Chunyan Yang

Phenolic antioxidants from Rosa soulieana flowers

Rosa soulieana has been widely used in traditional medicine to treat cardiovascular disorders. In this study, antioxidant activity-guided fractionation and purification of the methanol extract from the flowers of R. soulieana has led to the isolation of nine phenolic antioxidants, which were identified as catechin (1), tiliroside (2), astragalin (3), isoquercitrin (4), nicotiflorin (5), eugenol 4-O-β-d-(6′-O-galloyl) glucoside (6), michehedyosides D (7), citrusin C (8) and strictinin (9), respectively. Among them, compounds 5–9 were reported from the genus Rosa for the first time. All the compounds were also assayed by in vitro ABTS [2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt] radical cation scavenging activity. Among these bioactive isolates (1–9), compounds 1, 6, 7 and 9 exhibited strong scavenging activity in ABTS (SC50 = 10.17, 7.38, 8.60, 4.72 μmol/L, respectively) compared with the positive control l-ascorbic acid (SC50 = 15.97 μmol/L).

Neolignans, lignans and glycoside from the fruits of Melia toosendan

Four new neolignans, meliasendanins A-D (1-4), and a new glycoside, toosenoside A (5), together with ten known ones (6-15), were isolated from a n-BuOH partition of the fruits of Melia toosendan. Their structures were elucidated by analyses of extensive spectroscopic data and comparison of the NMR data with those reported previously. Meliasendanin A (1) was a rare neolignan containing isochroman moiety, and its absolute configuration was determined using a CD spectrum. Toosenoside A (5) was an unusual glycoside with a rare naturally occurring aglycone and its structure was confirmed by X-ray single crystal diffraction analysis. The antioxidant activity of the isolated neolignans and lignans was evaluated by ABTS radical-scavenging assay. Compounds 1 and 13 exhibited strong antioxidant activity, with IC₅₀ values of 62.8 and 45.1 μM, respectively.

Cost-effective scat-detection dogs: unleashing a powerful new tool for international mammalian conservation biology.

Recently, detection dogs have been utilized to collect fecal samples from cryptic and rare mammals. Despite the great promise of this technique for conservation biology, its broader application has been limited by the high cost (tens to hundreds of thousands of dollars) and logistical challenges of employing a scat-detection dog team while conducting international, collaborative research. Through an international collaboration of primatologists and the Chinese Ministry of Public Security, we trained and used a detection dog to find scat from three species of unhabituated, free-ranging primates, for less than

Isolation and Characterization of New Phenolic Compounds with Estrogen Biosynthesis-Inhibiting and Antioxidation Activities from Broussonetia papyrifera Leaves

3,000. We collected 137 non-human primate fecal samples that we confirmed by sequencing taxonomically informative genetic markers. Our detection dog team had a 92% accuracy rate, significantly outperforming our human-only team. Our results demonstrate that detection dogs can locate fecal samples from unhabituated primates with variable diets, locomotion, and grouping patterns, despite challenging field conditions. We provide a model for in-country training, while also building local capacity for conservation and genetic monitoring. Unlike previous efforts, our approach will allow for the wide adoption of scat-detection dogs in international conservation biology.

Using eDNA to detect the distribution and density of invasive crayfish in the Honghe-Hani rice terrace World Heritage site

Broussonetia papyrifera leaves (BPL) as a traditional Chinese medicine are also used in livestock feed for stimulating reproduction, adipose tissue and muscle development; however, the mechanism of their action is still unknown. Through estrogen biosynthesis-guided fractionation in human ovarian granulosa-like KGN cells, five new phenolic glycosides, broussoside A–E(1–5), along with fifteen known dietary phenolic compounds, were isolated from the n-butanol extract of BPL, and their structures were elucidated on the basis of NMR spectra analysis and chemical evidence. New compounds 3, 4, 5 and the known compounds 9 and 10 were found to potently inhibit estrogen biosynthesis in KGN cells. In addition, compounds 9, 17, 18, and 20 showed strong antioxidant activity against ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt) and DPPH (1, 1′-diphenyl -2-picryl-hydrazyl radical) assays. These findings suggest that BPL may improve meat quality through the regulation of estrogen biosynthesis. Furthermore, they may be useful for the discovery of potential aromatase modulators from natural products. Finally, they could be considered as a new source for natural antioxidants.

Plant diversity accurately predicts insect diversity in two tropical landscapes

The Honghe-Hani landscape in China is a UNESCO World Natural Heritage site due to the beauty of its thousands of rice terraces, but these structures are in danger from the invasive crayfish Procambarus clarkii. Crayfish dig nest holes, which collapse terrace walls and destroy rice production. Under the current control strategy, farmers self-report crayfish and are issued pesticide, but this strategy is not expected to eradicate the crayfish nor to prevent their spread since farmers are not able to detect small numbers of crayfish. Thus, we tested whether environmental DNA (eDNA) from paddy-water samples could provide a sensitive detection method. In an aquarium experiment, Real-time Quantitative polymerase chain reaction (qPCR) successfully detected crayfish, even at a simulated density of one crayfish per average-sized paddy (with one false negative). In a field test, we tested eDNA and bottle traps against direct counts of crayfish. eDNA successfully detected crayfish in all 25 paddies where crayfish were observed and in none of the 7 paddies where crayfish were absent. Bottle-trapping was successful in only 68% of the crayfish-present paddies. eDNA concentrations also correlated positively with crayfish counts. In sum, these results suggest that single samples of eDNA are able to detect small crayfish populations, but not perfectly. Thus, we conclude that a program of repeated eDNA sampling is now feasible and likely reliable for measuring crayfish geographic range and for detecting new invasion fronts in the Honghe Hani landscape, which would inform regional control efforts and help to prevent the further spread of this invasive crayfish.

Higher fungal diversity is correlated with lower CO2 emissions from dead wood in a natural forest.

Plant diversity surely determines arthropod diversity, but only moderate correlations between arthropod and plant species richness had been observed until Basset et al. (Science, 338, 2012 and 1481) finally undertook an unprecedentedly comprehensive sampling of a tropical forest and demonstrated that plant species richness could indeed accurately predict arthropod species richness. We now require a high‐throughput pipeline to operationalize this result so that we can (i) test competing explanations for tropical arthropod megadiversity, (ii) improve estimates of global eukaryotic species diversity, and (iii) use plant and arthropod communities as efficient proxies for each other, thus improving the efficiency of conservation planning and of detecting forest degradation and recovery. We therefore applied metabarcoding to Malaise‐trap samples across two tropical landscapes in China. We demonstrate that plant species richness can accurately predict arthropod (mostly insect) species richness and that plant and insect community compositions are highly correlated, even in landscapes that are large, heterogeneous and anthropogenically modified. Finally, we review how metabarcoding makes feasible highly replicated tests of the major competing explanations for tropical megadiversity.

A novel phenolic acid from the fruits of Rosa soulieana

Wood decomposition releases almost as much CO2 to the atmosphere as does fossil-fuel combustion, so the factors regulating wood decomposition can affect global carbon cycling. We used metabarcoding to estimate the fungal species diversities of naturally colonized decomposing wood in subtropical China and, for the first time, compared them to concurrent measures of CO2 emissions. Wood hosting more diverse fungal communities emitted less CO2, with Shannon diversity explaining 26 to 44% of emissions variation. Community analysis supports a ‘pure diversity’ effect of fungi on decomposition rates and thus suggests that interference competition is an underlying mechanism. Our findings extend the results of published experiments using low-diversity, laboratory-inoculated wood to a high-diversity, natural system. We hypothesize that high levels of saprotrophic fungal biodiversity could be providing globally important ecosystem services by maintaining dead-wood habitats and by slowing the atmospheric contribution of CO2 from the world’s stock of decomposing wood. However, large-scale surveys and controlled experimental tests in natural settings will be needed to test this hypothesis.

Environmental DNA for the enumeration and management of Pacific salmon

From the n-BuOH-soluble fraction of a MeOH extract of the fruits of Rosa soulieana, one new phenolic glucoside (1) was isolated along with five known compounds, comprising two lignin glycosides, two flavonoid glycosides and a phenolic glycoside. The chemical structure of the new compound was elucidated by extensive spectroscopic analyses, including ESI-MS, UV, IR, 1H and 13C NMR, DEPT and 2D NMR (HSQC and HMBC). All the isolated compounds were evaluated for their antioxidant activity by using ABTS (2,2′-azino-bis(3-ethylbenzoline-6-sulfonic acid)) assay. Among these compounds, 1, 3 and 6 exhibited strong scavenging activity in ABTS√+(SC50 = 102.10, 193.85, 65.38 μmol/L, respectively) compared with the positive control l-ascorbic acid (Vc) (SC50 = 117.16 μmol/L).

Phenolic Compounds from Glycyrrhiza uralensis and their Radical-Scavenging Activity

Pacific salmon are a keystone resource in Alaska, with an economic impact of well over ∼US