prunin and naringenin

Naringin is a flavanone glycoside in citrus fruits that has various biological functions. However, its bitterness affects the quality, economic value, and consumer acceptability of citrus products. Deglycosylation of naringin using naringinase decreases its bitterness and enhances its functional properties. In this study, eight microbial strains with naringinase activity were isolated from 33 yuzu-based fermented foods. Among them, naringinase from

Topics: Aspergillus oryzae; Flavanones; Humans; Neuroblastoma; Receptors, Cell Surface

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