Alejandro Barrero

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From a marine-derived strain of the fungus Emericella variecolor, varitriol (1), varioxirane (2), dihydroterrein (3), and varixanthone (4), besides the known mold metabolites ergosterol, terrein, shamixanthone, and tajixanthone hydrate, were identified. The chemical structures of 1-4 were established by means of spectroscopic techniques and some chemical(More)
Puupehenone, a sesquiterpene produced by certain sponges, was selected in the course of a blind screening for new potential inhibitors of angiogenesis. In our study, we compare the potential anti-angiogenic activities of puupehenone and another 11 related compounds that were either natural products from marine origin or their synthetic derivatives. The(More)
Six new diterpenic acids isolated as their methyl ester derivatives, i.e., methyl 12-oxo-8alpha,15-dihydroxyabiet-13-en-19-oate, methyl 12-oxo-8alpha-hydroxyabiet-13-en-19-oate, methyl 15-hydroperoxy-8alpha,12alpha-epidioxiabiet-13-en-19-oate, methyl 15-hydroxy-8alpha,12alpha-epidioxiabiet-13-en-19-oate, methyl(More)
In the search for novel bioactive products from filamentous fungi, sterols and triterpenoids found in Phycomyces blakesleeanus were analyzed using semipreparative HPLC, GC-MS, and NMR techniques. Structures proposed for the three new compounds identified, phycomysterol A (1), phycomysterol B (2), and neoergosterol (3), were confirmed by chemical synthesis.(More)
In the search for new sources of sesquiterpene lactones, six Centaurea species have been analyzed. The activity against the fungus Cunninghamella echinulata of (+)-cnicin (1) and (+)-salonitenolide (2), isolated from the Centaurea plants, as well as that of (+)-costunolide (3), (-)-dehydrocostuslactone (4), (-)-lychnopholide (5) and (-)-eremantholide C (6),(More)
The aerial parts of Anvillea radiata yielded a new germacranolide, 8alpha,9alpha-epoxyparthenolide (3), together with two known compounds, 9alpha-hydroxyparthenolide (1) and parthenolid-9-one (2). The structures of the compounds were elucidated from IR, HRMS, 1H and 13C-NMR, COSY, HETCOR, HMBC and HOHAHA spectral data. The major component 1 was tested for(More)
As a result of a combined theoretical and experimental study, we describe a two-step protocol for the preparation of an optically pure, multifunctional, cyclopentanic core shared by a number of natural products. This process is based on a hitherto unreported Ti(III)-mediated diastereoselective cyclization in which the hydroxy-directed template effect played(More)
Abst rac t -From the chloroform extract of the wood of Abies rnarocana, consisting mainly of lignans, the acetoxyl derivatives of the new sesquilignans, 4,4",7",9,9"-pentahydroxy-3,3',3"-trimethoxy-4',8":7,9'-bis-epoxy-8,8'-sesquineolignan and 4•4"•7"•9•9'•9"-hexahydr•xy-3•3'•3••-trimeth•xy-4'•8"-ep•xy-8•8'-sesquine••ignan were isolated; the trivial names,(More)
Highly efficient preparations of anticancer β-elemene and other bioactive elemanes were carried out using the natural product germacrone as a renewable starting material. The syntheses were achieved in only 3-5 steps with excellent overall yields (43-54%). An enantioselective approach to these molecules is also described.