Biovalorization of Friedelane Triterpenes Derived from Cork Processing Industry Byproducts
作者:Cristina Moiteiro、Maria João Marcelo Curto、Nagla Mohamed、María Bailén、Rafael Martínez-Díaz、Azucena González-Coloma
DOI:10.1021/jf0531151
日期:2006.5.1
(14), lactone 18, and the oxime 19 being stronger insecticides than the parent compound. Methyl-3-nor-2,4-secofriedelan-4-oxo-2-oic acid (12) and its acetylated derivative 12a also showed insecticidalactivity in contrast to their inactive parent compound 2. The postingestive effects and cytotoxicity of these compounds suggest a multifaceted insecticidal mode of action. These structural modifications
Four known friedelane-type triterpenoids, friedelin (1), 3-hydroxy-D:A-friedoolean-3-en-2-one (2), 2β-hydroxy-D:A-friedooleanan-3-one (3), and 3α-hydroxy-D:A-friedooleanan-2-one (4), and two known lupane-type triterpenoids, lupeol (5) and betulin (6), were isolated from the stem bark of Mallotus philippensis. Isolates 1 - 4 and their synthetic analogues, 3-acetoxy-D:A-friedoolean-3-en-2-one (2a) and 3α-acetoxy-D:A-friedooleanan-2-one (4a), were tested for their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol 13-acetate (TPA). The inhibitory effect of compounds 2 (IC50 = 292 mol ratio/32 pmol/TPA) and 4 (IC50 = 288) was stronger than those of the other compounds tested and the positive control, curcumin (IC50 = 343). Compound 4 strongly inhibited mouse skin tumor promotion in an in vivo two-stage carcinogenesis model. Studies have been conducted to identify the biologically active compounds extracted from the leaves, bark, and cones of trees that currently have no specific commercial use and are therefore treated as waste in the forestry industry.
13C NMR signal assignment of friedelin and 3α-hydroxyfriedelan-2-one
作者:Hugo E. Gottlieb、Parimi A. Ramaiah、David Lavie
DOI:10.1002/mrc.1260230805
日期:1985.8
The 13C NMR spectrum of the pentacyclic triterpene friedelin was fully assigned, taking into account signal multiplicities, correlations of the carbon lines with known proton resonances and Eu-induced shifts. This work clarifies the situation prevalent in the literature, in which three separate groups have published contradictory information. In addition, the carbon and proton spectra of the naturally occurring 3α-hydroxyfriedelan-2-one and its synthetic acetate were analysed. The different preferred conformations of the D/E rings for friedelin (boat-boat) and polpunonic acid (chair-chair) are rationalized.
考虑到信号倍率、碳线与已知质子共振的相关性以及 Eu 诱导的位移,对五环三萜油炸烯的 13C NMR 光谱进行了全面的分配。这项工作澄清了文献中普遍存在的情况,即三个不同的研究小组发表了相互矛盾的信息。此外,还分析了天然存在的 3α-hydroxyfriedelan-2-one 及其合成醋酸酯的碳和质子光谱。此外,还分析了天然 3α-hydroxyfriedelan-2-one 及其合成醋酸酯的碳和质子光谱。
Talapatra, Bani; Lahiri, Biswanath; Basak, Amit, Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 1983, vol. 22, # 8, p. 741 - 745
作者:Talapatra, Bani、Lahiri, Biswanath、Basak, Amit、Pradhan, Dilip K.、Talapatra, Sunil K.
DOI:——
日期:——
Patra, Amarendra; Chaudhuri, Swapan K., Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 1989, vol. 28, # 1-11, p. 376 - 380