prunin and naringin

Topics: Adsorption; Bacterial Proteins; Biocatalysis; Enzyme Stability; Enzymes, Immobilized; Flavanones; Glycoside Hydrolases; Hot Temperature; Hydrogen-Ion Concentration; Magnetic Phenomena; Magnetite Nanoparticles; Phlorhizin; Recombinant Proteins; Thermotoga

Trilobatin [4'-(β-D-glucopyranosyloxy)-2',4",6'-trihydroxydihydrochalcone] was synthesized from commercially available naringin in three steps with an overall yield of 30%. The key step was the acid-catalyzed site-selective hydrolysis of terminal α-rhamnopyranosidic linkage in neohesperidose involved in naringin under controlled conditions, by applying a high-pressure steam sterilizer.

Topics: Acids; Catalysis; Chalcones; Flavanones; Flavonoids; Glycoside Hydrolases; Hydrolysis; Molecular Structure; Phlorhizin; Polyphenols

An HPLC method that can separate naringin, prunin, and naringenin was used to help accurately measure the activities of naringinase and its subunits (α-L-rhamnosidase and β-D-glucosidase). The activities of the naringinase and β-d-glucosidase were determined through an indirect calculation of the naringenin concentration to avoid interference from its poor solubility. The measured enzymatic activities of the naringinase complex, α-L-rhamnosidase, and β-D-glucosidase were the as same as their theoretical activities when the substrates' (i.e., naringin or prunin) concentrations were 200 μg/mL, and the enzyme concentrations were within the range of 0.06-0.43, 0.067-0.53, and 0.15-1.13 U/mL, respectively. The β-D-glucosidase had a much higher Vmax than either naringinase or α-L-rhamnosidase, implying the hydrolysis of naringin to prunin was the limiting step of the enzyme reaction. The reliability of the method was finally validated through the repeatability test, indicating its feasibility for the determinations of the naringinase complex.

Topics: beta-Glucosidase; Chromatography, High Pressure Liquid; Enzyme Assays; Flavanones; Hydrolysis; Kinetics; Multienzyme Complexes; Phlorhizin

To establish a method of quality assurance for mass-screening (QAMS) for simultaneously determining six flavonoids in Hongzhu Capsules.. An HPLC (high performance liquid chromatography) method was developed as QAMS to determine neoeriocitrin, prunin, naringin, rhoifolin, miliditin and naringenin in Hongzhu Capsules. Using naringin as the internal reference substance, relative correction factors (RCF) of the five flavonoids were determined and given as follows (1.05, 0.782, 1.89, 1.27, 0.532). The contents of the flavonoids in Hongzhu Capsules were determined by QAMS and validated by the external standard method.. RCF values were determined by HPLC with good reproducibility. No significant difference between the quantitative results of QAMS and external standard method was observed.. The present-developed method is convenient and accurate to determine multiple components when some standard substances are unavailable, thus considered as a potential method for quality control of Hongzhu Capsules.

Topics: Capsules; Chromatography, High Pressure Liquid; Disaccharides; Drugs, Chinese Herbal; Flavanones; Flavonoids; Glycosides; Phlorhizin; Plants, Medicinal; Quality Control; Reproducibility of Results

To study the antimicrobial activity of naringin (NAR), a flavonoid extracted from citrus industry waste, and NAR derivatives [naringenin (NGE), prunin and alkyl prunin esters] against pathogenic bacteria such as L. monocytogenes, E. coli O157:H7 and S. aureus. The relationship between the structure of the chemical compounds and their antagonistic effect was also analysed.. The agar dilution technique and direct contact assaying were applied. NGE, prunin and NAR showed no antimicrobial activity at a concentration of 0.25 mmol l(-1). Similarly, fatty acids with a chain length between C2 and C18 showed no antimicrobial activity at the same concentration. However, prunin-6″-O-acyl esters presented high antibacterial activity, mainly against Gram-positive strains. This activity increased with increasing chain length (up to 10-12 carbon atoms). Alkyl prunin esters with 10-12 carbon atoms diminished viability of L. monocytogenes by about 3 log orders and S. aureus by 6 log orders after 2 h of contact at 37°C and at a concentration of 0.25 mmol l(-1). The compounds examined were not effective against any of the Gram-negative strains assayed, even at the highest concentration.. Addition of sugars to the aglycone did not enhance its antimicrobial activity. Attachment of a saturated aliphatic chain with 10-12 carbon atoms to the A ring of the flavonoid (or to sugars attached to this ring), seems to be the most promising modification. In conclusion, alkyl prunin esters with a chain length of C10-C12 have promising features as antimicrobial agents because of their high antilisterial and antistaphylococcal activity.. This study shows that it is possible to obtain NAR derivatives with important antimicrobial activity, especially against Gram-positive pathogenic bacteria. It also provides guidelines on the structural modifications in similar molecules to enhance the antimicrobial activity.

Topics: Anti-Bacterial Agents; Citrus; Escherichia coli O157; Flavanones; Listeria monocytogenes; Microbial Sensitivity Tests; Phlorhizin; Plant Extracts; Staphylococcus aureus; Structure-Activity Relationship