Authentication of the traditional medicinal plant Eleutherococcus senticosus by DNA and chemical analyses.

Shigoka (SGK), the rhizome of Eleutherococcus senticosus, is a traditional medicine used as a tonic in northeastern Asia and far eastern Russia. We analyzed the nuclear ribosomal DNA internal transcribed spacer (ITS) sequence of the medicine available on the Japanese and Chinese markets and found that at least 3 species were used as the source plant of the commercial SGKs and that only 70% of all samples was made from the correct species. Furthermore, we performed the quantitative determination of 3 marker compounds, eleutheroside B (EB), syringaresinol diglucoside (Syr), and isofraxidin (Iso) by ultraperformance liquid chromatography (UPLC)/mass spectrometry (MS). We found that EB and Iso are specific to the correct source plant of SGK. Of them, EB is thought to be the best marker compound for quality assurance of the SGK from the viewpoint of its pharmacological activity.

Authentication and chemical study of isodonis herba and isodonis extracts.

Isodonis Herba is used as a Japanese dietary supplement and folk medicine. The extract of the herb (Isodonis extract) is also used as a food additive whose major compound is enmein (1). Here we compared internal transcribed spacer sequences of nuclear ribosomal DNA from Isodonis Herba available on the Japanese and Chinese crude drug markets, and found that the former derived from Isodon japonicus and Isodon trichocarpus, while the latter derived from distinct species such as Isodon eriocalyx. The liquid chromatography/mass spectrometry profiles of Isodonis Herba were classified into four chemotypes (A to D) according to the ratio of the major constituents. Types B and C contained 1 and oridonin (2) as major components, respectively. An intermediate (or mixed) form of types B and C in various ratios was designed type A. Type D contained eriocalyxin B (3) as its major component. Japanese herba were types A-C, while Chinese herba were types C and D. The commercial Isodonis extract products tested were classified as type D, suggesting that they originated from Chinese Herba. Understanding the relationship between extract constituents and DNA profiles is important for the official specification of dietary supplements and food additives of plant origin.

DNA authentication of Plantago Herb based on nucleotide sequences of 18S-28S rRNA internal transcribed spacer region.

Internal transcribed spacer (ITS) regions of nuclear ribosomal RNA gene were amplified from 23 plant- and herbarium specimens belonging to eight Plantago species (P. asiatica, P. depressa, P. major, P. erosa, P. hostifolia, P. camtschatica, P. virginica and P. lanceolata). Sequence comparison indicated that these Plantago species could be identified based on the sequence type of the ITS locus. Sequence analysis of the ITS regions amplified from the crude drug Plantago Herb obtained in the markets indicated that all the drugs from Japan were derived from P. asiatica whereas the samples obtained in China were originated from various Plantago species including P. asiatica, P. depressa, P. major and P. erosa.

Regiocontrolled Iodoaminocyclization Reaction of an Ambident Nucleophile Mediated by Basic Metallic Reagent.

A new and general method of iodine-mediated cyclization reactions of allyl or homoallyl carbamates, ureas, and amides was found to give N-cyclized products as single regioisomers. The present reaction proceeded in good yield through regiocontrol (N-cyclization > O-cyclization) and the increase in the reactivity of an ambident nucleophile by a basic metallic reagent. The N-cyclization selectivity was remarkably affected by the additive employed. The iodoaminocyclization reaction of the homoallyl carbamates and ureas with a chiral center at the homoallylic position was found to proceed with high 1,3-cis- and 1,3-trans-selectivity, respectively.