RESUMO
Many bioactive plant compounds, known as phytochemicals, have the potential to improve health. Unfortunately, the bioavailability and bioactivity of phytochemicals such as polyphenolic flavonoids are reduced due to conjugation with sugar moieties. Here, we combine acid hydrolysis and tailored fermentation by lactic acid bacteria (Lactiplantibacillus plantarum) to convert the biologically less active flavonoid glycosides hesperidin and naringin into the more active aglycones hesperetin and naringenin. Using a comprehensive approach, we identify the most effective hydrolysis and fermentation conditions to increase the concentration of the aglycones in citrus extracts. The higher cellular transport and bioactivity of the biotransformed citrus extract are also demonstrated in vitro and in vivo. Superior antioxidant, anti-inflammatory and cell migration activities in vitro, as well as intestinal barrier protecting and antioxidant activities in Drosophila melanogaster are identified. In conclusion, the presented biotransformation approach improves the bioactivity of flavonoids, clearly traced back to the increase in aglycone content.
Assuntos
Citrus , Flavonoides , Animais , Flavonoides/farmacologia , Flavonoides/metabolismo , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Hidrólise , Fermentação , Drosophila melanogaster/metabolismoRESUMO
The preparation of diene-modified oligonucleotides as well as their properties and further derivatization are described. Self-complementary oligonucleotides containing a diene moiety in the loop region form stable, hairpin-like secondary structures. These hairpin mimics can be further derivatized via the Diels-Alder reaction. Diene modification in the stem region leads, in contrast, to a marked destabilization of the hairpin structure. No further reduction in stability is observed, however, upon conjugation of the stem-modified derivatives via the Diels-Alder reaction with an N-substituted maleimide dienophile.
Assuntos
Oligonucleotídeos/química , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Oligonucleotídeos/síntese química , Espectrometria de Massas por Ionização por Electrospray , Espectrofotometria UltravioletaRESUMO
The chemical crosslinking of modified nucleic acids via the Diels-Alder reaction is reported. For this purpose, 1,3-butadiene derived building blocks were incorporated into complementary oligodeoxynucleotides. Treatment of the obtained duplex with difunctional dienophiles results in the clean crosslinking of the two strands. Non-crosslinked adducts arising from a single Diels-Alder reaction of a maleimide to only one strand were not observed, indicating that the first reaction is the rate determining step of the overall process. Based on their thermal denaturation profiles, the crosslinked hybrids behave like two separate, hairpin-like structures, rather than like a single, continuous duplex.
Assuntos
Butadienos/química , Reagentes de Ligações Cruzadas/química , Maleimidas/química , Oligonucleotídeos/química , Termodinâmica , Modelos MolecularesRESUMO
A highly stable 1,3-butadiene-derived DNA hairpin mimic and its derivatisation via the Diels-Alder reaction with various dienophiles are described.