Phytochemical Analysis

Achyrobichalcone, a new biflavonoid found in Achyrocline satureioides, was recently isolated. To assess its quality, we develop, optimise and validate a stability-indicating HPLC method. The optimisation was performed by Box-Behnken design and robustness by Plackett-Burman design. Factors as column temperature, flow rate and acetonitrile content were significant for resolution between achyrobichalcone and impurities peaks and retention factor. The analyte was unstable only in alkaline media. The new method affords to evaluate the quality and stability of achyrobichalcone obtained by isolation.

Prompted by a livestock poisoning outbreak near Kingman, Arizona, analysis of Cryptantha inequata and C. utahensis revealed dehydropyrrolizidine alkaloids at approximately 0.05 % and 0.09% w/w respectively. Cryptantha inequata produced mainly echimidine, acetylechimidine and echiuplatine; dehydropyrrolizidine alkaloids previously associated with Echium plantagineum. Echiuplatine was elucidated as an amphoteric, open chain diester with angelic acid and 3-hydroxy-3-methylglutaric acid. Along with lycopsamine, intermedine and dihydroxyechiumine, C. utahensis produced cryptanthine, an open chain diester with angelic acid and 2,3-dihydroxy-2-methylbutanoic acid. All pyrrolizidine alkaloids detected were present in the plants mainly as their N-oxides. The dehydropyrrolizidine alkaloids detected are expected to be toxic but the low levels in the plants potentially mitigate the risk. The identification of the amphoteric echiuplatine provides a cautionary note with respect to the analysis of total dehydropyrrolizidine alkaloid content.

HPLC–ESI–QTOF was used to characterise the phenolic compounds from two olive-leaf extracts obtained by pressurised liquid extraction using water and ethanol as extracting solvents. The information provided by QTOF mass spectrometer enabled the in-depth characterisation of both olive-leaf extracts, allowing the tentative identification of 31 different phenolic compounds in these extracts, including secoiridoids, simple phenols, flavonoids, cinnamic-acid derivatives and benzoic acids. Lucidumoside C was also identified for the first time in olive leaves.

Amino Acids were determined by reversed phase sequential injection chromatography using fluorimetric detection of their indole derivatives, exploring an instrument configuration capable to handle pressures of up to 1000 psi. Separation was achieved by stepwise elution with six mobile phases with concentrations of methanol increasing from 8 to 65 % (v/v) in 10 mM phosphate buffer (pH 7.2). The proposed method found different profiles of dissolved free amino acids among three species of algae, suggesting its adequacy for metabolic studies.

• A microwave assisted extraction (MAE) of lupeol for industrial scale-up using response surface methodology (RSM) is proposed.
• Data from single factor analysis of a Plackett–Burman design were fitted to a Box–Behnken design (BBD) to build response surfaces.
• The BBD used a regression equation to predict optimal MAE conditions with optimum yield.
• Validation of the MAE process showed that the regression model fitted well with the experimental data, as evident from only a slight deviation (%RSD = 0.69) between predicted and experimental yield.

Dysphania graveolens is used in Mexican traditional medicine against gastrointestinal ailments. Previous investigations revealed that its flavonoids are important active principles; however, there is not a reliable and accurate analytical method for determining these compounds in the crude drug or preparations of the plant. Therefore, a suitable validated HPLC method for quantifying the major active flavonoids was developed. According to GC–MS analysis of the volatile compounds extracted by HS–SPME and by hydrodistillation, the most relevant volatile components in the species were monoterpenoids.

ELISA and Eastern blotting methods for analysis of triterpene glycosides in Centella asiatica were developed using polyclonal antibody against madecassoside.

Metabolomics based UPLC-Q-TOF-HDMS coupled with pattern recognition analyses was effective for analysis of constituents in the root of two kinds of Aconitume species. Twenty-two metabolites between the mother root of Aconitum carmichaelii Debx and lateral root of Aconitum carmichaelii Debx, 13 metabolites between the Aconitum carmichaelii Debx and root of Aconitum kusnezoffii Reichb have been identified.

In this study a comparison has been made between the metabolite composition of Brassica. napus L. organs including roots, stems, leaves, inflorescence and seeds. UPLC-qTOF-MS was utilized in order to localize metabolites belonging to various chemical classes (i.e. oxygenated fatty acids, flavonols, phenolic acids and sinapoyl choline derivatives). The vast majority of identified metabolites were flavonol glycosides that accumulated in most plant parts. Principal component analysis (PCA) and partial least squares-discriminant analysis (OPLS-DA) of biochemical profile were used for organs classification.