Enhancing Metabolome Annotation by Electron Impact Excitation of Ions from Organics-Molecular Networking.

Liquid chromatography-high-resolution mass spectrometry (LC-HRMS) is widely used in untargeted metabolomics, but large-scale and high-accuracy metabolite annotation remains a challenge due to the complex nature of biological samples. Recently introduced electron impact excitation of ions from organics (EIEIO) fragmentation can generate information-rich fragment ions. However, effective utilization of EIEIO tandem mass spectrometry (MS/MS) is hindered by the lack of reference spectral databases. Molecular networking (MN) shows great promise in large-scale metabolome annotation, but enhancing the correlation between spectral and structural similarity is essential to fully exploring the benefits of MN annotation. In this study, a novel approach was proposed to enhance metabolite annotation in untargeted metabolomics using EIEIO and MN. MS/MS spectra were acquired in EIEIO and collision-induced dissociation (CID) modes for over 400 reference metabolites. The study revealed a stronger correlation between the EIEIO spectra and metabolite structure. Moreover, the EIEIO spectral network outperformed the CID spectral network in capturing structural analogues. The annotation performance of the structural similarity network for untargeted LC-MS/MS was evaluated. For the spiked NIST SRM 1950 human plasma, the annotation coverage and accuracy were 72.94 and 74.19%, respectively. A total of 2337 metabolite features were successfully annotated in NIST SRM 1950 human plasma, which was twice that of LC-CID MS/MS. Finally, the developed method was applied to investigate prostate cancer. A total of 87 significantly differential metabolites were annotated. This study combining EIEIO and MN makes a valuable contribution to improving metabolome annotation.

Anti-ageing and Anti-lung Carcinoma Effects of Vulpinic Acid and Usnic Acid Compounds and Biological Investigations with Molecular Modeling Study.

Disorganization and breakdown of extracellular matrix proteins like fibronectin, collagen, and elastin are key characteristics of skin aging due to the increased activation of important proteolytic enzymes like elastases and collagenase enzymes. Also, inhibition of their enzymatic activities by natural molecules might be a promising factor to prevent extrinsic skin aging. All chemicals were obtained from Sigma-Aldrich unless otherwise stated. The assay employed was based on spectrophotometric methods reported in the literature. The collagenase and elastase inhibition assays of some phenolic compounds were performed according to the previous studies. These compounds showed excellent to good inhibitory activities of vulpinic acid against studied these enzymes with IC50 values of 195.36 µM for collagenase and 25.24 µM for elastase. The molecular docking calculations were conducted to investigate the chemical and biological activity of vulpinic acid and usnic acid against collagenase and elastase. The results indicated that these two compounds can interact with the essential residues of the enzymes and affect their activities. The calculations of binding free energies were also performed to obtain more details about the characteristics and free energies of the ligand-enzyme complexes. Additionally, both compounds exhibited the most potent inhibition in the three lung cancer cells, with an IC50 value of 21-68 µM, indicating that vulpinic acid is more potent than Doxorubicin, which exhibited an IC50 value of 21-29 µM.

[Characteristics of agricultural climate resource changes during the growth stages of tobacco during 1961-2017 in Panxi Region, China]. / 1961­2017年攀西烤烟生育期农业气候资源变化特征.

It is of great significance for the sustainable development of regional agriculture to understand the changes of agricultural climate resources during the growth period of local main crops. Based on data from 15 meteorological stations in tobacco planting area of Panxi region, Sichuan, from 1961 to 2017, the average temperature, diurnal temperature range, water deficit, and radiation were used to analyze the temporal and spatial distribution of agricultural climate resources such as light, temperature, and water in the whole growth period and each growth stages respectively. From 1961 to 2017, the average temperature of tobacco during the whole growth period gradually decreased from south to north in Panxi, while temperature showed an increasing trend in most areas. The area with significantly increased temperature accounted for 54.5% of the total planting area. The diurnal temperature range in most area of the eastern Panxi and some of the central Panxi showed an upward trend, and these areas accounted for 76.4% of the whole Panxi region. Water deficit gradually decreased from south to north, with an increasing trend in the whole region. The radiation during the growth stage of tobacco was high in the southwest and low in the northeast, and the climatic tendency was positive values in the southwest. During the study period, average temperature was the highest in the period from vigorous growth to the beginning of maturity, with an overall upward trend. The diurnal temperature rage and water deficit were the highest in transplanting squatting seedling stage. Radiation was the highest at the beginning of maturity, which increased slightly at the beginning of seedling growth.

New C16-noriridals and formyl-monocycloiridals from the rhizomes of Iris pseudoacorus.

Four new C16-noriridals (1-4) and two reported C16-noriridals (5-6), together with two new formyl-monocycloiridals (7-8) and three known monocycloiridals (9-11) were isolated from the rhizomes of Iris pseudoacorus. Irispseudoacorins A-D (1-4) and iridojaponals A-B (5-6) were C16-noriridals which shared a 6/5/7 tricyclic ring system (1-2, 5-6) or 6/5 tricyclic ring system (3-4). The formyl-monocycloiridals (7-8) were detected in the crude extracts of I. pseudoacorus by LC-MS analysis which suggested they were originated from natural sources rather than artificial products during the isolation. Their structures were determined by UV, IR, extensive NMR spectra and X-ray diffraction analyses. The known monocycloiridals 9-10 displayed pronounced cytotoxic effects against five human tumor cell lines. The IC50 values of 9 were ranging from 12.63 to 24.69µM.

[Shenfu injection induces the apoptosis of prostate cancer PC-3 cells].

OBJECTIVE: To study the effect of Shenfu Injection (SF) on the apoptosis of prostate cancer PC-3 cells and its possible mechanism. METHODS: We divided prostate cancer PC-3 cells into a blank control group and three experimental groups, the latter treated with SF at 50, 100, and 200 microl/ml, respectively, for 24, 48, and 72 hours. Then we determined the proliferation of the cells by MTT assay, measured their apoptosis by Annexin V/PI flow cytometry, and detected the expression of P53 mRNA by RT-qPCR. RESULTS: Compared with the blank control group, the survival rates of the prostate cancer PC-3 cells in the 50, 100, and 200 microl/ml SF groups were (93.76 +/- 2.63)%, (81.21 +/- 1.80)% and (18.01 +/- 3.84)% at 24 hours, (94.67 +/-1.11)%, (78.33 +/- 2.89)% and (10.34 +/- 1.44)% at48 hours, and (91.30 +/- 0.47)%, (36.67 +/- 1.56)% and (1.33 +/- 0.32)% at 72 hours, all significantly increased in a dose- and time-dependent manner (P < 0.05). The expression of p53 mRNA was also markedly increased in all the three experimental groups at 48 hours (P < 0. 05). CONCLUSION: SF can inhibit the proliferation and induce the apoptosis of PC-3 cells, which may due to its upregulation of the p53 mRNA expression.