Chemical constituents of Impatiens parvisepala and their α-glucosidase inhibition activity.

The first chemical study of the whole Impatiens parvisepala S. X. Yu & Y. T. Hou led to the isolation of a new triterpene saponin, named Iparvisepala-1 (6) along with ten known compounds, which cover three flavonoid glycosides (1-3), one dihydrochalcone glucoside (4), one triterpenoid saponin (5), one triterpene (7) and four miscellaneous compounds (8-11). Their structures were elucidated by MS, NMR spectroscopic analyses as well as by comparisons of spectra data with those of the related published literatures. Additionally, flavonoid glucoside 2 showed impressive effect on α-glucosidase inhibition with the IC50 value of 12.53 ± 0.39 µM, much better than that of the positive control acabose (IC50 = 197.53 ± 2.68 µM).

Chemical constituents of Impatiens chapaensis Tard. and their α-glucosidase inhibition activities.

Sixteen compounds (1-16) were isolated from Impatiens chapaensis. Chemical structures were determined by spectroscopic analyses and comparisons with previously published data. This report is the first to identify compounds 1, 5-7, 10, 12-14, and 16 from the genus Impatiens. Seven chosen isolates (5, 7, 10, 11, 12, 15, and 16) were submitted for α-glucosidase inhibition assays with acarbose as the positive control (IC50 = 227.14 ± 13.71 µM). Flavonoid 5 exhibited a significant inhibitory effect (IC50 = 101.00 ± 9.01 µM).

Phylogeny of Alpinia coriandriodora D. Fang and Implications for Character Evolution and Conservation.

BACKGROUND AND OBJECTIVE: Alpinia, the largest genus of Zingiberaceae, includes ca. 250 species. The A. coriandriodora D. Fang was recognized for Vietnamese flora. However, the systematic position of this species within Alpinia genus was unclear. The study aimed to understand the phylogenetic placement of A. coriandriodora based on the molecular data and interpret evolution of the key morphological characters. MATERIALS AND METHODS: The phylogenetic analysis were conducted by using the combined dataset of two DNA regions by both Maximum Likelihood (ML) and Bayesian Inference (BI) methods. Seven morphological characters were selected for morphological character evolution and the analysis was performed in Mesquite. RESULTS: Alpinia coriandriodora was supported closely related to southern Chinese species of Alpinia. Morphological character optimizations suggest that the presence/absence of tomentum in leaf, inflorescence rachis and ovary is an important character for the taxonomy of Alpinia. The character evolution analyses indicated that panicle is ancestral character in Alpinia. The A. coriandriodora shares different evolutionary histories based on our character re-construction to most members of Southeast Asian Alpinia. The presence of filament is supposed to be an adaptation to the pollination by insects for species of Alpinia. CONCLUSION: The present study revealed the molecular phylogenetic relationship of A. coriandriodora within Alpinia. The presence of filament could be an adaptation to the pollination by insects for species of Alpinia. Some reasonable conservation strategies are proposed to protect the species including maintenance of the plant's natural habitats, seeds or seedlings collection for germplasm storage and artificial breeding using biotechnology.

Chemical constituents from Melicope pteleifolia leaves.

Five acetophenones bearing spiroketal-hexofuranoside rings, one di-C-glycosidic acetophenone and two benzopyrans, along with 16 known compounds were isolated from the leaves of Melicope pteleifolia. Structures of all the isolates were elucidated using extensive spectroscopic methods, including 1D, 2D-NMR and HRESIMS. All the isolates were also evaluated for their neuraminidase inhibitory activities against H1N1, H9N2, wild-type H1N1 and oseltamivir-resistant H1N1 (H274Y mutation) virus strains. Of the isolates, tamarixetin 3-robinobioside was found to exhibit the strongest enzymatic inhibition (IC50 24.93 ± 3.46, 23.19 ± 5.41, 26.67 ± 5.16 and 40.16 ± 4.50 µM, respectively). Selected candidates, kaempferol 3-robinobioside, kaempferol 3-O-ß-d-glucopyranosyl (1 â†’ 2)-α-d-xylopyranoside and tamarixetin 3-robinobioside, also showed moderate reductions in H1N1-induced cytopathic effects on MDCK cells.