ABSTRACT
Sanggenone C, oxyresveratrol, catechin and l-epicatechin exist in Morus and Hulless Barley as natural polyphenols with antityrosinase activity. Little research on their synergistic and structure-function relationships of them has been reported in recent years. In this paper, the inhibition mechanisms of these four plant polyphenols were investigated by enzyme kinetics, HPLC, fluorescence spectra, and molecular docking methods. The results showed that oxyresveratrol (IC50 = 1.096 ± 0.048 µg/mL), sanggenone C (IC50 = 13.360 ± 1.029 µg/mL), l-epicatechin (IC50 = 55.730 ± 1.762 µg/mL), and catechin (IC50 = 148.500 ± 3.355 µg/mL) exhibited tyrosinase inhibition activity. When sangenone C (14 µg/mL) was mixed with l-epicatechin (56 µg/mL) at 4:1 (40 µL + 10 µL), the highest tyrosinase inhibition was achieved. Molecular docking showed that the number and position of phenolic hydroxyls of polyphenols were the key for tyrosinase inhibition activity. This study provided new ideas for the application of these four plant polyphenols from Hulless Barley and Morus as tyrosinase inhibitors in food preservation.
Subject(s)
Hordeum , Morus , Enzyme Inhibitors , Molecular Docking Simulation , Monophenol Monooxygenase , Plant Extracts , PolyphenolsABSTRACT
The characteristic fingerprint of conventional dairy Nanhanshuishi was established by X-ray diffraction (XRD), based on similarity of caculation on public peaks by MATLAB software, and the feasibility of new dairy technology of microwave method was explored between XRD and the dissolution rate in artificial simulation gastric juices. The result showed that similarity of shared peak in XRD of conventional dairy Nanhanshuishi was > 95%, This XRD characteristic fingerprint of conventional dairy Nanhanshuishi had strong specificity, could be used to provide a reference for identification and quality evaluation. This study also showed that the similarity of microware dairy products and conventional dairy products was good, and the sample of microwave 15 min was the best, and new dairy method by the microwave could replace the traditional method.
Subject(s)
Chemistry, Pharmaceutical/methods , Drugs, Chinese Herbal/chemistry , Milk/chemistry , Plants, Medicinal/chemistry , Animals , Chemistry, Pharmaceutical/instrumentation , Medicine, Tibetan Traditional , Microwaves , Quality Control , X-Ray DiffractionABSTRACT
A series of polyketide metabolites (1-6), including a new chlorinated diphenyl ether (4-chloro-7,4'-dihydroxy-5,2'-dimethoxy-2-methylformate-6'-methybenzophone, 1), were isolated from the solid-fermented rice culture of Penicillium griseofulvum cib-119. The structure of compound 1 was determined on the basis of NMR spectra and single-crystal X-ray diffraction analyses. In addition, compound 1 showed weak cytotoxic activity against prostatic carcinoma cell (PC-3). Compounds 3-5 exhibited significant antimicrobial activities against Staphylococcus aureus and Bacillus subtilis.
Subject(s)
Penicillium/chemistry , Phenyl Ethers/chemistry , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Bacillus subtilis/drug effects , Cell Line, Tumor , Cell Survival/drug effects , Humans , Male , Molecular Structure , Phenyl Ethers/pharmacology , Staphylococcus aureus/drug effects , X-Ray DiffractionABSTRACT
Hot water extracting and ethanol precipitating method was employed to isolate polysaccharides. RCP (Rhodiola crenulata polysaccharide) was fractionally precipitated with EtOH. RCP3 (Rhodiola crenulata polysaccharide 3) was one of the three fractions. RCPS was obtained after RCP3 was purified by deproteination; decolourization and gel chromatography on Sephadex G-100. The homogeneity and molecular masses of RCPS were proved by HLGPC. The amount of total carbohydrates of RCPS was measured with phenol-sulfuric acid method. IR spectrometry and UV-spectrophotometer were used to determine the characteristic absorption of RCPS. The monosaccharides contained in the RCPS were analyzed by GC. The amount of total carbohydrates in RCPS is 99.11%. The molecular weight was 27 876. IR spectrometry analysis indicated that RCPS showed typical signals of acid polysaccharide, including signals at 3 424.83, 2 934.10, 1 742.11, 1 438.96, 1 261.40, 1 103.54 and 832.86 cm(-1); UV-spectrophotometer analysis indicated that RCPS showed a signal of polysaccharide at 195 nm and no signals of protein, nucleic acid at 260 and 280 nm. The monosaccharide constituents of RCPS were Rha, Ara, Xyl, Man, Glu, Gal and GalA, and their molar proportions were 1 : 2.96 : 0.21 : 0.26 : 0.08 : 0.58 and 0.15, respectively.
