ABSTRACT
Due to the importance of the amino ketone motif in synthetic and medicinal chemistry, the number of protocols developed in recent years has considerably increased. This review serves to collate and critically evaluate novel methodologies published since 2011 towards this high value synthon. The chapters are divided by the requisite functionality in the starting material, and an emphasis is placed on discussing functional group compatibility and resultant product substitution patterns. Throughout, applications to medicinal targets are highlighted and mechanistic details are presented, and we further provide a short outlook for future development and emerging potential within this area.
ABSTRACT
A silver-mediated synthesis of α-amino ketones via the oxidative deconstruction of azetidinols has been developed using a readily scalable protocol with isolated yields up to 80%. The azetidinols are easily synthesized in one step and can act as protecting groups for these pharmaceutically relevant synthons. Furthermore, mechanistic insights are presented and these data have revealed that the transformation is likely to proceed through the ß-scission of an alkoxy radical, followed by oxidation and C-N cleavage of the resulting α-amido radical.
ABSTRACT
BACKGROUND: Momordica charantia Linn. (Cucurbitaceae), the wild variety of bitter melon and Morinda lucida Benth (Rubiaceae) were commonly used as a popular folk medicine in Benin. This research focused to measure the antioxidant and enzyme inhibitory effects of M. charantia and M. lucida leaves and their antidiabetic activity. METHODS: Antioxidant activities were evaluated by micro-dilution technique using DPPH free radical scavenging activity and ß-carotene-linoleate bleaching assay. The α-amylase inhibition assay was carried out utilizing the 3,5-dinitrosalicylic acid procedure, while ß-glucosidase inhibition assay was demonstrated using as substrate p-nitrophenyl-ß-D-glucopyranoside (PNPG). HPLC-DAD analysis was realized using a high-performance liquid chromatography systems with diode-array detector, L-3000. RESULTS: Chlorogenic acid, epicatechin, daidzein, rutin, naringin, quercetin, naringenin and genistein were identified as polyphenol compounds in the both plants extract. Dichloromethane and ethyl acetate extracts showed a good α-amylase inhibitory activity (56.46 ± 1.96% and 58.76 ± 2.74% respectively). M. lucida methanolic extract has shown IC50 of 0.51 ± 0.01 mg/mL, which is the lowest for DPPH scavenging activity. M. lucida dichloromethane extract showed the highest inhibitory capacity of ß-glucosidase activity (82.11. ± 2.15%). CONCLUSION: These results justify some traditional medicinal uses of both plants. The purified fractions could be used in future formulations, possibly incorporated in functional foods to combat certain diseases.
ABSTRACT
Nymphaea alba is an aquatic flowering plant from the Nymphaeaceae family that has been used for hundreds of years in traditional herbal medicine. The plant is characterized by different phytochemicals, depending on the geographical location. Herein, we have carried out, for the first time, the separation and HPLC-MS/MS identification of some antioxidant compounds, such as polyphenols and flavonoids from N. alba extracts from the Danube Delta Biosphere, and investigated their possible antiradical properties. An ultrasonic method has been exhaustively used for the extraction of the antioxidant compounds from the different anatomic parts of N. alba (fruit, flower, leaf, stem, and root). The extracts that were obtained using ultrasound irradiation showed a large polyphenol (19.42 mg EqGA/100 mg extract) and flavonoid (0.97 mg EqQ/100 mg extract) content. The fruit and flower extracts showed the highest antioxidant activity index (AAI). Among the 27 phytochemical compounds identified in all of the N. alba extracts, rutin and p-coumaric acid were found as the major components. The content of macroelements and microelements in N. alba extracts were compared, and it was found that their concentrations depend on the different anatomic parts of the plant. This research contributes to the study of Nymphaeaceae family, being the first exhaustive phytochemical study of N. alba from a wild population in Romania.
