scholarly journals Bioactivity-Guided Isolation of Phytochemicals from Vaccinium dunalianum Wight and Their Antioxidant and Enzyme Inhibitory Activities

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2075
Author(s):  
Tianrui Zhao ◽  
Mengxue Sun ◽  
Lingpeng Kong ◽  
Qingwang Xue ◽  
Yudan Wang ◽  
...  

Vaccinium dunalianum Wight, usually processed as a traditional folk tea beverage, is widely distributed in the southwest of China. The present study aimed to investigate the antioxidant, α-glucosidase and pancreatic lipase inhibitory activities of V.dunalianum extract and isolate the bioactive components. In this study, the crude extract (CE) from the buds of V. dunalianum was prepared by the ultrasound-assisted extraction method in 70% methanol and then purified with macroporous resin D101 to obtain the purified extract (PM). Five fractions (Fr. A–E) were further obtained by MPLC column (RP-C18). Bioactivity assays revealed that Fr. B with 40% methanol and Fr. D with 80% methanol had better antioxidant with 0.48 ± 0.03 and 0.62 ± 0.01 nM Trolox equivalent (TE)/mg extract for DPPH, 0.87 ± 0.02 and 1.58 ± 0.02 nM TE/mg extract for FRAP, 14.42 ± 0.41 and 19.25 ± 0.23 nM TE/mg extract for ABTS, and enzyme inhibitory effects with IC50 values of 95.21 ± 2.21 and 74.55 ± 3.85 for α-glucosidase, and 142.53 ± 11.45 and 128.76 ± 13.85 µg/mL for pancreatic lipase. Multivariate analysis indicated that the TPC and TFC were positively related to the antioxidant activities. Further phytochemical purification led to the isolation of ten compounds (1–10). 6-O-Caffeoylarbutin (7) showed significant inhibitory effects on α-glucosidase and pancreatic lipase enzymes with values of 38.38 ± 1.84 and 97.56 ± 7.53 µg/mL, and had the highest antioxidant capacity compared to the other compounds.

Food Research ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 578-584 ◽  
Author(s):  
Abdul Rohman ◽  
Irnawati

Pumpkin seed oil (PSO) has been known as functional food oil due to some bioactive components contained such as phenolics and tocopherols with beneficial effects to human health including antioxidants, prevention of certain cancers, and retardation of hypertension progression and alleviation of diabetes mellitus. To extract PSO from corresponding fruit seed, numerous extraction techniques either conventional like Soxhlet extraction or modern extraction systems such as ultrasound-assisted extraction and supercritical extraction were optimized and developed to get maximum yields of PSO with maximum bioactive components. PSO contained tocopherols and other phenolics compounds, therefore, it has potential application in the treatment of diseases related to oxidative stress. Due to the different price of PSO with other vegetable oils, the adulteration practice involving the substitution or addition of PSO with lower price oils such as palm oil and corn oils is possible, therefore analytical method capable of detecting the adulteration practice is available. The aim of this review was to highlight the physicochemical properties, extraction procedure, antioxidant activities and authentication analysis of PSO.


2020 ◽  
Vol 11 (3) ◽  
pp. 66
Author(s):  
Umar M. Badeggi ◽  
Jelili A. Badmus ◽  
Subelia S. Botha ◽  
Enas Ismail ◽  
Jeanine L. Marnewick ◽  
...  

In this study, procyanidin dimers and Leucosidea sericea total extract (LSTE) were employed in the synthesis of silver nanoparticles (AgNPs) and characterized by ultraviolet-visible (UV-Visible) spectroscopy, high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), and dynamic light scattering (DLS) techniques. AgNPs of about 2–7 nm were obtained. DLS and stability evaluations confirmed that the AgNPs/procyanidins conjugates were stable. The formed nanoparticles exhibited good inhibitory activities against the two enzymes studied. The IC50 values against the amylase enzyme were 14.92 ± 1.0, 13.24 ± 0.2, and 19.13 ± 0.8 µg/mL for AgNPs coordinated with LSTE, F1, and F2, respectively. The corresponding values for the glucosidase enzyme were 21.48 ± 0.9, 18.76 ± 1.0, and 8.75 ± 0.7 µg/mL. The antioxidant activities were comparable to those of the intact fractions. The AgNPs also demonstrated bacterial inhibitory activities against six bacterial species. While the minimum inhibitory concentrations (MIC) of F1-AgNPs against Pseudomonas aeruginosa and Staphylococcus aureus were 31.25 and 15.63 µg/mL respectively, those of LSTE-AgNPs and F2-AgNPs against these organisms were both 62.50 µg/mL. The F1-AgNPs demonstrated a better bactericidal effect and may be useful in food packaging. This research also showed the involvement of the procyanidins as reducing and capping agents in the formation of stable AgNPs with potential biological applications.


Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1187
Author(s):  
Ivana Generalić Mekinić ◽  
Vida Šimat ◽  
Viktorija Botić ◽  
Anita Crnjac ◽  
Marina Smoljo ◽  
...  

In this study, the influences of temperature (20, 40 and 60 °C) and extraction solvents (water, ethanol) on the ultrasound-assisted extraction of phenolics from the Adriatic macroalgae Dictyota dichotoma and Padina pavonica were studied. The extracts were analysed for major phenolic sub-groups (total phenolics, flavonoids and tannins) using spectrometric methods, while the individual phenolics were detected by HPLC. The antioxidant activities were evaluated using three methods: Ferric Reducing/Antioxidant Power (FRAP), scavenging of the stabile 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and Oxygen Radical Antioxidant Capacity (ORAC). The aim of the study was also to find the connection between the chemical composition of the extracts and their biological activity. Therefore, principal component analysis (PCA), which permits simple representation of different sample data and better visualisation of their correlations, was used. Higher extraction yields of the total phenolics, flavonoids and tannins were obtained using an alcoholic solvent, while a general conclusion about the applied temperature was not established. These extracts also showed good antioxidant activity, especially D. dichotoma extracts, with high reducing capacity (690–792 mM TE) and ORAC values (38.7–40.8 mM TE in 400-fold diluted extracts). The PCA pointed out the significant influence of flavonoids and tannins on the investigated properties. The results of this investigation could be interesting for future studies dealing with the application of these two algae in foods, cosmetics and pharmaceuticals.


2019 ◽  
Vol 39 (2) ◽  
pp. 378-387 ◽  
Author(s):  
Hui-Zhen LI ◽  
Yong-Lan TAN ◽  
Zhi-Jun ZHANG ◽  
Yao-Yao XIA ◽  
Xiao-Jun LI ◽  
...  

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Ling-Li Zheng ◽  
Guan Wen ◽  
Min-Yong Yuan ◽  
Feng Gao

Object. Ultrasound-assisted extraction of total flavonoids from corn silk and their antioxidant activities were studied.Methods. Response surface methodology was adopted to optimize the extraction conditions and antioxidant activities of the extracted total flavonoids were detected through ferric reducing antioxidant power (FRAP) assay.Results. Through a three-level, three-variable Box-Behnken design of response surface methodology (RSM) adopting yield as response, the optimal conditions were determined as follows: ultrasonic power 500 W, extraction time 20 min, material solvent ratio 1 : 20, and ethanol concentration 30%. Under the optimum conditions, the extraction yield of total flavonoids was 1.13%. FRAP value of total flavonoids extracted from corn silk was 467.59 μmol/L.Conclusion. The total flavonoids of corn silk could be developed as food natural antioxidant reagents.


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