Wild imitating vs greenhouse cultivated Dendrobium huoshanense: Chemical quality differences.

Dendrobium huoshanense (D. huoshanense) has been used as functional food supplements and herbal medicines for preventing and managing diseases with a long history in China. Due to its endangered natural resources and huge demand, people tend to cultivate D. huoshanense to protect this species. However, the quality of wild and cultivated herbs of the same species may change. This work quantified and compared the main quality traits and chemical components of wild imitating and greenhouse cultivated D. huoshanense with different growth years. As a result, wild and cultivated D. huoshanense had similar chemical composition, but there are significant differences in the content of many ingredients (polysaccharides, flavonoids, nucleosides, bibenzyls, lignans and volatile compounds). And the contents of many of these components increased with growing years. In addition, multivariate statistical analyses have been applied to classify and evaluate samples from different cultivation modes according to these components. In conclusion, our results demonstrated that the overall quality of greenhouse cultivated D. huoshanense was not as good as wild-grown, but this mode can be a promising and sustainable way of producing D. huoshanense.

Identification of lignans and quality assessment in Dendrobium officinale under different cultivation modes.

RATIONALE: Lignans have attracted much attention from researchers because of their wide distribution and industrial applications in plants, as well as the remarkable diversity of their biological activities. As the literature has mainly focused on the extraction and identification of monomeric compounds of lignans, most lignans in Dendrobium officinale, a traditional Chinese medicine with a long cultivation history and rich sources, have not been detected using quality control methods. The aim of this study was to identify the lignans in Dactilon officinale. METHODS: High-performance liquid chromatography (HPLC) coupled with diode array detection and HPLC multiple-stage tandem mass spectrometry was used to identify the chemical constituents of D. officinale. Simultaneously, the characteristic chromatograms of D. officinale were established. Additionally, a method was established to determine the content of syringaresinol-4,4'-di-O-ß-D-glucoside, syringaresinol-4-O-ß-D-glucoside and syringaresinol. RESULTS: Thirty-three lignans, including 17 tetrahydrofuran lignans, two dibenzylbutane lignans, three aryl tetrahydronaphthalene lignans and 11 8-O-4'-neolignans, were tentatively identified from the methanol extract of the stems of D. officinale. This is the first report of 8-O-4'-neolignans from D. officinale. In addition, a total of eight characteristic peaks were marked in characteristic chromatograms, which were identified as lyoniresinol-9'-O-ß-D-glucoside, syringaresinol-4,4'-di-O-ß-D-glucoside, 8-hydroxy-syringaresinol-4-O-ß-D-glucoside, 5,5'-dimethoxy-lariciresinol-4-O-ß-D-glucoside, syringaresinol-4-O-ß-D-glucoside, 4-hydroxy-3,3',5,5'-tetramethoxy-8,4'-oxyneoligna-7'-ene-9,9'-diol-9-O-ß-D-glucoside, 4-hydroxy-3,3',5,5'-tetramethoxy-8,4'-oxyneoligna-7'-ene-9,9'-diol-4-O-ß-D-glucoside and syringaresinol. Our results showed that no significant difference occurred in lignan composition among the 99 batches of D. officinale from different sources. However, the peak areas of the lignans of D. officinale planted under simulated wild culture were generally higher than those in greenhouses, and showed an upward trend with the increase in growth years. The average contents of syringaresinol-4,4'-di-O-ß-D-glucoside, syringaresinol-4-O-ß-D-glucoside and syringaresinol were 10.112-179.873, 51.227-222.294 and 6.368-120.341 µg/g, respectively. CONCLUSIONS: This study provided a basis for improving the quality control of D. officinale and could provide references for the identification of lignans in other Dendrobium species.

Identification of bibenzyls and evaluation of imitative wild planting techniques in Dendrobium officinale by HPLC-ESI-MSn.

Dendrobium officinale is a traditional Chinese herb with beneficial properties. Modern pharmacological studies show that bibenzyl is one of the antitumor active ingredients, but there is no effective quality control method for identifying ingredients. In this study, the composition of bibenzyls in Dendrobium officinale was studied by high-performance liquid chromatography coupled with electrospray ionization multistage mass spectrometry (HPLC-ESI-MSn ). A total of nine isolated bibenzyls and their glycosides, 22 bis (bibenzyls), and two phenylpropanol bibenzyl derivatives were identified. The results of HPLC characteristic chromatogram analysis and statistical analysis showed that the relative content of bibenzyls in wild imitation cultivation of samples had been significantly higher than that in greenhouse cultivation. In addition, the relative content of bibenzyls increased with the growth of the original plant. This study provided a scientific reference for controlling the quality of bibenzyls in Dendrobium officinale, developing the cultivation technology and improving the quality of Dendrobium officinale. HIGHLIGHTS: HPLC-ESI-MS/MS method for the analysis of bibenzyls and bis (bibenzyls) in Dendrobium officinale. Easy-to-use method facilitating rapid measurement of large sample quantities. The method requires only small volumes of samples for the analysis. Applicable for the establishment of Chinese medicine studies and the quality control standard of Chinese herbs.

Identification of three types of O-glycosylated flavonoids in Dendrobium loddigesii, Dendrobium primulinum, Dendrobium crepidatum, Dendrobium porphyrochilum, and Dendrobium hancockii using mass spectrometry.

RATIONALE: Flavonoids, representing the pharmacologically active ingredients, are found widely in Dendrobium species. The biodiversity of Dendrobium makes the identification of its varieties all the more complicated. Previous studies showed that C-glycosylated flavones and a few O-glycosylated flavonols could be used in the identification of various Dendrobium species. Accordingly, this study further explores the significance of the identification of various types of O-glycosylated flavonoids in Dendrobium species. METHODS: High-performance liquid chromatography coupled with electrospray ionization multistage tandem mass spectrometry (HPLC-ESI-MSn ) was used to identify the chemical constituents in five types of Dendrobium: Dendrobium loddigesii, Dendrobium primulinum, Dendrobium crepidatum, Dendrobium porphyrochilum, and Dendrobium hancockii. RESULTS: A total of 41 O-glycosylated flavonoids and 3 C-glycosylated flavones were identified, among which O-glycosylated dihydroflavones were the main flavonoids in D. loddigesii and D. primulinum, O-Glycosylated flavonols were rich in both D. crepidatum and D. porphyrochilum characterized by the main aglycone, substituted sugars, and their structural characteristics, and O-glycosylated flavones were the main constituents in D. hancockii. CONCLUSIONS: In this study, three types of O-glycosylated flavonoids in the five Dendrobium species were determined to have certain significance. This also provides a reference for the identification of other O-glycosylated flavonoids in Chinese herbs.

[Influence of surface water availability on mammal distributions in Nonggang National Nature Reserve, Guangxi, China].

Surface water is a major limiting factor affecting animal activities in karst ecosystems. From March, 2006 to June, 2007 and from October, 2010 to May, 2011, infra-red camera traps were installed along animal trails and temporary rain pools in Nonggang National Nature Reserve, Guangxi, China, to monitor mammal diversity and relative abundance. In total, 19 species from 17 genera, 12 families, and 5 orders were recorded, including two State Key Protection Class I species, the François' langur (Trachypithecus francoisi) and Assam macaque (Macaca assamensis). Although 42% of species only occurred in one of the microhabitats, differences in species assemblages between trails and pools were not significant. The results of our observation indicated that camera trapping was effective in monitoring medium to large sized mammals, and for recording illegal hunting. In addition, our results suggest that authorities should reinforce patrolling, especially at water pools during the dry season, and eradicate unsustainable extraction of underground water. Moreover, based on the advantages of large inhibited environments to animal species, especially to large predators, we also recommend connecting the three isolated sections of the reserve to promote species recovery and dispersal.

A new species of Kaloula (Amphibia: Anura: Microhylidae) from southern Guangxi, China.

A new species of narrow-mouthed frog of Kaloula is described in the Nonggang National Nature Reserve, Sino-Vietnamese border region of southern China. Kaloula nonggangensis sp. nov. is distinguished from its congeners by a combination of the following characters: medium size (SVL 41.4-52.7 mm in 18 adult males, 52.2 mm in 1 female); smooth or slightly rough olive dorsum with irregular dark-green marks and brown spots; tips of the fingers widely dilated and truncated; males with nearly fully webbed toes; males with two side protuberant osseous tubercles on the upper surface of the tips of fingers and chest beige with small lemon-colored spots. K. nonggangensis sp. nov. is found in habitats ranging from cultivated fields adjacent to the forest to primary evergreen forest in karst habitats. Based upon a 16S ribosomal RNA mitochondrial gene fragment, K. nonggangensis sp. nov. is embedded within the K. verrucosa group (including K borealis, K. rugifera and K. verrucosa), and displays a low genetic distance to these species (< 3%). Considering the distinct morphology and karyotype we nevertheless suggest a status as separate species for these allopatrically distributed lineages.

[Guild structure of forest breeding bird community in Nonggang Nature Reserve of Guangxi].

Surveys about the breeding bird guild structure in karst forest of Nonggang Nature Reserve, Guangxi Zhuang Autonomous Region, were conducted successively in May-July 2010, 2011 and 2012. The feeding modes, foraging strata and foraging heights of 44 breeding bird species were analyzed by clustering and principal component method. The results indicated that the avian community could be divided into 6 guilds, including ground feeding guild, lower feeding guild, upper feeding guild, multilayer feeding guild, trunk feeding guild and air strike guild. Depending on the vegetation structure of Nonggang karst forest and feeding habits, middle layer, lower layer and multilayer feeding guilds were dominant in the karst monsoon forest. Data suggests that the birds tried to alleviate competition pressures by increasing niche breadth, so multilayer feeding guild was formed.

[Seasonal feeding site selection of the Nonggang Babbler (Stachyris nonggangensis) in Nonggang, Guangxi, China].

We investigated the feeding sites of the Nonggang Babbler (Stachyris nonggangensis) during three time periods (July-September, 2010; November-December, 2010; January-February, 2011) in Nonggang National Nature Reserve, Guangxi, China with the line transect method and sampling method. Principal component analysis of the data identified that the feeding sites in the rainy season were dominated by factors consisting of tree layer, the layer of fallen leaves and the herb layer; whereas the feeding sites in the dry season were dominated by factors dependant on terrain, herb layer and shrub layer. The results of a circular distribution analysis showed that the Nonggang Babbler preferred feeding sites with a gentle slope in both the rainy season and dry season. The tests of differences of the variables between used and control plots indicated that with low arbor coverage in the rainy season, whereas with a low slope position, high shrub and thick fallen leaves in the dry season. In comparison with the rainy season, the feeding sites in the dry season tended to be at lower altitude, to have a lower slope position, lower grass coverage, and to be covered with a larger and thicker bed of fallen leaves. A logistic regression analysis suggested that altitude, slope, and shatter cover were the most important factors influencing feeding site selection in the rainy season. Slope position, arbor cover, grass cover, and the thickness of the shatter cover were the most important factors influencing feeding site selection in the dry season.