Browsing by Author "Noronha, J.P."
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- A new dihydroxysterol from the marine phytoplankton Diacronema sp.Publication . Rauter, A. P.; Filipe, M.M.; Prata, C.; Noronha, J.P.; Sampayo, M.A.M.; Justino, Jorge; Bermejo, J.Diacronema sp. was cultured and its sterols were separated by column chromatography on silica gel. The new sterol 24-ethyl-4α-methyl-cholestane-3,20-diol (1) was characterised by NMR and MS spectrometry, as well as (22E)-24-ethyl-4α-methyl-5α-cholest-22-en-3β-ol (2) and β-sitosterol, the major components of the sterol fractions. Neither the biosynthetic origin of the new dihydroxysterol nor its role in the biochemistry of Diacronema is known.
- A novel pentacyclic triterpene from Leontodon filiiPublication . Tostão, Z.; Noronha, J.P.; Cabrita, E.J.; Medeiros, J.; Justino, Jorge; Bermejo, J.; Rauter, A. P.A novel oleanene triterpenetetrol was isolated from the chloroform extract of the aerial parts of Leontodon filii. Its structure was shown to be 2β,3β,15α,21β-olean-12-ene-2,3,15,21-tetrol by chemical and spectroscopic methods. The fungicidal efficacy of the chloroform and methanol extracts of the plant was also evaluated, a protective effect being found against Plasmopara viticola, Botrytis cinerea, particularly powerful against Pyricularia oryzae.