Selective oxidation of lupeol by iodosylbenzene catalyzed by manganese porphyrins.

Manganese porphyrin-catalyzed oxidation of lupeol by iodosylbenzenewas achieved undermild conditionswith low isolated yields but with remarkable selectivity, depending on the catalyst of choice. Mn(III) mesotetraphenylporphyrin and Mn(III) meso-tetrakis(4-carbomethoxyphenyl)porphyrin provided an entry for the preparation of 3?,30-dihydroxylup-20(29)-ene (6?14% yields), whereas Mn(III) ?-octabromo-meso-tetrakis(4- carbomethoxyphenyl)porphyrin led to 20-oxo-3?-hydroxy-29-norlupeol (6% yield), as single products. Unreacted lupeol was recovered in quantitative yield. The oxidative transformations at lupeol C20 or C30 take place with no need for protection of C3 hydroxyl moiety

Celastraceae family : source of pentacyclic triterpenes with potential biological activity.

A família Celastraceae, comumente conhecida como família agridoce, devido ao sabor de seus frutos, possui diversos relatos de uso na medicina popular. Na América do Sul é representada, principalmente, pelo gênero Maytenus, que tem atraído a atenção de muitos pesquisadores por suas propriedades antitumorais. Dos metabólitos isolados, os triterpenos pentacíclicos se destacam, sendo que, os de esqueleto quinonametídeo são os marcadores quimiotaxônomicos dessa família. Os esqueletos triterpênicos têm 30 carbonos compreendendo cinco anéis de seis membros cada ou quatro anéis de seis membros mais um anel de cinco. Eles são de grande interesse devido às diversas atividades biológicas apresentadas, servindo como candidatos ou protótipos de novos fármacos. Devido a todas essas características, em poucos anos, inúmeros estudos têm sido dedicados aos triterpenos.The Celastraceae family, commonly known as bittersweet family due to flavor of its fruits, has several use reports in folk medicine. In South America it is mainly represented by the Maytenus genus, which has attracted the attention of many researchers for its anti-tumor properties. From the isolated metabolites, the pentacyclic triterpenes stand out, and of the skeleton of quinonamethide are chemotaxonomic markers of this family. The pentacyclic triterpene is based on a skeleton of 30 carbons comprising five six-membered rings or four six-membered rings plus one five-membered ring. They are of great interest due to the diverse biological activities presented, being candidates or prototypes of new drugs. Because of all these features recently numerous studies have been devoted to triterpenes

Constituintes químicos e atividade antiespermatogênica em folhas de Austroplenckia populnea (Celastraceae)

Folhas de Austroplenckia populnea (mangabarana, marmelinho do campo) foram submetidos a estudo fitoquímico. do extrato hexânico foram isolados e identificados três triterpenos pentacíclicos e um sesquiterpeno agarofurânico inédito. Realizou-se testes de atividade antiespermatogência utilizando parte deste extrato. Os resultados mostraram uma redução significativa do número de espermatozóides no epidídimo

Total assignment of 1H and 13C NMR spectra of two 3,4-secofriedelanes from Austroplenckia populnea.

Two new 3,4-secofriedelanes, 3,4-seco-28-hydroxyfriedelan-3-oic acid (1) and 3,4-secofriedelan-3-oic acid (2),were isolated from the leaves of Austroplenckia populnea (Celastraceae).The structureswere established by 2D NMR spectroscopic techniques (COSY, HMQC, HMBC and NOESY)

3-beta-(Stearyloxy)olean-12-ene from Austroplenckia populnea : structure elucidation by 2D-NMR and quantitative 13C-NMR spectroscopy.

3 -(Stearyloxy)olean-12-ene was isolated from a hexane extract of Austroplenckia populnea Reiss (Celastraceae) leaves. The structure was solved by means of quantitative 13C-NMR, HMBC, HMQC, COSY, NOESY, and NOE difference spectra. The mass spectrum showed an [M 1] ion peak at m/z 693, and the molecular formula C48H84O2 was confirmed by combustion analysis