Search

Procyanidins (PC) are formed by the polymerisation of flavan-3-ol monomers, which have excellent bioactivity and present great health benefits. However, the application range of the PC is greatly limited due to their poor stability. Therefore, in this study, starch aerogels were used as carriers to encapsulate PC. After screening, wheat starch aerogel (WSA) was finally chosen to encapsulate PC. Afterward, characterization (SEM, XRD, FT-IR, TGA and BET), stability testing, investigations on antioxidant activity, and in vitro tests simulating digestion were carried out. The results of relevant characterization showed that the micro surface structure of the procyanidin wheat starch aerogel (PC-WSA) presented a network structure, and PC were encapsulated in WSA. In addition, PC-WSA allows PC to be released in the final stage of simulated digestion. Meanwhile, the results of antioxidant experiments indicate that PC-WSA exhibits antioxidant activity after encapsulating PC. Moreover, the retention of PC in PC-WSA was still 53.63 ± 3.23% when stored at 70 °C for 20 days. After 6 days of light exposure, the retention of PC in PC-WSA under different light sources was all above 85%, which was higher than that of PC. In conclusion, the wheat starch aerogel could improve the stability of PC and has great potential for application. [ABSTRACT FROM AUTHOR]

Phillyrin has good biological activity, but it is insoluble in water, which restricts its use in various industries. In our work, we prepared phillyrin using a green and rapid method from Forsythia suspensa leaves, and its purity is greater than 93%. Then, phillyrin was made to interact with different kinds of cyclodextrins (CDs) as a way to improve the water solubility of phillyrin, and the interaction mechanism between CDs and phillyrin was speculated by various characterization methods. First, phase solubility experiments showed that the phase solubility curves of all three CD inclusion complexes were AL-shaped, indicating that all three inclusion complexes were prepared using phillyrin with CDs in a 1 : 1 stoichiometric ratio. And based on this result, three cyclodextrin inclusion compounds, phillyrin/HP-β-CD (complexation efficiency (CE): 82.58%, the loading efficiency (LE): 22.27%), phillyrin/DM-β-CD IC (CE: 89.31%, LE: 24.83%) and phillyrin/β-CD IC (CE: 68.59%, LE: 23.67%), were prepared. Then, phillyrin was successfully encapsulated as determined by various characterization analyses, after which the conformations of the inclusion complex interactions were analyzed by NMR and molecular docking. The result also indicated that the water solubility of the phillyrin/HP-β-CD, phillyrin/DM-β-CD IC and phillyrin/β-CD IC has significantly improved, which was 30.02, 41.91 and 14.56 times higher than that of pure phillyrin. And the inclusion of CDs also considerably improved the antioxidant capacity of phillyrin, and the DPPH clearance rates of the three inclusion compounds were 4.34, 4.46 and 4.79 times higher than those of pure phillyrin, respectively, and the ABTS clearance rates were 1.35, 1.70 and 1.62 times higher than that of pure phillyrin. The prepared inclusion complexes can be applied in the functional food industry as active ingredients. [ABSTRACT FROM AUTHOR]

We developed a protocol for the synthesis of functionalized pyrrolo[2,1- a ]isoquinoline derivatives (PIQDs) 3 from enaminones 1 using vinylene carbonate 2 . This strategy involved [3 + 2] and [4 + 2] cycloadditions via heating a mixture of substrates 1 with vinylene carbonate 2 and DCE at 60 °C, catalyzed by [Cp*RhCl 2 ] 2 and oxidized with Cu(OAc) 2 and AgSbF 6 promoted by NaOAc. As we increased the reaction temperature to 110 °C under the same conditions, we synthesized PIQDs 4 through sequential C-H activation, alkene insertion, migratory insertion, C-N reductive elimination, β-O elimination, and finally dehydration. As a result, a series of PIQDs 3 - 4 were generated by forming four bonds (2 C-C and 2 C-N bonds) in a single step. This strategy realizes the synthesis of linear molecules with potential biological activity, specifically natural-like heterocycles ( 3 - 4 ). It expands the application of vinylene carbonate as a C2 synthon in the construction of pyrrole and isoquinoline skeletons for the synthesis of functionalized PIQDs in combinatorial and parallel syntheses via one-pot reactions.

A novel protocol for the construction of highly functionalized indolizine derivatives, that is, 1 H -pyrrolo[3,4- b ]indolizine-1,3-diones (PIZDOs, 3 ) from 2-(pyridine-2-yl)acetates and maleimides via a regioselective oxidative [3 + 2] annulation was developed. The cascade oxidative reaction was enabled by heating a mixture of the two substrates in the presence of Ag 2 CO 3 as an oxidant and Cu(OAc)·H 2 O as a catalyst in chlorobenzene. Consequently, a series of PIZDOs 3 were synthesized with high regioselectivity in moderate yields. This protocol can be used in the synthesis of functionalized PIZDOs via the one-pot oxidative annulation reaction rather than through multistep reactions, which is suitable for both combinatorial and parallel syntheses of PIZDOs.