Bioactive Limonoids and Triterpenoids from the Fruits of Melia azedarach

Nine new limonoids, meliazedarines A-I (1-9), seven known analogues (10-16), and five known triterpenoids (17-21) were isolated from the fruits of Melia azedarach. Their structures were determined by analysis of 1D and 2D NMR, HRESIMS, X-ray diffraction, and electronic circular dichroism (ECD) data. Compound 7 showed significant cytotoxicity against the HCT116 cell line with IC₅₀ values of 0.3 ± 0.1 μM.

Finite element modeling of proximal femur with quantifiable weight-bearing area in standing position

Background

The positional distribution and size of the weight-bearing area of the femoral head in the standing position as well as the direct active surface of joint force can directly affect the result of finite element (FE) stress analysis. However, the division of this area was vague, imprecise, and un-individualized in most studies related to separate FE models of the femur. The purpose of this study was to quantify the positional distribution and size of the weight-bearing area of the femoral head in standing position by a set of simple methods, to realize individualized reconstruction of the proximal femur FE model.

Methods

Five adult volunteers were recruited for an X-ray and CT examination in the same simulated bipedal standing position with a specialized patented device. We extracted these image data, calculated the 2D weight-bearing area on the X-ray image, reconstructed the 3D model of the proximal femur based on CT data, and registered them to realize the 2D weight-bearing area to 3D transformation as the quantified weight-bearing surface. One of the 3D models of the proximal femur was randomly selected for finite element analysis (FEA), and we defined three different loading surfaces and compared their FEA results.

Results

A total of 10 weight-bearing surfaces in 5 volunteers were constructed, and they were mainly distributed on the dome and anterolateral of the femoral head with a crescent shape, in the range of 1218.63–1,871.06 mm². The results of FEA showed that stress magnitude and distribution in proximal femur FE models among three different loading conditions had significant differences, and the loading case with the quantized weight-bearing area was more in accordance with the physical phenomenon of the hip.

Conclusion

This study confirmed an effective FE modeling method of the proximal femur, which can quantify the weight-bearing area to define a more reasonable load surface setting without increasing the actual modeling difficulty.

Correlation between Body Mass Index and Periprosthetic Joint Infection following Total Joint Arthroplasty: A protocol for systematic review and meta analysis

BACKGROUND

Despite rapid reports on the correlation between body mass index (BMI) and periprosthetic joint infection (PJI) after total joint arthroplasty, some have conducted regression tests or meta-analyses with controversial results. In this study, we systematically meta-analyzed relevant trials and carefully evaluated the correlation for verification.

METHODS

Literature on the correlation between BMI and PJI following total joint arthroplasty was retrieved in PubMed, Embase and Cochrane Library due September 2019. Stata 13.0 software was adopted for data synthesis and analyses of publication bias and sensitivity. Random-effect models were used to summary the overall estimate of the multivariate adjusted odds ratio (OR)/hazard ratio/rate ratio with 95% confidence intervals (CIs).

RESULTS

A total of 29 observational studies representing 3,204,887 patients were included. The meta-analysis revealed that the risk of postoperative PJI significantly increased by 1.51 times in the obese group (OR = 1.51; 95% CI = 1.30-1.74 for the obese group vs. the non-obese group), and by 3.27 times in the morbid obese group (OR = 3.27; 95% CI = 2.46-4.34 for the morbid obese group vs the non-morbid obese group). A significant association remained consistent, as indicated by subgroup analyses and sensitivity analyses.

CONCLUSION

Our findings demonstrate that postoperative PJI is positively correlated with BMI, with obese patients showing a greater risk of developing PJI than non-obese patients. Similarly, morbid obese patients present a higher risk of PJI than non-morbid obese patients. However, this conclusion needs to be corroborated by more prospective studies.

Dimeric Diarylheptanoids with Neuroprotective Activities from Rhizomes of Alpinia officinarum

Two novel dimeric diarylheptanoids, alpinidinoids A [(±)-1] and B (2), with two unusual coupling patterns, together with a new naturally occurring diarylheptanoid dimer possessing a rare pyridine ring linkage (alpinidinoid C, 3), were isolated from the rhizomes of Alpinia officinarum. Their structures including absolute configurations were determined by extensive spectroscopic methods and theoretical calculations. All isolates were examined for their neuroprotective activities against oxygen-glucose deprivation and reoxygenation (OGD/R) damage in primary cortical neurons. Remarkably, the dextrorotatory enantiomer of alpinidinoid A [(+)-1] significantly ameliorated OGD/R-induced neuronal apoptosis, which was dependent on the activation of the AKT/mTOR signaling pathway.

Intercrops can mitigate pollen-mediated gene flow from transgenic cotton while simultaneously reducing pest densities

Genetically modified (GM) cotton, engineered to express Bt toxins that protect it from insect damage, has become the most successfully commercialized GM crop in China since its authorization in 1997. In light of the potential ecological consequences of pollen-mediated gene flow (PGF) from GM plants, a two year field trial was conducted to test the effects on PGF of sunflower, Helianthus annuus, buckwheat, Fagopyrum esculentum, and soybean, Glycine max, as intercrops in non-GM cotton fields during 2017 and 2018. DNA tests for hybridized seed were used to estimate rates of PGF in intercrop treatments. PGF was the lowest in cotton intercropped with either buckwheat or sunflower, likely due to the trapping of pollen in these flowers, and/or the diversion of pollinators away from cotton flowers. PGF declined as an exponential function of distance from the GM cotton; Y = -lnx was the model of best fit for estimating pollen dispersal potential. A sunflower intercrop reduced the peak abundance of Aphis gossypii, (Hemiptera: Aphididae), Bemisia tabaci (Hemiptera: Aleyrodidae), and Nysius ericae (Hemiptera: Lygaeidae) on cotton plants, although densities of Tetranychus cinnabarinus (Acari: Tetranychidae), were increased. A buckwheat intercrop had very similar effects on these pests, likely due to attraction of their natural enemies. We conclude that sunflower and buckwheat are suitable intercrops for reducing PGF from GM cotton, and may be useful for reducing PGF from other insect-pollinated GM crops in the agricultural landscape, while simultaneously contributing to control of specific pests. This is the first demonstration, to our knowledge, that intercrops can be used to reduce PGF from transgenic plants.

Ethanol extract of Ophiorrhiza pumila suppresses liver cancer cell proliferation and migration

Background

Ophiorrhiza pumila, belonging to the genus Ophiorrhiza (Rubiaceae), is distributed throughout tropical and subtropical Asia. In this study, we evaluated for the first time the anti-proliferation and anti-migration effects of ethanol extract of O. pumila (OPE) on HepG2 and SMMC-7721 cells, and explored the related mechanism.

Methods

OPE was prepared by percolation with 95% ethanol and its main compounds were analyzed by HPLC-MS². The anti-proliferation effect of OPE was evaluated by the CCK-8 assay and colony formation assay. Cell cycle distribution, apoptosis, and reactive oxygen species (ROS) level were detected by flow cytometry. Migration and invasion abilities were detected by Transwell migration/invasion assays. The expression of correlated proteins was determined using western blotting.

Results

A total of 5 tentative compounds were identified from OPE, including pumiloside, deoxypumiloside, camptothecin, aknadinine, and β-stigmasterol. OPE displayed strong cytostatic effects on HepG2 and SMMC-7721 cells. OPE induced G2/M phase cell cycle arrest, increased apoptosis, and augmented ROS production in these cell lines. In addition, OPE possessed a significant inhibition on cell migration and invasion by reduction of MMP-9 and MMP-2 expression. Moreover, OPE significantly suppressed the phosphorylation of p65.

Conclusions

Our data showed that OPE suppresses liver cancer cell proliferation and migration, which is possibly involved with the inhibition of the NF-κB pathway.

Risk factors associated with osteonecrosis of femoral head after internal fixation of femoral neck fracture:a systematic review and meta-analysis

BACKGROUND

Although the risk factors associated with osteonecrosis of femoral head (ONFH) after internal fixation of femoral neck fracture (IFFNF) have been frequently reported, the results remain controversial. Therefore, its related risk factors were systematically evaluated and meta-classified in this study.

METHODS

Literature on risk factors of ONFH caused by IFFNF was retrieved in PubMed, Embase and Cochrane Library due June 2019. Review Manager 5.3 software was applied to data synthesis, and Stata 13.0 software was adopted for analyses of publication bias and sensitivity.

RESULTS

A total of 17 case-control studies with 2065 patients were included. The risk of ONFH after IF was 0.40-fold higher in patients with Garden III-IV FNF than that in patients with Garden I-II (OR: 0.40, 95%CI: 0.29-0.55). The risk of OFNH with retained IF was uplifted by 0.04 times (OR: 0.04, 95%CI: 0.02-0.07). There was nonsignificant relationship between gender and ONFH after IFFNF (OR: 1.27, 95%CI: 0.84-1.94). Moreover, ONFH after IFFNF presented no association with age (OR:1.66, 95%CI: 0.89-3.11), injury-operation interval (OR:1.29, 95%CI: 0.82-2.04), fracture reduction mode (OR:1.98, 95%CI: 0.92-4.26), preoperative traction (OR:1.69, 95%CI: 0.29-9.98) and mechanism of injury (OR:0.53, 95%CI: 0.06-4.83). Egger's and Begg's tests indicated a publication bias (P = 0.001).

CONCLUSION

It was demonstrated that Garden classification and retained IF were important influencing factors of ONFH after IFFNF. Gender, age, injury-operation interval, fracture reduction mode, preoperative traction and the mechanism of ONFH were irrelevant to the complication.

Effects of chromatographic conditions and mass spectrometric parameters on the ionization and fragmentation of triterpene saponins of Ilex asprella in liquid chromatography-mass spectrometry analysis

High performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (HPLC-QTOF-MS) is widely used to qualitatively characterize the chemical profiles of herbal medicines, in which the generated adducts and fragments are crucial for confirming molecular ion (deprotonated/protonated ion) and deducing structure of detected components. However, how chromatographic and mass spectrometric (LC-MS) conditions/parameters affect the quantity and intensity of adducts and fragments of detected components is scarcely concerned. In present study, three types of triterpene saponins from the root of Ilex asprella (RIA) were selected as a case study to systematically investigate the effects of LC/MS conditions/parameters on their ionization and fragmentation, so as to obtain higher intensity (higher detection sensitivity) and quantity (rich information) of adducts and fragments for the characterization of components in RIA. It was found that for LC conditions, methanol as organic phase was more benefit for generating more adducts with higher intensity; formic acid as a modifier suppressed the formation of [M-2H]^2-, thus promoted the generation of other types of adducts at lower concentration but inhibited the generation when the concentration exceeded 0.1%. MS parameters affect scarcely the quantity but mainly intensity of adducts, cone voltage, source temperature and desolvation gas flow have relatively higher impacts when compared with other parameters. Collision energy affected both quantity and intensity of fragments. MS parameters at the medium value largely increased the quantity and intensity of adducts and fragments. Three-types of triterpene saponins presented structurally specific ionization and fragmentation due to their amounts of acidic substitutes. A total of 55 components were detected and definitely or tentatively identified in RIA under the optimized LC-MS conditions, among which 35 triterpene saponins were firstly discovered. This is the first report that proposes and validates a systematic approach for assessing the effects of LC/MS conditions/parameters on the ionization and fragmentation of analytes, which could be helpful for the optimization of LC-MS conditions for effective chemical profiling analysis of herbal medicines.

Hunterines A-C, Three Unusual Monoterpenoid Indole Alkaloids from Hunteria zeylanica

Three new monoterpenoid indole alkaloids (MIAs), hunterines A-C (1-3), were isolated from Hunteria zeylanica. Compound 1 possesses a unique skeleton with an unprecedented azabicyclo[4.3.1]decane ring system. Compounds 2 and 3 are a pair of epimeric vobasinylindole alkaloid heterodimers. Their structures including absolute configurations were established by spectroscopic analyses, X-ray diffraction, computational calculation, and the modified Mosher's method. Plausible biogenetic pathways of 1-3 were also proposed. Alkaloid 1 showed moderate cytotoxic activity against the HepG2 cell line.

[Effect of electroacupunture on supplementary analgesia and the levels of serum β-endorphin and prostaglandin E2 in patients with total knee arthroplasty]

OBJECTIVE

To observe the effect on supplementary analgesia after total knee arthroplasty (TKA) treated with electroacupunture, and explore it's mechanism.

METHODS

A total of 40 patients with severe knee osteoarthritis were randomized into an observation group and a control group, 20 cases in each one. During the operation, patients were given epidural anesthesia in the two groups, conventional patient controlled epidural analgesia and oral celecoxib were applied after the operation. In the observation group, electroacupunture was used at Liangqiu (ST 34), Xuehai (SP 10), Yinlingquan (SP 9), Zusanli (ST 36), Fenglong (ST 40) and Qiuxu (GB 40) on the operation side from the 1st to 7th day after the operation to support analgesia, 30 min for each time, once a day. The visual analogue scale (VAS) was used to record postoperative pain of resting state and active state. The levels of serum prostaglandin E₂ and β-endorphin were measured on the 1st and 7th day after surgery in the two groups.

RESULTS

In the observation group, the VAS scores of resting state and active state were superior to the control group on the 3rd, 5th and 7th day after the operaton (all P<0.05); after the treatment, the level of serum β-endorphin was increased and the level of serum prostaglandin E₂ was reduced in the two groups (all P<0.05), and the change of the observation group was larger than that of the control group (both P<0.05).

CONCLUSION

Electroacupunture has the effect of supplementary analgesia for patients after TKA, the mechanism may be related to promote the synthesis of β-endorphin and inhibit the synthesis of prostaglandin E₂.

[Spatial and Temporal Distribution Characteristics and the Retention Effects of Nutrients in Xiangjiaba Reservoir]

After the construction of the Xiangjiaba Dam, the hydrodynamic conditions, nutrient distributions, and transport conditions of the Jinsha River were changed. Here, the nutrient distribution characteristics and retention effects of Xiangjiaba Reservoir were investigated according to the results of water quality monitoring from 2015 to 2016. Spatial and temporal variations in TN, TP, SiO₃^2-Si, and other nutrients, and retention flux and retention rate were analyzed. The results showed that the nutrient mass concentration of TN, TP, and SiO₃^2--Si was 0.905 mg·L^-1, 0.034 mg·L^-1, and 7.98 mg·L^-1, respectively. The distribution of TN was affected by point sources and the concentration of TN was large in urban areas. This distribution of TP was mainly granular and the mass concentrations decreased along the river path. The mass concentration of SiO₃^2--Si did not significantly vary over time and space. Furthermore, Xiangjiaba Reservoir had a persistent effect on nutrient salts; the average annual retention of TN, TP, and SiO₃^2--Si was 2.30×10⁴ t·a^-1, 0.146×10⁴ t·a^-1, and -2.4×10⁴ t·a^-1, respectively. During different seasons, the retention of TN and SiO₃^2--Si varied between positive or negative; however, TP appeared to be consistent. The average monthly retention efficiency of TN, TP, and SiO₃^2--Si was 17.5%, 32.8%, and -2.14%, respectively. Overall, retention efficiencies were higher during the dry season than that wet season, and phosphorus retention was most pronounced. The retention of TN in the reservoir may be related to denitrification and the input of external load; the flux of SiO₃^2--Si was mainly affected by runoff; and the particle morphology of phosphorus, as well as reservoir period, were the main factors affecting TP retention. There were no clear correlations between nutrient retention and the mass concentrations of TN and SiO₃^2--Si, but the nutrient retention effect of Xiangjiaba Reservoir reduced TP concentrations along the river path and increased TP concentration with vertical depth.

Eleven New Triterpenoid Glycosides from the Roots of Ilex asprella

Asprellosides A-K, nine new ursane-type triterpenoid glycosides (1-9), and two new oleanane-type triterpenoid glycosides (10 and 11), including six rare sulfated triterpenoid glycosides, were isolated from the roots of Ilex asprella. Their structures were determined on the basis of comprehensive spectroscopic analysis and chemical methods. Among these compounds, asprelloside B (2) and asprelloside C (3) are the first examples of triterpenoid glycosides bearing a rare 3,4-O-disulfo-xylopyranosyl residue. All the saponins isolated showed no significant effects against respiratory syncytial virus (RSV) and lipopolysaccharide-induced nitric oxide production in Raw264.7 macrophages.

Cablinosides A and B, Two Glycosidic Phenylacetic Acid Derivatives from the Leaves of Pogostemon cablin

A pair of new glycosidic epimers, cablinosides A (1a) and B (1b) were isolated from the leaves of Pogostemon cablin. The structures with absolute configurations of 1a and 1b were elucidated by extensive NMR investigation, and quantum chemical CD calculations. The epimer mixture 1 showed moderate α-glucosidase inhibitory activity and no significant cytotoxic activity against HepG2 cells.

[Electroacupuncture Intervention Reduces Post-surgical Pain of Patients Undergoing Total Knee Arthroplasty]

OBJECTIVE

To observe the analgesic effect and safety of electroacupuncture (EA) intervention for patients undergoing total knee arthroplasty (TKA).

METHODS

A total of 40 patients undergoing TKA were randomly assigned to control group (simple multi-mode analgesia, n＝20) and EA group (EA combined with multi-mode analgesia, n＝20). Both groups were treated with epidural anesthesia during surgical operation, and conventional epidural automatic analgesia and oral Celecoxib after surgery. Following surgery, EA was applied to Liangqiu (ST 34)-Xuehai (SP 10), Yinlingquan (SP 9)-Zusanli (ST 36), Fenglong (ST 40)-Qiuxu(GB 40) on the operation side for 30 min, once daily for 7 consecutive days. The patients' pain state during rest and motion was assessed by using visual analogue scale (VAS). The active and passive knee flexion range of motion (ROM), use of painkillers including the number of patient's controlled epidural analgesia (PCEA) during 48 h after surgery, and other complications were recorded.

RESULTS

After the treatment, the VAS scores under rest and motion state were both significantly lower in the EA group than in the control group on day 3, 5 and 7 after surgery (P<0.05). During 48 h after surgery, the number of PECA was significantly lower in the EA group than in the control group (P<0.05). Of the two 20 cases in the control and EA groups, 3 and 1 asked to receive muscular injection of Tramadol Hydrochloride for pain relief, 3 and 2 experienced nausea-vomiting, 2 and 1 had dizziness and headache, and 2 and 1 had a chest distress feeling, respectively, which had no significant differences between the two groups (P>0.05). The white blood cell (WBC) count in both groups were decreased gradually from day 1 to 7 after surgery, and plasma C-reactive protein content on day 5 and 7 were also lowered in both groups, without statistical differences between the two groups in the post-operative complications, dosages of additional postoperative analgesic drugs, and levels of plasma WBC and C-reactive protein (P>0.05).

CONCLUSION

EA can effectively improve the early postoperative pain of TKA, reduce the incidence of postoperative complications and the use of analgesic drugs in TKA patients.

Daily expression of two circadian clock genes in compound eyes of Helicoverpa armigera: evidence for peripheral tissue circadian timing

Circadian clock genes in peripheral tissues usually play an important role in regulating the circadian rhythms. Light is the most important environmental signal for synchronizing endogenous rhythms with the daily light-dark cycle, and compound eyes are known as the principal circadian photoreceptor for photic entrainment in most moths. However, there is little evidence for circadian timing in compound eyes. In the current study, we isolated the timeless gene, designated Ha-tim (GenBank accession number: KM233162), from the cotton bollworm Helicoverpa armigera. Ha-tim and period (Ha-per) showed low messenger RNA levels in the compound eyes compared to the other tested adult organs. Ha-tim and Ha-per transcript levels were dependent on an endogenous rhythm that fluctuated over a daily cycle in the compound eyes and heads. The cycles of Ha-tim and Ha-per transcript levels followed similar time courses, and identical expression patterns of the two genes were observed in the compound eyes and heads. Ha-tim and Ha-per were down-regulated in the compound eyes after light exposure, copulation and starvation. These results indicated that Ha-tim and Ha-per transcript levels were regulated by endogenous and exogenous factors. Our study helped to improve our understanding of the circadian clock machinery in compound eyes and other peripheral tissues.

Huo Xue Tong Luo capsule, a vasoactive herbal formula prevents progression of asymptomatic osteonecrosis of femoral head: A prospective study

Background/objective

A prospective cohort study aimed to evaluate the clinical efficacy of a specific vasoactive herbal formula, Huo Xue Tong Luo capsule (HXTL capsule), for the treatment of patients with asymptomatic osteonecrosis of femoral head (ONFH).

Methods

We evaluated a clinical trial of 55 patients (59 hips) with asymptomatic ONFH (no joint collapse) evaluated by Steinberg staging system and necrosis range classification criteria. Then, they were given HXTL capsule under specific protocol. Among them, 39 males and 16 females with an average age of 36.4 ± 10.1 years were followed up for an average of 4.38 years during treatment. The aggravation of clinical and imaging results was assessed by initial pain and joint collapse. The clinical and imaging outcomes of these patients were compared with those of a historical control group from the literature under critical inclusion criteria.

Results

At the latest follow-up, initial pain occurred in five of 59 (8.5%) hips of patients taking HXTL capsule compared with 31 of 81 (38.3%) controls (p < 0.001), and joint collapse occurred in 13 of 59 (22.0%) hips of patients taking HXTL capsule compared with 26 of 81 (32.1%) controls (p < 0.001). There was no association between joint collapse and multiple key factors of ONFH. Only the location of type C2 necrotic lesions (hazard ratio, 4.12; 95% confidence interval, 2.64–18.91) and the extent of large necrotic lesions (hazard ratio, 3.39; 95% confidence interval, 1.43–16.21) predicted joint collapse.

Conclusion

As an agent formulated by vasoactive herbals, HXTL capsule with specific protocol is an effective medicine for relieving hip pain and preventing joint collapse in patients with asymptomatic ONFH.

The translational potential of this article

The translation potential of this prospective cohort study is that the initially officially approved clinical indication for HXTL capsule for treatment of ONFH is due to its possible effect of revascularization on angiogenesis of necrosis. It is has been now proven to be effective for a new clinical application.

Synthesis of novel 6,7-dimethoxy-4-anilinoquinolines as potent c-Met inhibitors

HGF/c-Met signalling pathway plays an important role in the development of cancers. A series of 6,7-dimethoxy-4-anilinoquinolines possessing benzimidazole moiety were synthesised and identified as potent inhibitors of the tyrosine kinase c-Met. Their in vitro biological activities against three cancer cell lines (A549, MCF-7, and MKN-45) were also evaluated. Most of these compounds exhibited moderate to remarkable potency. Among them, compound 12n showed the most potent inhibitory activity against c-Met with IC₅₀ value of 0.030 ± 0.008 µM and it also showed excellent anticancer activity against the tested cancer cell lines at low micromolar concentration. Molecular docking verified the results and revealed the possible binding mode of the most promising compound 12n into the ATP-binding site of c-Met kinase.

c-Met kinase inhibitors: an update patent review (2014-2017)

INTRODUCTION

The receptor tyrosine kinase c-Met is involved in the formation, metastasis and invasion of various malignant tumors thus it has been an attractive target for anti-tumor drug designing. Many compositions targeting c-Met have been developed in pharmaceutical industry for cancer therapy and some of them are in clinical study now. Among them, Crizotinib was the first small molecular inhibitor approved by FDA in 2011.

AREAS COVERED

This review briefly summarizes the signal transduction pathway about c-Met, its role in oncogenesis, most recent patents of small-molecule inhibitors and antibodies of c-Met from 2014 to 2017.

EXPERT OPINION

To date, some c-Met inhibitors have been launched in the market. In addition, their clinical performances have shown encouraging value in cancer therapy. Many potential agents are still in preclinical or clinical study now and achieve some promising progressions. Some patients have developed resistance to c-Met inhibitors which results in the need to develop inhibitors with novel structures. Development of several potent drugs also tends to be pharmacodynamically active against multiple targets.

Molecular Identification of Two Thioredoxin Genes From Grapholita molesta and Their Function in Resistance to Emamectin Benzoate

Thioredoxins (Trxs), a member of the thioredoxin system, play crucial roles in maintaining intracellular redox homeostasis and protecting organisms against oxidative stress. In this study, we cloned and characterized two genes, GmTrx2 and GmTrx-like1, from Grapholita molesta. Sequence analysis showed that GmTrx2 and GmTrx-like1 had highly conserved active sites CGPC and CXXC motif, respectively, and shared high sequence identity with selected insect species. The quantitative real-time polymerase chain reaction results revealed that GmTrx2 was mainly detected at first instar, whereas GmTrx-like1 was highly concentrated at prepupa day. The transcripts of GmTrx2 and GmTrx-like1 were both highly expressed in the head and salivary glands. The expression levels of GmTrx2 and GmTrx-like1 were induced by low or high temperature, E. coli, M. anisopliae, H2O2, and pesticides (emamectin benzoate). We further detected interference efficiency of GmTrx2 and GmTrx-like1 in G. molesta larvae and found that peroxidase capacity, hydrogen peroxide content, and ascorbate content all increased after knockdown of GmTrx2 or GmTrx-like1. Furthermore, the hydrogen peroxide concentration was increased by emamectin benzoate and the sensitivity for larvae to emamectin benzoate was improved after GmTrx2 or GmTrx-like1 was silenced. Our results indicated that GmTrx2 and GmTrx-like1 played vital roles in protecting G. molesta against oxidative damage and also provided the theoretical basis for understanding the antioxidant defense mechanisms of the Trx system in insects.

[Effects of Biochar on Nitrous Oxide Fluxes and the Abundance of Related Functional Genes from Agriculture Soil in the North China Plain]

To explore the effect and mechanism of biochar application in reducing nitrous oxide (N₂O) content in agricultural soil, from March 27 to June 5 2015, pot experiments were conducted to study the effects of biochar application rates (CK, C1:5%, C2:10%, C3:15%, and C4:30%) (mass fraction) on soil N₂O fluxes and the functional marker genes ammonia monooxygenase (amoA), nirK, nirS, and nosZ, which are responsible for nitrification and denitrification. The results revealed the following. ①The application of low doses of biochar (5%) promoted N₂O emission. The application of middle and high doses of biochar reduced N₂O emission. Furthermore, the application of biochar (15%) was found to be the best practice to reduce N₂O emission. ② At the beginning of the experiment, biochar had a significant effect on the abundance of soil amoA and denitrification bacteria gene. Furthermore, the abundance of AOA and nirS had a significant positive correlation with the biochar rate, and the abundance of nirK gene and biochar rate were significant. There was a significant negative correlation between AOB and nosZ gene abundance and biochar rate. At the end of the experiment, AOA abundance correlated negatively with biochar rate, while there was a significantly positive relationship between AOB abundance and biochar rate. ③ At the beginning of the experiment, the N₂O fluxes exhibited a significant negative correlation with AOA and nirS gene, indicating that N₂O production was controlled by the abundance of AOA and nirS gene under high soil moisture content. At the end of the experiment, there was a significant positive correlation between N₂O flux and nosZ gene, indicating that the production of N₂O was regulated by the abundance of nosZ gene under low soil water content. The results of this study showed that the application of biochar altered the abundance of amoA and denitrification bacteria genes, and reduced N₂O emission. These results provide a theoretical basis for a rational application of biochar in farmland.

Ervadivamines A and B, Two Unusual Trimeric Monoterpenoid Indole Alkaloids from Ervatamia divaricata

Ervadivamines A (1) and B (2), two unprecedented trimeric monoterpenoid indole alkaloids, were isolated from Ervatamia divaricata. They are the first examples of vobasine-iboga-vobasine-type alkaloid with both C-C and C-N linkage patterns. Their structures including absolute configurations were fully accomplished by extensive spectroscopic analysis, single-crystal X-ray diffraction, and electric circular dichroism methods. The plausible biogenetic pathways of these trimeric alkaloids were also proposed. In addition, compound 1 exhibited significant cytotoxicity against four cancer cells.