Complete assignments of ¹H and ¹³C NMR resonances of oleanolic acid, 18α‐oleanolic acid, ursolic acid and their 11‐oxo derivatives

Abstract

One way to increase the rate of an electrochemical process is to increase the area of the interface between the electrode and the electrolyte. A novel polymer electrode, with a very high effective surface area and a nanometer‐scale continuous conducting network that extends into a large volume, is presented and its preparation from a commercially available aqueous dispersion of a conducting polymer described. An application to supercapacitors is detailed, as a demonstration of the properties that are a consequence of the unique structure of the material.

URSOLIC ACID AND CIS-TILIROSIDE PRODUCED BY Merremia tomentosa AFFECT OVIPOSITION OF Leucoptera coffeella ON COFFEE PLANTS

“…The non-polar fraction (soluble in hexane) afforded no purified substance after several steps, but the last sub-fraction in the chromatographic fractionation of the semipolar fraction (soluble in EtOAc) yielded a pure substance after washings with hexane/EtOAc that was identified as ursolic acid (1, Figure 1) based on the NMR data (Table 2S, Figures 1S-11S), which were in agreement with the data published in the literature for the same substance. 50,51 The production of ursolic acid (1) by M. tomentosa is per se interesting, since this substance presents pharmacological activities, and some assays have demonstrated that it is far less toxic to human beings than the available commercial insecticides to control L. coffeella in coffee fields. 52 Furthermore, it reduced the oviposition of this insect (Table 1), showing potential for use in the development of new products to control this pest.…”

NEW DEGRADED QUINONE DITERPENOID FROM THE STEMS OF Byrsonima coccolobifolia Kunth. (Malpighiaceae)

“…In a second study, the hexane and EtOAc extracts of the roots of the specimen collected in the central Brazilian cerrado were submitted to several chromatographic columns, which eventually lead to the identification of the triterpenes α-amyrin, β-amyrin, 26 oleanolic acid, 27 glochidonol, 28 and the mixture of stigmasterol, β-sitosterol and campesterol. 29,30 The new quinone diterpene derivative was identified by 1 H NMR and 2D NMR experiments, such as HSQC, HMBC, and 1D NOE (Table 1), as well high-resolution mass spectrometry.…”

“…31 All the compounds isolated from the roots of the second specimen were identified through comparison of their spectral data with the literature. [26][27][28][29][30] …”

Bioactivity guided isolation and characterization of the phytoconstituents from the Tridax procumbens

“…These compounds were identified as kaempferol (Carotenuto et al, 1996) and lupeol (Ali et al, 2007) respectively. SA-6 was isolated from the n-butanol fraction and was identified as 18-α-oleanolic acid based on the spectral information (Seebacher et al, 2003).…”

“…The butanol fraction (10.0 g) was separated over silica gel column with a solvent system of CHCl 3 :MeOH: H 2 O (9:4:0.5-3:5:0.5) as the eluent to give five fractions, among them the major fraction was purified by repeated CC using methanol as eluent, to give SA-6. Characterization of isolated compounds was done by comparing the spectral data in the literature (Carotenuto et al, 1996;Ali et al, 2007;Seebacher et al, 2003).…”