Phytochemical analysis and antifungal potential of two Launaea mucronata (Forssk.) Muschl and Launaea nudicaulis (L.) Hook.fil. wildly growing in Anbar province, Iraq

Ethnopharmacological relevance: Plant fungi are a serious problem in agriculture. Even though synthetic fungicides are an efficient control method, several negative side effects emerge from their extensive use, such as health problems, environmental pollution, and the emergence of resistant microorganisms. Thus, it is becoming more and more urgent to search for alternative control methods.

Aim of the study: The aim of our study was to analyze phytochemical composition and antifungal potential of Launaea mucronata (Forssk.) Muschl. and Launaea nudicaulis (L.) Hook. fil. wildly growing in Anbar province, Iraq. In addition, molecular analysis was used to identify the plants species and molecular docking analysis was investigated between the major phytochemicals present in these plants and three selected fungal proteins, in order to assess the antifungal activity of the selected biochemicals against these proteins.

Materials and methods: Molecular analysis was performed using ITS sequencing protocol. The phytochemical analysis was done using GC-MS technique, while molecular docking analysis was performed by FRED application between selected compounds from each plant and three enzymes: 17β-hydroxysteroid dehydrogenase, endochitinase, and 14-α-demethylase. Finally, the antifungal activity was assessed by measuring inhibition percentage of Fusarium solani and Macrophomina phaseolina growth treated with ethanomethanolic extract of each plant.

Results: Molecular analysis identified the selected plants as L. mucronata and L. nudicaulis, with an ITS region of 600 bp. Phytochemical analysis of Launaea spp. reported the presence of 35 compounds in each ethanomethanolic extract, belonging to different classes. L. mucronata was mainly formed of lupeol (9.33%), whereas L. nudicaulis extract was dominated by the heterocyclic compound 4-(3-methoxyphenoxy)-1,2,5-oxadiazol-3-amine (20.2%). Furthermore, molecular docking analysis showed that 4H-pyran-4-one,2,3-dihydro-3,5-dihydroxy-6-methyl from L. mucronata and gulonic acid Ƴ-lactone from L. nudicaulis possessed the highest affinity score to 17-β-hydroxysteroid dehydrogenase (-4.584 and -7.811 kcal/mol, respectively). Sucrose from L. mucronata and glutaric acid, di(3,4-difluorobenzyl) ester from L. nudicaulis gave the highest affinity to endochitinase (-7.979 and - 8.446 kcal/mol, respectively). In addition, sterol 14-α-demethylase was affinitive to sucrose from L. mucronata and glutaric acid, di(3,4-difluorobenzyl) ester from L. nudicaulis via energetic score of -10.002 and -9.582 kcal/mol, respectively. Both extracts exhibited antifungal activity against F. solani and M. phaseolina in a dose-dependent manner.

Conclusions: This study confirms the antifungal potential of both Launaea spp. explained by the presence of phytochemicals with antimicrobial properties. These compounds have potential to be used as new drugs to treat infectious diseases caused by pathogens. Consequently, plants from Launaea genus could be a raw material for many studies such as therapeutic, taxonomical, drug modelling, and antifungal agent.