Comparative study of primary and secondary metabolites in apricot (Prunus armeniaca L.) cultivars

BACKGROUND: Apricot is one of the most popular Prunus species grown in the temperate zone and great variation in the contents of primary and secondary metabolites has been reported in its fruit. However, little is known on the phenolic profiles and antioxidant potential of important local cultivars. The objective of the study was to identify valuable parental lines for breeding of cultivars with high health‐promoting effects. RESULTS: Primary metabolites (sugars, organic acids) and secondary metabolites (phenolics) were quantified by high‐performance liquid chromatography–mass spectrometry (HPLC/MS) in fruit of 13 apricot cultivars: total sugars ranged from 59.2 to 212.5 g kg^?1 fresh weight (FW) and total organic acids from 4.2 to 20.8 g kg^?1 FW. Four hydroxycinnamic acids and three flavonols were quantified; their content was significantly higher in skin compared to pulp. Similarly, antioxidative potential was significantly higher in skin and ranged from 125.4 to 726.5 mg ascorbic acid equivalents kg^?1 FW. A positive correlation between total phenolic content and antioxidant potential was determined. Multivariate analysis subdivided the cultivars into five major groups, mostly influenced by the content of individual and total phenolics as well as the antioxidant potential of apricot skin and pulp. CONCLUSION: In regard to high phenolic content in connection with antioxidant potential, three cultivars stand out as the richest in analyzed quality parameters: ‘Mula Sadik’, ‘Bergeron’ and ‘Chuan Zhi Hong’. They also contained high amounts of primary metabolites and should be promoted for further planting and included in apricot breeding programs. Copyright © 2010 Society of Chemical Industry     

Polyacryl–nanoclay composite for anticorrosion application

Polyacryl–nanoclay composites are new class of materials obtained by dispersing montmorillonite clay nanoplatelets (nanoclay) into the polymer matrix. In present work we investigate and confirmed that montmorillonite nanoclay significantly enhances barrier properties of acrylic composite. Two stage of dispersion process was used to prepare polyacry–nanoclay composites. Different percentages of montmorillonite clay nanolayers were added to polyacryl dispersion and applied on steel panel with 0% (w/w), 1% (w/w), 2% (w/w) and 4% (w/w) of nanoclay as composites. Performance of nanoclay intercalation in polyacryl composite was measured by X-ray diffraction (XRD) and the structure characteristics of samples were analyzed with transmission electron microscopy (TEM). The effectiveness of prepared nanocomposites was identified by the hardness measurements and mechanical properties. Further anticorrosion characteristics, especially barrier properties were indirectly detected by electrochemical impedance spectroscopy (EIS). This method was also used for the determination of montmorilonite nanoclay optimal concentration in acrylic composite where optimal barrier properties were achieved.     

Comparative study of different methods for the extraction of DNA from fish species commercially available in South Africa

This study describes the comparison of five DNA extraction methods (urea-SDS-proteinase K; phenol-chloroform; salt extraction; SureFood^® PREP Allergen kit and Wizard^® Genomic DNA Purification kit) in terms of their ability to extract high yields of pure, readily amplifiable DNA from the muscle tissue of 29 fish species available in South Africa. Although variations in the yield and purity of extracted DNA were observed between methods, all five methods produced DNA suitable for PCR amplification. Overall, the SureFood^® PREP method was of the simplest and least hazardous to perform, extracting significantly (P < 0.05) higher DNA yields than all other methods evaluated.     

Anthocyanins and fruit colour in plums (Prunus domestica L.) during ripening

The accumulation of anthocyanins and the evolution of fruit colour were investigated during ripening of Prunus domestica L. Using HPLC, the fruit of the ‘Jojo’, ‘Valor’, ‘?a?anska rodna’ and ‘?a?anska najbolja’ cultivars were quantified for anthocyanins during a 25-day period of ripening (a 33-day period in the case of ‘Jojo’). The major anthocyanin was cyanidin 3-rutinoside which, in ripe fruits, ranged from 4.1 to 23.4 mg/100 g FW (from 52.6% to 73.0%). It was followed by peonidin 3-rutinoside (from 6.5% to 37.9%), cyanidin 3-glucoside (from 1.8% to 18.4%), cyanidin 3-xyloside (from 4.7% to 7.8%) and peonidin 3-glucoside (from 0.0% to 0.4%). The ripening process resulted in a concentration increase of total anthocyanins and changed the ratios amongst the anthocyanins. The colour parameters, L^∗, a^∗, b^∗, chroma and hue angle, of partially ripe plums were higher than those in the ripe fruit, but the CIRG index of partially ripe fruit was always lower than that of ripe fruit. The total anthocyanins were weakly correlated with each of the colour parameters; their relationships varied between cultivars and ripening stage. Correlation coefficients between individual anthocyanins and colour parameters in ripe plums were cultivar-dependent.     

Sugars,organic acids,phenolic composition and antioxidant activity of sweet cherry (Prunus avium L.)

Sugars, organic acids, phenolics and anthocyanins in fruits of 13 sweet cherry cultivars: Badascony, Burlat, Early Van Compact, Fercer, Fernier, Ferprime, Lala Star, Lapins, Noire de Meched, Sylvia, Vesseaux, Vigred (red-coloured) and Ferrador (bi-coloured) were quantified by HPLC. Sweet cherry cultivars of different pomological characteristics and different time of ripening were evaluated sensorily. Cultivars were evaluated for their total phenolic content and antioxidant activity. The sum of sugars (glucose, fructose, sucrose and sorbitol) ranged from 125 to 265 g/kg fresh weight (FW) and the sum of organic acids (malic, citric, shikimic and fumaric) ranged from 3.67 to 8.66 g/kg FW. Total phenolic content ranged from 44.3 to 87.9 mg gallic acid equivalents/100 g FW and antioxidant activity ranged from 8.0 to 17.2 mg ascorbic acid equivalent antioxidant capacity mg/100 g FW. The correlation of antioxidant activity with total phenolics content and content of anthocyanins was cultivar dependent.     

Combining OSMAC Approach and Untargeted Metabolomics for the Identification of New Glycolipids with Potent Antiviral Activity Produced by a Marine Rhodococcus

Natural products of microbial origin have inspired most of the commercial pharmaceuticals, especially those from Actinobacteria. However, the redundancy of molecules in the discovery process represents a serious issue. The untargeted approach, One Strain Many Compounds (OSMAC), is one of the most promising strategies to induce the expression of silent genes, especially when combined with genome mining and advanced metabolomics analysis. In this work, the whole genome of the marine isolate Rhodococcus sp. I2R was sequenced and analyzed by antiSMASH for the identification of biosynthetic gene clusters. The strain was cultivated in 22 different growth media and the generated extracts were subjected to metabolomic analysis and functional screening. Notably, only a single growth condition induced the production of unique compounds, which were partially purified and structurally characterized by liquid chromatography high-resolution tandem mass spectrometry (LC-HRMS/MS). This strategy led to identifying a bioactive fraction containing >30 new glycolipids holding unusual functional groups. The active fraction showed a potent antiviral effect against enveloped viruses, such as herpes simplex virus and human coronaviruses, and high antiproliferative activity in PC3 prostate cancer cell line. The identified compounds belong to the biosurfactants class, amphiphilic molecules, which play a crucial role in the biotech and biomedical industry.