Cholesterol undergoes ozonolysis to afford a variety of oxysterol products, including cholesterol-5,6-epoxide (CholEp) and the isomeric aldehydes secosterol A (seco A) and secosterol B (seco B). These oxysterols display numerous important biological activities, including protein adduction; however, much remains to be learned about the identity of the reactive species and the range of proteins m...

A pair of new 3,4;9,10-seco-cycloartane type triterpenoid stereoisomerides: 24R,25-dihydroxy-3,4;9,10-seco-4(28)-cycloarten-10,3-olide (1) named Illiciumolide A and 24S,25-dihydroxy-3,4;9,10-seco-4(28)-cycloarten-10,3-olide (2) named Illiciumolide B were isolated from the stem bark of Illicium difengpi, as well as five known biogenetically related triterpenoids, including sootepin E (3), betuli...

Mercúrio total e metilmercúrio foram avaliados em três espécies de moluscos (Perna perna mexilhão, Crassostrea rhizophorae ostra, Anomalocardia brasiliana vôngole) provenientes de dois estuários no estado do Rio de Janeiro, impactados por matéria orgânica e metais pesados. O mexilhão foi a espécie que apresentou melhor capacidade para acumular o mercúrio dentre as espécies de molusco estudadas....

The time of appearance of a persistent and demographically-viable hunter-gatherer population in late Pleistocene southern South America must be determined by evaluating evidence from as large as possible a sample of candidate archaeological sites in the region. We co-ordinated the AMS dating of multiple bone and charcoal samples from previously-excavated strata at the following sites: Arroyo Se...

New access to the 7, 17-seco norditerpenoid alkaloids 9 (60%) from yunnaconitine (5), as well as 14 (46%) and 15 (22%) from isotalatizidine (10), via selective hydrolysis, chlorination and reduction with NaBH4 is described.

Figu (Seco edge detec emp We describe a non-photorealistic camera (‘NPR camera’) to robustly capture edge information in real scenes. New stylized images are synthesized by highlighting or de-emphasizing the detected edges.

Elevated levels of cholesterol aldehyde, 3β-hydroxy-5-oxo-5,6-secocholestan-6-al (secosterol-A, also called 5,6-secosterol), and its aldolization product (secosterol-B) have been detected in human atherosclerotic plaques and tissues samples of brains affected by neurodegeneration, such as Alzheimer's disease and Lewy body dementia suggesting that increased formation of these compounds may be as...

A novel seco-limonoid, rel-(1S,5R,9S,7R,8S,9R,10S,11R,13S,14R,15R,17R)-11,19-dihydroxy-7-acetoxy-7-deoxoichangin (raputiolide) (1), and two novel quinolone alkaloids N-methyl-2-phenoxyquinolin-4(1H)-one (heptaphyllone A) (2) and 6-methylbenzofuro[2,3-b]quinolin-4(1H)-one (heptaphyllone B) (3), along with the known seco-limonoid ichangin (4), were isolated from Raputia heptaphylla PITTIER (Rutac...

A new dibenzocyclooctadiene lignan, acetylepigomisin R ( 1), and a new 3,4-seco-lanostane-type triterpene, seco-coccinic acid F ( 2), along with three known dibenzocyclooctadiene lignans, isovaleroylbinankadsurin A ( 3), kadsuralignan J ( 4), and binankadsurin A ( 5), and one lanostane-type triterpene, 20( R),24( E)-3-oxo-9 beta-lanosta-7,24-dien-26-oic acid ( 6), were isolated from the methano...