The chemical study of the ascidian Aplidium haouarianum has led to the isolation of the new metabolites haouamines A (1) and B (2) which belong to a novel class of alkaloids. The structure of 1 was established by interpretation of its spectroscopic data and those of the N-methyl derivative 3, and confirmed by X-ray crystallographic analysis. The structure of 2 was deduced by spectroscopic study of its peracetyl derivative 2a. In solution each haouamine exists as an unseparable mixture of two interconverting isomers derived by the presence of a highly strained 3-aza-[7]-paracyclophane moiety in their structures. Compound 1 exhibits a selective cytotoxic activity against the HT-29 human colon carcinoma cell line.
The sponge Spongia agaricina from Tarifa, Cadiz, Spain, contains two new 9,11-secosterols, [3-0-deacetylluffasterol B (1) and 3-0-deacetyl-22,23-dihydro-24,28-dehydroluffasterol B (2)] and two new sesterterpenoids [12,16-di-epi-12-0-deacetyl-16-0-acetylfuroscalarol (3) and 16-epi-scalarolbutenolide (4)], in addition to the known compounds 5-15. The structures of all compounds were elucidated by interpretation of' spectroscopic data. The metabolites 1-3 showed significant cytotoxicity against four tumor cell lines (C50 1 microgram/mL).
The allylic hydroxylation of enones using dioxygen as the oxidant has been studied. The reaction was first examined in the absence of any catalyst, using β-ionone as a model substrate. Then a new copper-aluminium mixed oxide, Cu-Al Ox, was prepared and characterized in order to be used as a catalyst. This oxide showed good activity, and provided the corresponding γor ε-hydroxylated enones, starting from different α,βor α,β,γ,δ-unsaturated ketones. In all cases, the [a]
The sponge Cacospongia scalaris from Tarifa Island,
Spain, contains in addition to five known
compounds (1−5), the new scalarane
sestertepenes 18-epi-scalaradial (6),
19-dihydroscalaradial
(7), 12-epi-acetylscalarolide (8), and
16-acetylfuroscalarol (9) together with three
uncommon
norscalaranes norscalaral A (10), norscalaral B
(11), and norscalaral C (12). The structures
were
elucidated by interpretation of spectral data.
18-epi-Scalaradial (6) represents the
missing
stereoisomer on structure−activity studies carried out with compounds
of this series and did not
react with methylamine. The new compounds isolated from C.
scalaris showed significant in vitro
cytotoxicity against five tumor cell lines with
18-epi-scalaradial showing the greatest activity
(ED50
= 0.2 μg/mL).
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