The Impact of Plant Essential Oils on the Growth of the Pathogens Botrytis cinerea, Fusarium solani, and Phytophthora pseudocryptogea.

Essential oils (EOs) extracted from aromatic and medicinal plants have the potential to inhibit the growth of various pathogens and, thus, be useful in the control of dangerous diseases. The application of environmentally friendly approaches to protect agricultural and forestry ecosystems from invasive and hazardous species has become more significant in last decades. Therefore, the identification and characterization of essential oils with a strong inhibitory activity against aggressive and widespread pathogens are of key importance in plant protection research. The main purpose of our study is to evaluate the impact of essential oils originating from different genotypes of bee balm, mint, and marigold on Botrytis cinerea, Fusarium solani, and Phytophthora pseudocryptogea. Twelve essential oils, including five EOs originating from Monarda fistulosa, one oil each from Monarda russeliana, Mentha longifolia, Mentha piperita, Tagetes patula, and Tagetes erecta, and two EOs from Tagetes tenuifolia were derived by steam or water distillation. The chemical composition of the tested EOs was determined by GS-MS analyses and their corresponding chemotypes were identified. The most effective against all three pathogens were determined to be the EOs originating from M. fistulosa and M. russeliana. B. cinerea, and P. pseudocryptogea were also significantly affected by the M. piperita essential oil. The most efficient EOs involved in this investigation and their potential to control plant pathogens are discussed.

Metabolite profiling by means of GC-MS combined with principal component analyses of natural populations of Nectaroscordum siculum ssp. bulgaricum (Janka) Stearn.

Nectaroscordum siculum ssp. bulgaricum (Janka) Stearn (Allium siculum subsp. dioscoridis (Sm.) K. Richt.) is a traditional culinary spice from South-East Europe. Studies of N. siculum have focused mainly on the botanical and taxonomic characteristics of this species and there is no data available in the scientific literature about its metabolite profile. Thus, the aim of the current study was metabolite profiling of four wild populations of N. siculum grown in Bulgaria by gas chromatography coupled to mass spectrometry (GC-MS) and subsequent principal component analysis (PCA) of the data obtained. The identified primary metabolites (carbohydrates, amino acids, organic acids and lipids) are initial compounds for the biosynthesis of different plant secondary metabolites, such as polyphenols and flavour compounds with valuable biological activities for humans. The health benefits of the phenolic acids identified in this study have been a prerequisite for the implementation of N. siculum in different food systems in order to increase their quality and biological value.

Alkaloid profiles and acetylcholinesterase inhibitory activities of Fumaria species from Bulgaria.

GC-MS analysis of alkaloid profiles of five Fumaria species, naturally grown in Bulgaria (F. officinalis, F. thuretii, F. kralikii, F. rostellata and F. schrammii) and analysis of acetylcholinesterase inhibitory activity of alkaloid extracts were performed. Fourteen isoquinoline alkaloids were identified, with the principle ones being protopine, cryptopine, sinactine, parfumine, fumariline, fumarophycine, and fumaritine. Protopine contents, defined by HPLC analysis varied between 210.6 ± 8.8 µg/g DW (F. schrammii) and 334.5 ± 7.1 µg/g DW. (F. rostellata). While all of the investigated alkaloid extracts significantly inhibited acetylcholinesterase activity, the F. kralikii demonstrated the highest level of inhibition (IC(50) 0.13 ± 0.01 mg extract/mL).