Chemical constituents from the stem of Ficus pumila.

A new biphenyl compound: 5-aldehyde-4'-hydroxy-2,2'-dimethoxybiphenyl (1), along with 11 known phenolic compounds (2-12) were isolated from the stem of Ficus pumila Linn. Their structures were established by spectroscopic methods, including MS, UV, IR, 1 D and 2 D NMR. Compounds 4 and 10 showed weakly cytotoxicity against MCF-7, with IC50 values of 32.5 and 37.3 µM, respectively.

Nicotine depresses facial stimulation-evoked molecular layer interneuron-Purkinje cell synaptic transmission via α7 nicotinic acetylcholine receptors in mouse cerebellar cortex.

Nicotine modulates cerebellar physiology function by interacting with nicotinic acetylcholine receptors (nAChRs) and is involved in modulation of cerebellar cortical circuitry functions. Here, we investigated the effect of nicotine on sensory stimulation-evoked molecular layer interneuron-Purkinje cell (MLI-PC) synaptic transmission mouse cerebellar cortex using in vivo cell-attached recording technique and pharmacological methods. The results show that micro-application of nicotine to the cerebellar molecular layer significantly decreased sensory stimulation-evoked MLI-PC synaptic transmission in mouse cerebellar cortex. Nicotine-induced depression in sensory stimulation-evoked MLI-PC synaptic transmission was abolished by either a non-selective nAChR blocker, hexamethonium, or the α7-nAChR antagonist methyllycaconitine (MLA), but not the selective α4ß2-nAChR antagonist dihydro-ß-erythroidine. Notably, molecular layer micro-application of nicotine did not significantly affect the number of spontaneous or facial stimulation-evoked action potentials of MLIs. Moreover, nicotine produced significant increases in the amplitude and frequency of miniature inhibitory postsynaptic currents of PCs, which were abolished by MLA in cerebellar slices. These results indicate that micro-application of nicotine to the cerebellar molecular layer depresses facial stimulation-induced MLI-PC synaptic transmission by activating α7 nAChRs, suggesting that cholinergic inputs modulate MLI-PC synapses to process sensory information in the cerebellar cortex of mice in vivo.

One new piperazinedione isolated from a mangrove-derived fungus Aspergillus niger JX-5.

One new piperazinedione derivative, nigerpiperazine A (1), along with six known compounds (2-7) were isolated from the fungus Aspergillus niger JX-5 from mangrove Ceriops tagal. Nigerpiperazine A (1) was elucidated by spectroscopic analyses and 13C NMR chemical shift calculations, compounds 4 and 5 were determined by X-ray and the CD spectra. The absolute configuration of 4 was identified by X-ray for the first time. Compounds 1 and 4 showed inhibitory activities against Helicoverpa armigera Hubner with the IC50 values of 200 and 100 µg/mL, respectively.

A new isoflavone from the fruits of Ficus auriculata and its antibacterial activity.

A new isoflavone (Z)-5,7,4'-trihydroxy-3'-[3-hydroxy-3-methyl-1-butenyl] isoflavone (1) together with seven known isoflavones (2-8) were isolated from the fruits of the Ficus auriculata. Their structures were established on the basis of 1 D, 2 D-NMR spectroscopic data and HR-ESI-MS analysis. All compounds were evaluated for their antibacterial activities against five pathogenic bacteria in vitro. Compounds 3 and 4 exhibited significant antibacterial activities against five pathogenic bacteria with the MIC values ranging from 1.25 to 20 µg/mL.[Formula: see text].

Phenolic glycosides from the stems of Homalium stenophyllum.

The phytochemical investigation of the stems of Homalium stenophyllum afforded seven new phenolic glycosides (1-5 and 8-9) and two known compounds (6 and 7). Their structures were elucidated by comprehensive analyses of NMR spectroscopic, mass spectrometric data and chemical hydrolysis. Additionally, their anti-inflammatory activities against the NO production in LPS-induced macrophages were evaluated.

Aristololactam alkaloids from the roots of Dasymaschalon rostratum.

A novel aristololactam alkaloid, dasymalactam A (1), together with nine known analogues (2-10), were isolated from the roots of Dasymaschalon rostratum. Their structures were elucidated by IR, NMR and MS spectrums and comparisons with data reported in the literature. All compounds demonstrated weak cytotoxicity against Hela, MCF-7, A-549, MGC-803, and COLO-205 human cancer cell lines.

Two new cephalochromin derivative from the Alternaria sp. ZG22.

Two new cephalochromin derivatives, prenylcephalochromin A (1), prenylcephalochromin B (2), along with cephalochromin (3) were isolated from the Alternaria sp. ZG22 obtained from a Dasymaschalon rostratum collected from the Hainan. The structures of two new compounds were elucidated by comprehensive spectroscopic methods. Compounds 1-3 showed α-glucosidase inhibitory activity.

A conceptual framework to untangle the concept of urban ecosystem services.

Urban ecosystem service (UES) is becoming an influential concept to guide the planning, design, and management of urban landscapes towards urban sustainability. However, its use is hindered by definitional ambiguity, and the conceptual bases underpinning its application remain weak. This is exemplified by two different but equally valid interpretations of UES: "urban ecosystem services", referring to ecosystem services from analogs of natural and semi-natural ecosystems within urban boundaries, and "urban ecosystem services", a much broader term that includes the former group as well as urban services in a city. While we recognize that a single definition of UES is not possible nor necessary as its application is context-dependent, it is nevertheless useful to clarify the relationships between these interpretations to promote consistent use, and importantly, explore how a broader interpretation of UES might advance its applications in areas that have been neglected. We developed a conceptual framework that links UES to natural and human-derived capital to explain the relationships between the dual meanings of UES and proposed three normative propositions to guide its application: (1) integrate holistically multiple components of natural capital to provide UES, (2) reduce dependence on non-renewable abiotic resources and human-derived capital, and (3) enhance UES through technology. The framework we developed helps to resolve the current ambiguity in the meanings of UES, highlights the need to recognise neglected aspects of natural capital important for UES, and can be used to clarify relationships with related concepts conveying dependence of human well-being on nature.

Social media, nature, and life satisfaction: global evidence of the biophilia hypothesis.

Humans may have evolved a need to connect with nature, and nature provides substantial cultural and social values to humans. However, quantifying the connection between humans and nature at a global scale remains challenging. We lack answers to fundamental questions: how do humans experience nature in different contexts (daily routines, fun activities, weddings, honeymoons, other celebrations, and vacations) and how do nature experiences differ across countries? We answer these questions by coupling social media and artificial intelligence using 31,534 social media photographs across 185 countries. We find that nature was more likely to appear in photographs taken during a fun activity, honeymoon, or vacation compared to photographs of daily routines. More importantly, the proportion of photographs with nature taken during fun activities is associated with national life satisfaction scores. This study provides global evidence of the biophilia hypothesis by showing a connection between humans and nature that contributes to life satisfaction and highlights how nature serves as background to many of our positive memories.

Using social media user attributes to understand human-environment interactions at urban parks.

Urban parks and green spaces are among the few places where city dwellers can have regular contact with nature and engage in outdoor recreation. Social media data provide opportunities to understand such human-environment interactions. While studies have demonstrated that geo-located photographs are useful indicators of recreation across different spaces, recreation behaviour also varies between different groups of people. Our study used social media to assess behavioural patterns across different groups of park users in tropical Singapore. 4,674 users were grouped based on the location and content of their photographs on the Flickr platform. We analysed how these groups varied spatially in the parks they visited, as well as in their photography behaviour. Over 250,000 photographs were analysed, including those uploaded and favourited by users, and all photographs taken at city parks. There were significant differences in the number and types of park photographs between tourists and locals, and between user-group axes formed from users' photograph content. Spatial mapping of different user groups showed distinct patterns in the parks they were attracted to. Future work should consider such variability both within and between data sources, to provide a more context-dependent understanding of human-environment interactions and preferences for outdoor recreation.

Three new methylated Δ8-pregnene steroids from the Polyalthia laui-derived fungus Stemphylium sp. AZGP4-2.

Three new methylated Δ8-pregnene steroids, stemphylisteroids A-C (1-3) were isolated from the medicinal plant Polyalthia laui-derived fungus Stemphylium sp. AZGP4-2. Their structures were elucidated by the detailed analysis of comprehensive spectroscopic data. The absolute configuration of 1 was determined by X-ray crystallographic analysis. Compound 1 show antibacterial activity against Escherichia coli with the MIC value of 6.25 µg/mL, and 2 exhibited a broad spectrum of antibacterial activities against six pathogenic bacteria with the MIC values ranging from 12.5 to 50 µg/mL. The discovery of three methylated Δ8-pregnene steroids 1-3 are a further addition to diverse and complex array of methylated steroids.

Four New Chromone Derivatives from Colletotrichum gloeosporioides.

Four previously unreported chromones, 5-hydroxy-2-(hydroxymethyl)-8-methoxy-4H-chromen-4-one (1), (5R,7S)-5,7-dihydroxy-2-propyl-5,6,7,8-tetrahydro-4H-chromen-4-one (2), (5R,7S)-5,7-dihydroxy-2-methyl-5,6,7,8-tetrahydro-4H-chromen-4-one (3), and (5R,7S)-5,7-dihydroxy-2-[(E)-prop-1-en-1-yl]-5,6,7,8-tetrahydro-4H-chromen-4-one (4), as well as one known analogue 5-hydroxy-2-methyl-4H-chromen-4-one (5) were isolated from the fermentation broth of the endophytic fungus Colletotrichum gloeosporioides derived from the mangrove Ceriops tagal. Their structures were elucidated based on extensive spectroscopic analyses. The absolute configurations of 2-4 were determined by comparison the experimental and calculated electronic circular dichroism (ECD) spectra. Compound 2 showed cytotoxic activity against A549 cell line with the IC50 value of 0.094 mm.

Particulate matter mitigation via plants: Understanding complex relationships with leaf traits.

Elevated levels of airborne particulate matter (PM) pose health risks to populations living in many cities worldwide. To remediate the impact of air pollution, urban greening has been increasingly explored as a possible way to remove PM from the surroundings. However, existing research focuses mainly on species-specific assessments within temperate climates that may not necessarily grow outside of their local regions. To address sampling limitations associated with the great species diversity in the tropics, our study quantified three key functional traits-leaf hairiness, average leaf area (ALA) and specific leaf area (SLA)-each spanning a wide range of values across 20 tropical species. Wind-tunnel experiments were used to assess surface deposition velocity on leaves; the size fractions PM10 and PM2.5 were measured through multiple rounds of filtration and gravimetric analysis. The effects of upper- and lower-surfaces of leaves on deposition velocity and their interactions with hairiness were also investigated. Results show that greater upper-surface hairiness and a low SLA were consistent predictors of higher deposition velocity for both PM-size fractions. Hairs on leaves serve as obstacles while low SLA tends to be associated with smaller and thicker leaves, together favoring the deposition and retention of PM. The possible mechanisms behind important plant traits and their interactions are discussed. By testing quantifiable effects of specific plant traits, we provide generalizable findings that may be applied to urban greening efforts. Future work to consider other gaseous pollutants and plant-scale effects can help ensure a more comprehensive evaluation of plant suitability for pollutant mitigation.

Three new polyketides from a mangrove-derived fungus Colletotrichum gloeosporioides.

Three new polyketides, (2S)-2,3-dihydro-5,6-dihydroxy-2-methyl-4H-1-benzopyran-4-one (1), (2'R)-2-(2'-hydroxypropyl)-4-methoxyl-1,3-benzenediol (2), and 4-ethyl-3-hydroxy-6-propenyl-2H-pyran-2-one (3) were isolated from the culture broth of Colletotrichum gloeosporioides, an endophytic fungus derived from the mangrove Ceriops tagal. The structures of 1-3 were elucidated on the basis of NMR spectra and HR-ESI-MS data. Their absolute configurations were determined by comparing with the experimental and calculated ECD spectrum. Compounds 1 and 3 showed potent antibacterial activities against some of the tested microbes.

3,4- seco-Norclerodane Diterpenoids from the Roots of Polyalthia laui.

Ten new clerodane diterpenoids, polylauioids A-J (1-10), and five known analogues (11-15) were isolated from the roots of Polyalthia laui. Among the new compounds, 3 and 8 are artifacts. The structures were elucidated using spectroscopic methods and by comparison with published NMR spectroscopic data. The absolute configurations of 4, 5, and 7 were defined based on single-crystal X-ray diffraction and electronic circular dichroism data. Compounds 1 and 2 represent the first examples of rearranged 3,4- seco-norclerodane diterpenoids, and a putative biosynthesis pathway for these compounds is proposed. Compounds 1, 4, 6, 7, 9, and 10 showed anti-HIV activities with EC50 values ranging from 12.2 to 35.2 µM.

A new morphinandienone alkaloid from the stems of Fissistigma tungfangense.

A new morphinandienone alkaloid, fissistigmine A (1), together with three known alkaloids (2-4), were isolated and identified from the stems of Fissistigma tungfangense. Among them, fissistigmine A (1) represents the first example of a novel naturally occurring morphinandienone alkaloid with a unique cleavage of the C-9-N-17 bond. All isolated compounds were evaluated for their anti-rheumatoid arthritis activities via examining their anti-proliferative effects on synoviocytes in vitro. Compound 1 exhibited inhibitory effect on the proliferation of synoviocytes with an IC50 value of 114.6 ± 2.2 µM.

Furofuran lignans and alkaloids from Clinacanthus nutans.

One new furofuran lignan 2-methoxy-9ß-hydroxydiasesamin (1), and four analogues (2-5), together with eight alkaloids (6-13), were isolated from the ethanol extract of the aerial part of Clinacanthus nutans. Their structures were elucidated by the detailed analysis of comprehensive spectroscopic data. All the compounds were isolated from the genus of Clinacanthus for the first time. In addition, lignans isolated from C. nutans was reported for the first time. Compound 1 exhibited modest activity against three human tumor cell lines Hela, MCF-7, and A549, with IC50 values of 68.55, 60.00, and 59.17 µM, respectively.

A new norisoprenoid from the leaves of Ficus pumila.

One new norisoprenoid 3,9-dihydroxy dihydro actinidiolide (1), together with eleven known compounds (2-12), were isolated from ethanol extract of the leaves of Ficus pumila collected in Hainan Province, China. Their structures were elucidated by the detailed analysis of comprehensive spectroscopic data. Compounds 1, 2, 4, 5, 8 and 10-12 were isolated from the F. pumila for the first time. All compounds were evaluated for their cytotoxic activity. Compounds 3 and 9 showed weak cytotoxic activity against Hela, MCF-7 and A549 cell lines.

Biologically active oligostilbenes from the stems of Vatica mangachapoi and chemotaxonomic significance.

Phytochemical investigation of the stems of Vatica mangachapoi (Dipterocarpaceae) led to the isolation and structural elucidation of twenty-seven oligostilbenes (1-27), including a new natural compound 1. The structure of 1 was elucidated on the basis of spectroscopic analyses including NMR, MS and ECD data, and the known compounds were identified by comparisons with those reported in the literature. The absolute configuration of 1 was first time determined by a combination of NOESY spectrum and quantum chemical computation. Among of isolates were tested for their anti-osteoporosis and anti-HIV-1 activities in vitro by the MTT method. Moreover, the chemotaxonomic significance of these compounds was summarised.