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Copyright of Rodriguésia is the property of Revista Rodriguesia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Rodriguésia is the property of Revista Rodriguesia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Rodriguésia is the property of Revista Rodriguesia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

AbstractIn this study, biocatalytic transesterification reaction using Novozyme 435® (N435) lipase was employed to enhance the hydrophobicity of esculin, aiming to improve its solubility for commercial applications and enhance its bioactivity and oral viability. The acylation reaction of esculin with vinyl acetate was conducted at 60 °C and 200 rpm for 24 h. After chromatographic and spectroscopic analysis, two products were identified: the first one was monoacylated at the 6′-OH position of the glucosyl moiety of esculin (TR: 10.3 min and m/z 382.93 [M + H]+), and the second one was diacylated at the 6′-OH and 3′-OH positions (TR: 13.0 min and m/z 424.93 [M + H]+). The latter was the major product, with a conversion rate of 53.550 ± 0.368%, while the monoacetylated one showed 8.715 ± 0.064%. Both products were isolated by high-speed counter-current chromatography (HSCCC) using a two-phase system HEMWat 1:9:1:9 and characterized by NMR. In this way, these results improve the practical application of esculin, through the obtention of esculin mono and diacetates by fast and efficient biocatalysis reaction. [ABSTRACT FROM AUTHOR]

Research into natural products has led to the discovery of new drugs. This work shows relevant data on the antibacterial activity of Ocotea notata leaves. Dichloromethane fraction (DF) from leaves of O. notata showed antibacterial activity at the concentration of 512 μg/mL against strains of Staphylococcus. The DF was fractionated to investigate bioactive compounds and yielded six subfractions (DF1-DF6). The DF3, DF5, and DF6 showed bacteriostatic activity, and DF4 showed bactericidal activity at the concentration of 2048 μg/mL and additive effect when combined with the antibiotic oxacillin. The flavonoids miquelianin (1), isoquercitrin (2), reynoutrin (3), guaijaverin (4), and afzelin (5) were isolated from the DF4 and characterized via NMR and HPLC-DAD-MS/MS analyses. Flavonoids 1-5, especially reynoutrin (3), seem to be responsible for the DF4 antibacterial activity. Reynoutrin showed activity against Staphylococcus epidermidis ATCC 12228 and S. aureus methicillin-resistant ATCC 33591. This is the first report regarding the reynoutrin antibacterial activity and the first description of the flavonoid guaijaverin for O. notata., (© 2024 Wiley-VHCA AG, Zurich, Switzerland.)