Absolute Configuration of a Tetrahydrophenanthrene from Heliotropium ovalifolium by LC-NMR of Its Mosher Esters

A new tetrahydrophenanthrene (1, (1R,2R)-1-hydroxy-2-methoxy-6,9-dimethyl-2,3-dihydrophenanthren-4(1H)-one (heliophenanthrone)) has been isolated from the aerial parts of Heliotropium ovalifolium. Its structure was elucidated on the basis of spectroscopic data, and the absolute configuration of the asymmetric centers was determined from LC-NMR data of the Mosher ester derivatives

Phytochemistry and in vitro Anti-sickling activity of Senna Occidentalis L. (Fabaceae)

Introduction Sickle cell disease is an inherited genetic disorder characterized by the presence of abnormal hemoglobin, leading to the deformation of red blood cells and serious complications. It is a major public health problem in many countries of inter-tropical Africa. In the Democratic Republic of the Congo, over a million people (2%) are affected by this hemoglobinopathy. Purpose This study aimed to scientifically validate the anti-sickle cell activity of aqueous extracts of S. occindentalis seeds and to identify the chemical constituents responsible for this activity. Methods In this study, we used S. occidentalis seeds harvested at Ilebo in Central Kasai Province, while the blood samples used were taken from sickle-cell patients. The phytochemical composition was determined according to the standard method described previously by Iteku et al. and Nkasa et al. The Emmel test was carried out according to the standard protocol described previously by Bongo et al. Results The results obtained in this study showed that the seeds of this plant are rich in secondary metabolites such as total polyphenols (flavonoids, anthocyanins, leuco-athocyanins, tannins, and saponins), di-terpenes, alkaloids, and bound quinones. However, these seeds do not contain triterpenoids and steroids. Total seed extracts from this plant showed significant anti-sickle cell activity. Conclusion This study identified a medicinal plant used by the sickle cell disease community

Determination of trace amounts of ginkgolic acids in Ginkgo biloba L. leaf extracts and phytopharmaceuticals by liquid chromatography-electrospray mass spectrometry.

Ginkgolic acids (GAs) are toxic phenolic compounds present in the fruits and leaves of Ginkgo biloba L. (Ginkgoacae). Their maximum level in phytopharmaceuticals containing ginkgo extracts has been recently restricted to 5 microg/g by the Commission E of the former Federal German Health Authority. In order to detect ginkgolic acids at these low levels, a sensitive and selective analytical method, based on liquid chromatography-electrospray mass spectrometry (LC-ES-MS) has been developed. The three main phenolic acids (1-3) of the chloroform fruit extract were isolated and used as standards for quantification. In the LC-ES-MS negative ion mode, calibration curves with good linearities (r=0.9973, n=6) were obtained in the range of 0.5-10 microg/g for compounds 1, 2 and between 0.1 and 7.5 microg/g (r=0.9949, n=6) for ginkgolic acid 3. The detection limits at a SIN ratio of 3 were 0.1 (3) and 0.25 microg/g (1, 2). Recoveries were around 101% at 5 microg/g for the substances detected in the leaf extracts. Good precision was achieved with relative standard deviations of less than 4% (n=6). The optimised method was applied to verify whether the amount of gingkolic acids was below 5 microg/g in a standardised leaf extract which is a constituent of a phytopreparation

Determination of pyrrolizidine alkaloids in senecio species by liquid chromatography/thermospray-mass spectrometry and liquid chromatography/nuclear magnetic resonance spectroscopy.

A new method using direct on-line coupling between HPLC, MS and (1 )H-NMR was developed for the detection and identification of pyrrolizidine alkaloids (PAs) in crude extracts of Senecio species. The PAs present in the extracts were separated on a C-18 reversed-phase column with an alkaline acetonitrile-water gradient. Molecular weight information of each peak was obtained by LC/MS and specific fragments were recorded by complementary MS/MS experiments. In order to distinguish isomeric structures of PAs, complementary LC/ (1)H-NMR analyses were performed in both on-flow and stop-flow modes with alkaline acetonitrile-D (2)O and methanol-D (2)O as mobile phases. This approach led to the identification of the known PAs of S. vulgaris; retrorsine, seneciphylline, and senecionine. The method was also applied for the analysis of African Senecio species: S. mariettae and S. venosus. Retrorsine was identified as the main PA in both species. Detection of the PAs in small amounts was achieved by LC/MS. Higher amounts of extracts (mg) had to be injected to obtain good quality on-flow LC/ (1)H-NMR