Chemometric analysis of Tunisian durum wheat metabolites using UPLC-ESI-QTOF-MS/MS.

Bioactive compounds in wheat have received a great interest in the last few years due to their nutritional and health benefits. Various analytical procedures were used to identify these compounds in wheat kernels. An ultra-performance liquid chromatography coupled to electrospray ionization quadrupole-time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS/MS) was used for the screening of bioactive compounds in seven Tunisian durum wheat extracts. The aim of this study was to realize a screening of several classes of bioactive compounds in the same analysis and to identify specific metabolite markers for discriminating the durum wheat varieties. The UPLC-ESI-QTOF-MS/MS allows the detection of 81 metabolites, belonging to different chemical families such as sugars, organic acids, amino acids, fatty acids, and phenolic compounds represented by benzoic and cinnamic acid derivatives, phenolic alcohols, flavones, lignans, and condensed tannins. Chemical profiles identified varied greatly between different wheat genotypes. As far as the authors know, this is the first time that different chemical classes were detected at the same time in durum wheat kernels using UPLC-ESI-QTOF-MS/MS. This study gives the most complete map of metabolites in Tunisian durum wheat and proves that UPLC-QTOF-MS/MS coupled with chemometric analysis is a great tool for discrimination between durum wheat cultivars.

Pearl millet populations characterized by Fusarium prevalence, morphological traits, phenolic content, and antioxidant potential.

BACKGROUND: Pearl millet (Pennisetum glaucum L.) has become increasingly attractive due to its health benefits. It is grown as food for human consumption and fodder for livestock in Africa and Asia. This study focused on five pearl millet populations from different agro-ecological zones from Tunisia, and on characterization by morphological traits, total phenolic and flavonoid content, antioxidant activity, and occurrence of Fusarium. RESULTS: Analysis of variance revealed highly significant differences between populations for the quantitative traits. The highest grain weights occurred in the pearl millet cultivated in Zaafrana and Gergis of Tunisia. Early flowering and early maturing populations cultivated in the center (Zaafrana, Rejiche) and south (Gergis) of Tunisia tended to have a higher grain yield. The Zaafrana population showed the highest value of green fodder potentiel (number and weight of leaves/cultivar and the weight of tillers and total plant/cultivar) followed by Gergis and Rejiche. The Kelibia population showed the highest total phenolic and flavonoid content. Rejiche exhibited the greatest antioxidant activity. Trans-cinnamic, protocatechuic, and hydroxybenzoic acids were the major phenolic compounds in all the extracts. Three Fusarium species were identified in Tunisian pearl millet populations based on morphologic and molecular characterization. Fusarium graminearum and Fusarium culmorum occurred most frequently. The average incidence of the three Fusarium species was relatively low (<5%) in all populations. The lowest infection rate (0.1%) was recorded in the samples from Zaafrana. CONCLUSION: Chemometric analysis confirmed the usefulness of the above traits for discrimination of pearl millet populations, where a considerable variation according to geographical origin and bioclimatic conditions was observed. © 2020 Society of Chemical Industry.

Potent virucidal effect of pheophorbide a and pyropheophorbide a on enveloped viruses.

In this study, we evaluated the inhibitory effect of ethanol and aqueous extracts from a stem of Opuntia ficus indica on replication of three kinds of viruses: two enveloped viruses [herpes simplex virus type 2 (HSV-2), influenza A virus (IFV-A)], and one non-enveloped virus [poliovirus type 1 (PV-1)]. Only ethanol extract from the cactus stem showed significant antiviral activity in vitro. Two chlorophyll derivatives, pheophorbide a and pyropheophorbide a, were isolated as active substances exhibiting potent virucidal effects on HSV-2 and IFV-A, but no activity against PV-1 was observed. These findings suggest that these active compounds might recognize specific glycoproteins of enveloped viruses, precluding their binding to host cell receptors and inhibiting viral infections.