Hydroxamic acid (HA) derivates displayed antibacterial and antifungal activities. HA with various numbers of carbon atoms (C2, C6, C8, C10, C12 and C17), complexed to different metal ions Fe(II/III), Ni(II), Cu(II) and Zn(II) were evaluated for their antimycobacterial activities and their anti-biofilm activities. Some derivates, among others HA12Fe2, inhibited the development of Mycobacterium tuberculosis, Mycobacterium bovis BCG and Mycobacterium marinum biofilms and could even attack pre-formed Pseudomonas aeruginosa biofilm. Proteomic profiles showed that the potential targets of HA10FeCl were mainly related to mycobacteria stress adaptation, involving cell wall lipid biosynthesis, drug resistance and tolerance, siderophore metabolism. This study provides new insights regarding the antimycobacterial activities of the HA and their complexes, especially about their potential antibiofilm activities.

Chiral hydroxamic acid (HA) and bis-hydroxamic acid (BHA) ligands have made significant contributions to the field of asymmetric synthesis, particularly in the synthesis of natural products. These ligands possess unique molecular structures that allow for exceptional stereochemical control, leading to their widespread use in catalytic systems. This review highlights the advancements made in asymmetric synthesis using chiral hydroxamic acid and bis-hydroxamic acid ligands and their impact on the synthesis of complex natural products. The discussion encompasses their role in enantioselective C-C bond formation, the functionalization of C-H bonds, asymmetric transformations involving heteroatoms, and their application in the total synthesis of natural products. The versatility and efficiency of chiral hydroxamic acid ligands and bis-hydroxamic acid ligands make them invaluable tools for synthetic chemists working towards the efficient and selective synthesis of natural products. This review provides a comprehensive overview of their contributions, showcasing their potential to expand the boundaries of chemical synthesis and access the diverse array of natural product scaffolds.

A fatty hydroxamic acid (FHA) mixture synthesized from olive oil triacylglycerides by hydroxylaminolysis and composed predominantly of oleyl and linoleyl hydroxamic acid (OHA and LHA, respectively) was characterized by means of IR, Raman, MS and 1D and 2D ¹H- and ¹³C-NMR spectroscopy. The ratio of OHA and LHA (4:1) was confirmed by MALDI TOF/TOF mass spectrometry. The radical scavenging and the Fe²⁺-chelating activity, as well as antioxidant activity in β-carotene-linoleic acid and the Fe³⁺-reducing power assays of the FHAs yielded positive results. The results of FHA cell toxicity on normal fibroblast (BJ) and a tumour cell line (HeLa) revealed that the normal cell line was sensitive to FHAs within the entire range of applied concentrations (5 × 10⁻⁴ mg/mL to 5 × 10⁻¹ mg/mL), while the HeLa tumour cell line was sensitive only at the highest FHA concentration (5 × 10⁻¹ mg/mL). In silico target prediction indicated cannabinoid receptors 1 and 2, the fatty-acid amide hydrolase 1 and hystone deacetylases as the most probable targets of OHA and LHA. According to ADMET predictor analysis, the safety profiles of OHA and LHA are comparable to that of SAHA (vorinostat) the histone deacetylase inhibitor in use as an antineoplastic and immunomodulating agent.

Histone deacetylase (HDAC) inhibitors are class of drugs used in the cancer treatment. Here, we developed a library of 19 analogues of Vorinostat, an HDAC inhibitor used in lymphomas treatment. In Vorinostat, we replaced the hydrophobic phenyl group with various tricyclic ‘caps’ possessing a central, eight-membered, heterocyclic ring, and investigated the HDAC activity and cytotoxic effect on the cancer and normal cell lines. We found that three out of the 19 compounds, based on dibenzo[b,f]azocin-6(5H)-one, 11,12-dihydrodibenzo[b,f]azocin-6(5H)-one and benzo[b]naphtho[2,3-f][1,5]diazocine-6,14(5H,13H)-dione scaffolds, showed better HDACs inhibition than the referenced Vorinostat. In leukemic cell line MV4-11 and in lymphoma cell line – Daudi three compounds showed lower IC50 values than Vorinostat. These compounds had higher activity and selectivity against MV4-11 and Daudi cell lines than reference Vorinostat. We also observed a strong correlation between HDACs inhibition and the cytotoxic effect. Cell lines derived from solid tumors: A549 (lung carcinoma) and MCF-7 (breast adenocarcinoma) as well as reference Balb/3T3 (normal murine fibroblasts) were less susceptible to compounds tested. Developed derivatives show superior properties than Vorinostat, thus they are applicable as selective agents for leukemia and lymphoma treatment.

The structures of recently discovered primarolides A and B suggest their non-enzymatic formation from a common 2-formylbenzophenone precursor. This hypothesis is based on the experimentally proven facile conversion of pestalone (also a 2-formyl-benzophenone) either into the isomeric lactone pestalalactone or the structurally related isoindolinone pestalachloride A. In a related fashion, the racemic isoindolinone natural product mariline A is supposed to biosynthetically originate from the corresponding keto-aldehyde and an aniline, as experimentally supported by model studies. Due to the close structural relationship with known systems, it appears highly probable that primarolides A and B were generated under the fermentation conditions from a massarinin-related 2-formylbenzophenone (proprimarolide) by reaction either with aniline or a nucleophilic catalyst, respectively. Suberoylanilide hydroxamic acid (SAHA), used as an additive during the fermentation, is supposed to act both as a source of aniline and as a nucleophilic catalyst.