Analysis and chemotaxonomic significance of pyrrolizidine alkaloids from two Boraginaceae species growing in Algeria.

In the current study the pyrrolizidine alkaloid profiles of the species Echium sabulicola ssp. decipiens (Pomel) Klotz and Solenanthus lanatus DC were studied in various extracts. In addition, a chemotaxonomic study within the genus and the family was carried out. The analysis was carried out by using gas chromatography coupled to mass spectrometry and by comparing the Kovats Indices and molecular and fragment ions with literature data. Twenty-three alkaloids were tentatively identified. The results showed the presence of already reported compounds as well as previously unreported ones leading both to a confirmation of the botanical classification of the two studied species and to a brand new path in the chemotaxonomy of Boraginaceae family. The presence of some pyrrolizidine alkaloids sets limits for the usage of these plants for medicinal purposes. The identified compounds confirm the botanical classification of the studied species as members of the Boraginaceae family and their presence advices against their use in the ethnopharmacological field.

First study on the pyrrolizidine alkaloids of Pardoglossum cheirifolium (L.) E.Barbier & Mathez.: GC-MS analysis of their volatile components in the whole plant.

In this work, the first study on the pyrrolizidine alkaloids content of Pardoglossum cheirifolium (L.) E.Barbier & Mathez. was reported. The studied exemplar was collected in Algeria and the analysis was carried out by means of GC-MS on the crude base extract deriving from the whole plant. Nine compounds were tentatively identified and they all represent new phytochemicals at the species level. Their presence confirms the botanical classification of the plant as a member of the Boraginaceae family. In addition, it points out some interesting chemosystematic relations within the family.

HPLC-DAD-ESI-MS/MS screening of phytochemical compounds and the bioactive properties of different plant parts of Zizyphus lotus (L.) Desf.

Zizyphus lotus L. (Desf.) has been widely used as a homemade ingredient to treat numerous diseases in Algerian folk medicine. In this context, decoction, infusion and hydroethanolic extracts were prepared from the branches, leaves, roots, and stem barks. The extracts were characterized regarding their phytochemical composition by HPLC-DAD-ESI/MSn and were assessed for in vitro bioactivity (cytotoxicity, anti-inflammatory activity, and antibacterial activity). A total of 29 compounds (flavonoid derivatives and secoiridoids) were identified in Z. lotus, 15 being detected in leaves, 10 in branches, 5 in roots and 7 in stem barks. The highest contents of these compounds, especially secoiridoids, were detected in branches followed by leaves, oleuropein being the main compound detected in leaves and oleoside in branches. The aqueous preparations of the leaves and root barks revealed the highest cytotoxicity and anti-inflammatory potential. On the other hand, as for the antibacterial activity, the hydroethanolic extract of the branches showed the highest potential, especially against the MSSA strain. Hence, the chemical diversity found in Z. lotus makes it a source of bioactive ingredients that can be applied in the formulations of different ingredients in the food and pharmaceutical industries.

Phytochemical profiles, antioxidant and anti-acetylcholinesterasic activities of the leaf extracts of Rhamnus lycioides subsp. oleoides (L.) Jahand. & Maire in different solvents.

In this work, the extracts obtained with different solvents from the leaves of Rhamnus lycioides subsp. oleoides (L.) Jahand. & Maire were studied for their phytochemical profile and then for their antioxidant and acetylcholinesterase inhibitory activities. The phytochemical profiles of the extracts in n-hexane, dichloromethane, ethyl acetate, methanol, anthraquinone rich and water, showed the presence of different compounds belonging to several classes of natural products such as flavonoids, anthraquinones, saccharides and fatty acids. For what concerns the biological tests, the ethyl acetate, methanol and anthraquinone rich extracts showed the highest activities in both assays due to the high amount of compounds possessing those properties such as flavonoids and anthraquinones. By consequence, these specific extracts of the species may be considered to be potential sources of natural antioxidant and anti-acetylcholinesterasic compounds.

Detailed phytochemical characterization and bioactive properties of Myrtus nivelii Batt & Trab.

The endemic Algerian myrtle, Myrtus nivelii Batt & Trab., was evaluated for its bioactive properties, such as antioxidant, anti-inflammatory, cytotoxic and antibacterial activities, and correlated with the individual phenolic compounds identified in its crude aqueous extract and subsequent organic fractions (ethyl acetate and butanol). Flavonols, such as myricetin, kaempferol and quercetin glycoside derivatives, were the major phenolic compounds found, along with the presence of ellagitannins. The ethyl acetate fraction contained the highest amount of phenolic compounds, followed by the butanol fraction and, finally, the crude aqueous extract. In general, all samples exhibited an excellent bioactivity, namely the ethyl acetate fraction that presented strong antioxidant activity, when compared to the standard trolox, strong cytotoxicity and antibacterial activity, especially against MRSA and MSSA. The present study revealed that the ethyl acetate fraction of M. nivelii could be used as a source of bioactive compounds in the food and pharmaceutical industries.

Acetylcholinesterase inhibitory activity of pyrrolizidine alkaloids from Echium confusum Coincy.

Four pyrrolizidine alkaloids, namely 7-O-angeloyllycopsamine N-oxide 1, echimidine N-oxide 2, echimidine 3 and 7-O-angeloylretronecine 4, were isolated for the first time from the whole plant ethanolic extract of Echium confusum Coincy, through bioassay-guided approach. Their structures were determined by spectroscopic means. All the isolates compounds showed moderate activities in inhibiting AChE, with IC50 0.276-0.769.

Pyrrolizidine alkaloids from Solenanthus lanatus DC. with acetylcholinesterase inhibitory activity.

The whole plant ethanolic extract of Solenanthus lanatus was used for the isolation of acetylcholinesterase inhibitors. A new pyrrolizidine alkaloid, 7-O-angeloylechinatine N-oxide, 1, was isolated together with three known compounds of the same class (3'-O-acetylheliosupine N-oxide, 2, heliosupine N-oxide, 3, and heliosupine, 4), by bioassay-guided approach. Their structures were elucidated by spectroscopic methods. All the isolated compounds showed inhibition activity against the AChE, with IC50 0.53-0.60 mM.

Antifungal activity and phytochemical screening of extracts from Phoenix dactylifera L. cultivars.

In this study, the rachis extracts of eight date palm Phoenix dactylifera L. cultivars were analysed by phytochemical screening and bioautography on Fusarium oxysporum f. sp. albedinis (Foa). The choice of cultivars was based on their reaction to Foa (resistant, tolerant and sensitive). Phytochemical screening was realised for flavonoids, tannins, alkaloids and coumarins. Antifungal effects were mostly represented by dichloromethanic extracts (seven out of nine inhibition zones). The best results were represented by the dichloromethanic extract of the cultivar 'Bent-Cherk' rachis (6.50 ± 1.41 mm) and the ethyl acetate extract of the cultivar 'Rotbi' rachis (6.00 ± 1.41 mm). The date palm cultivars presented some similarities concerning phytochemical screening results related to their resistance or sensibility to Foa. From the correlation between phytochemical screening and bioautography, it was observed that the majority of bioactive compounds against Foa seem to be polyphenols. Thus, the natural defence mechanism in vivo against Foa is probably related to the action of polyphenols. The difference between resistant, tolerant and sensitive cultivars is related to their mechanism of action.