Flavonoids from the leaves and stems of Sedum japonicum var. senanense and their antioxidant activity

Twenty flavonoids (1-20) were isolated from the leaves and stems of Sedum japonicum var. senanense endemic to Japan. Among them, nine compounds were reported in nature for the first time, and identified as herbacetin 3-O-neohesperidoside-8-O-(2‴-acetylxyloside) (2), gossypetin 8-O-(2″-acetylxyloside) (4), gossypetin 8-O-(3″-acetylxyloside) (5), gossypetin 3-O-glucoside-8-O-(3‴-acetylxyloside) (9), gossypetin 3-O-glucoside-8-O-(2‴,3‴-diacetylxyloside) (10), gossypetin 3-O-neohesperidoside-8-O-xyloside (11), gossypetin 3-O-neohesperidoside-8-O-(2⁗-acetylxyloside) (12), gossypetin 3-O-neohesperidoside-8-O-(3⁗-acetylxyloside) (13) and gossypetin 3-O-glucoside-8-O-xylofuranoside (14) by UV spectral survey, HR-MS, LC-MS, acid hydrolysis, NMR including 1H and 13C NMR, COSY, NOESY, HSQC and HMBC. Moreover, nine major flavonoids were surveyed for antioxidant activity by H-ORAC method. As the results, gossypetin 3-O-glucoside-8-O-(2‴-acetylxyoside) (8) showed the highest antioxidant activity. Conversely, gossypetin 3-O-neohesperidoside-8-O-xyloside (11) and gossypetin 3-O-neohesperidoside-8-O-(2⁗-acetylxyloside) (12) which attach neohesperidose showed the lowest values.

Deep Eutectic Solvents: An Eco-friendly Design for Drug Engineering

In the spirit of circular economy and sustainable chemistry, the use of environmentally friendly chemical products in pharmacy has become a hot topic. In recent years, organic solvents have been the subject of a great range of restriction policies due to their harmful effects on the environment and toxicity to human health. In parallel, deep eutectic solvents (DESs) have emerged as suitable greener solvents with beneficial environmental impacts and a rich palette of physicochemical advantages related to their low cost and biocompatibility. Additionally, DESs can enable remarkable solubilizing effect for several active pharmaceutical ingredients (APIs), thus forming therapeutic DESs (TheDESs). In this work, special attention is paid to DESs, presenting a precise definition, classification, methods of preparation, and characterization. A description of natural DESs (NaDESs), i. e., eutectic solvents present in natural sources, is also reported. Moreover, the present review article is the first one to detail the different approaches for judiciously selecting the constituents of DESs in order to minimize the number of experiments. The role of DESs in the biomedical and pharmaceutical sectors and their impact on the development of successful therapies are also discussed.

Flavonoids from Sedum japonicum subsp. oryzifolium (Crassulaceae)

Twenty-two flavonoids were isolated from the leaves and stems of Sedum japonicum subsp. oryzifolium (Crassulaceae). Of these compounds, five flavonoids were reported in nature for the first time, and identified as herbacetin 3-O-xyloside-8-O-glucoside, herbacetin 3-O-glucoside-8-O-(2′′′-acetylxyloside), gossypetin 3-O-glucoside-8-O-arabinoside, gossypetin 3-O-glucoside-8-O-(2′′′-acetylxyloside) and hibiscetin 3-O-glucoside-8-O-arabinoside via UV, HR-MS, LC-MS, acid hydrolysis and NMR. Other seventeen known flavonoids were identified as herbacetin 3-O-glucoside-8-O-arabinoside, herbacetin 3-O-glucoside-8-O-xyloside, gossypetin 3-O-glucoside-8-O-xyloside, quercetin, quercetin 3-O-glucoside, quercetin 3-O-xylosyl-(1→2)-rhamnoside-7-O-rhamnoside, quercetin 3-O-rhamnoside-7-O-glucoside, kaempferol, kaempferol 3-O-glucoside, kaempferol 7-O-rhamnoside, kaempferol 3,7-di-O-rhamnoside, kaempferol 3-O-glucoside-7-O-rhamnoside, kaempferol 3-O-glucosyl-(1→2)-rhamnoside-7-O-rhamnoside, kaempferol 3-O-xylosyl-(1→2)-rhamnoside, kaempferol 3-O-xylosyl-(1→2)-rhamnoside-7-O-rhamnoside, myricetin 3-O-glucoside and cyanidin 3-O-glucoside. Some flavonol 3,8-di-O-glycosides were found in Sedum japonicum subsp. oryzifolium as major flavonoids in this survey. They were presumed to be the diagnostic flavonoids in the species. Flavonoids were reported from S. japonicum for the first time.