Bithiophenic MALDI matrices as valuable leads for the selective detection of alkaloids.

Alkaloids represent a group of biologically most interesting compounds commonly used in modern medicines but also known for exhibiting severe toxic effects. Therefore, the detection of alkaloids is an important issue in quality control of plants, dietary supplements, and herbal pharmaceutical and mostly facilitated by methods such as GC or LC-MS. However, benefitting from the development of selective matrices as well as requiring very little sample preparation, MALDI-MS may also provide a valuable supplement to these standard analytical methods. With this in mind, the present study highlights recent advances in the development of bithiophenic matrix molecules designed for the selective detection of alkaloids. Overall four new bithiophenic matrix molecules (BMs) were tested on different analytes belonging to various chemical families such as alkaloids, curcuminoids, benzopyrones, flavonoids, steroids, and peptides (I). All BMs were further compared to the commercial matrices α-cyano-4-hydroxycinnamic acid (CHCA) and 2,5-dihydroxybenzoic acid (DHB) in terms of their signal response as well as their matrix noise formation (II). Based on these results the most promising candidate, 3-(5'-pentafluorophenylmethylsulfanyl-[2,2']bithiophenyl-5-ylsulfanyl)propionitrile (PFPT3P), was tested on highly complex samples such as the crude extracts of Colchicum autumnale, RYTMOPASC ® solution (a herbal pharmaceutical containing sparteine and rubijervine), as well as strychnine-spiked human plasma (III). For the latter, an evaluation of the limit of detection was performed. Eventually, a simplified protocol for the direct MALDI detection of major alkaloids from pulverized plant material of Atropa belladonna and Senecio vulgaris is presented (IV). Graphical abstract Selective MALDI MATRICES for Alkaloid Detection.

Chemical Composition, Antioxidant and Cytotoxic Activities of Roots and Fruits of Berberis libanotica.

Fourteen compounds belonging to different chemical classes were characterized in the roots and fruits extracts from Berberis libanotica, using the same HPLC-DAD-MS method. Thirteen were reported, for the first time, from the fruits whereas the roots contained mostly alkaloids of which 3 out of 5 are reported for the first time. Their structures were established on the basis of MS data as gallic acid (1), chlorogenic acid (2), delphinidin (3), oxyacanthine (4), rutin (5), hyperoside (6), berbamine (7), isoquercitrin (8), quercitrin (9), jatrorrhizine (10), palmatine (11), berberine (12), quercetin (13) and luteolin (14). Extracts containing compounds 4 and 7 showed significant cytotoxicity against the HT29 cell line with an IC50 of 12.2-26.1 µg/mL. Fruits extracts, due mostly to compounds 1 and 2, showed potent antioxidant activities with an EC50 of 0.0025-0.019 mg/mL.

Alternative and complementary antileishmanial treatments: assessment of the antileishmanial activity of 27 Lebanese plants, including 11 endemic species.

Aqueous, methanolic, and dichloromethane extracts from 27 Lebanese plants were investigated for their in vitro immunomodulatory and antileishmanial activities as compared to their toxicity against human cells. Extracts from yellow chamomile (Anthemis tinctoria), white larkspur (Consolida rigida), Syrian broom (Cytisus syriacus), coast spurge (Euphorbia paralias), shield fibigia (Fibigia clypeata), Auchers golden-drop (Onosma aucheriana), shell-flower sage (Salvia multicaulis), snowy woundwort (Stachys nivea), Palestine woundwort (Stachys palaestina), and polium-leaved speedwell (Veronica polifolia) exhibited interesting antileishmanial activities on the intracellular amastigote form of the parasite, while several extracts from A. tinctoria, F. clypeata, and O. aucheriana were shown to induce nitrous oxide (NO) production by human macrophages. Further experiments should be performed in order to purify and characterize the chemical compounds responsible for these activities.

Daucane sesquiterpenes from Ferula hermonis.

The dried roots of Ferula hermonis yielded three new daucanes, (1R,4R)-4-hydroxydauca-7-ene-6-one (1), (1R,4R)-4-hydroxydauca-7-ene-6,9-dione (2), and (1R,3S,8S)-3-ethoxy-8-angeloyloxydauca-4-en-9-one (3), together with the three known sesquiterpenes, ferutinin, teferidin, and (+)-alpha-bisabolol. The structures of compounds 1-3 were elucidated on the basis of spectroscopic evidence. The effect of these compounds on the proliferation of estrogen-dependent MCF-7 cells was evaluated, and it was found that compounds 1 and 3 exhibited proliferative activity, whereas 2 showed an antiproliferative effect.