Akihito Takano

Effects of Two Terpene Alcohols on the Antibacterial Activity and the Mode of Action of Farnesol against Staphylococcus aureus

We have studied changes in the antibacterial activity and the mode of action of farnesol against Staphylococcus aureus when two terpene alcohols with an aliphatic carbon chain were added, individually, to a bacterial suspension that contained farnesol. Geraniol increased the growth-inhibitory activity of farnesol, but suppressed its ability to damage cell membranes, which is one of the predominant features of the growth-inhibitory activity of farnesol. Geranylgeraniol decreased the growth-inhibitory activity of farnesol and also suppressed its cell-damaging activity. It is possible that the presence of a terpene alcohol can both enhance and suppress the antibacterial activity of farnesol, and even change its mode of action. Thus, it is important to study not only the antibacterial activity of each constituent of an essential oil but also the interactions between them in efforts to characterize the antibacterial activity of the essential oil.

Metabolome analysis of Ephedra plants with different contents of ephedrine alkaloids by using UPLC-Q-TOF-MS.

Metabolome analysis of four varieties of Ephedra plants, which contain different amounts of ephedrine alkaloids, was demonstrated in this study. The metabolites were comprehensively analyzed by using ultra performance liquid chromatography (UPLC) coupled with quadrupole time-of-flight mass spectrometry (Q-TOF-MS) and the ephedrine alkaloids were also profiled. Subsequently, multivariate analyses of principal component analysis (PCA) and batch-learning self-organizing mapping (BL-SOM) analysis were applied to the raw data of the total ion chromatogram (TIC). PCA was performed to visualize the fingerprints characteristic for each Ephedra variant and the independent metabolome clusters were formed. The metabolite fingerprints were also visualized by BL-SOM analysis and were displayed as a lattice of colored individual cells which was characteristic for each Ephedra variant. BL-SOM analysis was also used for identification of chemical marker peaks because the information assigned to a cell represented either increases or decreases in peak intensities. Using this analysis, ephedrine alkaloids were successfully selected from the TICs as chemical markers for each Ephedra variant and this result suggested that BL-SOM analysis was an effective method for the selection of marker metabolites. We report our study here as a practical case of metabolomic study on medicinal resources.

Triterpenoids from Adiantum caudatum.

Three triterpenoids, 8alpha-hydroxyfernan-25,7beta-olide, 3alpha-hydroxy-4alpha-methoxyfilicane and 19alpha-hydroxyferna-7,9(11)-diene were isolated from the fresh fronds of Adiantum caudatum. Their structures were elucidated by spectroscopic techniques. Thirteen known triterpenoids were also identified from this fern.

High-Performance Liquid Chromatography Analysis of Capsaicin Content in 16 Capsicum Fruits from Nepal

Capsicum fruit, a popular spice as chili pepper, is an important ingredient of the formulations used in traditional medicines. Moreover, Capsicum fruit is listed as an official drug in several pharmacopoeias. Capsaicin, the most abundant component in Capsicum fruit, exhibits its therapeutic and adverse effects in a dose-dependent manner. Therefore, the known capsaicin content is the prerequisite for optimizing any formulation based on Capsicum fruit as a crude drug. We studied 16 samples of Capsicum fruits grown at different altitudes in Nepal and determined their capsaicin content by high-performance liquid chromatography. The capsaicin content was found to range from 2.19 to 19.73 mg/g of dry weight of Capsicum fruits. Capsaicin content in pericarp was found to be higher than in seeds. No correlation was found between the shape or size of the fruits and its capsaicin content. Our findings indicate that many of the formulations prepared from Capsicum fruit, even as described in pharmacopoeias, may vary in their strength, therapeutic activity, and possible side effects if the capsaicin content in Capsicum fruit is not standardized.

Antibacterial Activities Against Staphylococcus aureus of Terpene Alcohols With Aliphatic Carbon Chains

Abstract The antibacterial activities against Staphylococcus aureus of terpene alcohols with aliphatic carbon chains of various lengths were investigated. Farnesol and nerolidol, which each contain two isoprene units, had the strongest antibacterial activities and damaging effects on cell membranes of all the terpene alcohols tested. Plaunotol, which is a diterpene, had antibacterial activity similar to that of sesquiterpenes. The relationship between the length of the carbon chain bonded to the hydroxyl group and activity suggests that the length of the carbon chain is an important determinant of antibacterial activity and cell membrane-damaging activity. It was concluded that the carbon chain length of C10-C12 was appropriate to show the activity.

Development of an immunoassay using an anti-wogonin glucuronide monoclonal antibody

ABSTRACT Wogonin 7-O-β-D-glucuronide (Wgn) is a bioactive flavone present in the dried root of Scutellaria baicalensis Georgi. To generate a monoclonal antibody (MAb) against Wgn, BALB/c mice injected with Wgn–bovine serum albumin yielded splenocytes that we fused with SP2/0 myeloma cells using the polyethylene glycol method. We obtained a hybridoma designated 315A that produced a MAb reactive to Wgn. The anti-Wgn MAb 315A was applied to an indirect competitive enzyme-linked immunosorbent assay (icELISA) to quantify Wgn. Subsequent validation revealed that icELISA using the 315A anti-Wgn MAb is an accurate and reliable method for the quantification of Wgn in S. baicalensis.

Squalene Cyclases and Cycloartenol Synthases from Polystichum polyblepharum and Six Allied Ferns

Ferns are the most primitive of all vascular plants. One of the characteristics distinguishing them from flowering plants is its triterpene metabolism. Most cyclic triterpenes in ferns are hydrocarbons derived from the direct cyclization of squalene by squalene cyclases (SCs). Both ferns and more complex plants share sterols and biosynthetic enzymes, such as cycloartenol synthases (CASs). Polystichum belongs to Dryopteridaceae, and is one of the most species-rich of all fern genera. Several Polystichum ferns in Japan are classified as one of three possible chemotypes, based on their triterpene profiles. In this study, we describe the molecular cloning and functional characterization of cDNAs encoding a SC (PPH) and a CAS (PPX) from the type species Polystichum polyblepharum. Heterologous expression in Pichia pastoris revealed that PPH and PPX are hydroxyhopane synthase and CAS, respectively. By using the PPH and PPX sequences, we successfully isolated SC- and CAS-encoding cDNAs from six Polystichum ferns. Phylogenetic analysis, based on SCs and oxidosqualene cyclase sequences, suggested that the Polystichum subclade in the fern SC and CAS clades reflects the chemotype—but not the molecular phylogeny constructed using plastid molecular markers. These results show a possible relation between triterpenes and their biosynthetic enzymes in Polystichum.