Comprehensive Review of Recent Advances in Chiral A-Ring Flavonoid Containing Compounds: Structure, Bioactivities, and Synthesis

Abstract

Flavonoids are a group of natural polyphenolic substances that are abundant in vegetables, fruits, grains, and tea. Chiral A-ring-containing flavonoids are an important group of natural flavonoid derivatives applicable in a wide range of biological activities such as, cytotoxic, anti-inflammatory, anti-microbial, antioxidant, and enzyme inhibition. The desirable development of chiral A-ring-containing flavonoids by isolation, semi-synthesis or total synthesis in a short duration proves their great value in medicinal chemistry research. In this review, the research progress of chiral A-ring-containing flavonoids, including isolation and extraction, structural identification, pharmacological activities, and synthetic methods, is comprehensively and systematically summarized. Furthermore, we provide suggestions for future research on the synthesis and biomedical applications of flavonoids.

Cytotoxic, Antibacterial, and Antioxidant Activities of the Leaf Extract of Sinningia bullata

“…Pharmacological potentials and antioxidant activity are usually correlated [ 14 , 15 ]. Thus, we evaluated the antioxidant activity of different extracts of S. bullata using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay ( Figure 2 ).…”

“…Pharmacological potentials and antioxidant activity are usually correlated [ 14 , 15 ]. Sb-L-A showed the highest DPPH radical scavenging activity with an IC 50 value of 180.8 ± 2.8 μg/mL, while the tuber extracts had poor radical scavenging potential ( Table 3 ).…”

“…Many natural compounds exhibiting anticancer properties are phenols and flavonoids that can influence cell cycles [ 11 , 12 , 13 ]. In addition, pharmacological potentials and antioxidant activity are usually correlated [ 14 , 15 ]. Thus, TPC, TFC, and antioxidation activity of different extracts are worth determining to evaluate the pharmacological potentials of S. bullata .…”

Investigating the Comparting between the Ultrafast Excited-State Electron Transfer in both Polyfluorene-Graphene and Polyfluorene- DCB Interfaces

“…[19] Recently, polyfluorene with azide derivatives have been covalently linked with graphene flakes, and the produced materials have been demonstrated to have low bandgaps and high charge carrier mobility and are potential materials for solar cells. [20] It is therefore an interesting challenge to explore the electron or energy transfers in non-covalent polyfluorene associations, which can provide a unique study on bimolecular electron transfer reactions of polyfluorene in solution phase. [20][21][22][23] Like in the case of photoexcitation dynamics of small molecules, vertical excitation of the electron donor-acceptor system would also induce electron or energy transfer, [21] and the rate of the photoinduced electron transfer (PET), charges separation (CS), and charge recombination (CR) can be related to the quenching mechanism.…”

“…[20] It is therefore an interesting challenge to explore the electron or energy transfers in non-covalent polyfluorene associations, which can provide a unique study on bimolecular electron transfer reactions of polyfluorene in solution phase. [20][21][22][23] Like in the case of photoexcitation dynamics of small molecules, vertical excitation of the electron donor-acceptor system would also induce electron or energy transfer, [21] and the rate of the photoinduced electron transfer (PET), charges separation (CS), and charge recombination (CR) can be related to the quenching mechanism. [22] Thus, understanding the quenching dynamics of polyfluorene as well as electron or energy transfer from the excited polyfluorene to the quenchers are critically important to develop solar cell materials based on water-or organic solvent-soluble polyfluorenes [23] and on solid-phase polyfluorenes.…”