In precise field trials in the years 2010 and 2011 the effect of genotype and location in cultivars with yellow, white, purple or red flesh on the content of chlorogenic acid (CA) and in 2011 and 2012 the effect of organic cultivation were evaluated. The results show a statistically significant effect of genotype to CA content, which ranged from 74.0 mg/kg fresh matter (FM) (Agria) to 825 mg/kg FM (Vitelotte). Demonstrable effect of flesh colour on CA content between cultivars with coloured flesh was found (430 mg/kg FM) in comparison with cultivars with yellow or white flesh (71.1 mg/kg FM). For cultivars with coloured flesh rather the genotype specific cultivar ruled than the purple or red flesh colour. In terms of the influence of location, higher CA levels were found on warm locations with frequent periods of drought in comparison with locations of high altitude climatic conditions which are favourable for potato cultivation. In the organically grown potatoes significantly higher levels of CA were found as compared with conventional treatment.

Magnolia plants are used both as food supplements and as cosmetic and medicinal products. The objectives of this work consisted of preparing extracts from leaves and flowers of eight Magnolia plants, and of determining concentrations of magnolol (1 to 100 mg·g−1), honokiol (0.11 to 250 mg·g−1), and obovatol (0.09 to 650 mg·g−1), typical neolignans for the genus Magnolia, in extracts made by using a methanol/water (80/20) mixture. The tested Magnolia plants, over sixty years old, were obtained from Průhonický Park (Prague area, Czech Republic): M. tripetala MTR 1531, M. obovata MOB 1511, and six hybrid plants Magnolia × pruhoniciana, results of a crossbreeding of M. tripetala MTR 1531 with M. obovata MOB 1511. The identification of neolignans was performed by HRMS after a reversed-phase high-performance liquid chromatography (RP-HPLC) fractionation of an extract from M. tripetala MTR 1531. The highest concentrations of neolignans were found in the flowers, most often in their reproductive parts, and obovatol was the most abundant in every tested plant. The highest concentrations of neolignans were detected in parent plants, and lower concentrations in hybrid magnolias. Flower extracts from the parent plants M. tripetala MTR 1531 and M. obovata MOB 1511, flower extracts from the hybrid plants Magnolia × pruhoniciana MPR 0271, MPR 0151, and MPR 1531, and leaf extract from the hybrid plant Magnolia × pruhoniciana MPR 0271 inhibited growth of Staphylococcus aureus.