Chemical Constituents Isolated from the Leaves of Toricellia angulata Oliv. var. intermedia (Harms.) Hu

In our survey on the chemical composition of Chinese folk medicines, nine compounds were isolated from methanol extract of the leaves of Toricellia angulata Oliv. var. intermedia (Harms.) Hu (Corniaceae). The structures of these compounds were elucidated on the basis of NMR data analysis, which were identified as dimethyl 2-(hydroxymethyl)-5-oxocyclohexane-1,4-dicarboxylate (1), methyl succinate (2), 5-hydroxymethyl-2-furfuraldehyde (3), 7-hydroxy-6-methoxycoumarin (4), loliolide (5), (8 S)-deca-2-trans-2,9-diene-4,6-diyn-1,8-diol (6), methyl malate (7), griselinoside (8), and methyl linoleate (9), respectively. Among them, compound 1 is a new cyclohexanone derivative and given a trivial name torriangulate A, while others are categorized to be organic acids (2, 7, and 9), a coumarin derivative (4), a terpene lactone (5), a polyacetylene (6), and an iridoid glycoside (8). Compounds 3–5 were isolated from this genus for the first time and compound 9 was first identified from this species. The discovered compounds with novel or known structures further reveal the chemical basis of T. angulata var . intermedia, which lays a foundation for the development of T. angulata var . intermedia used as a traditionally folk medicine.

Nitrogenous Compounds Produced by the Deep Sea Derived Fungus Leptosphaeria sp. SCSIO 41005

Four nitrogenous compounds, including two new compounds methyl-4-((1-hydroxy-3-methylpentan-2-yl)amino)–3-methyl-4-oxobutanoate (1), 4-((1-acetoxy-3-methylpentan-2-yl)amino)–3-methyl-4-oxobutanoic acid (2), and two amino acid derivatives (3, 4), were isolated from the deep sea derived fungus Leptosphaeria sp. SCSIO 41005, together with a cyclohexanone derivative (5) as new natural compound and other three known compounds (6–8). Their structures were elucidated by means of comprehensive 1D, 2D NMR and HR-ESI-MS spectroscopic methods. All the compounds were evaluated for their cytotoxic and antiviral activities.

β Elimination of a phosphonate group from an alkoxyl radical — Intramolecular acylation using acylphosphonate derivatives as carbonyl group acceptors

The possibility of β elimination of a phosphonate group in radical reactions was studied. The facile β elimination of the phosphonate group from an alkoxyl radical was observed for the first time, whereas the β elimination of the phosphonate group from an aminyl and an alkyl radical did not occur. On the basis of our findings, the use of an acylphosphonate as a carbonyl group radical acceptor was investigated. Radical cyclization of the acylphosphonate in the presence of hexamethylditin in benzene at 300 nm for 2 h gave a cyclopentanone or a cyclohexanone derivative in good yield without the formation of a direct reduction product. The reaction can be carried out in the presence of a catalytic amount of hexamethylditin (0.2 equiv.) under similar conditions. In addition, an alkyl phosphonothiolformate group can act as an alkylthiocarbonyl group equivalent radical acceptor, providing ready access to a thiolactone synthesis.Key words: radical, β elimination, acylation, cyclization, acylphosphonate.

Notizen: Reactions of Harmaline and its Derivatives, V A one-Step Synthesis of Reserpine Analogues

The reaction of harmaline with the cyclohexanone derivative (4) affords the reserpine analogue (5) in high yields, thus providing a one step approach to such pharmacologically important substances.