Physio-chemical profiling and bioactivity of annona squamosa extracts for aphids pest repelling

Aphids (Aphidoidea) are very devastating pests in agriculture since they inject toxins, suck sap, and transmit phytopathogenic viruses that reduce the crop yield. Although synthetic insecticides are very effective, their prolonged usage has a risk to human health and environment, thus there is a need to utilize sustainable biopesticides. This study provides profiling of Annona squamosa (sugar-apple) seed and pulp-extracts to assess their use as environmentally friendly pesticide. The objective of this study is to extract bioactive compounds from the seeds and fruit pulp of Annona Squamosa using Soxhlet and maceration respectively, to profile the proximate analysis, physicochemical and biological properties of the Annona squamosa extract and to evaluate the toxicological effect of the extract towards aphids in terms of mortality test, skin color and behavioral changes after exposure in 72 hours. Bioactive compounds were extracted in Annona squamosa seeds by using Soxhlet extraction with methanol extract obtained the highest yield which is 10.8% followed by chloroform (8.54%), ethyl acetate (6.54%) and petroleum ether (4.42%). Maceration extraction using ethanol as solvent obtained a percentage yield of 40.16%. The study evaluated physio-chemical, biological, and toxicological characteristics. Proximate analysis showed that pulp contains high moisture content (78.24±0.47%) and ash content (3.17±0.04) than seeds and is slightly acidic with pH value 5 and 6 respectively. The chemical characterization using GC-MS, FTIR, and HPLC methods demonstrated the presence of the main bioactive functional groups and compounds, including polyphenols, fatty acids and terpenoids. Total Phenolic Content (TPC) was determined using Folin-Ciocalteu method. The findings showed that the extracts of Annona squamosa pulp are rich in phenolic compounds having the highest TPC value (0.8619±0.0047 mg GAE/g) among the seed extracts. The antioxidant and antibacterial activities of the extracts were assessed using DPPH radical scavenging assays and disc diffusion method respectively. Antioxidant activity showed methanol seed extract and ethanol pulp extract have high antioxidant activity with value of %RSA 83.7628±1.42 and 87.9914±0.33 at 800ppm respectively. The disc diffusion method was used to test the antibacterial efficacy against Escherichia coli and Staphylococcus aureus showing petroleum ether extracts have highest zone of inhibition with 8.5mm and 10.0mm respectively. Toxicology analysis against aphids populations was carried out and chloroform seed extract has highest percentage of mortality (%100) within 24 hours. No toxicity was reported against the ethanol pulp extract. Overall, the findings highlight the potential of Annona squamosa, especially seed extracts as a natural biopesticide with antioxidant, antibacterial and aphicidal effects that can be utilized in the sustainable control of crops.