Recently, new daphnane, tigliane, and jatrophane diterpenoids have been isolated from various Euphorbiaceae species, of which some have been shown to be potent inhibitors of chikungunya virus (CHIKV) replication. To further explore this type of compound, the antiviral activity of a series of 29 commercially available natural diterpenoids was evaluated. Phorbol-12,13-didecanoate (11) proved to be the most potent inhibitor, with an EC50 value of 6.0 ± 0.9 nM and a selectivity index (SI) of 686, which is in line with the previously reported anti-CHIKV potency for the structurally related 12-O-tetradecanoylphorbol-13-acetate (13). Most of the other compounds exhibited low to moderate activity, including an ingenane-type diterpene ester, compound 28, with an EC50 value of 1.2 ± 0.1 μM and SI = 6.4. Diterpene compounds are known also to inhibit HIV replication, so the antiviral activities of compounds 1-29 were evaluated also against HIV-1 and HIV-2. Tigliane- (4β-hydroxyphorbol analogues 10, 11, 13, 15, 16, and 18) and ingenane-type (27 and 28) diterpene esters were shown to inhibit HIV replication in vitro at the nanomolar level. A Pearson analysis performed with the anti-CHIKV and anti-HIV data sets demonstrated a linear relationship, which supported the hypothesis made that PKC may be an important target in CHIKV replication.

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The metabolites from the coumarin class, present in tissues of plants belonging mainly to the Rutaceae and Apiaceae families, included compounds with high chemical diversity such as simple coumarins and furocoumarins. These health-promoting components are recognized for their valuable biological activities in herbal preparations but also for their phototoxic effects. In this work, a targeted liquid chromatography (LC) coupled with tandem mass spectrometry (MS2) was developed for the screening of 39 reference standards of coumarins and furocoumarins in essential oils and plant extracts. Chromatographic separation was accomplished on reversed phase column using water/acetonitrile as the mobile phase and detection was performed on a hybrid QqQ/linear ion trap spectrometer fitted with an atmospheric pressure chemical ionization (APCI) source operating in positive ion mode. This analytical approach was applied to investigate the coumarin compositions of fruit essential oils and methanolic extracts obtained from separated parts (fruit, leaf, stem, trunk, and root) of Zanthoxylum zanthoxyloides. Ten coumarins and six furanocoumarins were reported in this species and data analyses were used to assess the suitability of these compounds to the metabolomics-based differentiation of plant organs. The quantification criteria of the metabolites in extract samples included linearity, limit of quantification, limit of detection, and matrix effect were validated. As reported for other species of the Rutaceae family, the concentration of coumarins was drastically higher in Z. zanthoxyloides fruits than in other plant organs.

Flavonoids are a large group of phenolic secondary metabolites having a wide range of biochemical and pharmacological effects. In this work, a targeted liquid chromatography (LC) coupled with tandem mass spectrometry (MS 2) was used to characterize the flavonoid compositions of methanolic plant extracts from separated parts (fruits, leaves, stems, trunk barks, and root barks) of Zanthoxylum zanthoxyloides. Nine flavonoids were reported in this species, including three flavanones, five flavonols and one flavone. Quantitative analysis of flavonoid profiles from Z. zanthoxyloides extracts is useful to a better understanding of the pattern and distribution of metabolites in extract samples. The concentrations of two glycosylated flavanones (neohesperidin and hesperidin) and one flavonol (quercetin) were higher in root and trunk samples compared to fruit samples. These compounds were reported in small amounts in the stem and leaf samples. In contrast, four flavonols (hyperoside, quercetin-3-O-glucopyranoside, datiscin and quercitrin) were present in significant levels only in the leaf extracts. The presence of glycosylated flavanone (eriocitrin) has been reported only in fruit extract. The antioxidant properties of different extracts were tested regarding their scavenging activities on ABTS •+ radical. Leaf and trunk bark extracts exhibited antioxidant activities, while the extracts obtained from other organs (fruits, stems, and root barks) showed low antioxidant properties.

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Screening of flavonoid compounds in fruit, leaf, stem and root bark extracts of Z. leprieurii was achieved by liquid chromatography (LC) coupled with tandem mass spectrometry (MS2). Among the 186 reference compounds tested, four flavonoids were identified in one or other of the organ extracts from each plant (fruit, leaf, root barks and stem): neodiosmin and hesperidin were identified in all extracts. The presence of datiscin was reported only in leaves while that of rutin was identified in fruits and leaves. Of these four flavonoids, three (neodiosmin, datiscin and rutin) are detected for the first time in Z. leprieurii. The antioxidant properties of different extracts were tested regarding their scavenging activities on ABTS•+ radical. Fruit, leaf and stem extracts had low antioxidant potential and root bark extracts exhibited very low antioxidant activity. Keywords: Zanthoxylum leprieurii, flavonoids, LC-MS/MS and antioxidant activity.