Composition of American distilled tall oils

Anti-neuroinflammatory diterpenoids from the endangered conifer Podocarpus imbricatus

Ten diterpenoids including three new abietanes (1-3) were isolated from the twigs and needles of Podocarpus imbricatus, an endangered conifer growing in a Cantonese garden. The new structures were established by means of spectroscopic methods. Among the isolates, 3β-hydroxy-abieta-8,11,13-trien-7-one (5), decandrin G (6), and 7,15-pimaradien-18-oic acid (8) showed significant anti-neuroinflammatory activities by inhibiting the overproduction of nitric oxide (NO) in lipopolysaccharide (LPS)-stimulated murine BV-2 microglial cells, with IC₅₀ values of 3.7, 11.1, and 4.5 μM, respectively.

Formation of oligomeric alkenylperoxides during the oxidation of unsaturated fatty acids: an electrospray ionization tandem mass spectrometry study

This study reports the identification of oligomeric alkenylperoxides by electrospray ionization mass spectrometry (ESI-MS) and tandem mass spectrometry (ESI-MS(2)), during the oxidation of oleic, linoleic and linolenic acids with Fenton's (Fe(2+)/H(2)O(2)) and Fe(2+)/O(2) systems. The reactions were followed by ferrous oxidation-xylenol orange method together with GC-MS and GC-FID, allowing to observe that both oxidation systems are different in terms of hydroperoxide evolution, probably due to the presence of different intermediate reactive species: perferryl ion and OH(·) radical responsible for the decomposition of lipid hydroperoxides and formation of new compounds. The analysis of ESI-MS in the negative mode, obtained after oxidation of each fatty acid, confirmed the presence of the monomeric oxidation products together with other compounds at high mass region above m/z 550. These new ions were attributed to oligomeric structures, identified by the fragmentation pathways observed in the tandem mass spectra.

Antimicrobial diterpenes from the stem bark of Mitrephora celebica

Four diterpenes were isolated from the stem bark of Mitrephora celebica through bioassay-guided fractionation. Ent-trachyloban-19-oic acid (1) and ent-kaur-16-en-19-oic acid (2) were identified as the compounds responsible for the antimicrobial activity of the plant against methicillin-resistant Staphylococcus aureus and Mycobacterium smegmatis. 8(14),15-pimaradien-18-oic acid (3) and 7,15-pimaradien-18-oic acid (4) were isolated from the same fraction and were inactive against the microorganisms.