In the present study, the chemical composition and total phenolic (TPC) and total flavonoid contents (TFC) of eight soybean cultivars (Giza 21, Giza 22, Giza 35, Giza 111, Giza 82, Giza 83, Crawford, and Holliday) were estimated. Moreover, antioxidant activity and in vitro cytotoxic activities against HepG-2 and MCF-7 were evaluated. Giza 21, Giza 111, and Crawford cultivars recorded higher than 40% crude protein. The analysis revealed that TPC values in seed extracts ranged from 10.5 mg GAE/g extract in Giza 35 to 6.4 mg GAE/g extract in Giza 22. TFC varied from 1.20 mg QE/g extract in Giza 111 to 0.55 mg QE/g extract in Crawford. Giza 35 exhibited the highest content of genistein and daidzein and the highest free radical scavenging activity (61.833%). The results of the MTT assay demonstrated that the soybean methanolic extracts inhibited the proliferation of HepG-2 and MCF-7 cells in a dose-dependent manner. Giza 35 exhibited the highest cytotoxic activity. In conclusion, Giza 35 cultivar recorded the highest TPC and TFC values and antioxidant and cytotoxic activities. Therefore, this cultivar can be used as a source for the production of pharmaceutical and medicinal products rather than as a nutritional source of protein.

Aflatoxins are toxic and carcinogenic components produced by some Aspergillus species such as Aspergillus flavus. Polyketide synthases enzyme (PKS) plays a central role in aflatoxin s biosynthesis of in Aspergillus flavus, especially the product template (PT) domain, which controls the aldol cyclization of the polyketide forerunner during the biosynthesis of the aflatoxin pathway process. Here, we apply the in silico approaches to validate 623 natural components obtained from the South African Natural Compound Database (SANCDB), to distinguish the PT domain s prospected inhibitors. From the 623 compounds, docking results showed that there are 330 different compounds with energy binding lower than the natural substrate (palmitic acid or PLM) of the Product Templet domain (PT). Three factors were selected to determine the best 10 inhibiting components; 1) energy binding, 2) the strengthen chemical interactions, 3) the drug-likeness. The top ten inhibiting components are kraussianone 6, kraussianone 1, neodiospyrin, clionamine D, bromotopsentin, isodiospyrin, spongotine A, kraussianone 3, 14β-Hydroxybufa-3,5,20,22-tetraenolide and kraussianone 7. The chemical interactions between 3HRQ domain and the natural substrate in the active site amino acids are highly similar to the 3HRQ with the top ten components, but the main differences are in the binding energy which is the best in the top ten ligands. Those ten components give successful inhibition with PT domain which will lead to the formula to be used for inhibition and control aflatoxin contamination of agriculture crop yields and lessen the degree of harming and sicknesses that are coming about because of acquiring measures of aflatoxin.