Determination of ginsenoside content in Panax ginseng C.A. Meyer and Panax quinquefolius L. root materials and finished products by high-performance liquid chromatography with ultraviolet absorbance detection: interlaboratory study.

An interlaboratory study was conducted on an HPLC method with UV absorbance detection, previously validated using AOAC single-laboratory validation guidelines, for the determination of the six major ginsenosides (Rg1, Re, Rb1, Rc, Rb2, and Rd) in Panax ginseng C.A. Meyer and Panax quinquefolius L. root materials, extracts, and finished products. Fourteen participating laboratories analyzed five test materials (P. ginseng whole root, P. ginseng powdered extract, P. quinquefolius whole root, P. quinquefolius powdered extract, and P. ginseng powdered extract spiked in a matrix blank) as blind duplicates, and two test materials (P. ginseng powdered whole root tablet and P. quinquefolius powdered extract hard-filled capsule) as single samples. Due to the variability of the ginsenosides (low level concentration of Rb2 in P. quinquefolius raw materials and in P. ginseng spiked matrix blanks, and the possibility of incomplete hydrolysis of the finished products during processing), it was deemed more applicable to analyze total ginsenosides rather than individual ones. Outliers were evaluated and omitted using the Cochran's test and single and double Grubbs' tests. The reproducibility RSD (RSD(R)) for the blind duplicate samples ranged from 4.38 to 5.39%, with reproducibility Horwitz Ratio (HorRat(R)) values ranging from 1.5 to 1.9. For the single replicate samples, the data sets were evaluated solely by their repeatability HorRat (HorRat(r)), which were 2.9 and 3.5 for the capsule and tablet samples, respectively. Based on these results, the method is recommended for AOAC Official First Action for the determination of total ginsenosides in P. ginseng and P. quinquefolius root materials and powdered extracts.

Quantitative and qualitative HPLC analysis of thermogenic weight loss products.

An HPLC qualitative and quantitative method of seven analytes (caffeine, ephedrine, forskolin, icariin, pseudoephedrine, synephrine, and yohimbine) in thermogenic weight loss preparations available on the market is described in this paper. After 45 min the seven analytes were separated and detected in the acetonitrile: water (80:20) extract. The method uses a Waters XTerra RP18 (5 microm particle size) column as the stationary phase, a gradient mobile phase of water (5.0 mM SDS) and acetonitrile, and a UV detection of 210 nm. The correlation coefficients for the calibration curves and the recovery rates ranged from 0.994 to 0.999 and from 97.45% to 101.05%, respectively. The qualitative and quantitative results are discussed.

Analysis of products suspected of containing Aristolochia or Asarum species.

Aristolochia species have been administered by those trained in traditional Chinese medicine (TCM) for centuries. After determining Aristolochia fangchi was an adulterant that caused death due to renal failure in a number of patients at a Belgian weight loss clinic, many countries took steps to regulate products containing Aristolochia fangchi as well as other Aristolochia species. The US FDA issued a Consumer Advisory 'advising consumers to stop using any products that may likely contain aristolochic acid'. The Aristolochia and Asarum genera both have been found to contain aristolochic acids. A number of websites have been found from which individuals can order products containing either Aristolochia or Asarum as an ingredient through US merchants. We purchased 25 products from such sites and analyzed them for the presence of aristolochic acid I and II by HPLC with PDA. Six of the products contained detectable amounts of I and II.

An improved HPLC method for quantitative determination of six triterpenes in Centella asiatica extracts and commercial products.

An improved HPLC qualitative and quantitative method of six triterpenes (asiaticoside, madecassoside, asiatic acid, madecassic acid, terminolic acid, and asiaticoside-B) in Centella asiatica (raw plant material and preparations) is described in this paper. After 50 minutes the six active triterpenes were separated and detected in the methanolic extract at a limit of 0.01 microg/ml. The method uses a Phenomenex Aqua 5mu C18 (200 A) column as the stationary phase, a gradient mobile phase of water (0.1% TFA), acetonitrile (0.1% TFA), and methyl tert-butyl ether (0.1% TFA), and UV detection at 206 nm. The correlation coefficients for the calibration curves and the recovery rates ranged from 0.995 to 0.999 and from 98.39% to 100.02%, respectively. The qualitative and quantitative results are discussed.

Determination of aristolochic acid I and II in North American species of Asarum and Aristolochia.

Wild ginger, Asarum canadense, which has folk uses as a medicinal and food plant, has been reported to contain aristolochic acid I. Rhizomes of North American species of Aristolochiaceae were surveyed for the presence of aristolochic acids by HPLC. Aristolochic acid I (1) and aristolochic acid II (2) were present in Aristolochia species and Hexastylis; 1 alone was detected in multiple accessions of A. canadense and Asarum caudatum, though not in Asarum wagneri. Concentrations in A. canadense were highly variable, reaching as much as 0.037 percent of dry weight.

Dihydroagarofuran sesquiterpene alkaloids from Maytenus putterlickoides.

Two new dihydroagarofuran sesquiterpene alkaloids, putterines A (2) and B (3), and a known alkaloid, mayteine (1), were isolated from the root of Maytenus putterlickoides. The structures of these compounds were elucidated by various spectroscopic techniques, including 1H and 13C NMR, COSY, ROESY, HMBC, and high-resolution FABMS.