Bio-Guided Fractionation of Prenylated Benzaldehyde Derivatives as Potent Antimicrobial and Antibiofilm from Ammi majus L. Fruits-Associated Aspergillus amstelodami

Abstract

Ammi majus L.; Family Apiaceae; is a plant indigenous to Egypt. Its fruits contain bioactive compounds such as furanocoumarins and flavonoids of important biological activities. An endophytic fungus was isolated from the fruits and identified as Aspergillus amstelodami (MK215708) by morphology, microscopical characterization, and molecular identification. To our knowledge this is the first time an endophytic fungus has been isolated from the fruits. The antimicrobial activity of the Ammi majus ethanol fruits extract (AME) and fungal ethyl acetate extract (FEA) were investigated, where the FEA showed higher antimicrobial activity, against all the tested standard strains. Phytochemical investigation of the FEA extract yielded five prenylated benzaldehyde derivative compounds isolated for the first time from this species: Dihydroauroglaucin (1), tetrahydroauroglaucin (2), 2-(3,6-dihydroxyhepta-1,4-dien-1-yl)-3,6-dihydroxy-5-(dimethylallyl)benzaldehyde (3), isotetrahydroauroglaucin )4), and flavoglaucin (5). Structure elucidation was carried out using (1H- and 13C-NMR). Fractions and the major isolated compound 1 were evaluated for their antimicrobial and antibiofilm activity. Compound 1 showed high antimicrobial activity against Escherichia coli with minimum inhibitory concentration (MIC) = 1.95 µg/mL, Streptococcus mutans (MIC = 1.95 µg/mL), and Staphylococcus aureus (MIC = 3.9 µg/mL). It exhibited high antibiofilm activity with minimum biofilm inhibitory concentration (MBIC) = 7.81 µg/mL against Staphylococcus aureus and Escherichia coli biofilms and MBIC = 15.63 µg/mL against Streptococcus mutans and Candida albicans and moderate activity (MBIC = 31.25 µg/mL) against Pseudomonas aeruginosa biofilm. This reveals that dihydroauroglaucin, a prenylated benzaldehyde derivative, has a broad spectrum antimicrobial activity. In conclusion, it was observed that the MICs of the FEA are much lower than that of the AME against all susceptible strains, confirming that the antimicrobial activity of Ammi majus may be due to the ability of its endophytic fungi to produce effective secondary metabolites.

Fungal Endophytes: A Potential Source of Antibacterial Compounds

“…Compound 168 showed activity against E. coli, Streptococcus mutans and S. aureus, with MICs of 1.95, 1.95 and 3.9 µg/mL, respectively. The highest antibiofilm activity at concentrataion 7.81 µg/mL against S. aureus and E. coli biofilms, at 15.63 µg/mL concentration against S. mutans and moderate activity (MBIC = 31.25 µg/mL) against P. aeruginosa biofilm was measured [89].…”

Development of novel isatin–nicotinohydrazide hybrids with potent activity against susceptible/resistantMycobacterium tuberculosisand bronchitis causing–bacteria

“…The antibacterial activity for the synthesised compounds 5a–m , 9a–c , and 14 was evaluated against bronchitis causing-bacteria; Gram-negative Mycoplasma pneumoniae (ATCC 15531), K. pneumoniae (ATCC 43816), H. influenzae (ATCC 10211), M. catarrhalis (ATCC 25238), B. pertussis (ATCC 9340) and Gram-positive S. pneumoniae (ATCC 1659) using XTT Susceptibility Assay ( Table 2 ) 33 , 34 . The results showed that, most of the evaluated compounds produced a significant antibacterial activity in comparison to the reference drug Azithromycin against the tested bacterial strains.…”

“…A colorimetric broth microdilution method was utilised to determine the MIC for the tested hybrids following the XTT [2,3-bis(2-methoxy-4-nitro-5-sulfo-phenyl)-2H-tetrazolium-5-carboxanilide]-reduction assay 33 , 34 . MICs for the tested hybrids was assessed against bacteria causing bronchitis; Gram-negative bacteria: H. influenzae ATCC 10211 , M. pneumoniae ATCC 15531 , K. pneumoniae ATCC 43816, M. catarrhalis ATCC 25238 , and Bordetella pertussis ATCC 9340 , as well as S. pneumoniae ATCC 1659 , representing Gram-positive bacterium, that obtained from the American type culture collection.…”

Purification and Chemical Characterization of a Potent Acaricide and a Closely Related Inactive Metabolite Produced by Eurotium rubrum C47

“…The 1 H and 13 C NMR data of 9b ( Table 1 ) were very similar to those of 9c, the only difference in the 13 C NMR spectra was that two methylenes (δ C 24.2, C-8 and δ C 32.2, C-9) in 9c were replaced by a double bond (δ C 120.3, C-8 and δ C 142.9, C-9) in 9b, according with one additional unsaturation and the position of the double bond was determined by analysis COSY and HMBC data. All the spectroscopic information was compared with the literature and the compound was identified as aspergin ( Figure 4 B), also named tetrahydroauroglaucin and dehydroflavoglaucin [ 21 , 22 , 23 ].…”