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Lysine acetylation is a common posttranslational modification that regulates numerous biochemical functions in both eukaryotic and prokaryotic species. In addition, several new non-acetyl acylations are structurally different from lysine acetylation and participate in diverse physiological functions. Here, a comprehensive analysis of several lysine acylomes was performed by combining the high-affinity antibody enrichment with high-resolution LC-MS/MS. In total, we identified 2536 lysine acetylated sites, 4723 propionylated sites, 2150 succinylated sites and 3001 malonylated sites in Bacillus subtilis, respectively. These acylated proteins account for 35.8% of total protein in this bacterium. The four lysine acylomes showed a motif preference for glutamate surrounding the modified lysine residues, and a functional preference for several metabolic pathways, such as carbon metabolism, fatty acid metabolism, and ribosome. In addition, more protein-protein interaction clusters were identified in the propionylated substrates than other three lysine acylomes. In summary, our study presents a global landscape of acylation in the Gram-positive model organism Bacillus and their potential functions in metabolism and physiology.

Targeting histone epigenetic modification is an important strategy for anticancer therapy. Histone deacetylase inhibitors (HDACis) have been clinically approved in the treatment of diverse hematological cancers, but mechanisms of drug resistance and poor therapeutic efficacy in solid malignancies remain largely unknown. In this study, we applied a mass spectrometry-based quantitative proteomic strategy to investigate the molecular differences in HDACi vorinostat (SAHA) sensitive and resistant cell lines. The proteomic results revealed that the glycolysis pathway was highly enriched after vorinostat treatment in the resistant cell line, leading to the prediction of a new drug combination, SAHA and hexokinase inhibitor (2-deoxyglucose). The efficacy of this combination was further verified in several solid tumor cell lines. Quantitative proteomics revealed that alterations in the transcription process and protein homeostasis could play roles in the synergetic utilization of these two compounds. Our study showed the application of proteomics in elucidating the drug mechanism and predicting drug combination and the potential of expanding the utilization of HDACi.

Global identification of protein C-termini is highly challenging due to their low abundance in conventional shotgun proteomics. Several enrichment strategies have been developed to facilitate the detection of C-terminal peptides. One major issue of previous approaches is the limited C-terminome coverage. Herein, we integrated LysargiNase digestion, chemical acetylation on neo-N-terminus, and a-ion-aided peptide matching into poly(allylamine)-based C-terminomics (termed as LAACTer). In this strategy, we leveraged LysargiNase, a protease with cleavage specificity N-terminal to Lys and Arg residues, to cover previously unidentifiable C-terminome and employed chemical acetylation and a-ion-aided peptide matching to efficiently boost peptide identifications. Triplicates of LAACTer identified a total of 834 C-termini from proteome of 293T cell, which expanded the coverage by 164% (643 more unique C-termini) compared with the parallel experiments using the original workflow. Compared with the largest human C-terminome data sets (containing 800-900 C-termini), LAACTer not only achieved comparable profiling depth but also yielded 465 previously unidentified C-termini. In a SILAC (stable isotope labeling with amino acids in cell culture)-based quantitative study for identification of GluC-cleaved products, LAACTer quantified 300% more C-terminal peptides than the original workflow. Using LAACTer and the original workflow, we performed global analysis for the C-terminal sequences of 293T cell. The original and processed C-termini displayed distinct sequence patterns, implying the "C-end rules" that regulates protein stability could be more complex than just amino acid motifs. In conclusion, we reason LAACTer could be a powerful proteomic tool for in-depth C-terminomics and would benefit better functional understanding of protein C-termini.

Nonalcoholic steatohepatitis (NASH) is an advanced stage of nonalcoholic fatty liver disease (NAFLD) with serious consequences that currently lacks approved pharmacological therapies. Recent studies suggest the close relationship between the pathogenesis of NAFLD and the dysregulation of RNA splicing machinery. Here, we reveal death-associated protein kinase-related apoptosis-inducing kinase-2 (DRAK2) is markedly upregulated in the livers of both NAFLD/NASH patients and NAFLD/NASH diet-fed mice. Hepatic deletion of DRAK2 suppresses the progression of hepatic steatosis to NASH. Comprehensive analyses of the phosphoproteome and transcriptome indicated a crucial role of DRAK2 in RNA splicing and identified the splicing factor SRSF6 as a direct binding protein of DRAK2. Further studies demonstrated that binding to DRAK2 inhibits SRSF6 phosphorylation by the SRSF kinase SRPK1 and regulates alternative splicing of mitochondrial function-related genes. In conclusion, our findings reveal an indispensable role of DRAK2 in NAFLD/NASH and offer a potential therapeutic target for this disease.

Nonalcoholic hepatosteatosis (NASH) is an advanced stage of nonalcoholic fatty liver disease (NAFLD) with serious consequences that currently lacks approved pharmacological therapies. Recent studies suggest the close relationship between the pathogenesis of NAFLD and the dysregulation of RNA splicing machinery. Here, we revealed death-associated protein kinase-related apoptosis-inducing kinase-2(Drak2) is markedly upregulated in the livers of both patients and NAFLD/NASH diets-fed mice. Hepatic deletion of Drak2 suppresses the progression of hepatic steatosis to NASH. Comprehensive analyses of the phosphoproteome and transcriptome, indicated a crucial role of Drak2 in RNA splicing, and identified the splicing factor SRSF6 as a direct binding protein of Drak2. Further studies demonstrated that the binding of Drak2 inhibits phosphorylation of SRSF6 by the SRSF kinase(SRPK1) and regulates alternative splicing of mitochondrial function-related genes. In conclusion, our findings reveal an indispensable role of Drak2 in NAFLD/NASH and offer a potential therapeutic target for this disease.

Objective The objective of this study was to evaluate the bioequivalence between single-dose intravenous (IV) infusion injection (the infusion time was 15 minutes and 45 minutes) and tablets of 1,000 mg levetiracetam in healthy Chinese male subjects. Materials and methods This was a randomized, open-label, three-way crossover bioequivalence study. All of the 24 healthy male subjects received a treatment of 45-minute IV infusion, 15-minute IV infusion, and oral tablets. Results After a single dose, the AUC, Vd, Cl, and T1/2 were all essentially consistent among the treatment; tmax of 15-minute IV, 45-minute IV, and oral tablets were 0.25 hours, 0.75 hours, and 0.5 hours, respectively. The Cmax of the 15-minute IV was higher than the value of the 45-minute IV and the oral tablets. The geometric mean of the 15-minute IV/oral and the 45-minute IV/oral ratios were 101.02% (90% CI, 98.95 - 103.12) and 98.22% (90% CI, 96.22 - 100.27), respectively, for AUC0-t. And those for Cmax were 169.09% (90% CI, 155.21 - 184.21) and 106.95 (90% CI, 98.20 - 116.48), respectively. There were no severe adverse events or other adverse events with clinical significance during the study. Conclusion In these healthy subjects, the results showed that 45-minute IV and oral tablets were bioequivalent. The tlsubgmaxl/subg of the 15-minute IV and oral tablets were significantly different. The tmax of the oral tablets was between that of the 15-minute IV and the 45-minute IV. The elimination of injection and oral tablets in humans was similar. Levetiracetam concentrated solution for injection and oral tablets were safe for healthy Chinese male subjects in this study. .

Protein acylation plays important roles in bacterial pathogenesis through regulation of enzymatic activity, protein stability, nucleic acid binding ability, and protein-protein interactions. Mycobacteria, a genus including invasive pathogens known to cause serious diseases, shapes its pathogenicity through adaptation of its energy metabolism to microenvironments encountered within mammalian hosts. In this process, acetyl-CoA and propionyl-CoA function as important intermediates. However, the function of acetyl-CoA/propionyl-CoA driven protein acylation remains to be elucidated. Herein, we systematically investigated protein acetylome/propionylome in the nonpathogenic Mycobacterium smegmatis through antibody-enrichment-based proteomic analysis in which 146 acetylated sites on 121 proteins and 26 propionylated sites on 25 proteins were identified. After that, characteristic differences of the two acylomes were elucidated through such bioinformatic methods as motif analysis, protein-protein analysis, Gene Ontology analysis, and KEGG analysis. In addition, quantitative mass spectrometric method was used to evaluate the site-specific and motif-biased catalytic mechanism mediated by the cAMP-dependent acetyltransferase MsKat in M. smegmatis. Furthermore, we raised the possibility that both O-serine and Ne-lysine acetylation might coregulate the propionyl-CoA synthetase. This study described the landscape of acetylome and propionylome in the M. smegmatis, showing an unexpected role of protein acylation regulation in mycobacteria.

Cholesterol assimilation is a critical step in mycobacterial chronic infection. However, knowledge from the dynamic characterization of cholesterol metabolism in mycobacteria at the protein expression and PTM levels remains limited. Our study uncovered the landscape of protein expression, lysine acetylation, lysine propionylation, and S/T/Y phosphorylation during the metabolic changes from glucose to cholesterol in mycobacteria. The data showed that cholesterol-induced carbon shift resulted in the elevation of protein expression and lysine acylation in diverse metabolic enzymes involved in cholesterol degradation and that the presence of cholesterol also promoted the perturbations at the phosphorylation level in the kinase system in mycobacteria. This study systematically characterized the regulation of cholesterol catabolism at several different levels, which provided the detailed references in mycobacterial proteome and potential antimycobacterial strategies., Cholesterol of the host macrophage membrane is vital for mycobacterial infection, replication, and persistence. During chronic infection within host lung tissues, cholesterol facilitates the phagocytosis of mycobacteria into macrophages. Cholesterol degradation leads to increased flux of acetyl-coenzyme A (CoA) and propionyl-CoA, providing energy and building blocks for virulence macromolecules as well as donors for global protein acylation. Potential functions of lysine acylation are gradually revealed in bacterial survival and pathogenesis. However, the mycobacterial proteome and posttranslational modification (PTM) changes involved in the cholesterol catabolism bioprocess remain unclear. Here, we used nonpathogenic Mycobacterium smegmatis as a model and simultaneously monitored mycobacterial proteome and acetylome changes in the presence of glucose and cholesterol. We discovered that cholesterol metabolic enzymes were upregulated with respect to both protein expression levels and lysine acylation levels during the metabolic shift from glucose to cholesterol. After that, adenylating enzymes related to cholesterol metabolism were proven to be precisely regulated at the propionylation level by mycobacterial acyltransferase M. smegmatis Kat (MsKat) in response to cellular propionyl-CoA accumulation. Furthermore, the kinase expression and phosphorylation levels were also changed along with fluctuations in cholesterol levels. Our results expanded current knowledge of acylation regulation in the cholesterol catabolism of mycobacteria and provided references for possible antimycobacterium strategy. IMPORTANCE Cholesterol assimilation is a critical step in mycobacterial chronic infection. However, knowledge from the dynamic characterization of cholesterol metabolism in mycobacteria at the protein expression and PTM levels remains limited. Our study uncovered the landscape of protein expression, lysine acetylation, lysine propionylation, and S/T/Y phosphorylation during the metabolic changes from glucose to cholesterol in mycobacteria. The data showed that cholesterol-induced carbon shift resulted in the elevation of protein expression and lysine acylation in diverse metabolic enzymes involved in cholesterol degradation and that the presence of cholesterol also promoted the perturbations at the phosphorylation level in the kinase system in mycobacteria. This study systematically characterized the regulation of cholesterol catabolism at several different levels, which provided the detailed references in mycobacterial proteome and potential antimycobacterial strategies.

The selection of a data processing method for use in mass spectrometry-based label-free proteome quantification contributes significantly to its accuracy and precision. In this study, we comprehensively evaluated 7 commonly-used label-free quantification methods (MaxQuant-Spectrum count, MaxQuant-iBAQ, MaxQuant-LFQ, MaxQuant-LFAQ, Proteome Discoverer, MetaMorpheus, TPP-StPeter) with a focus on missing values, precision, accuracy, selectivity, and reproducibility of low abundance protein quantification in both single shot and fractionation. Our results showed that among the tested strategies, MaxQuant in MaxLFQ mode outperformed other strategies in terms of accuracy and precision in both whole proteome and low abundance proteome quantification, whereas the Proteome Discoverer (PD) strategy using SEQUEST as a search engine performed better in terms of quantifiable low abundance proteome coverage. We subsequently applied the PD and MaxLFQ strategies in a blood proteomic dataset and found that many FDA-approved tumor prognostic biomarkers could be identified as well as quantified using the PD strategy, indicating the potential advantage of PD in label-free quantification studies. These results provide a reference for method choice in label-free quantification data analysis. SIGNIFICANCE: Mass spectrometry-based label-free quantification methods play an important role in label-free proteome data analysis. In this study, we evaluated 7 commonly-used label-free quantification methods with respect to the following aspects: missing values, precision, accuracy, selectivity, and reproducibility for low abundance protein quantification. The results showed that, among the strategies evaluated, the PD strategy with SEQUEST as a search engine performed better in terms of low abundance protein coverage. This study provides a reference for method choice in label-free quantification data analysis.

Propionylation at protein lysine residue is characterized to be present in both eukaryotic and prokaryotic species. However, the majority of lysine propionylation substrates still remain largely unknown. Using affinity enrichment and mass-spectrometric-based proteomics, we identified 1467 lysine propionylation sites in 603 proteins in E. coli. Quantitative propionylome analysis further revealed that global lysine propionylation level was drastically increased in response to propionate treatment, a carbon source for many microorganisms and also a common food preservative. The results indicated that propionylation may play a regulatory role in propionate metabolism and propionyl-CoA degradation. In contrast with lysine acetylation and succinylation, our results revealed that the lysine propionylation level of substrates showed an obvious decrease in response to high glucose, suggesting a distinct role of propionylation in bacteria carbohydrate metabolism. This study further showed that bacterial lysine deacetylase CobB and acetyltransferase PatZ could also have regulatory activities for lysine propionylation in E. coli. Our quantitative propionylation substrate analysis between cobB wild-type and cobB knockout strain led to the identification of 13 CobB potentially regulated propionylation sites. Together, these findings revealed the broad propionylation substrates in E. coli and suggested new roles of lysine propionylation in bacterial physiology.

Genomic studies of lung adenocarcinoma (LUAD) have advanced our understanding of the disease's biology and accelerated targeted therapy. However, the proteomic characteristics of LUAD remain poorly understood. We carried out a comprehensive proteomics analysis of 103 cases of LUAD in Chinese patients. Integrative analysis of proteome, phosphoproteome, transcriptome, and whole-exome sequencing data revealed cancer-associated characteristics, such as tumor-associated protein variants, distinct proteomics features, and clinical outcomes in patients at an early stage or with EGFR and TP53 mutations. Proteome-based stratification of LUAD revealed three subtypes (S-I, S-II, and S-III) related to different clinical and molecular features. Further, we nominated potential drug targets and validated the plasma protein level of HSP 90β as a potential prognostic biomarker for LUAD in an independent cohort. Our integrative proteomics analysis enables a more comprehensive understanding of the molecular landscape of LUAD and offers an opportunity for more precise diagnosis and treatment.

The effect of regulatory system on the engineered biosynthetic pathway in chassis cells remains incompletely understood in microorganisms. Acyl-CoAs function as key precursors for the biosynthesis of various natural products and the dominant donors for protein acylation. The polyphenol pinosylvin, with high antimicrobial and antifungal activities, is biosynthesized with malonyl-CoA as its direct precursors. But correlation between lysine malonylation and pinosylvin biosynthesis remains unknown. Herein, we found that the malonyl-CoA-driven lysine malonylation plays an important role in interaction between the engineered pathway of pinosylvin synthesis and E. coli chassis cell. Oversupply of malonyl-CoA leads to an increase in malonylation level of global proteome as well as the enzymes in the artificial pathway, thereby decreasing yield of pinosylvin. The results revealed that the intricate balance of cellular acyl-CoA concentrations is critical for the yields of acyl-CoA-derived natural products. We next modified the enzymes in the biosynthetic pathway to adjust their acylation level and successfully improved the yield of pinosylvin. Our study uncovers the effect of protein acylation on the biosynthetic pathway, helps optimization of synthetic constructs, and provides new strategies in metabolic engineering and synthetic biology at the protein post-translational level.

Coenzyme A (CoA) esters of short fatty acids (acyl-CoAs) function as key precursors for the biosynthesis of various natural products and the dominant donors for lysine acylation. Herein, we investigated the functional interplay between beneficial and adverse effects of acyl-CoA supplements on the production of acyl-CoA-derived natural products in microorganisms by using erythromycin-biosynthesized Saccharopolyspora erythraea as a model: accumulation of propionyl-CoA benefited erythromycin biosynthesis, but lysine propionylation inhibited the activities of important enzymes involved in biosynthetic pathways of erythromycin. The results showed that the overexpression of NAD+-dependent deacylase could circumvent the inhibitory effects of high acyl-CoA concentrations. In addition, we demonstrated the similar lysine acylation mechanism in other acyl-CoA-derived natural product biosynthesis, such as malonyl-CoA-derived alkaloid and butyryl-CoA-derived bioalcohol. These observations systematically uncovered the important role of protein acylation on interaction between the accumulation of high concentrations of acyl-CoAs and the efficiency of their use in metabolic pathways.

The studies of protein methylation mainly focus on lysine and arginine residues due to their diverse roles in essential cellular processes from gene expression to signal transduction. Nevertheless, atypical protein methylation occurring on amino acid residues, such as glutamine and glutamic acid, is largely neglected until recently. In addition, the systematic analysis for the distribution of methylation on different amino acids in various species is still lacking, which hinders our understanding of its functional roles. In this study, we deeply explored the methylated sites in three species Escherichia coli, Saccharomyces cerevisiae, and HeLa cells by employing MS-based proteomic approach coupled with heavy methyl SILAC method. We identify a total of 234 methylated sites on 187 proteins with high localization confidence, including 94 unreported methylated sites on nine different amino acid residues. KEGG and gene ontology analysis show the pathways enriched with methylated proteins are mainly involved in central metabolism for E. coli and S. cerevisiae, but related to spliceosome for HeLa cells. The analysis of methylation preference on different amino acids is conducted in three species. Protein N-terminal methylation is dominant in E. coli while methylated lysines and arginines are widely identified in S. cerevisiae and HeLa cells, respectively. To study whether some atypical protein methylation has biological relevance in the pathological process in mammalian cells, we focus on histone methylation in diet-induced obese (DIO) mouse. Two glutamate methylation sites showed statistical significance in DIO mice compared with chow-fed mice, suggesting their potential roles in diabetes and obesity. Together, these findings expanded the methylome database from microbes to mammals, which will benefit our further appreciation for the protein methylation as well as its possible functions on disease.

Lysine methylation is a widespread protein post-translational modification showing essentialities in versatile cellular process. EZH2, a methyltransferase specifically trimethylates the lysine 27 of histone H3 and its aberrance in several cancers promotes the development of its inhibitors against hematological tumors. In this study, we presented a deep exploration of lysine mono-, di- and trimethylomes in EZH2 wild-type and Y641 mutant lymphoma cell lines. Our results showed that several substrates were modified in different methylation levels. Moreover, these methylated lysine residues could also undergo other types of PTMs. Combined with the differences proved in protein expression, lysine acetylation, lysine ubiquitylation and protein N-termianl acetylation level, our study underlined the substrate specificity of lysine methylation and its crosstalk with other types of PTMs. Totally, our study raised new insights into the global cellular methylation features in hematological cell lines, which provided further inspects into the distribution and function of lysine methylation. SIGNIFICANCE: Our study showed the global landscape of mono-, di- and trimethylomes in the EZH2-aberrant DLBCL cell lines, revealing the molecular characteristics of lysine methylation. Combined with the protein abundance and potential crosstalk among different types of PTMs, our study raised new insights into the global cellular methylation features in hematological tumors and provided further inspects into the distribution and function of lysine methylation.

ACT domains (amino acid-binding domains) are linked to a wide range of metabolic enzymes that are regulated by amino acid concentration. Seventy proteins with ACT-GCN5-related N-acetyltransferase (GNAT) domain organization were found in actinomycetales. In this study, we investigate the ACT-containing GNAT acetyltransferase, Micau_1670 (MaKat), from Micromonospora aurantiaca ATCC 27029. Arginine and cysteine were identified as ligands by monitoring the conformational changes that occur upon amino acids binding to the ACT domain in the MaKat protein using FRET assay. It was found that MaKat is an amino acid-regulated protein acetyltransferase, whereas arginine and cysteine stimulated the activity of MaKat with regard to acetylation of acetyl-CoA synthetase (Micau_0428). Our research reveals the biochemical characterization of a protein acetyltransferase that contains a fusion of a GNAT domain with an ACT domain and provides a novel signaling pathway for regulating cellular protein acetylation. These findings indicate that acetylation of proteins and acetyltransferase activity may be tightly linked to cellular concentrations of some amino acids in actinomycetales.

The Zhongba ophiolite is located in the western part of the Yarlung Zangbo Suture Zone (YZSZ) separating Eurasia to the north from the Indian plate to the south. This ophiolite comprises a well-preserved mantle sequence dominated by harzburgites with minor dunites. Highly depleted modal, mineral and bulk rock compositions of the harzburgites indicate that they are residues after moderate to high degrees of partial melting (13–24%) mainly in the spinel-stability field. These rocks display typical U-shaped chondrite-normalized Rare Earth Element (REE) patterns and fractionated chondrite-normalized Platinum Group Element (PGE) patterns. These characteristics, in combination with their hybrid mineral and whole-rock compositions intermediate between those of abyssal and forearc peridotites, indicate melt-rock interaction resulting in the selective enrichment of LREE and Pd. We propose a two-stage model to explain the generation of the Zhongba harzburgites: 1) original generation from a MORB-source upper mantle, and 2) subsequent trapping as part of a mantle wedge above a subduction zone. Comparable observations from the ophiolitic massifs along the whole YZSZ allow us to propose that a ca. 2500-km long complex subduction system was active between India and the Lhasa terrane, Burma, and the Karakoram microcontinent within the Neo-Tethys during the Early Cretaceous, similar to the modern active intra-oceanic subduction systems in the Western Pacific.

Objectives The aim of this study is to investigate the population pharmacokinetics (PopPK) of cyclosporine (CsA) in the Chinese hematopoietic stem cell transplantation (HSCT) recipients for promoting the individualization of CsA administration. Methods A total of 887 retrospective drug monitoring data points were collected from 58 HSCT recipients. Whole blood samples were collected at predose (C0) and 2 hours (C2) post dose. The administration of CsA was intermittent intravenous infusion, continuous intravenous infusion and oral. Population modeling was performed using the NONMEM (nonlinear mixedeffect modeling) program. A one compartment pharmacokinetic model was used to fit the data. Results Body surface area (BSA), administration route and postoperative days were identified as significant covariates for clearance (CL) according to the final model: CL = 31.0 × (BSA/1.59)0.761 × (ROUT) × (POD), where ROUT was 1.91 if the administration route was intravenous infusion, otherwise it is equal to 1. The POD was 0.818, 0.753, 0.539, and 0.509 for posttransplant Days 0 - 10, 11 - 20, 21 - 30 and more than 30 days, respectively. Administration route was a significant covariate for volume (V) according to the final model: V = 192 × (ROUT), where ROUT was 4.10, 3.63 and 1 when the administration route was continuous intravenous infusion, intermittent intravenous infusion and oral. The other covariates were not identified as a significant effect on CsA pharmacokinetic parameters. Conclusion Body surface area, administration route and postoperative days should be considered in individual pharmacotherapy of cyclosporine for HSCT patient to achieve the desired therapeutic target.

Neuroligins (NLs) are postsynaptic membrane proteins expressed in the brain and mediate synaptogenesis. Neuroligin family proteins can specifically induce either excitatory or inhibitory synapses. Deletions or point mutations in neuroligin genes are found in patients with autism spectrum disorders (ASD) or mental retardations. The dysfunctions of these mutations have been tested in multiple neuroligin mouse models. In most of the models, including the human autism-linked NL3 and NL4 mutation mice, there are social interaction defects, memory impairment and repetitive behaviors. Researchers also found the excitatory/inhibitory synapse ratio altered in those mice, as well as receptor subunit composition. However, inconsistencies and debates also exist between different research approaches. In this review, we summarize the neuroligin mouse models currently available, examine the detailed alterations detected in those mice and compare the differences within different mouse models or different investigation methods, to obtain an overall picture of the current progress on neuroligin mouse models.

To develop a urine pretreatment method of Solid Phase Extraction (SPE) for the quantitative determination of a number of aristolochic acids (AAs) and aristololactams (ALs) in rat urine.The HPLC peak area of AA-I , AA-II, AL-I and AL-II, and other sixteen AAs and ALs was chosen as evaluating index to study the extract results of five Solid Phase Extraction columns (Agilent C18/100 mg, Alltech HG18/100 mg, Alltech C18/100 mg, Alltech C18/300 mg and Agilent Phenyl/200 mg) comparatively. The influences of two washing solvents (water and 1% acetic acid-0.02% triethylamine solution) and seven eluting solvents (ether, acetone, chloroform, ethyl acetate, dichloromethane, methanol and acetonitrile) on extract results of AAs and ALs are comparatively studied with the extracting recoveries of AA-I , AA-II, AL-I and AL-II as indicators. The HPLC peak area of AA-I , AA-II, AL-I and AL-II, and other seven AAs and ALs with good separation being targets, several factors which affect extracting efficiency of analytes, including activating volume, cleansing volume, washing volume and eluting volume, are optimized by orthogonal design experiments with four factors at three levels.The established method of SPE is as follows: Agilent Phenyl SPE column of 200 mg, activating with 1.0 mL methanol, cleansing with 1 mL water, adding 1.0 mL rat urine sample, washing with 0.8 mL 1% acetic acid 0.02% triethylamine solution, and eluting with 3.0 mL methanol.The established method of SPE is efficient, selective, simple and fast, and can be used as urine pretreatment method to analyze a variety of aristolochic acids and aristololactams in rat urine.

Taking Caulis Aristolochiae Manshuriensis (Guanmutong in Chinese, derived from the stem of Aristolochia manshuriensis) as an example, to study the affection of different preparations on the content of toxic constituents in traditional Chinese medicines.The separation was performed on a zorbax SB-C18 column with mobile phase of acetonitrile-3.7 mmol x L(-1) phosphoric acid buffer, detected at 260 nm.The extraction percentage of aristolochic acids I, II and IV a in water extraction (1 h x 2) of Guanmutong were 53.4%, 75.5% and 61.9%, respectively; the remaining quantity of aristolochic acids I, II and IVa in the dregs of the decoction were 22.3%, 15.7% and 30.3%, respectively; Aristolochic acid I was still main substance among these aristolohic acids in the decoction of Guanmutong.The content of toxic constituents of the traditional Chinese medicines varies evidently with different preparations of Guanmutong. So the preparation methods of traditional Chinese medicines should be suitably selected according to characteristics of the toxic constituents so as to lessen the body damages of human.