Ipomoea aquatica leaf extracts obtained through different solvent systems of varying polarity; n-hexane, ethanol and aqueous. Qualitative phytochemical screening was performed using standard chemical tests and antioxidant activity was assessed by the DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging assay across four concentrations (0.125–1.0 mg/ml). Phytochemical analysis revealed that both the ethanol and aqueous extracts were abundant with tannins, saponins, flavonoids, phenols and reducing sugars. In contrast, the n-hexane extract only had terpenoids and steroids and found no alkaloids in any of the extracts. The ethanolic extract stood out with the highest antioxidant inhibition, ranging from 80.80% to 85.86%, followed by the aqueous extract at 65.61% to 71.94% and the n-hexane extract at 61.47% to 67.51%. All three extracts displayed a consistent dose-dependent response. Even though I. aquatica is widely used in traditional medicine and enjoyed as a leafy vegetable throughout Asia, there’s still a lack of detailed documentation regarding its phytochemical properties and antioxidant mechanisms. The present study aims to thoroughly characterize its secondary metabolite profile and measure its free radical scavenging ability, providing scientific backing for its traditional uses and paving the way for its potential in functional food and pharmaceutical applications.
Keywords: Functional food, leafy vegetable, pharmaceutical application and secondary metabolites
Introduction
In recent decades, natural plant-derived compounds have attracted a lot of scientific interest due to their wide range of biological activities and their relatively low toxicity when compared to synthetic options (Narayanankutty et al. 2024). One of the most important groups among these compounds is antioxidants, which work to neutralize reactive oxygen species (ROS) and free radicals that are linked to oxidative stress – a major factor in the development of chronic diseases like cancer, heart issues, diabetes and neurodegenerative disorders (Pham-Huy et al., 2008; Chaudhary et al., 2023; Chandimali et al., 2025). As the demand for safe, effective and naturally sourced antioxidants continues to rise, researchers are increasingly focused on exploring the phytochemical properties of edible and medicinal plants (Hossain et al., 2025). I. aquatica Forsk., commonly known as water spinach, a semi-aquatic tropical plant is found throughout South and Southeast Asia, including countries like India, Bangladesh, China and the Philippines (Joshi et al., 2021; Saikia et al., 2023). It’s a popular leafy vegetable and has been used in traditional medicine for treating various conditions such as jaundice, liver problems, fever, skin issues and insulin-dependent diabetes (Dua et al., 2015; Sharma and Diwan, 2015). While the plant is well-known for its nutritional benefits-packed with vitamins, minerals and dietary fiber-the full extent of its secondary metabolites and the scientific backing for its medicinal properties still need more thorough investigation.
Figure 1: Leaves and flowers of I. aquatica
Phytochemical screening is a crucial step in validating plant-based remedies. It helps us identify various classes of bioactive compounds, including flavonoids, phenols, tannins, saponins, alkaloids, terpenoids, and steroids, all of which contribute to a plant’s healing properties (Jena et al., 2025). The choice of extraction solvent is vital because it influences which compounds we can recover; polarity plays a key role in the solubility and yield of different phytochemical classes. For instance, polar solvents like ethanol and water are great at extracting phenolic compounds and flavonoids, which are closely linked to antioxidant activity. On the other hand, non-polar solvents such as n-hexane tend to extract lipophilic compounds like terpenoids and steroids (Lee et al., 2024). Even though I. aquatica has a long history of traditional use and is significant in diets, there’s still a lack of comparative phytochemical studies across solvents with varying polarities and their antioxidant potential in the scientific community. The present study aims to analyze the secondary metabolite composition of leaf extracts from I. aquatica using n-hexane, ethanol and water, while also assessing their in vitro antioxidant activity through the DPPH free radical scavenging assay. Ultimately, current investigation provide solid evidence for its ethnomedicinal uses and highlight its potential as a natural source of bioactive antioxidants for pharmaceutical and nutraceutical applications.
Methodology
The present study is based on field survey, experimental analysis and an extensive survey of published literature related to I. aquatica. Scientific databases, including Google Scholar, Scopus, PubMed and Web of Science, were consulted to retrieve peer-reviewed research articles, review papers, ethnobotanical surveys and pharmacological studies. Keywords including “Ipomoea aquatica,” “food value,” “medicinal uses,” “bioactive compounds” and “potent scavenging bioactive compounds” were used to identify relevant publications. The field survey was carried out during March-April of 2026. Identification was complied with reference to flora guide (Saxena and Brahmam, 1995). The experimental analysis was carried out to validate the phytoconstituents presence and antioxidant potential of I. aquatica leaves through phytochemical screening and DPPH assay. Detection of nine secondary metabolites was conducted using standard methods (Devi et al., 2023; Jena et al., 2024).
Detection of secondary metabolites through phytochemical screening
Test for tannin: About 1 ml of the leaf extract was taken. 3-5 drops of 10% lead acetate solution were added to it. The gelatinous precipitate formation confirmed the presence of tannin (Table 1).
Test for saponin: About 1 ml of the leaf extract was taken and 1 ml of distilled water was added and shaken well. The formation of persistent froth was observed confirming the presence of saponin.
Test for flavonoids: About 1 ml of the leaf extract was taken. 2 ml of 2% NaOH solution and 3 to 4 drops of dilute hydrochloric acid were added to it. The colour initially turned to an intense yellow colour with NaOH solution and later became colourless. This colour change appearance confirmed the presence of flavonoids.
Test for terpenoids: About 1 ml of the leaf extract was added with 6 drops of chloroform and placed in the water bath for a few minutes. Then 6 drops of concentrated H2SO4 were added. The reddish- brown interface confirmed the presence of terpenoids.
Test for phenolic groups: About 1 ml of the filtrate extract was taken. A few drops of 5% Ferric chloride solution were added. The dark bluish-black appearance confirmed the presence of phenolic compounds.
Test for reducing sugars: About 1 ml of the leaf extract was taken and 2 drops of Fehling’s solution A followed by Fehling’s solution B were added and kept in the water bath for some time. The presence of red-orange precipitate confirmed the presence of reducing sugar.
Test for steroids: About 1 ml of the leaf extract was taken. 1 ml of chloroform and 1 ml of concentrated sulphuric acid was added gently into it touching test tube mouth. The appearance of upper red and lower yellow with green fluorescence provides the presence of steroids.
Test for alkaloids: About 1 ml of the leaf extract was taken and added 3 to 4 drops of Dragendroff’s reagent. The formation of a reddish-brown precipitate confirmed the presence of alkaloids.
Antioxidant DPPH assay
1.aquatica leaves were collected from nearby Mahanadi areas of Cuttack District, Odisha, India. The leaves were thoroughly washed, cut and macerated with different solvents like n-hexane, ethanol and distilled water separately (Figures 1 & 2). The DPPH radical scavenging assay was used to evaluate the filtered extract following Dehar et al., (2026) with minor modifications. 1 ml of 0.1 mM DPPH solution prepared in methanol was added to prepared concentrations of aqueous, ethanolic and n-hexane extracts (1.0, 0.5, 0.25 and 0.125 mg/mL) using the respective solvents adjusting the final volume to 2 ml. 1 mL 0.1 mM DPPH in 1 mL methanol was used as control. Sample blanks (without DPPH) were used for background correction of absorbance. Reaction mixtures were exposed to dark incubation at room temperature for 20 minutes and the absorbance was spectrophotometrically taken at 517 nm. Percentage of radical scavenging activity was calculated using the following formula (Table 2).
% Inhibition= A0 – As /A0× 100
Where, A₀ is the absorbance of the control and Aₛ is the absorbance of the sample after blank correction.
Figure 2: Collected I. aquatica leaves for experimental analysis
Results and discussion
Phytochemical Screening
The qualitative phytochemical analysis of I. aquatica leaf extracts showed a distinct distribution of secondary metabolites that depended on the solvent used (Table 1). Both ethanolic and aqueous extracts tested positive for tannins, saponins, flavonoids, phenols and reducing sugars, while the n-hexane extract was found to contain only terpenoids and steroids. Interestingly, alkaloids were not detected in any of the three fractions. This observation aligns with the principle of polarity-driven extraction, where polar solvents tend to extract hydrophilic compounds like phenolics and flavonoids, whereas non-polar solvents like n-hexane are better at extracting lipophilic substances. The presence of flavonoids, phenols and tannins in the polar extracts is particularly important from a pharmacological standpoint, as these compounds are known for their antioxidant, anti-inflammatory and liver-protective properties. This supports the traditional use of the plant in treating liver issues and managing diabetes. The lack of alkaloids in all fractions is also noteworthy, as it may enhance the plant’s safety profile, making it a popular choice as an edible vegetable.
Table 1: Detection of secondary metabolites of different extracts of I. aquatica leaves
Bioactive compounds | Extracts | ||
n-hexane | Ethanolic | Aqueous | |
Tannin | Absent | Present | Present |
Saponin | Absent | Present | Present |
Flavonoids | Absent | Present | Present |
Terpenoids | Present | Absent | Absent |
Phenol | Absent | Present | Present |
Reducing sugars | Absent | Present | Present |
Steroids | Present | Absent | Absent |
Alkaloids | Absent | Absent | Absent |
In vitro antioxidant activity
All three extracts showed a concentration-dependent ability to scavenge DPPH radicals across the tested range of 0.125–1.0 mg/ml (Table 2 and Figure 3). The ethanolic extract stood out with the highest inhibition values, ranging from 80.80% to 85.86%, followed by the aqueous extract at 65.61% to 71.94%, and the n-hexane extract, which had values between 61.47% and 67.51%. The impressive antioxidant activity of the ethanolic extract can be linked to its rich content of phenolic and flavonoid compounds, which are known to effectively neutralize free radicals through mechanisms like hydrogen atom donation and electron transfer. The slightly lower activity of the aqueous extract, even though it contains similar phytochemical classes, likely stems from a reduced efficiency in extracting polar compounds compared to ethanol. Meanwhile, the remaining activity in the n-hexane extract may be due to the antioxidant properties of its terpenoid and steroid components. The consistent dose-dependent response observed across all extracts further supports the reliability of these results, confirming that the activity is indeed mediated by the compounds present. In summary, the present findings highlight I. aquatica leaf extracts especially the ethanolic fraction as a powerful natural source of antioxidants, with exciting potential for pharmaceutical and nutraceutical applications.
Table 2: Antioxidant potential of I. aquatica leaf extracts
Concentration | Inhibition (%) | ||
n-Hexane | Ethanolic | Aqueous | |
1.0 | 67.51 | 85.86 | 71.94 |
0.5 | 66.45 | 83.12 | 70.67 |
0.25 | 62.23 | 81.85 | 68.77 |
0.125 | 61.47 | 80.83 | 65.61 |
Figure 3: Antioxidant activity of I. aquatica leaf extracts
Conclusion
The leaf extracts of I. aquatica, especially the ethanolic fraction, showcased a remarkable array of phytochemicals and impressive in vitro antioxidant activity, with DPPH inhibition soaring to 85.86%. This strong ability to scavenge radicals aligns perfectly with the high levels of phenolic and flavonoid compounds found in the polar extracts. These results not only back up the plant’s traditional medicinal uses but also highlight its potential as a valuable natural antioxidant for use in pharmaceuticals and nutraceuticals.
References
Chandimali N, Bak SG, Park EH, Lim HJ, Won YS, Kim EK, Park SI and Lee SJ. (2025). Free radicals and their impact on health and antioxidant defenses: a review. Cell Death Discovery. 11(19). DOI: 10.1038/s41420-024-02278-8.
Chaudhary P, Janmeda P, Docea AO, Yeskaliyeva B, Razis AFA, Modu B, Calina D and Sharifi-Rad J. (2023). Oxidative stress, free radicals and antioxidants: potential crosstalk in the pathophysiology of human diseases. Frontiers in Chemistry. 11: 1158198. DOI: 10.3389/fchem.2023.1158198.
Dehar PS, Jena N, Malwal M and Kumar NA. (2026). Phyllanthus acidus (L.) Skeels (fruits) as a promising source of natural antioxidants: an overview. Journal of Biodiversity and Conservation. 10(2): 63-71.
Devi RS, Satapathy KB and Kumar S. (2023). Validation of tribal claims for formulation of future drugs through evaluation of ethno-pharmacological values of Ludwigia adscendens. Medicinal Plants. 15(4): 691-697.
Dua TK, Dewanjee S, Khanra R, Bhattacharya N, Bhaskar B, Zia-Ul- Haq M and Feo VD. (2015). The effects of two common edible herbs, Ipomoea aquatica and Enhydra fluctuans, on cadmium-induced pathophysiology: a focus on oxidative defence and anti-apoptotic mechanism. Journal of Translational Medicine. 13: 245. DOI: 10.1186/s12967-015-0598-6.
Hossain MS, Wazed MA, Asha S, Amin MR and Shimul IM. (2025). Dietary phytochemicals in health and disease: mechanisms, clinical evidence and applications- a comprehensive review. Food Science & Nutrition. 13(3): e70101. DOI: 10.1002/fsn3.70101.
Jena N, Rout S, Devi RS and Kumar S. (2024). Phytochemical and cytotoxicity analysis of fruits of Zanthoxylum asiaticum (L.) Appelhans, Groppo & J. Wen: a minor fruit plant of Odisha, India. E-planet. 22(1): 62-70.
Jena N, Vimala, Singh B, Patra A, Sharma BP, Hossain E and Kumar S. (2025). Methods for ethnobotanical data collection, phytochemistry, antioxidant, anthelmintic and antimicrobial activities for pharmacological evaluation of medicinal plants. Journal of Biodiversity and Conservation. 9(2): 87-107.
Joshi P, Kumari A, Chauhan AK and Singh M. (2021). Development of water spinach powder and its characterization. Journal of Food Science and Technology. 58(9): 3533-3539.
Lee JE, Jayakody JTM, Kim JI, Jeong JW, Choi KM, Kim TS, Seo C, Azimi I, Hyun JM and Ryu BM. (2024). The influence of solvent choice on the extraction of bioactive compounds from Asteraceae: a comparative review. Foods. 13(19): 3151. DOI: 10.3390/foods13193151.
Narayanankutty A, Famurewa A and Oprea E. (2024). Natural bioactive compounds and human health. Molecules. 29(14): 3372. DOI: 10.3390/molecules29143372.
Pham-Huy LA, He H and Pham-Huy C. (2008). Free radicals, antioxidants in disease and health. International Journal of Biomedical Science. 4(2): 89-96.
Saikia K, Dey S, Hazarika SN, Handique GK, Thakur D and Handique AK. (2023). Chemical and biochemical characterization of Ipomoea aquatica: genoprotective potential and inhibitory mechanism of its phytochemicals against α-amylase and α-glucosidase. Frontiers in Nutrition. 10: 1304903. DOI: 10.3389/fnut.2023.1304903.
Saxena Ho and Brahmam M. (1995). The Flora of Orissa, Volume 2. Regional Research Laboratory, Bhubaneswar and Orissa Forest Development Corporation Limited, Bhubaneswar, Odisha, India.
Sharma S and Diwan R. (2015). Ipomoea aquatica a common leafy vegetable of Chhattisgarh. International Journal of Scientific Research in Biological Sciences. 2(5): 1-3.
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