A New Phenolic Alkaloid from Halocnemum strobilaceum endophytes: antimicrobial, antioxidant and biofilm Inhibitory activities

Human infections caused by microbial biofilm formation represent a growing major health threat. A new amino methyl phenolic alkaloid was isolated from the corn grit culture of the endophytic isolate Penicillium citrinum-314 associated with Halocnemum strobilaceum, a halophyte growing in the Egyptian marshes . The new alkaloid was identified by 1, 2D NMR and HR-ESI-MS-MS and given the trivial name halociline. The antioxidant, antimicrobial and antibiofilm activities were recorded. Furthermore, another known compound, 1, 3, 6-trihydroxy-7-methoxy-9H-xanthen-9-one was obtained in smaller amounts and revealed a non microbicidal 100% reduction in biofilm formation, with (MBIC) value of 62.5µg/mL (228µM) against Pseudomonas aeruginosa (Ferm-BAM), a FRAP value of 447.941 ± 37.876 mM/L as well as a marked safety profile against three cancer cell lines. Through in-silico molecular docking study, in the binding sites of Pseudomonas enzymes, key ligand enzyme interactions were determined to support the in-vitro results.

Keywords: New phenolic alkaloid/ molecular docking/ biofilm formation/ endophytes/ Halocnemum strobilaceum.