Lachnuoic Acids A−F: Ambuic Acid Congeners from a Saprotrophic Lachnum Species

Abstract

Chemical prospection of an extract derived from a saprotrophic fungus Lachnum sp. IW157 resulted in the isolation and characterization of six unprecedentedly reported ambuic acid analogues named lachnuoic acids A–F (1–6). Chemical structures of 1–6 were determined based on comprehensive 1D and 2D NMR spectroscopic analyses together with HR‐ESI‐MS spectrometry. The relative configurations of 1–3 were defined by ROESY spectroscopic analyses while their absolute configurations were unambiguously determined by Mosher’s esters method. All isolated compounds were subjected to cytotoxic, antimicrobial, antibiofilm and nematicidal activity assays where only lachnuoic acid A (1) revealed potent antimicrobial activity against Staphylococcus aureus and Bacillus subtilis at MIC values of 16.6 and 8.3 µg/mL, respectively.

Laburnicotides A–F: Acyclic N-Acetyl Oligopeptides from the Nematode-Cyst-Associated Fungus Laburnicola nematophila

“…According to our main research aim to find out new anti-infective and/or biocontrol agents, all isolated compounds were subjected to cytotoxic, antimicrobial, antiviral, and nematicidal activity assays following the previously reported protocols. ,,, However, the obtained results (Tables S6–S8) revealed that none of the tested compounds revealed activity in any of the conducted assays. Despite that, these negative results encouraged us to exploit the reported literature discussing oligopeptides for finding related derivatives with potential bioactivities.…”

“…baumannii), Chromobacterium violaceum, Escherichia coli, and Pseudomonas aeruginosa (P. aeruginosa)), and five fungal species (Candida albicans, Mucor hiemalis, Rhodotorula glutinis, Schizosaccharomyces pombe, and Wickerhamomyces anomalus), utilizing established methodologies. ,,, Methanol served as the negative control with a volume of 20 μL, while the choice of positive controls was tailored to the specific organism under investigation. For bacterial strains, oxytetracycline, ciprofloxacin, kanamycin, and gentamicin were employed as references for B.…”

“…The evaluation of antimicrobial efficacy was conducted through a serial dilution method to determine the minimum inhibitory concentrations (MICs) of isolated compounds against various Gram-positive bacteria ( Bacillus subtilis ( B. subtilis ), Mycobacterium smegmatis ( M. smegmatis ), and Staphylococcus aureus ), Gram-negative bacteria ( Acinetobacter baumannii ( A. baumannii ), Chromobacterium violaceum , Escherichia coli , and Pseudomonas aeruginosa ( P. aeruginosa )), and five fungal species ( Candida albicans , Mucor hiemalis , Rhodotorula glutinis , Schizosaccharomyces pombe , and Wickerhamomyces anomalus ), utilizing established methodologies. 16 , 20 , 23 , 24 Methanol served as the negative control with a volume of 20 μL, while the choice of positive controls was tailored to the specific organism under investigation. For bacterial strains, oxytetracycline, ciprofloxacin, kanamycin, and gentamicin were employed as references for B. subtilis , A. baumannii , M. smegmatis , and P. aeruginosa , respectively; nystatin was the standard for all fungi.…”

“…Ivermectin, at a concentration of 1 μg mL –1 , served as the positive control, and methanol was used as the negative control. This assay was executed according to the procedures outlined by Phutthacharoen et al 23 …”

Dentifragilones A–B and Other Benzoic Acid Derivatives from the European Basidiomycete Dentipellis fragilis

“…Molecules 2024, 29, x FOR PEER REVIEW A literature search of 1 revealed its common structural features of strobiloscyphones [10], pestallic acids [11], dentipellin [4], and the recently reported lachnoic acids [12], where they shared the presence of a 2-cyclohexenone moiety in their structures. A careful interpretation of the obtained 1D and 2D NMR spectral data of 1 (Table 1, Figure 2) suggested the structure depicted in Figure 1, with a 1,1-dimethyl-2-propenyl functionality being attached at C-6.…”