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Background: The synthesis and biological investigation of pyrrolidine (L-gulo) iminosugars bearing an organic boron pharmacophore in ortho and meta positions of an N-benzyl group is reported. This paper completes the structure–activity relationship data for this novel family of boron-bearing iminosugars. These can establish reversible intramolecular interactions via dative bonding from nucleophilic amino acid side chains to the empty p-orbital of the boron atom. Methods: Inhibitory activities against two panels of glycosidases and cancer cell lines were investigated to ascertain structure–activity relationship profiles for these novel iminosugar drug leads. Results: These iminosugars display selective, moderate-to-weak inhibitions (IC₅₀s = 116–617 μM) of β-D-galactosidase (bovine liver), and indications of inhibition of β-D-glucosidases (almond, bovine liver) (IC₅₀s = 633 and 710 μM) and α-D-glucosidases (rice, yeast, rat intestinal maltase) (IC₅₀s = 106–784 μM). The boronic acid group emerges as a useful pharmacophore for management of lysosomal storage disorders via the chaperone-mediated therapy approach. The cancer assays revealed that the A2780 ovarian carcinoma cell line is selectively inhibited by all compounds screened and the MIA-Pa-Ca2 pancreatic carcinoma cell line is selectively inhibited by most compounds. Growth inhibition and GI₅₀ values were most potent for the meta 7 side-product. Conclusions: Beyond the cancer cell line inhibition and dose-response capabilities, the real therapeutic potential of these borylated drugs lies in their switch on/switch off activation under boron neutron capture therapy (BNCT) radiotherapeutic conditions, thus providing an important area of application for borylated monosaccharides. Full article

The current study aimed to determine the major and minor nutritional constituents of Sorbus domestica L. fruits. It was revealed that palmitic acid was the most commonly occurring saturated fatty acid, while linoleic acid represented the major polyunsaturated fatty acid. The sterol fraction consisted mainly of β-sitosterol. Small amounts of lipophilic pigments were quantified. Potassium, iron, and boron were the most abundant macro-, micro-, and ultra-trace elements. The amino acid composition analysis suggested that the non-essential amino acids predominated over the essential ones. Soluble sugars (fructose and glucose) represented a large part of the total carbohydrate content, but pectin formed the major part of polysaccharides. Malic acid was the most abundant organic acid whereas quercetin-3-β-glucoside, neochlorogenic, and 3,4-dihydroxybenzoic acids were the major phenolic constituents. Fruits exhibited free-radical scavenging and protecting ability against peroxyl and hydroxyl radicals. Service tree fruits provided valuable bioactive constituents having a high nutritional value and potential health benefits. Full article

The application of various isonitrile-based multicomponent reactions to protected (2-oxoethyl)boronic acid (as the carbonyl component) is described. The Ugi reaction, both in the four components and in the four centers–three components versions, and the van Leusen reaction, proved effective at providing small libraries of MIDA-protected β-aminoboronic acids. The corresponding free β-aminoboronic acids, quantitatively recovered through basic mild deprotection, were found to be quite stable and were fully characterized, including by ¹¹B-NMR spectroscopy. Single-crystal X-ray diffraction analysis, applied both to a MIDA-protected and a free β-aminoboronic acid derivative, provided evidence for different conformations in the solid-state. Finally, the antimicrobial activities of selected compounds were evaluated by measuring their minimal inhibitory concentration (MIC) values, and the binding mode of the most promising derivative on OXA-23 class D β-lactamase was predicted by a molecular modeling study. Full article