Separation and characterization of phenolic compounds from Terminalia ivoiriensis using liquid chromatography-positive electrospray ionization tandem mass spectroscopy

Terminalia ivoriensis A. Chev. (Combretaceae) is an Ivorian medicinal plant. There is little ethnobotanical and almost no chemical information available for this species. The aim of this study was to isolate phenolic compounds from T. ivoriensis. In this way, its ethyl acetate extract (Ea) was fractionated by silica gel column chromatography followed by Sephadex LH20 filtration. Elution solvents were methanol (MeOH), methylene chloride (Mc) and ethyl acetate (EtOAc). Analysis of the obtained fractions (F1-F4) by liquid chromatography coupled to positive electro-spray ionization tandem mass spectrometry (LC-ESI-MS/MS) afforded six known polyphenols: 1) 3,3'-di-O-methylellagic acid); 2) 3,7,8-tri-O-methylellagic acid; 3) Progallin A; 4) 3,3',4-O-Trimethyl-4'-O-β-Dglucopyranosylellagic acid; 5) Punicalagin and, 6) Punicalin. All these natural products were isolated here for the first time from this plant. They presented various biological activities among which were anti-inflammatory, antioxidant and anti-HIV activities.Keywords: Terminalia, ivoriensis, LC-ESI-MS, isolation, characterization, polyphenols, activity, antiinflammatory, antioxidant, anti-HIV.African Journal of Biotechnology Vol. 12(27), pp. 4393-439

Use of the Nosyl Group as a Functional Protecting Group in Applications of a Michael/Smiles Tandem Process

Concise preparations of elaborated polycyclic and heterocyclic systems present in natural products were obtained using the nosyl group as a functional protecting group not only to mask the reactivity of a sensitive moiety but also to provide a structure desired in the final target. The group is transferred to the substrate during deprotection through a novel extension of the Truce–Smiles rearrangement in tandem with a 1,4-addition. This strategy provides access to a ring system laden with valuable functionalities for subsequent manipulations and can serve as a versatile building block for the construction of more complex molecular architectures such as indoles in a manner compatible with the concepts of green chemistry and atom economy

A Stereoselective Arylative-Cyclopropanation Process

A new stereoselective arylative cyclopropanation process involving treatment of halogenated dienone systems in the presence of a Michael donor containing a nitro-aryl-sulfone has been developed. This transformation enables production of an arylated cyclopropane under mild conditions and occurs via a Michael–Smiles ring closure cascade process, reflecting the concepts of green chemistry and atom economy

Carbon–Phosphorus Bond Formation on Anilines Mediated by a Hypervalent Iodine Reagent

Substituted anilines containing a sulfonyl group may be oxidized in situ in the presence of methanol and a hypervalent iodine reagent to form an active iminium species. Subsequent addition of phosphines or phosphites in the same pot produces <i>meta</i>-substituted anilines in good yields. This formal C–H bond functionalization is a direct and efficient means of selectively substituting the <i>meta</i>-position of anilines to produce aromatic phosphonium ions or phosphonates

Design and synthesis of new tricyclic quinoline derivatives from intramolecular cyclization of benzylidene malonic derivatives

879-883Quinolines are very important compounds due to their numerous biological and pharmacological applications. This article describes the synthesis of new tricyclic quinoline derivatives via intramolecular cyclization of malonic benzylidene derivatives. The malonic benzylidene derivatives 2a-c have been obtained by condensation of N-substituted aldehydes 1a-c with malononitrile or ethyl cyanoacetate. These latter have been cyclized by reflux in DMF to give the compounds 3a-f. The structures of the compounds have been determined by 1 H and 13C NMR spectroscopy, and High-Resolution Mass Spectrometry (HRMS) analysis. Two of the synthesized compounds have been identified and confirmed by X-ray crystallography