1-(2-Hydr­oxy-4,5-dimeth­oxyphen­yl)propan-1-one

In the title compound, C11H14O4, isolated from the stems of Trigonostemon xyphophylloides, an intra­molecular O—H⋯O hydrogen bond helps to establish an essentially planar conformation for the mol­ecule (r.m.s. deviation = 0.044 Å)

2-Hydr­oxy-1-methoxyxanthen-9-one monohydrate

In the title compound, C14H10O4·H2O, isolated from the roots of Calophyllum membranaceum, the xanthene ring system is almost planar (r.m.s. deviation = 0.008 Å). In the crystal structure, inter­molecular O—H⋯O and O—H⋯(O,O) hydrogen bonds connect the mol­ecules

2-Hy­droxy-3-nitro­benzaldehyde

The title compound, C7H5NO4, isolated from the leaves of Actephila merrilliana, is essentially planar (r.m.s. deviation = 0.026 Å). The conformation is supported by an intra­molecular O—H⋯O hydrogen bond, which generates an S(6) ring. In the crystal, C—H⋯O inter­actions and aromatic π–π stacking [centroid–centroid distance = 3.754 (4) Å] help to establish the packing

1-(5-Hydroxy-7-methoxy-2,2-dimethyl-2H-chromen-6-yl)ethan-1-one

The title chromene, C14H16O4, was isolated from the stems of Polyalthia plagioneura Diels. The mol­ecular structure is stabilized by an intra­molecular O–H⋯O hydrogen bond, which generates an S(6) ring. In the crystal, the mol­ecules are linked by C—H⋯O inter­actions, generating [010] chains

Construction of a bimolecular fluorescence complementation (BiFC) platform for protein interaction assays in plants

Protein–protein interactions are essential for signal transduction in cells. Bimolecular fluorescence complementation (BiFC) is a novel technology that utilises green fluorescent proteins to visualize protein–protein interactions and subcellular protein localisation. BiFC based on pSATN vectors are a good system for high-level expression of fused protein. A series of pCAMBIA vectors were most widely used in plant transgene and transient expression. To provide multiple options in the study of protein interactions that utilise BiFC, we reconstructed a new pair of BiFC vectors, pCAMBIA1301-nEYFP and pCAMBIA1301-cEYFP. These vectors were generated by eliminating restriction enzyme cutting sites (BanII, SacI, KpnI, SmaI, BamHI, SalI, PstI and SbfI) at the multiple cloning sites (MCSs) of pCAMBIA1301 (p1301), and introducing cEYFP/nEYFP cassettes containing MCSs generated from pSATN medium. Fluorescence can be imaged when AtCBL1 and AtCIPK23 are co-injected, but imaging cannot be done when co-injecting AtCBL1 and AtCIPK23-NAF-deleted (AtCIPK23m), suggesting that the proposed modified vector system is effective for the study of protein interactions.Keywords: Protein–protein, bimolecular fluorescence complementation (BiFC), vector reconstructio

Soil CO2 and N2O emissions and microbial abundances altered by temperature rise and nitrogen addition in active-layer soils of permafrost peatland

Changes in soil CO2 and N2O emissions due to climate change and nitrogen input will result in increased levels of atmospheric CO2 and N2O, thereby feeding back into Earth’s climate. Understanding the responses of soil carbon and nitrogen emissions mediated by microbe from permafrost peatland to temperature rising is important for modeling the regional carbon and nitrogen balance. This study conducted a laboratory incubation experiment at 15 and 20°C to observe the impact of increasing temperature on soil CO2 and N2O emissions and soil microbial abundances in permafrost peatland. An NH4NO3 solution was added to soil at a concentration of 50 mg N kg−1 to investigate the effect of nitrogen addition. The results indicated that elevated temperature, available nitrogen, and their combined effects significantly increased CO2 and N2O emissions in permafrost peatland. However, the temperature sensitivities of soil CO2 and N2O emissions were not affected by nitrogen addition. Warming significantly increased the abundances of methanogens, methanotrophs, and nirK-type denitrifiers, and the contents of soil dissolved organic carbon (DOC) and ammonia nitrogen, whereas nirS-type denitrifiers, β-1,4-glucosidase (βG), cellobiohydrolase (CBH), and acid phosphatase (AP) activities significantly decreased. Nitrogen addition significantly increased soil nirS-type denitrifiers abundances, β-1,4-N- acetylglucosaminidase (NAG) activities, and ammonia nitrogen and nitrate nitrogen contents, but significantly reduced bacterial, methanogen abundances, CBH, and AP activities. A rising temperature and nitrogen addition had synergistic effects on soil fungal and methanotroph abundances, NAG activities, and DOC and DON contents. Soil CO2 emissions showed a significantly positive correlation with soil fungal abundances, NAG activities, and ammonia nitrogen and nitrate nitrogen contents. Soil N2O emissions showed positive correlations with soil fungal, methanotroph, and nirK-type denitrifiers abundances, and DOC, ammonia nitrogen, and nitrate contents. These results demonstrate the importance of soil microbes, labile carbon, and nitrogen for regulating soil carbon and nitrogen emissions. The results of this study can assist simulating the effects of global climate change on carbon and nitrogen cycling in permafrost peatlands

Global pattern and controls of soil microbial metabolic quotient

imbalanceThe microbial metabolic quotient (MMQ), microbial respiration per unit of biomass, is a fundamental factor controlling heterotrophic respiration, the largest carbon flux in soils. The magnitude and controls of MMQ at regional scale remain uncertain. We compiled a comprehensive data set of MMQ to investigate the global patterns and controls of MMQ in top 30 cm soils. Published MMQ values, generally measured in laboratory microcosms, were adjusted on ambient soil temperature using long-term (30 yr) average site soil temperature and a Q₁₀ = 2. The area-weighted global average of MMQ_Soil is estimated as 1.8 (1.5-2.2) (95% confidence interval) μmol C·h⁻¹·mmol⁻¹ microbial biomass carbon (MBC) with substantial variations across biomes and between cropland and natural ecosystems. Variation was most closely associated with biological factors, followed by edaphic and meteorological parameters. MMQ_Soil was greatest in sandy clay and sandy clay loam and showed a pH maximum of 6.7 ± 0.1 (mean ± se). At large scale, MMQ_Soil varied with latitude and mean annual temperature (MAT), and was negatively correlated with microbial N:P ratio, supporting growth rate theory. These trends led to large differences in MMQ_Soil between natural ecosystems and cropland. When MMQ was adjusted to 11°C (MMQ_Ref), the global MAT in the top 30 cm of soils, the area-weighted global averages of MMQ_Ref was 1.5 (1.3-1.8) μmol C·mmol MBC⁻¹·h⁻¹. The values, trends, and controls of MMQ_Soil add to our understanding of soil microbial influences on soil carbon cycling and could be used to represent microbial activity in global carbon models

A novel DSPP mutation causes dentinogenesis imperfecta type II in a large Mongolian family

<p>Abstract</p> <p>Background</p> <p>Several studies have shown that the clinical phenotypes of dentinogenesis imperfecta type II (DGI-II) may be caused by mutations in <it>dentin sialophosphoprotein </it>(<it>DSPP</it>). However, no previous studies have documented the clinical phenotype and genetic basis of DGI-II in a Mongolian family from China.</p> <p>Methods</p> <p>We identified a large five-generation Mongolian family from China with DGI-II, comprising 64 living family members of whom 22 were affected. Linkage analysis of five polymorphic markers flanking <it>DSPP </it>gene was used to genotype the families and to construct the haplotypes of these families. All five DSPP exons including the intron-exon boundaries were PCR-amplified and sequenced in 48 members of this large family.</p> <p>Results</p> <p>All affected individuals showed discoloration and severe attrition of their teeth, with obliterated pulp chambers and without progressive high frequency hearing loss or skeletal abnormalities. No recombination was found at five polymorphic markers flanking DSPP in the family. Direct DNA sequencing identified a novel A→G transition mutation adjacent to the donor splicing site within intron 3 in all affected individuals but not in the unaffected family members and 50 unrelated Mongolian individuals.</p> <p>Conclusion</p> <p>This study identified a novel mutation (IVS3+3A→G) in <it>DSPP</it>, which caused DGI-II in a large Mongolian family. This expands the spectrum of mutations leading to DGI-II.</p

Inhibition of HIV-1 entry by extracts derived from traditional Chinese medicinal herbal plants

<p>Abstract</p> <p>Background</p> <p>Highly active anti-retroviral therapy (HAART) is the current HIV/AIDS treatment modality. Despite the fact that HAART is very effective in suppressing HIV-1 replication and reducing the mortality of HIV/AIDS patients, it has become increasingly clear that HAART does not offer an ultimate cure to HIV/AIDS. The high cost of the HAART regimen has impeded its delivery to over 90% of the HIV/AIDS population in the world. This reality has urgently called for the need to develop inexpensive alternative anti-HIV/AIDS therapy. This need has further manifested by recent clinical trial failures in anti-HIV-1 vaccines and microbicides. In the current study, we characterized a panel of extracts of traditional Chinese medicinal herbal plants for their activities against HIV-1 replication.</p> <p>Methods</p> <p>Crude and fractionated extracts were prepared from various parts of nine traditional Chinese medicinal herbal plants in Hainan Island, China. These extracts were first screened for their anti-HIV activity and cytotoxicity in human CD4+ Jurkat cells. Then, a single-round pseudotyped HIV-luciferase reporter virus system (HIV-Luc) was used to identify potential anti-HIV mechanisms of these extracts.</p> <p>Results</p> <p>Two extracts, one from <it>Euphorbiaceae</it>, <it>Trigonostema xyphophylloides </it>(TXE) and one from <it>Dipterocarpaceae</it>, <it>Vatica astrotricha </it>(VAD) inhibited HIV-1 replication and syncytia formation in CD4+ Jurkat cells, and had little adverse effects on host cell proliferation and survival. TXE and VAD did not show any direct inhibitory effects on the HIV-1 RT enzymatic activity. Treatment of these two extracts during the infection significantly blocked infection of the reporter virus. However, pre-treatment of the reporter virus with the extracts and treatment of the extracts post-infection had little effects on the infectivity or gene expression of the reporter virus.</p> <p>Conclusion</p> <p>These results demonstrate that TXE and VAD inhibit HIV-1 replication likely by blocking HIV-1 interaction with target cells, i.e., the interaction between gp120 and CD4/CCR5 or gp120 and CD4/CXCR4 and point to the potential of developing these two extracts to be HIV-1 entry inhibitors.</p