Chemotaxonomic Study of the Covid-Organics of Madagascar Based on the Chemical Composition of Their Essential Oils

The aim of this study was to investigate the chemical composition of the essential oils of “Covid-Organics” of Madagascar (62% Artemisia annua and two other undisclosed medicinal plants) used as curative and preventive treatments of Covid-19, to identify its constituent species. The essential oils isolated by hydro-distillation from two samples (curative and preventive) were analyzed by GC-FID and GC-MS. These essential oils (curative and preventive) were mainly dominated by camphor (17.9% and 11.9%, respectively), spathulenol (4.8% and 11.8%, respectively), α-acorenol (4.3% and 3.7%, respectively), (E)-β-caryophyllene (3.4% and 4.2%, respectively), 1,8-cineole (3.1% and 3.6%, respectively), hexadecanoïc acid (3.8% and 3.2%, respectively) and caryophyllene oxide (3.4% and 2.4%, respectively). From the chemical composition, two species were identified, A. annua characterised by camphor and Cinnamomumcamphora (Ravintsara) characterised by 1,8-cineole and sabinene. However, we were unable to identify the third species.

The Phenols of the Genus <i>Agave</i>(Agavaceae)

A review is presented about the studies that have been carried out on the phenolic composition of the species of the genus Agave in order to show which species of the genus has been analyzed, what is the potential of the species of Agave as source of phenolics with important biological activities, and what is the significance of the phenolic profiles as chemotaxonomic markers in the genus. The results of the analysis of a dozen of Agave species reveal an important richness of phenolic compounds, including flavonoids, homoisoflavonoids, and phenolic acids, and a broad diversity of biological activities associated to those compounds, as antioxidant, antibacterial, antifungal, antinematod, and immunomodulatory capabilities. The phenols of Agave also have a major potential as specific chemotaxonomic markers.

Constituents from leaves of Macaranga hemsleyana

Objective:To study constituents of the leaves of Macaranga hemsleyana,and evaluate their inhibitory effects against NOD-like receptor thermal protein domain associated protein 3(NLRP3)inflammasome activation,and antiproliferative activity.Methods:The constituents were isolated and purified by column chromatography on MCI gel CHP20P/P120,silica gel,Sephadex LH-20,and HPLC.The structures of compounds were determined by 1D,2D NMR,and HR-ESI-MS data.The inhibitory effect of compounds on inflammasome activation was determined by lactate dehydrogenase(LDH)procedure.The antiproliferative activity was evaluated using MTT assay.Results:The study led to the isolation of 23 compounds,including one new compound,identified as(2Z)-3-[4-(β-D-glucopyranosyloxy)-2′-hydroxy-5′-methoxyphenyl]-2-propenoic acid(1),together with 22 known compounds recognized as 1,4-dihydro-4-oxo-3-pyridinecarbonitrile(2),methyl 4-methoxynicotinate(3),4-methoxynicotinonitrile(4),1-(3-O-β-D-glucopyranosyl-4,5-dihydroxyphenyl)-ethanone(5),neoisoastilbin(6),isoastilbin(7),aromadendrin(8),neoastilbin(9),astilbin(10),quercitrin(11),neoschaftoside(12),apigenin 6,8-bis-C-α-L-arabinoside(13),vitexin(14),bergenin(15),scopoletin(16),glucopyranoside salicyl(17),koaburside(18),benzylβ-D-glucoside(19),icariside B5(20),roseoside(21),loliolide(22),and adenosine(23).The tested compounds did not show LDH inhibition nor antiproliferative activity.Conclusion:Compound 1 was a new glycoside.Compounds 2 and 3 were obtained for the first time from natural source.The 22 known compounds constituted of alkaloids(2–4,23),phenolics(5,15,17,18),flavonoids(6–14),coumarin(16),benzyl glycoside(19),and norsesquiterpenes(20–22).All the compounds,1–23,were revealed from M.hemsleyana for the first time.This is the initial uncovering of molecules 1–10,12,13,17–19,and 23 from the genus Macaranga.The isolated compounds,11,14–16,and 20–22 established taxonomic classification of M.hemsleyana in Euphorbiaceae family.Flavonoids were outstanding as chemosystematic markers of Macaranga genus.