A spectrum-effect based method for screening antibacterial constituents in Niuhuang Shangqing Pill using comprehensive two-dimensional liquid chromatography.

To investigate and screen the active antibacterial constituents of Niuhuang Shangqing Pill (NSP), the current study developed a two-dimensional liquid chromatography (2DLC) method combining microcalorimetry technique. 60% ethanol extracts from 10 batches of different commercial NSP samples were analyzed and their chemical fingerprint were developed by the comprehensive 2DLC system of Shimadzu Nexera X2. Anti-streptococcus pneumoniae (SP) constituents were determined by microcalorimetry. Thermal kinetic parameters of the SP thermogram affected by 60% ethanol extracts from 10 NSP samples were analyzed by principal component analysis. Spectrum-effect correlation between comprehensive 2DLC fingerprint and the antibacterial activity were analyzed by orthogonal partial least squares (OPLS) and orthogonal partial least squares discriminant analysis (OPLS-DA). Findings showed that peak X1 (unknown), X9 (aloe-emodin), X10 (baicalein), X11 (unknown), X14 (wogonin), X15 (glycyrrhizic acid) and X17 (unknown) are the relevant components that are in positive correlation with inhibitory rate. Regarding inhibitory rate, X17 is the most powerful one, followed by X14, X15, X10, X11, X1 and X9, suggesting that compound X17, wogonin, glycyrrhizic acid and baicalein are the major active antibacterial components of NSP. The current method employing 2DLC with microcalorimetry technique proposes a new insight for screening and identifying antibacterial components in complex herbal formula.

Urinary metabonomics study of anti-depressive mechanisms of Millettia speciosa Champ on rats with chronic unpredictable mild stress-induced depression.

As a traditional Chinese medicine (TCM), Millettia speciosa Champ (MSC), exerts a wide range of pharmacological activities. Our research group previously found that MSC has antidepressant effects, but the specific antidepressant mechanisms remain unclear. Therefore, in this study, urine metabolomics based on ultra-performance liquid chromatography/quadrupole time of flight mass spectrometry (UPLC-Q-TOF/MS) combined with pharmacodynamics was used to explore the pathogenesis of depression and the antidepressant effects of MSC. The results showed that MSC treatment could significantly improve chronic unpredictable mild stress (CUMS)-induced depression. Urine metabolic showed that the profiles of the CUMS model group were significantly separated from the control group, while the drug-treated groups were closer to the control group, especially the MSC group treated with a 14 g/kg dose of MSC. Furthermore, 9 metabolites, including glutaric acid, L-isoleucine, L-Dopa, sebacic acid, 3-methylhistidine, allantoin, caprylic acid, tryptophol, and 2-phenylethanol glucuronide, were identified as potential biomarkers of depression. Metabolic pathway analysis showed that these potential biomarkers were mainly involved in valine, leucine, and isoleucine biosynthesis, aminoacyl-tRNA biosynthesis, valine, leucine and isoleucine degradation, tyrosine metabolism, histidine metabolism, fatty acid biosynthesis, and pentose and glucuronate interconversions. Through Receiver operating characteristic (ROC) analysis and Pearson correlation analysis, the combination of L-isoleucine, sebacic acid, and allantoin, were further screened out as potential pharmacodynamic biomarkers associated with the efficacy of MSC. This study suggests that the integration of metabolomics with pharmacodynamics helps to further understand the pathogenesis of depression and provides novel insight into the efficacy of TCM.

The study of neuroprotective effect of ferulic acid based on cell metabolomics.

Ferulic acid (FA), a naturally derived phenolic compound, has antioxidant and antidepressant-like effects. It is still a challenge to study its mechanism due to the complexity of the pathophysiology of depression. In this study, ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) was used to perform metabolomics studies based on biochemical changes in differentiated rat pheochromocytoma (PC12) cells treated with corticosterone-induced neurological damage after FA treatment. A total of 31 metabolites were identified as potential biomarkers for corticosterone-induced PC12 cells injury. Among them, 24 metabolites were regulated after FA treatment. Pathway analysis revealed that these metabolites were mainly involved in the amino acid metabolism, energy metabolism and glycerophospholipid metabolism. In addition, based on the results of metabolomics, three cell signaling pathways related to glutamate were discovered. To further study the interactions between FA and major targets in three signaling pathways, a molecular docking method was employed. The results showed that FA had the strongest binding power with protein kinase B (AKT). Furthermore, the result of mRNA changes analyzed by quantitative real time RT-PCR indicated that AKT and protein kinase A (PKA) in the signaling pathway were up regulated after treatment with FA compared with model group. This study shows that strategies based on cell metabolomics associated with molecular docking and molecular biology is a helpful tool to elucidate the neuroprotective mechanism of FA.

Comparative analysis of the compatibility effects of Danggui-Sini Decoction on a blood stasis syndrome rat model using untargeted metabolomics.

Danggui-Sini Decoction (DSD) is one of the most widely used traditional Chinese medicine formulae (TCMF) for treating various diseases caused by cold coagulation and blood stasis due to its effect of nourishing blood to warm meridians in clinical use. However, studies of the mechanism of how it dispels blood stasis and its compatible regularity are challenging because of the complex pathophysiology of blood stasis syndrome (BSS) and the complexity of DSD, with multiple active ingredients acting on different targets. Observing variations of endogenous metabolites in rats with BSS after administering DSD may further our understanding of the mechanism of BSS and the compatible regularity of DSD. In this study, to understand the pathogenesis of BSS and assess the compatibility effects of DSD, an ultra-performance liquid chromatography quadrupole-time of flight mass spectrometry-based untargeted metabolomics approach was used. Serum metabolic profiles in rats with BSS that was induced by an ice water bath associated with subcutaneous injection of epinephrine hydrochloride were compared with the intervention groups which were administered with DSD or its compatibility. Using pattern recognition analysis, a clear separation between the BSS model and control group was observed; DSD and its compatibility intervention groups were clustered closer toward the control than the model group, which corroborates results of hemorheology studies. In addition, 20 metabolites were considered as potential biomarkers associated with the development of BSS. Nine metabolites were regulated by DSD in intervening blood stasis, they were considered to be correlated with the effect of nourishing blood to warm meridians. Additionally, the results suggested that the intervention effect of DSD on BSS may involve regulating four pathways, namely, arachidonic acid metabolism, glycerophospholipid metabolism, bile acid biosynthesis, and pyruvate metabolism. Moreover, each functional unit (monarch, minister, and assistant) in DSD regulates different metabolites and metabolic pathways to achieve different effects on dispelling blood stasis; however, their intervention efficacies are inferior to the holistic formula, which may be due to the synergism of the bioactive ingredients in seven herbs of DSD. This study demonstrated that metabolomics is a powerful tool for evaluating the efficacy and compatibility effects of traditional Chinese medicine (TCM).

Investigation of the hepatoprotective effect of Corydalis saxicola Bunting on carbon tetrachloride-induced liver fibrosis in rats by 1H-NMR-based metabonomics and network pharmacology approaches.

Liver fibrosis is a common consequence of chronic liver diseases resulting from multiple etiologies. Furthermore, prolonged unresolved liver fibrosis may gradually progress to cirrhosis, and eventually evolve into hepatocellular carcinoma (HCC). Corydalis saxicola Bunting (CS), a type of traditional Chinese folk medicine, has been reported to have hepatoprotective effects on the liver. However, the exact mechanism of how it cures liver fibrosis requires further elucidation. In this work, an integrated approach combining proton nuclear magnetic resonance (1H-NMR)-based metabonomics and network pharmacology was adopted to elucidate the anti-fibrosis mechanism of CS. Metabonomic study of serum biochemical changes by carbon tetrachloride (CCl4)-induced liver fibrosis in rats after CS treatment were performed using 1H-NMR analysis. Metabolic profiling by means of partial least squares-discriminate analysis (PLS-DA) indicated that the metabolic perturbation caused by CCl4 was reduced after CS treatment. As a result, lipids, leucine, alanine, acetate, O-acetyl-glycoprotein and creatine were significantly restored after CS treatment, which regulated valine, leucine and isoleucine metabolism; arginine and proline metabolism; lipid metabolism and pyruvate metabolism. Additionally, 157 potential targets of CS and 265 targets of liver fibrosis were identified by means of network pharmacology. Subsequently, 5 target proteins, which are the intersection of potential CS targets and liver fibrosis targets, indicated that CS has potential anti-fibrosis effects through regulating alanine aminotransferase (ALT) activity, the farnesoid X receptor (FXR), cyclooxygenase-2 (COX-2), matrix metalloproteinase-1 (MMP-1) and angiotensinogen. Chelerythrine and sanguinarine were the potential active compounds in CS for treating liver fibrosis through regulating ALT activity. This study is the first report to study the anti-fibrosis effects of CS on the basis of combining a metabonomics and network pharmacology approaches, and it may be a potentially powerful tool to study the efficacy and mechanisms of traditional Chinese folk medicines.

Distinguishing Smilax glabra and Smilax china rhizomes by flow-injection mass spectrometry combined with principal component analysis.

Flow-injection mass spectrometry (FIMS) coupled with a chemometric method is proposed in this study to profile and distinguish between rhizomes of Smilax glabra (S. glabra) and Smilax china (S. china). The proposed method employed an electrospray-time-of-flight MS. The MS fingerprints were analyzed using principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) with the aid of SIMCA software. Findings showed that the two kinds of samples perfectly fell into their own classes. Further predictive study showed desirable predictability and the tested samples were successfully and reliably identified. The study demonstrated that the proposed method could serve as a powerful tool for distinguishing between S. glabra and S. china.

Low-cost humic acid-bonded silica as an effective solid-phase extraction sorbent for convenient determination of aflatoxins in edible oils.

Aflatoxins (AFs) are highly toxic, mutagenic, carcinogenic, and teratogenic secondary metabolites produced by the toxigenic fungi Aspergillus flavus and Aspergillus parasiticus. AFs tend to contaminate a wide range of foods which is a serious and recurring food safety problem worldwide. Currently, immunoaffinity chromatography (IAC) has become the most conventional sample clean-up method for determining AFs in foodstuffs. However, IAC method is limited in the large-scale food analysis because it requires the use of expensive disposable cartridges and the IA procedure is time-consuming. Herein, to achieve the cost-effective determination of AFs in edible oils, we developed a promising solid-phase extraction (SPE) method based on commercially available humic acid-bonded silica (HAS) sorbent, followed by high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) analysis. In HAS-SPE, AFs can be captured by the HAS sorbent with both hydrophobic and hydrophilic interactions, whereas the oil matrix was captured only with the hydrophobic interactions. The oil matrix can be sufficiently washed off with isopropanol, while the AFs were still retained on the SPE packing, thus achieving selective extraction of AFs and clean-up of oil matrices. Under the optimal conditions of HAS-SPE, satisfactory recoveries ranging from 82% to 106% for four AFs (B1, B2, G1, and G2) were achieved in various oil matrices, containing blended oil, tea oil, rapeseed oil, peanut oil, sunflower seed oil, corn oil, blended olive oil, rice oil, soybean oil, and sesame oil. Only minor matrix effects ranging from 99% to 105% for four AFs were observed. Moreover, the LODs of AFs between 0.012 and 0.035 µg/kg completely meet the regulatory levels fixed by the EU, China or other countries. The methodology was further validated for assaying the naturally contaminated peanut oils, and consistent results between the HAS-SPE and the referenced IAC were obtained. In addition, HAS-SPE can directly treat diluted oil sample without liquid-liquid extraction and is automatable, thus making it simple and convenient for the large-scale determination of AFs in edible oils. Using this method, we successfully detected four AFs in the naturally contaminated peanut oils, which is, to the best of our knowledge, the first report about the determination of AFs in edible oils using HA-based SPE.

Urinary metabonomics study of the hepatoprotective effects of total alkaloids from Corydalis saxicola Bunting on carbon tetrachloride-induced chronic hepatotoxicity in rats using 1H NMR analysis.

Chronic liver injury has been shown to cause liver fibrosis due to the sustained pathophysiological wound healing response of the liver, and eventually progresses to cirrhosis. The total alkaloids of Corydalis saxicola Bunting (TACS), a collection of important bioactive ingredients derived from the traditional Chinese folk medicine Corydalis saxicola Bunting (CS), have been reported to have protective effects on the liver. However, the underlying molecular mechanisms need further elucidation. In this study, the urinary metabonomics and the biochemical changes in rats with carbon tetrachloride (CCl4)-induced chronic liver injury due to treatment TACS or administration of the positive control drug-bifendate were studied via proton nuclear magnetic resonance (1H NMR) analysis. Partial least squares-discriminate analysis (PLS-DA) suggested that metabolic perturbation caused by CCl4 damage was recovered with TACS and bifendate treatment. A total of seven metabolites including 2-oxoglutarate, citrate, dimethylamine, taurine, phenylacetylglycine, creatinine and hippurate were considered as potential biomarkers involved in the development of CCl4-induced chronic liver injury. According to pathway analysis using identified metabolites and correlation network construction, the tricarboxylic acid (TCA) cycle, gut microbiota metabolism and taurine and hypotaurine metabolism were recognized as the most affected metabolic pathways associated with CCl4 chronic hepatotoxicity. Notably, the changes in 2-oxoglutarate, citrate, taurine and hippurate during the process of CCl4-induced chronic liver injury were significantly restored by TACS treatment, which suggested that TACS synergistically mediated the regulation of multiple metabolic pathways including the TCA cycle, gut microbiota metabolism and taurine and hypotaurine metabolism. This study could bring valuable insight to evaluating the efficacy of TACS intervention therapy, help deepen the understanding of the hepatoprotective mechanisms of TACS and enable optimal diagnosis of chronic liver injury.

Six new furostanol glycosides from Smilax glauco-china and their cytotoxic activity.

Six new steroidal saponins, namely glauco-chinaosides A-F, and one known compound were isolated from the tubers of Smilax glauco-china. Their structures were elucidated by a combination of spectroscopic analysis and hydrolysis followed by spectral and chromatographic analysis. Compounds 1-7 were tested in vitro for their cytotoxic activities against four human tumor cell lines (SH-SY5Y, SGC-7901, HCT-116, and Lovo). Compounds 1, 2, and 5 exhibited cytotoxic activity against SGC-7901, with IC50 values of 2.7, 11.5, and 6.8 µM, respectively.

Serum metabonomics study of the hepatoprotective effect of Corydalis saxicola Bunting on carbon tetrachloride-induced acute hepatotoxicity in rats by (1)H NMR analysis.

Corydalis saxicola Bunting (CS), a traditional Chinese folk medicine, has been effectively used for treating liver disease in Zhuang nationality in South China. However, the exact hepatoprotective mechanism of CS was still looking forward to further elucidation by far. In present work, metabonomic study of biochemical changes in the serum of carbon tetrachloride (CCl4)-induced acute liver injury rats after CS treatment were performed using proton nuclear magnetic resonance ((1)H-NMR) analysis. Metabolic profiling by means of principal components analysis (PCA) and partial least squares-discriminate analysis (PLS-DA) indicated that the metabolic perturbation caused by CCl4 was reduced by CS treatment. A total of 9 metabolites including isoleucine (1), lactate (2), alanine (3), glutamine (4), acetone (5), succinate (6), phosphocholine (7), d-glucose (8) and glycerol (9) were considered as potential biomarkers involved in the development of CCl4-induced acute liver injury. According to pathway analysis by metabolites identified and correlation network construction by Pearson's correlation coefficency matrix, alanine, aspartate and glutamate metabolism and glycerolipid metabolism were recognized as the most influenced metabolic pathways associated with CCl4 injury. As a result, notably, deviations of metabolites 1, 3, 4, 7 and 9 in the process of CCl4-induced acute liver injury were improved by CS treatment, which suggested that CS mediated synergistically abnormalities of the metabolic pathways, composed of alanine, aspartate and glutamate metabolism and glycerolipid metabolism. In this study, it was the first report to investigate the hepatoprotective effect of the CS based on metabonomics strategy, which may be a potentially powerful tool to interpret the action mechanism of traditional Chinese folk medicines.

[Discrimination of Chemical Constituents Changes of Citrus reticulata Pericarp Before and After Processing with Vinegar Based on Partial Least Squares-Discriminate Analysis].

Objective: To investigate the chemical constituents changes of Citrus reticulata pericarp before and after processing with vinegar,and to provide scientific basis for the study of active components in Citrus reticulata pericarp. Methods: Citrus reticulata pericarp was processed with vinegar according to the Zhongyao Paozhixue Cidian. The extracts of unprocessed and processed Citrus reticulata pericarp were detected by HPLC. Partial least squares-discriminate analysis( PLS-DA) was employed to reveal the discrimination between different samples. Results: 15 chemical constituents had significant changes in Citrus reticulata pericarp before and after processing with vinegar. Two components increased significantly after processing with vinegar were characterized as narirutin and hesperidin respectively. Conclusion: The chemical constituents in Citrus reticulata pericarp are found to be changed after processing with vinegar, two components with significant increasing indicate the basis of the variation of bioactivity in vinegar-processed Citrus reticulata pericarp, which provides evidence to interpret its clinical usage.

[¹H-NMR based metabonomic approach to evaluate anti-coagulant effect of Danggui Sini decoction].

To study the anti-coagulant effect and influence of danggui Sini decoction (DSD) on rat's plasma endogenous metabolites by animal experiment and ¹H-NMR based metabolomics method. After intragastric administration of Danggui Sini Decoction for 7 days, Plasma thrombin time (TT) was measured. Rat plasma metabolic fingerprint in two groups was analyzed using ¹H-NMR, based on which the principal component analysis( PCA) and orthogonal partial least-squares discriminant analysis(OPLS-DA) models for metabonomic analysis. Potential biomarkers were screened by using variable importance in the projection (VIP) and T test. DSD could prolong TT of the rat significantly (P < 0.05). Compared with control group, six kinds of endogenous metabolites in DSD group change significantly (P < 0.05), among which isobutyrate, carnitine and phenylalanine content had an upward trend (P < 0.01) and lysine, Histidine and cholesterol content had a downward trend (P < 0.05). It is likely that carnitine, phenylalanine, Histidine and cholesterol are the potential metabolic markers in the anti-coagulant process and DSD affects the platelet aggregation and the expression of tissue factor and fiber protease by regulating the energy, amino acid and lipid metabolism.

Characterization and determination of antioxidant components in the leaves of Camellia chrysantha (Hu) Tuyama based on composition-activity relationship approach.

Camellia chrysantha (Hu) Tuyama (CCT), an ornamental plant possessing antioxidant activity, has been infused as tea and drank for its health benefits. The antioxidant components in CCT, however, had not been clearly characterized. To quickly identify the antioxidant constituents of CCT, a composition-activity relationship strategy based on ultra high-pressure liquid chromatography coupled with linear ion trap hybrid orbitrap mass spectrometry and orthogonal partial least-squares method has been applied. As a result, 16 variables were found to make significant contributions to the 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity. Six of them were identified as catechin (1), epicatechin (5), vitexin (8), isovitexin (10), quercetin-7-O-ß-D-glucopyranoside (12) and kaempferol (16). The strength of 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity was found to be 12 > 1 > 5 > 16 > 8 > 10 by validation test. Meanwhile, a liquid chromatography-electrospray ionization-mass spectrometry method was established for quantitative determination of six marker compounds in CCT samples from different preparations. The validation of the method, including linearity, sensitivity (limitation of detection and limitation of quantification), repeatability, precision, stability, and recoveries, was carried out and demonstrated to meet the requirements of quantitative analysis. This is the first report on the comprehensive characterization and determination of chemical constituents in CCT by ultra high-pressure liquid chromatography coupled with linear ion trap hybrid orbitrap mass spectrometry. The results indicate that the composition-activity relationship approach may be a useful method for the discovery of active constituents in natural plants and the quality control of medicinal herbs.

Comprehensive chemical analysis of the rhizomes of Drynaria fortunei by orthogonal pre-separation and liquid chromatography mass spectrometry.

The chemical composition of Drynaria fortunei, a traditional Chinese herbal medicine, is very complicated. In order to separate these chemicals to obtain their structural information, an orthogonal sample enrichment procedure was established. The ethyl acetate extract of D. fortunei was pre-separated by Sephadex LH-20 × polyamide columns to yield 15 fractions. These fractions were analyzed successively using a reversed-phase Agilent Zorbax SB-C18 column, coupled with diode array detection and electrospray ionization tandem mass spectrometry. The method reduced co-elution and enriched minor compounds on the basis of their chemical features. A total of 369 compounds were detected by LC/MSn, compared to less than 50 compounds without pre-separation. The pretreatment facilitated the analytical separation of flavonoids, proanthocyanidins, triterpenoids, phenolic acids, and lignans in D. fortunei, and allowed a comprehensive chemical profiling of these constituents. This method could be applied to other multicomponent herbal extracts.

Treatment of a non-typical hepatic pseudolesion complicated by greatly elevated alpha fetoprotein: case report and literature review.

BACKGROUND: Hepatic pseudolesions detected by helical computed tomography (CT) are not rare, but it is difficult to make a final diagnosis when the hepatic lesion is complicated by the presence of greatly elevated alpha fetoprotein (AFP). Clinical treatment of non-typical hepatic pseudolesions complicated by greatly elevated AFP should confirm the diagnosis and minimize trauma. CASE PRESENTATION: Non-invasive procedures including ultrasonography, CT, and micro-invasive digital subtraction angiography could not safely differentiate this lesion from a malignant focus when it was complicated by greatly elevated AFP. Laparoscopic hepatectomy was performed, and pathological analysis showed chronic hepatitis, nodular regenerative hyperplasia, focal nodular hyperplasia of the liver, and mild vascular malformation. The tissue was HbsAg(-), HbcAg(-), and AFP(+). CONCLUSION: Heightened awareness of hepatic pseudolesion complicated by primarily elevated AFP will help physicians avoid unnecessary invasive procedures. Hepatic biopsy is inevitable because of greatly elevated AFP. For suspected hepatic pseudolesion with elevated AFP, needle-core biopsy and follow-up surveillance instead of hepatectomy are recommended to find the source of AFP and make a final diagnosis of pseudolesion.

[Evolution of miRNA in plants].

Due to the important role of miRNA in regulation of plant gene expression, researchers have focused on the prediction, identification, functional and evolutionary analysis of miRNA. As genome sequencing has been completed in many species, the integration of genomic sequences with evolutionary data of miRNA provides more and more evidence and hypotheses for the origin and evolution of miRNA. However, the evolution of miRNA in plants has not been extensively reviewed. In this article, we reviewed several aspects of the evolution of miRNA in plants, including the origin hypothesis of miRNA, the birth and death of miRNA, and the functional evolution of miRNA, which provides a reference for future research.

Flavan-3-ols from the rhizomes of Drynaria fortunei.

One monomer flavan-3-ol, 4α-carboxymethyl-(+)-catechin methyl ester, two monomer flavan-3-ol glycosides, (+)-afzelechin-3-O-ß-allopyranoside, (+)-afzelechin-6-C-ß-glucopyranoside, two dimer flavan-3-ols, (-)-epiafzelechin-(4ß→8)-4ß-carboxymethyl-(-)-epicatechin methyl ester, and -(-)-epiafzelechin-(4ß→8)-4α-carboxymethyl-(-)epiafzelechin ethyl ester, and one trimer flavan-3-ol, (-)-epiafzelechin-(4ß→8)-(-)-epiafzelechin-(4ß→8)-4ß-carboxymethyl-(-)-epiafzelechin methyl ester, together with thirteen known flavan-3-ols were isolated from the rhizomes of Drynaria fortunei (Kunze) J.Sm (Polypodiaceae). The structures were established by analysis of their HRESIMS, 1D, 2D NMR spectroscopic, and CD data. In order to obtain improved resolution, the high-resolution NMR spectra of the dimers and trimer were measured at -40 °C.

Retention behaviors of natural products in reversed-phase liquid chromatography using mobile phase comprising methanol, acetonitrile and water.

The three-component mobile phase, methanol-acetonitrile-water, has been frequently used for the separation of natural products in complicated herbal extracts by reversed-phase liquid chromatography, especially when two-component solvent systems do not work. However, the rational for optimization of this three-solvent system is not clear, so far. In this study, the retention behavior of different types of natural products in RP-LC with a methanol-acetonitrile-water elution system was studied. A total of 27 compounds from four classes, including steroids, flavonoids, phenolic acids, and triterpene saponins were analyzed by high-performance liquid chromatography coupled with mass spectrometry or ultraviolet detectors. It was interesting to find that prolonged retention times and improved separation capabilities were obtained when the acetonitrile-to-methanol ratio was 3-16%. This rule applied to all four classes of natural products under different instrumental conditions, and could be valuable for the separation of natural products in complicated samples.

[Two new phenolic acids from Drynariae rhizoma].

To study the chemical constituents of Drynariae Rhizoma, nine phenolic acids were isolated from a 70% ethanol extract by using a combination of various chromatographic techniques including column chromatography over silica gel, ODS, Sephadex LH-20, and semi-preparative HPLC. By spectroscopic techniques including 1H NMR, 13C NMR, 2D NMR, and HR-ESI-MS, these compounds were identified as 4, 4'-dihydroxy-3, 3'-imino-di-benzoic acid (1), protocatechuic acid (2), gallic acid (3), p-hydroxybenzoic acid (4), (E)-caffeic acid (5), ethyl trans-3, 4-dihydroxycinnamate (6), caffeic acid 4-O-beta-D-glucopyranoside (7), p-coumaric acid 4-O-beta-D-glucopyranoside (8), and 23(S)-12-O-caffeoyl-12-hydroxyllauric acid glycerol ester (9), separately. Among them, 1 and 9 are new compounds, and 3, 4, and 6 were isolated from Drynaria species for the first time.

Hybrid diarylbenzopyrimidine non-nucleoside reverse transcriptase inhibitors as promising new leads for improved anti-HIV-1 chemotherapy.

Molecular hybridization of the known anti-HIV-1 template DPC083 and etravirine based on docking model overlay has been generated a novel series of diarylbenzopyrimidine analogues (DABPs) (5a-z). These new hybrids were assessed for their activity against HIV in MT-4 cell cultures. Most of these compounds showed good activity against wild-type HIV-1 and mutant viruses. In particular, compound 5r showed the most potent activity against wild-type HIV-1 with an EC50 value of 1.8 nM, and with a selectivity index up to 111,954. It also proved more active against mutant L100I, K103N, Y188L, and K103N+Y181C RT HIV-1 strains than efavirenz.