Mass Spectrometry is an important tool for the identification and structural elucidation of natural products. A review of the last fifteen years of research in this field, applied to natural glycosides, is presented.
The n-butanol fraction (BF) obtained from the crude extract of the marine sponge Petromica citrina, the halistanol-enriched fraction (TSH fraction), and the isolated compounds halistanol sulfate (1) and halistanol sulfate C (2), were evaluated for their inhibitory effects on the replication of the Herpes Simplex Virus type 1 (HSV-1, KOS strain) by the viral… (More)
A screening of metabolites guided by antimicrobial and citotoxic bioassays was conducted with several fungi. The bioactive compounds were isolated and identified from the active extracts.
In this article, we describe the synthesis of a small library of short peptoids composed of four glycine residues and acylated with a fatty acid that showed a remarkable in vitro activity against two fungal plant pathogens. Their straightforward synthesis implied two consecutive Ugi reactions and can be efficiently extended to the construction of highly… (More)
Alternaria spp. have been reported to be the most frequent phytopathogenic fungi invading tomatoes. Certain species are capable of producing several mycotoxins in infected plants and in agricultural commodities. AAL toxins are produced by Alternaria arborescens, which is the causal agent of tomato stem canker, and one of the species involved in the tomato… (More)
Most sterols, such as cholesterol and ergosterol, become functional only after the removal of the two methyl groups at C-4 from their biosynthetic precursors. Nevertheless, some findings suggest that 4,4-dimethyl sterols might be involved in specific physiological processes. In this paper we present the synthesis of a collection of analogues of 4,4-dimethyl… (More)
Five new polyoxygenated marine steroids-punicinols A-E (1-5)-were isolated from the gorgonian Leptogorgia punicea and characterized by spectroscopic methods (IR, MS, 1H, 13C and 2-D NMR). The five compounds induced in vitro cytotoxic effects against lung cancer A549 cells, while punicinols A and B were the most active, with IC50 values of 9.7 μM and 9.6 μM,… (More)
Six analogues of salpichrolides with a simplified side chain (6-11) were synthesized using a new methodology to obtain steroids with an aromatic D-ring. The key step was the elimination of HBr in a vicinal dibromo D-homosteroid by treatment with 1,4-diazabicyclo[2.2.2]octane (DABCO). All new compounds were completely characterized by 2D NMR techniques and… (More)
In this paper we report the synthesis of a new family of sterol analogues that have two amidic bonds on the side chain. These azasterols were obtained by a straightforward procedure including an Ugi condensation that allows the facile attachment of a polyfunctionalized side chain into the steroidal framework. Some of the new compounds showed an interesting… (More)