Search results for "betulin"
showing 5 items of 35 documents
Electrosynthesis of Stable Betulin‐Derived Nitrile Oxides and their Application in Synthesis of Cytostatic Lupane‐Type Triterpenoid‐Isoxazole Conjuga…
2021
Harmful and Protective Effects of Terpenoids from African Medicinal Plants
2014
Terpenoids represent the most widespread group of natural products and can be found in all classes of living things. Many defensive compounds include sesquiterpenoids and diterpenoids from angiosperm species. Several terpenoids are biologically active and are exploited in the fight against cancer, malaria, inflammation, and a variety of infectious diseases. Nonetheless, some compounds of this group showed toxic effects causing gastrointestinal problems or central nervous system manifestations among others. Several bioactive terpenoids were identified in African medicine with numbers of them having organ-protective effects while few are known for their nonbeneficial properties for humans. In…
Gēni Taphrina betulina genomā, kas iespējams kodē auksīna biosintēzes ceļus
2016
Taphrina betulina ir dimorfiska agrīnā askomicēte, kas inficē vairākas bērzu sugas un tām izraisa hiperplāzijas, ko sauc par vējslotām. Šādas hiperplāzijas ir tipisks simptoms auksīnu producējošo mikroorganismu infekcijām. Auksīns ir ticis izolēts no T. betulina un vairākām citām Taphrina ģints sēnēm. Auksīna biosintēzes ceļi kā arī to loma infekciju norisē lielākajai daļai sēņu ir vai nu slikti izpētīti, vai nav atklāti vispār. Šī dabra mērķis bija atrasts un anotēt par galvenā augu auksīna indolil-3-etiķskābes sintēzi atbildīgos gēnus T. betulina genomā. Gēnu meklēšanai T. betulina genomā lielākokārt tika izmantotas manuāli anotētās proteīnu sekvences no Taphrina deformans genoma. Genoma …
Investigations on the Steroidal Anti-Inflammatory Activity of Triterpenoids fromDiospyros leucomelas*
1995
Three triterpenes were isolated from Diospyros leucomelas and identified as betulin, betulinic acid, and ursolic acid. They showed anti-inflammatory activity in the carrageenan and serotonin paw edema tests and TPA and EPP ear edema tests. The blockade of their effects by progesterone, actinomycin D, and cycloheximide has served to determine the mechanism of action in relationship with that of glucocorticoids. Betulinic acid was the most affected and therefore a mode of action similar to these drugs may be postulated for it.
Wood-derived estrogens: studies in vitro with breast cancer cell lines and in vivo in trout.
1996
The wood-derived compound, beta-sitosterol (purity > 90%), was shown to be estrogenic in fish. It induced the expression of the vitellogenin gene in the liver of juvenile and methyltestosterone-treated rainbow trout. Structural similarities to beta-sitosterol notwithstanding, cholesterol, citrostadienol, beta-sitostanol, and 5-androstene-3 beta,17 beta-diol, an estrogenic member of the androstenic steroid group, were inactive. An abietic acid mixture (37% abietic acid, 6% dehydroabietic acid, and a remainder of unknown compounds) showed slight hormonal activity in feed, but it was completely inactive when given intraperitoneally in implants. The estrogenic component of the abietic acid prep…