Preliminary chemical characterization of ethanolic extracts from Colombian plants with promising anti - Trypanosoma cruzi activity.

Chagas disease is caused by Trypanosoma cruzi, and it is an important cause of morbidity and mortality in Latin America. There are no vaccines, and the chemotherapy available to treat this infection has serious side effects. In a search for alternative treatments, we determined the in vitro susceptibility of epimastigote and trypomastigote forms of T. cruzi and the cytotoxic effects on peripheral blood mononuclear cells (PBMCs) of ethanolic extracts obtained from six different plant species. The ethanolic extracts of Ageratina vacciniaefolia, Clethra fimbriata and Siparuna sessiliflora showed antiprotozoal activity against epimastigotes and low cytotoxicity in mammalian cells. However, only the ethanolic extract of C. fimbriata showed activity against T. cruzi trypomastigotes, and it had low cytotoxicity in PBMCs. An analysis on the phytochemical composition of C. fimbriata extract showed that its metabolites were primarily represented by two families of compounds: flavonoids and terpenoids. Lastly, we analyzed whether the A. vacciniaefolia, C. fimbriata, or S. sessiliflora ethanolic extracts induced IFN-γ or TNF-α production. Significantly, ethanolic extracts of C. fimbriata induced TNF-α production and S. sessiliflora induced both cytokines. In addition, C. fimbriata and S. sessiliflora induced the simultaneous secretion of IFN-γ and TNF-α in CD8+ T cells. The antiprotozoal and immunomodulatory activity of C. fimbriata may be related to the presence of flavonoid and triterpene compounds in the extract. Thus, these findings suggest that C. fimbriata may represent a valuable source of new bioactive compounds for the therapeutic treatment of Chagas disease that combines trypanocidal activity with the capacity to boost the immune response.

Uptake and dissipation of neonicotinoid residues in nectar and foliage of systemically treated woody landscape plants.

Systemic neonicotinoid insecticides used in urban arboriculture could pose a risk to bees and other pollinators foraging on treated plants. We measured uptake and dissipation of soil-applied imidacloprid and dinotefuran in nectar and leaves of 2 woody plant species, a broadleaf evergreen tree (Ilex × attenuata) and a deciduous shrub (Clethra alnifolia), to assess concentrations to which pollinators and pests might be exposed in landscape settings. Three application timings, autumn (postbloom), spring (prebloom), and summer (early postbloom), were evaluated to see if taking advantage of differences in the neonicotinoids' systemic mobility and persistence might enable pest control while minimizing transference into nectar. Nectar and tissue samples were collected from in-ground plants and analyzed for residues by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) in 2 successive years. Concentrations found in nectar following autumn or spring applications ranged from 166 to 515 ng/g for imidacloprid and from 70 to 1235 ng/gg for dinotefuran, depending on plant and timing. These residues exceed concentrations shown to adversely affect individual- and colony-level traits of bees. Summer application mitigated concentrations of imidacloprid (8-31 ng/g), but not dinotefuran (235-1191 ng/g), in nectar. Our data suggest that dinotefuran may be more persistent than is generally believed. Implications for integrated pest and pollinator management in urban landscapes are discussed. Environ Toxicol Chem 2018;37:860-870. © 2017 SETAC.

The Chemical Constituents of Uninvestigated Plants in Hiroshima Prefecture.

Recently, the investigation of bioactive constituents from natural products has been performed extensively around the world, yet many plants remain to be studied, even now. The author is especially interested in saponins, which are included in various natural products and Kampo medicines. Based on these study aims, we isolated the chemical constituents of Dianthus japonicus and Clethra barbinervis. The aerial parts of Dianthus japonicus were isolated into nine new (1-9) and seven known oleanane-type triterpene saponins. The structural elucidation of their chemical constituents was examined by several spectroscopic methods. Two new C-glycosyl flavones, two glycosidic derivative of anthranilic acid amides and a maltol glucoside were also isolated from this plant. The isolated compounds were evaluated according to cytotoxic inhibition toward A549 cell lines. Compounds 7-9 showed moderate inhibitory activity. The isolation of a MeOH extract of Clethra barbinervis leaves led to three new triterpene glucosides, i.e. an ursane (ryobunin A, 22), a seco-ursane (ryobunin B, 23) and an oleanane-type glucoside (ryobunin C, 24), along with four known compounds.

Evaluation of microelement contents in Clethra barbinervis as food for human and animals in contrasting geological areas.

The young leaves of Clethra barbinervis Sieb. et Zucc, which is a deciduous tree species found in secondary forests widely in Japan, are used in spring as a local traditional food by local populations, and the bark of this plant is also preferred by sika deer, Cervus nippon. However, C. barbinervis has been known to accumulate heavy metals in its leaves. Then, we aimed to clarify the characteristics of microelement contents in C. barbinervis and to discuss the value of this species as food for humans and animals through the analysis of seasonal changes and distribution in various organs of C. barbinervis growing under two different geological conditions. We found that C. barbinervis is an accumulating and tolerant plant for Ni, Co and Mn. It accumulates Ni from serpentine soil containing Ni at high concentration, and Co and Mn from acidic soils based on crystalline schist. The seasonal variation in element concentrations in leaves indicates that the young leaves contain Cu at high concentration and that eating them in spring season may be advantageous to humans, due to the associated increase in Cu intake. The high concentrations of Cu and Zn in the bark of C. barbinervis might explain why deer prefer to eat the bark of this species.

Structures of ryobunins A-C from the leaves of Clethra barbinervis.

From a MeOH extract of the leaves of Clethra barbinervis Sieb. et Zucc., ryobunins A-C, three new triterpene glucosides, i.e. one ursane, one seco-ursane and one oleanane-type glucoside, along with four known compounds were isolated. Their structures were elucidated based on chemical and spectral evidence.

Triterpene saponins from Clethra barbinervis and their hyaluronidase inhibitory activities.

An extract of Clethra barbinervis with an inhibitory effect on hyaluronidase activity was fractionated guided by the results of an assay. From the active fractions, seven new triterpene saponins (1-4, 6-8) and a new lignan glycoside (14) were isolated together with 14 known compounds (5, 9-13, 15-22). Some of the saponins (2, 3, 9) were revealed as hyaluronidase inhibitors similar to epicatechin (17).

Simultaneous determination of nickel and copper by H-point standard addition method-first-order derivative spectrophotometry in plant samples after separation and preconcentration on modified natural clinoptilolite as a new sorbent.

For the simultaneous determination of nickel(ll) and copper(ll) in plant samples, a rapid and accurate method was developed. In this method, solid-phase extraction (SPE) and first-order derivative spectrophotometry (FDS) are combined, and the result is coupled with the H-point standard addition method (HPSAM). Compared with normal spectrophotometry, derivative spectrophotometry offers the advantages of increased selectivity and sensitivity. As there is no need for carrying out any pretreatment of the sample, the spectrophotometry method is easy, but because of a high detection limit, it is not so practical. In order to decrease the detection limit, it is suggested to combine spectrophotometry with a preconcentration method such as SPE. In the present work, after separation and preconcentration of Ni(ll) and Cu(ll) on modified clinoptilolite zeolite that is loaded with 2-[1-(2-hydroxy-5-sulforphenyl)-3-phenyl-5-formaza-no]-benzoic acid monosodium salt (zincon) as a selective chromogenic reagent, FDS-HPSAM, which is a simple and selective spectrophotometric method, has been applied for simultaneous determination of these ions. With optimum conditions, the detection limit in original solutions is 0.7 and 0.5 ng/mL, respectively, for nickel and copper. The linear concentration ranges in the proposed method for nickel and copper ions in original solutions are 1.1 to 3.0 x 10(3) and 0.9 to 2.0 x 10(3) ng/mL, respectively. The recommended procedure is applied to successful determination of Cu(ll) and Ni(ll) in standard and real samples.