Minor sesquiterpenes from the volatile oil from leaves of Guarea guidonia Sleumer (Meliaceae).

The essential oil from leaves of Guarea guidonia was subjected to chromatographic separation procedures to afford nine sesquiterpenes; two of them are new eudesmane derivatives. The chemical structures of the obtained compounds were characterised by spectrometric analysis, mainly mass spectrometry and NMR.

New (9betaH)-lanostanes and lanostanes from Mikania aff. jeffreyi (Asteraceae).

Four new (9betaH)-lanostanes, i.e., (9betaH)-3beta-acetoxylanosta-7,24-diene, (9betaH)-3-oxolanosta-7,24-diene, (9betaH,24R)-3beta-acetoxy-24-hydroxylanosta-7,25-diene, and (9betaH,24S)-3beta-acetoxy-24-hydroxylanosta-7,25-diene, two new lanostanes, i.

Effects of the flavonoid casticin from Brazilian Croton betulaster in cerebral cortical progenitors in vitro: direct and indirect action through astrocytes.

Neurodegenerative diseases are a major constraint on the social and economic development of many countries. Evidence has suggested that phytochemicals have an impact on brain pathology; however, both their mechanisms of action and their cell targets are incompletely known. Here, we investigated the effects of the flavonoid casticin, extracted from Croton betulaster, a common plant in the state of Bahia in Brazil, on rat cerebral cortex neurons in vitro.

Aldingenin derivatives from the red alga Laurencia aldingensis.

Three brominated bisabolene-type sesquiterpene derivatives, aldingenin B, C and D, together with cholesterol and palmitic acid, have been isolated from the red alga Laurencia aldingensis (Ceramiales, Rodophyta) and their structures elucidated by spectroscopic methods including NMR analysis.

Volatile oil from Guarea macrophylla ssp. tuberculata: seasonal variation and electroantennographic detection by Hypsipyla grandella.

GC and GC-MS analyses of the volatile oils from Guarea macrophylla (Meliaceae) collected during three different periods in one year (February, June and October) indicated a seasonal variation in chemical composition. Whilst sesquiterpenes were the predominant class of components present in the leaf oil, a seasonal dependent variation in the degree of oxygenation of these compounds was detected, which seemed to be associated with phenological factors. The leaf oil, and fractions thereof, were subjected to GC coupled with electroantennographic detection employing antennae of females of Hypsipyla grandella, an insect pest that attacks several meliaceous species.

Sesquiterpene lactone from Wunderlichia crulsiana inhibits the respiratory burst of leukocytes triggered by distinct biochemical pathways.

The sesquiterpene lactone tubiferin was chemically purified from the brazilian native plant Wunderlichia crulsiana and identified by NMR and GC/MS data. Its ability to inhibit the respiratory burst of peritoneal inflammatory polymorphonuclear leukocytes (PMN) stimulated upon addition of phorbol miristate acetate (PMA), opsonized zymosan (OZ), and N-formyl-methionyl-leucyl-phenylalanine (fMLP) was evaluated. The tubiferin inhibition was more pronounced when PMN were stimulated through the protein kinase C pathway (PMA) compared to the alternative complement pathway (OZ).

Terpenoids from Guarea guidonia.

The volatile oil and the methanol extract from the leaves of Guarea guidonia, Meliaceae, were individually submitted to chromatographic separation. A sesquiterpene (2S*)-eudesma-5,7-dien-2-ol, together with six known ones, were isolated from the volatile oil. The methanolic extract afforded two known and two new triterpenes (23S*)-cycloart-24-ene-3 beta,23-diol and (23R*)-cycloart-24-ene-3 beta,23-diol, besides three known sesquiterpenes, one known diterpene and two steroids.

Cycloartane triterpenoids from Guarea macrophylla.

Nine cycloartane triterpenoids, including two new derivatives 22,25-dihydroxy-cycloart-23E-en-3-one and 24-methylenecycloartane-3 beta,22-diol have been isolated from leaves of Guarea macrophylla. The structures were elucidated by interpretation of spectral data, mainly 1H and 13C NMR, including bidimensional analysis (HOMOCOSY, HMQC and HMBC).