Isolation and identification of hydroxythiohomosildenafil in herbal dietary supplements sold as sexual performance enhancement products.

An unknown compound is detected and isolated from two herbal dietary supplements bought on the internet. The structure of the unknown compound is elucidated using ESI-MS/MS, NMR, UV and IR. The compound, named hydroxythiohomosildenafil, is identified as an analogue of sildenafil in which the oxygen atom is substituted with a sulfur atom in the pyrazolopyrimidine moiety, and a hydroxyethyl group instead of a methyl group is attached to the piperazinyl nitrogen. It is the first report of this compound being detected in herbal dietary supplements. The UV, IR and completely assigned NMR data of hydroxythiohomosildenafil is recorded.

Medicinal plants as potential sources of lead compounds with anti-platelet and anti-coagulant activities.

Medicinal plants are potential sources of lead compounds which can be further developed or optimised into novel therapeutics. This paper gives an overview of drug discovery from plants and an up-to-date and comprehensive review of plants and phytoconstituents reported to have anti-platelet and anti-coagulant activities.

Detection of aristolochic acid I, tetrandrine and fangchinoline in medicinal plants by high performance liquid chromatography and liquid chromatography/mass spectrometry.

Problems with identification and labeling of medicinal plants, as well as substitution/adulteration of non-toxic plants by toxic ones have previously led to cancer, renal failure and even deaths. The non-toxic Stephania tetrandra (Fangji) has been known to be substituted by Aristolochia fangchi (Guang fangji), which contains the nephrotoxic and carcinogenic aristolochic acid (AA). In this study, 10 samples of "Fangji" were bought from local medicinal shops. HPLC-DAD chromatographic fingerprints of each methanol extract were compared with those of A. fangchi and S. tetrandra, using aristolochic acid I (AAI), tetrandrine and fangchinoline as marker compounds. Nine of the samples were found to be similar to A. fangchi. The presence of AAI in the nine samples was confirmed using LC-MS/MS. Neither tetrandrine nor fangchinoline were detected in these samples. The methods developed in this study allow the simultaneous detection of AAI, fangchinoline and tetrandrine. The results suggest possible substitution of S. tetrandra by A. fangchi at wholesale or retail level. This study highlights the importance of greater control of medicinal plants with toxic components as these may still be readily accessible to the public.

Genetic diversity and variation of saponin contents in Panax notoginseng roots from a single farm.

Radix notoginseng, the root of Panax notoginseng (Burk.) F. H. Chen, has been widely used in traditional Chinese medicine. Its main components, saponins, have been reported to have many pharmacological activities. To test the general assumption that herbs of a single species planted and harvested from a single location are uniform in chemical and genetic makeup, chemical analysis and DNA fingerprinting were carried out. High-performance TLC together with HPLC analysis were used to analyze 17 randomly sampled 3-year-old roots from a single farm for the presence of six saponins. Five roots showed distinct chemical profiles with changed ratios of ginsenosides Rd/Rg1, Re/Rg1, or Rb1/Rg1. The same samples, together with some 1- and 2-year-old samples, were also subjected to fluorescent amplified fragment length polymorphism (AFLP) analysis, and their internal transcribed spacer 2 (ITS 2) regions were sequenced. Fluorescent AFLP analysis was found to be much more polymorphic than the ITS 2 sequence and showed clear evidence of genetic diversity within the tested population. In conclusion, genetic diversity and variation of saponin contents between individual P. notoginseng roots have been detected. We suggest that genetic diversity affects the contents of the six saponins. The saponin contents variation and genetic diversity were also found among P. notoginseng root samples collected from China and Singapore markets. Since variable saponin contents may affect therapeutic efficacy, combining the use of genetic profiling with chemical profiling will help ensure greater uniformity in the quality of P. notoginseng roots. The genetic and chemical diversity within a population also provides the opportunity for breeding new cultivars with more desirable chemical constituents.

Chemical fingerprinting of Isatis indigotica root by RP-HPLC and hierarchical clustering analysis.

The aim was to establish a method for extraction and chemical fingerprinting of extracts of Isatis indigotica roots ("Ban-Lan-Gen") and to apply the method developed to 18 Ban-Lan-Gen samples. RP-HPLC with gradient elution was performed on authentic reference standards of powdered I. indigotica roots, indigotin and indirubin purchased from the National Institute for the Control of Pharmaceutical and Biological Products (NICPBP) of China. Eighteen "Ban-Lan-Gen" samples (including the reference powdered herb) were bought from Singapore and different regions in China. Comparisons of the chromatograms showed that the samples can be divided into three groups. The chromatograms of the extracts of five samples were found to be similar to that of the extract of the authentic sample. Eight other samples had similar peaks as the authentic sample but the intensities of the peaks were generally lower, except for the peaks between retention times of 10-40 min. Peaks in these regions were more intense than those found in the extract of the authentic sample. Forty-five characteristic peaks could be found in the extracts of all the above samples. Peaks at retention times 52 and 53 min were determined to be indigotin and indirubin, respectively. The remaining four samples had similar chemical fingerprints to each other but were different from that of the authentic sample. Hierarchical clustering analysis gave similar results as the visual comparison. The RP-HPLC method developed allows simple identification and comparisons of I. indigotica roots. This is the first report of hierarchical clustering analysis of I. indigotica root.

HPLC and GC-MS screening of Chinese proprietary medicine for undeclared therapeutic substances.

Traditional Chinese medicine includes raw medicinal materials and Chinese proprietary medicine (CPM). Despite being of natural origin, toxic effects, adulteration with synthetic therapeutic substances and even deaths had been associated with CPM. There is thus a need to develop analytical technique to rapidly screen for undeclared toxic and therapeutic substances in CPM. In this study, a high performance liquid chromatography-diode-array detection method was developed and used to screen for undeclared therapeutic substances in CPM. An ultraviolet (UV) library of 266 drugs had been compiled. Solute identification was performed by comparing the analytical data (UV spectra, retention time and relative retention time) with those of the 266 standards. Gas chromatography-mass spectrometry was used as a confirmation method. These chromatographic methods had been shown to be selective and reproducible in screening for undeclared drugs in CPM. Using the method developed, 41 CPM samples in seven categories were screened for undeclared therapeutic substances. One anti-asthmatic CPM was found to contain codeine.

Chinese proprietary medicine in Singapore: regulatory control of toxic heavy metals and undeclared drugs.

Traditional Chinese medicine (TCM) is gaining popularity as a form of complementary and alternative medicine. Reports of efficacy of TCM are increasing in numbers. TCM includes both crude Chinese medicinal materials (plants, animal parts and minerals) and Chinese proprietary medicine (CPM) [final dosage forms]. Despite the belief that CPM and herbal remedies are of natural origin, unlike Western medicine, and are hence safe and without many adverse effects, there have been numerous reports of adverse effects associated with herbal remedies. Factors affecting the safety of herbal medicines include intrinsic toxicity, adulteration, substitution, contamination, misidentification, lack of standardisation, incorrect preparation and/or dosage and inappropriate labelling and/or advertising. Hence, new regulations on the control of CPM were enforced in Singapore with effect from 1 September 1999. These include licensing and labelling requirements, as well as control of microbial contamination. This article also reviews reports of excessive toxic heavy metals and undeclared drugs in CPM in Singapore between 1990 and 1997. The names, uses, toxic heavy metal or drug detected and the year of detection are tabulated. Information on the brand or manufacturer's name are provided whenever available. The public and healthcare professionals should be better informed of the basic concept of TCM and its usefulness, as well as the potential adverse effects associated with its use. Greater control over the safety and quality of CPM could be achieved through good manufacturing practice, regulatory control, research, education, reporting usage of Chinese medicine (as in drug history) as well as reporting of adverse events.

LC and LC-MS-MS analyses of undeclared codeine in antiasthmatic Chinese proprietary medicine.

This paper describes an accurate and sensitive reversed phase high-performance liquid chromatographic (RP-HPLC) method for the detection and quantification of undeclared codeine in a Chinese Proprietary Medicine (CPM) for asthma. A rapid and specific liquid chromatography-mass spectrometry-mass spectrometry (LC-MS-MS) method was applied to confirm the presence of codeine by selected reaction monitoring (SRM). Codeine was extracted from the capsules by dissolving in sodium dihydrogen phosphate buffer (10 mM, pH = 2.2) and ethanol, then made alkaline (pH = 9) and extracted using chloroform. The amount of codeine in AsthmaWan was found to be 61.8 microg/capsule (R.S.D. = 7.9%, n = 9). Excellent resolution was obtained despite the complexity of the product which claimed to contain at least nine herbal ingredients, none of which will give rise to codeine. As a further confirmation method, LC-MS-MS is accurate and specific. The LC method has been validated for linearity, limit of detection, limit of quantification, accuracy and specificity. Greater awareness of and control over undeclared drugs in complementary medicine are necessary to ensure patients' safety.