1 Introduction

Sapindus is a member of the Sapindaceae family and consists of evergreen or deciduous trees with extensive distribution in tropical and subtropical regions, including South Asia, Southeast Asia, and parts of the Americas. Fruits are oval-shaped or round with an abundance of natural saponins, and they have been used traditionally for a long time in cleaning agents (Figure 1). Sapindus plants are of significant importance as high-quality raw materials for industrial application with good adaptability, low environmental requirements, and minimal cultivation costs (Chen et al., 2021; Pratiwi et al., 2024).

Figure 1 Morphological characteristics of Sapindus fruits (Adopted from Pratiwi et al., 2024)

Sapindus fruits are saponin-rich with potent insecticidal, antibacterial, and antifungal activities. They also contain secondary metabolites like flavonoids, phenolic acids, and tannins that interact synergistically to amplify their bioactivity (Garcia et al., 2020). Though the existing research primarily addresses extraction and initial mechanisms of action of active components, research on optimizing extraction procedures, stability of the component, and commercialization on large industrial levels is still lacking (Sochacki and Vogt, 2022).

With the rapid expansion of green agriculture, biopesticides have emerged as a key replacement for conventional chemical pesticides in terms of safety, environment friendliness, and efficacy (Singh et al., 2015). Biopesticides play significant roles in preventing pesticide residues and promoting ecological sustainability, with market demand growing swiftly. The potent insecticidal and antimicrobial action of active compounds present in Sapindus fruits makes them ideal candidates for natural biopesticides to support sustainable agricultural development (Porsche et al., 2017).

This study systematically surveys extraction and separation techniques for the active constituents of Sapindus fruit, investigates their mechanisms of antibacterial and insecticidal action, and develops efficient biopesticide products from these compounds. By optimized extraction techniques, improved efficiency and purity of the active constituents, and evaluation of their field application efficiency and economic acceptability, this study provides a theoretical foundation for the efficient use of Sapindus fruit. In addition, it presents fresh approaches to green farming, with significant scientific value and practical significance for research and development and utilization of biopesticides.

2 Analysis of Active Components in Sapindus Fruit

2.1 Structure and biological activity of saponins in Sapindus fruit

Saponins are a prevalent group of bioactive compounds found in Sapindus fruit pericarp, particularly Sapindus mukorossi. Saponins are widely known to exhibit surface activity and remarkable biological activity (Figure 2). The structure of saponins usually includes a triterpenoid aglycone substituted with one or more sugar residues. In Sapindus mukorossi, specific saponins such as Sapindoside B, Sapindoside A, and Mukurozi-saponin E1 have been described (Ling et al., 2019; Sochacki and Vogt, 2022). They have various biological activities, including antifungal activity against fungi like Venturia inaequalis and Botrytis cinerea. Sapindus rarak saponins have also been reported to exhibit molluscicidal activity, which could suggest their use in the management of pests (Filho et al., 2023).

Figure 2  Commercially available dried Sapindus pericarp (Adopted from Sochacki and Vogt, 2022)

2.2 Functions and mechanisms of other active components

Other than saponins, Sapindus fruits also contain other bioactive components such as acyclic sesquiterpene oligoglycosides and flavonoids. They are the reason for the medicinal properties of the plant, such as antioxidant and antimicrobial activities. Antioxidant activity is largely attributed to the occurrence of polyphenolic compounds which have been found to positively correlate with reduction potential and lipid peroxidation inhibition. Flavonoids and sesquiterpene glycosides are also accountable for the antimicrobial activity of the plant, particularly against dermatophytes (Li et al., 2013).

2.3 Inhibitory effects of active components on pests and pathogens

The bioactive phytochemicals of Sapindus fruits, especially saponins, have exhibited encouraging inhibitory activities against various pests and pathogens. For instance, the saponins from Sapindus mukorossi prevented Venturia inaequalis symptoms and sporulation by 99% under greenhouse conditions and reduced the severity of Botrytis cinerea by 63% under field testing (Heng et al., 2014). These findings suggest that Sapindus saponins can be effectively utilized in biopesticide formulations to control fungal pathogens. Additionally, the molluscicidal activity of Sapindus rarak saponins also proves their suitability for pest control (Xu et al., 2021).

3 Extraction Process of Active Components in Sapindus Fruit

3.1 Extraction methods and optimization

Active ingredients extraction from Sapindus fruits primarily involves the use of solvents and various forms of extraction. Water extraction was also employed, which yielded a good amount of saponins with a purity of 61.38% when carried out for 4 hours under a material-to-liquid ratio of 1:6. Also, foam fractionation has been used in an attempt to purify saponins at a high level of purity of 90.3%. Maximizing these processes involves the control of variables such as solvent concentration, extraction time, and liquid-to-material ratio to realize high yield and purity (Liu et al., 2019).

3.2 Influence of extraction conditions on efficiency of active components

The success of recovery of active ingredients from Sapindus fruits relies on several conditions. For instance, the choice of solvent and extraction time can significantly affect the yield and quality of saponins. Water extraction for 4 hours is effective but further purification through fermentation can increase the purity to 78.97%. The use of high temperature and some internal components of foam fractionation can also enhance the saponin recovery rate and enrichment ratio (Dinda et al., 2017).

3.3 Purification and separation techniques for active components

Purification and separation of active constituents from Sapindus fruits are necessary in order to obtain high-purity saponins. Techniques such as high-performance liquid chromatography (HPLC) and foam fractionation are used most frequently. HPLC allows for fractionation and identification of specific saponins, e.g., sapindoside B and hederagenin-pentosylhexoside. Foam fractionation, a two-step technique, was effective in achieving a high purity of saponins with an enrichment ratio of 133.4 (Cahyana et al., 2020).

3.4 Cost-effectiveness analysis of extraction processes

Economic feasibility of Sapindus fruit extraction methods relies on the balance between yield, purity, and operating costs. Water-based extraction is fairly cost-effective due to its simplicity and the fact that water is a readily available solvent, but it may be susceptible to requiring additional purification steps like fermentation to ensure very high purity levels (Hu et al., 2021). Foam fractionation, while more costly due to the need for specialized conditions and equipment, is of high recovery and purity, which in itself could be sufficient justification for use in industrial applications. For bulk production, usually the extraction and purification methods applied should find a balance between the desired purity and cost viability (Pore et al., 2010).

4 Application Research of Active Components in Biopesticides

4.1 Toxicological mechanisms of Sapindus fruit active components on target pests

The bioactive compounds of Sapindus fruits, particularly trypsin inhibitors, have shown potential in controlling pest populations. The purified Sapindus mukorossi seed trypsin inhibitor acts as a non-competitive inhibitor towards the gut peptidases of Bactrocera cucurbitae, a severe pest of a number of crops. This inhibitor disrupts the digestive functions of the pest by repressing the trypsin and chymotrypsin gene expression, but stimulating the stress-related gene expression such as Catalase and Superoxide Dismutase. This interference by biochemical means leads to inhibited larval growth and development, demonstrating the effectiveness of Sapindus components as active biopesticides.

4.2 Study on the inhibitory effects of Sapindus active components on pathogens

Sapindus mukorossi extracts exhibited strong antifungal activity. Saponins isolated from the pericarp of the fruit suppressed the growth of fungal pathogens like Venturia inaequalis and Botrytis cinerea. Greenhouse tests revealed that treatment with a chloroform-methanol extract resulted in 99% symptom and sporulation reduction of V. inaequalis on apple seedlings. Field applications of an aqueous extract resulted in a 63% reduction in B. cinerea severity in grapes. These results indicate the potential of Sapindus saponins in fungal crop disease management (Li et al., 2019).

4.3 Synergistic effects of active components in biopesticide formulations

The combination of different active components from Sapindus fruits can enhance the biopesticide formulation activity. The presence of more than a single bioactive compound, such as trypsin inhibitors and saponins, can be effective against different pests and pathogens simultaneously, which can lead to a synergistic effect (Taufik et al., 2022). For instance, while trypsin inhibitors target insect pests by inhibiting their digestive enzymes, saponins simultaneously have the ability to inhibit fungal growth, tackling pest control from a comprehensive perspective. Such synergy may increase overall efficacy and sustainability of biopesticide application (Minping et al., 2021).

4.4 Field trials and efficacy evaluation of biopesticides

Field experiments were conducted to evaluate the efficacy of Sapindus-based biopesticides. The application of Sapindus extracts in practical agricultural practice was determined to be hopeful. For example, the application of Sapindus saponins in field experiments significantly reduced the severity of fungal disease in grape and apple. These kinds of experiments are needed to ascertain the practical viability and effectiveness of Sapindus-based biopesticides in different environmental conditions. The efficacy outcomes of these trials validate the promise for the use of Sapindus components in commercial biopesticide products (Samiksha et al., 2019).

5 Development and Promotion of Sapindus Fruit Biopesticides

5.1 Process design for the production of Sapindus-based biopesticides

The Sapindus-derived biopesticide production process entails optimized extraction of active compounds, including saponins, through eco-friendly methods like water or ethanol extraction. Purified active compounds are later generated through methods like membrane filtration and column chromatography to concentrate active compounds. Formulation involves mixing these active compounds with stabilizers, emulsifiers, and carriers to ensure product stability and performance. Scalable manufacture entails regulated precision during blending, packaging, and storage to maintain quality (Wei et al., 2021). The design also involves low-waste and energy-efficient production to answer green manufacturing standards.

5.2 Cost-benefit analysis and economic feasibility study

The economic feasibility of biopesticides derived from Sapindus lies in their dual benefits of cost savings and environmental friendliness. Sapindus fruits are readily available in most geographical regions at minimal harvesting and cultivation costs that equate to a competitive raw material. Economic analysis of production shows that utilizing the best extraction and formulation practices reduces the consumption of resources and operating expenses. Market analysis indicates high demand for biopesticides with growing customer preference for environmentally friendly products. Being a high-margin business with an estimated margin of over 25% on large-scale production, the biopesticides venture is a lucrative opportunity for organic agriculture (Jeong et al., 2023).

5.3 Demonstration applications of the product in agricultural production

Sapindus-based biopesticides were tested in field trials and proved effective against various agricultural pests and pathogens. For instance, the product is highly effective in controlling aphids, whiteflies, and fungal diseases like powdery mildew with efficacy level similar to that of chemical pesticides (Upadhyay and Singh, 2011). Field trials on rice, vegetables, and fruits showed considerable yield gains and less pest damage. Ease of use, compatibility with existing agriculture practices, and no adverse effects on non-target species were mentioned by farmers, further justifying the product's worth for commercial agricultural application (Tiwari et al., 2008).

5.4 Challenges and solutions in technology promotion

Despite its potential, Sapindus-based biopesticide promotion is beset by problems of low farmer awareness, high up-front production costs, and regulatory hurdles. To counter these, education initiatives and training sessions can facilitate the way to farmer trust and acceptance by demonstrating the effectiveness and worth of the product. Subsidies and low-interest financing can defray the cost of production and induce investments in green technologies. Collaboration with government agencies and adherence to global standards of certification can ease regulatory clearance and facilitate market entry. Alliance formation with agricultural cooperatives and utilization of electronic marketing platforms can also boost product coverage and consumption for the sustainable promotion of Sapindus-based biopesticides (Selvaraj et al., 2020).

6 Research Prospects of Sapindus Fruit Active Components in Biopesticides

6.1 Optimization directions for extraction and application technologies

Extraction and use technology optimization of active compounds from Sapindus fruits will be central to their enhanced effectiveness as biopesticides. Future research suggests the possibility of Sapindus mukorossi seed trypsin inhibitors, previously shown to suppress pests like Bactrocera cucurbitae (Fenibo et al., 2022). Optimization of extraction methods for high purity and yield of these bioactive molecules will be a focus for future research. In addition, development of application processes with greater efficiency, such as encapsulation or formulation using other natural carriers, can increase the stability and delivery of these biopesticides in agricultural settings (Pratiwi et al., 2024).

6.2 Comparison and integration with other biopesticides

Comparison of the efficacy of Sapindus-based biopesticides with other natural control agents is essential to compare their relative advantages and suitability for integration (Kowalska et al., 2020). The trypsin inhibitor from Sapindus mukorossi has exhibited excellent pest-controlling activity and hence could be a good selection for addition to existing formulations of biopesticides (Gupta et al., 2023). Mixing Sapindus compounds with other biopesticides could increase their spectrum of activity and restrict pest resistance development. Compatibility with other biopesticidal active ingredients and synergistic actions need to be examined through studies to develop integrated pest management programs (Fenibo et al., 2022; Hernandez-Tenorio et al., 2022) (Figure 3).

Figure 3 New ICT based fertility management model in private dairy farm India as well as abroad

6.3 Potential expansion in multifunctional agricultural fields

The multifunctional benefit of Sapindus fruit components extends beyond pest control, with them also offering opportunities for broader agricultural applications. In addition to being insecticidal, the bioactive components, such as the trypsin inhibitor, possess antibacterial action that can be used in the management of plant diseases (Ajuna et al., 2023). Converting Sapindus-derived products into broader multifunctional applications can potentially drive crop protection and sustainability. Subsequent research must elucidate the entire biological activity of the compounds and their potential applications within integrated disease and pest control systems (Huang and Hong, 2024).

7 Concluding Remarks

This work thoroughly explored extraction, purification, and application of Sapindus fruit active compounds for biopesticide formulation. The emphasis was on optimizing eco-friendly extraction methods to achieve maximum yield and purity of the most important active ingredient with high pesticidal efficacy. Efficient formulation techniques were developed for stabilizing these active materials, rendering them effective in the long term and farm-compatible. Field trials demonstrated the efficacy of Sapindus-based biopesticides to manage pests and pathogens successfully, a healthier alternative to synthetic pesticides with low environmental footprint.

The study contributes significantly towards biopesticide technology development with an emphasis on the integration of natural resources and sustainable production methods. By utilizing Sapindus fruits, which are readily available and a renewable resource, the study conforms to the global trend of promoting green agriculture and reducing the application of chemical pesticides (Huang, 2024). The low price, harmlessness, and environmental friendliness of Sapindus-based biopesticides have great potential in the development of sustainable pest management. Moreover, the study validates the diversification of crop protection tools, developing resilience in agro-ecosystems, and advancing the goals of sustainable agriculture.

Further studies should attempt to widen the scope of pests and pathogens controlled using Sapindus-based biopesticides to meet wider applicability across various crops and agro-climatic zones. Further research on the synergistic activity of blending Sapindus active ingredients with other natural or synthetic compounds could improve the efficacy of the products and lower the rates of application. Observation of the long-term environmental impact and safety profiles of these biopesticides will further enhance their credibility and acceptability across global markets. On the applied side, scale production through green manufacturing technologies and the implementation of precision application equipment, such as drones and IoT-enabled sprayers, can drive the adoption rates as well as efficiency in real farm conditions.

Acknowledgments

The authors thank researcher Ms. Wang for her support and assistance in data acquisition and information collection.

Conflict of Interest Disclosure

The authors affirm that this research was conducted without any commercial or financial relationships that could be construed as a potential conflict of interest.

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