Antonio Guerriero

Parthenolide and its photochemically synthesized 1(10)Z isomer: chemical reactivity and structure–activity relationship studies in human leucocyte chemotaxis

The present study has achieved the photochemical conversion of a germacrolide into a melampolide. The investigation on their chemical properties allowed us to evaluate the minimum interatomic distance needed for transannular bridging of C(10) ring in germacrolides and to explain the regiochemical selectivity of electrophilic cyclizations. The antiinflammatory activity of parthenolide and its semisynthetic derivatives was evaluated by in vitro chemotaxis assay with human neutrophiles. These structure-activity relationship studies have led to hypothesize a new pharmacophore and have provided useful information for computationally designed drugs.

Degraded limonoids from Melia azedarach and biogenetic implications

The roots of Melia azedarach yielded three new degraded limonoids: teracrylmelazolide A, melazolide A and teracrylmelazolide B, possessing a previously undescribed skeleton. The known pyroangolensolide, fraxinellone and its three derivatives, 30-hydroxyfraxinellone, 9 alpha- and 9 beta-hydroxyfraxinellone, were also isolated. Their stereochemisty was elucidated on the basis of spectral data and chemical reactions.

Epinardins A-D, new pyrroloiminoquinone alkaloids of undetermined deep-water green demosponges from pre-Antarctic Indian ocean

Abstract Four novel pyrroloiminoquinone alkaloids that differ from members of the discorhabdin/prianosin family for having an allylic alcohol functionality in place of the enone system, epinardins A-D (8–11), have been isolated from undetermined deep-water green demosponges collected in pre-Antarctic waters near the Crozet Islands. Relative stereochemistry has been fully assigned from high-field NMR spectra. Epinardin C (10) proved strongly cytotoxic towards doxorubicin-resistant L1210/DX tumoural cells in vitro.

Agelastatin a, a new skeleton cytotoxic alkaloid of the oroidin family. Isolation from the axinellid sponge Agelas dendromorpha of the coral sea

Agelastatin A, isolated from the axinellid sponge Agelas dendromorpha of the Coral Sea, is a new-skeleton alkaloid with, unusually for the oroidin family to which it belongs, marked cytotoxicity toward tumour cells in culture.

Cavernicolin-1 and cavernicolin-2, epimeric dibromolactams from the mediterranean sponge aplysina (venongia) cavernicola

Abstract Cavernicolin-1 and Cavernicolin-2, two epimeric compounds having a γ-lactam ring fused to a dibromocyclohexenone ring, have been isolated from the Mediterranean sponge Aplysina (Verongia) cavernicola .

Penlanfuran, a new furanoid sesquiterpene from the marine sponge dysideafragilis (mont.) of Brittany. A striking difference with the same Hawaiian species.

Abstract Penlanfuran ( 2 ), a furanoid sesquiterpene with a novel skeleton for sponge products, has been afforded by the marine sponge Dysidea fragilis (Mont.) of Brittany; the same Hawaiian species gave different sesquiterpenoids.

A new, unexpected marine source of a molting hormone. Isolation of ecdysterone in large amounts from the zoanthidGerardia savaglia

Ecdysterone was found in large amounts in the Mediterranean zoanthidGerardia savaglia both immediately after its collection and after it had been kept for 15 months in an aquarium. This is the first time that an ecdysteroid has been found in a marine animal which does not belong to the phylum Arthropoda.

A butenolide atypical of the Ranunculaceae: aquilegiolide from Aquilegia atrata (var. Atroviolacea)

Abstract Roots of Aquilegia atrata have afforded 6β-hydroxy-2(6,7-dihydro-7aβH)-benzofuranone (aquilegiolide) and its 7aαH-isomer, or their enantiomers, two butenolides atypical of the Ranunculaceae. Hot aqueous 20 % sulphuric acid rapidly equilibrates the two isomers in a 1:4 ratio.

On the first marine natural product having low enantiomeric purity

Resulting from enzymatic reactions, natural products are the standard of reference for high optical purity. In fact, natural products commonly reveal specific rotations from polarimetric measurements. The few cases of racemic natural products and, particularly, the rare cases of quasi-racemic natural products [1] are of special biological interest. Therefore, we are pleased to be able to report on the first case of a marine natural product (monobromocavernicolin, 1) with low enantiomeric purity. These results were obtained after a number of unsuccessful attempts to clarify the origin of small optical rotations with 3 and its C-2-epimer [2], all these products coming from the sponge Aplysina cavernicola.

Aztèquynol A, the first clearly defined, C-branched polyacetylene and the analogue Aztèquynol B. Isolation from the tropical marine sponge Petrosia sp.

Abstract Aztequynol A ( 1 ), isolated from the nepheliospongid sponge, Petrosia sp., from the Banc Azteque off New Caledonia, represents the first case of a structurally defined C-branched polyacetylene based on high-energy collisionally-activated decomposition tandem mass spectrometry of lithium adducts which may have wide application in natural product structural analysis.