Synthesis of the Isodityrosine Moiety of Seongsanamide A-D and Its Derivatives.

The concise and highly convergent synthesis of the isodityrosine unit of seongsanamide A-D and its derivatives bearing a diaryl ether moiety is described. In this work, the synthetic strategy features palladium-catalyzed C(sp3)-H functionalization and a Cu/ligand-catalyzed coupling reaction. We report a practical protocol for the palladium-catalyzed mono-arylation of ß-methyl C(sp3)-H of an alanine derivative bearing a 2-thiomethylaniline auxiliary. The reaction is compatible with a variety of functional groups, providing practical access to numerous ß-aryl-α-amino acids; these acids can be converted into various tyrosine and dihydroxyphenylalanine (DOPA) derivatives. Then, a CuI/N,N-dimethylglycine-catalyzed arylation of the already synthesized DOPA derivatives with aryl iodides is described for the synthesis of isodityrosine derivatives.

["Six-step strategy" for effective compounds in Chinese medicinal prescriptions based on in vitro-in vivo integration and its application in research on component-based Chinese medicine].

The discovery and identification of effective components are pivotal in the research on Chinese medicinal prescriptions. Given two basic conditions for effective components in Chinese medicinal prescriptions, i.e., active structure and a certain level of drug exposure in the body(including the intestine), a "six-step strategy" for the effective compounds in Chinese medicinal prescriptions based on in vitro-in vivo integration(SSS for short) has been proposed and established, as well as the key technologies. SSS contains qualitative and quantitative analyses of components in five steps, including those in Chinese medicinal extract, intestinal contents, portal vein blood, liver, and peripheral blood. The components(prototype components and metabolites) with a certain exposure level(including in the intestine) and those with large differences between in vitro content and in vivo exposure or in exposure among various parts in the body are selected as the minority prioritized candidates. The sixth step is to screen the pharmacological activity of candidate components specifically extracted from Chinese medicinal materials or artificially synthesized. SSS can significantly narrow the screening range, enhance the hit rate, and speed up the identification of effective components specifically targeting indications. Based on the effective components identified by the SSS, the "upstream" can be linked(mechanism research based on the effective components with clear structures) and the "downstream" can be combined(development of innovative component-based Chinese medicine with definite pharmacodynamic composition). In this study, the concept of component-based Chinese medicine and specific applications of SSS in the development of component-based Chinese medicine are also introduced.

Sarsasapogenin improves adipose tissue inflammation and ameliorates insulin resistance in high-fat diet-fed C57BL/6J mice.

Insulin resistance is a major cause of type 2 diabetes and metabolic syndrome. Macrophage infiltration into obese adipose tissue promotes inflammatory responses that contribute to the pathogenesis of insulin resistance. Suppression of adipose tissue inflammatory responses is postulated to increase insulin sensitivity in obese patients and animals. Sarsasapogenin (ZGY) is one of the metabolites of timosaponin AIII in the gut, which has been shown to exert anti-inflammatory action. In this study, we investigated the effects of ZGY treatment on obesity-induced insulin resistance in mice. We showed that pretreatment with ZGY (80 mg·kg-1·d-1, ig, for 18 days) significantly inhibited acute adipose tissue inflammatory responses in LPS-treated mice. In high-fat diet (HFD)-fed obese mice, oral administration of ZGY (80 mg·kg-1·d-1, for 6 weeks) ameliorated insulin resistance and alleviated inflammation in adipose tissues by reducing the infiltration of macrophages. Furthermore, we demonstrated that ZGY not only directly inhibited inflammatory responses in macrophages and adipocytes, but also interrupts the crosstalk between macrophages and adipocytes in vitro, improving adipocyte insulin resistance. The insulin-sensitizing and anti-inflammatory effects of ZGY may result from inactivation of the IKK /NF-κB and JNK inflammatory signaling pathways in adipocytes. Collectively, our findings suggest that ZGY ameliorates insulin resistance and alleviates the adipose inflammatory state in HFD mice, suggesting that ZGY may be a potential agent for the treatment of insulin resistance and obesity-related metabolic diseases.

Synthesis and Cytotoxic Activity of Novel C-23-Modified Asiatic Acid Derivatives.

We selectively oxidized the C-23 hydroxyl group in an asiatic acid (AA) derivative and then, for the first time with AA, modification of the C-23 carboxyl group was conducted to synthesize a series of new AA derivatives. The evaluation of their cytotoxic activities against two human cancer cell lines (SKOV-3 and HCT116) using the MTT assay in vitro revealed a distinctive structure activity relationship (SAR) associated with the intramolecular hydrogen bonding of the amide moiety at C-23. According to the established SAR, the cytotoxic activities of four promising compounds were then evaluated against MCF-7, A549, A2780, HepG2 and HL-60 cancer cell lines. Compound 10 had the best cytotoxic activity among all tested derivatives in the HL-60 cell line, giving IC50 = 0.47 µM, while showing no cytotoxic effect against human normal cells (HUVEC).

Stereospecific synthesis and rearrangement of 22S-23-acetylsapogenins.

The BF3·Et2O-catalysed acetolysis of steroid sapogenins diosgenin, sarsasapogenin and tigogenin in dichloromethane as the solvent instead of acetic anhydride afforded (20S)- and (20R)-22,26-epoxycholestanes (compounds 1 and 2). 22S-23-Acetylsapogenins (compounds 4) were synthesized stereospecifically from 20R-22,26-epoxycholestanes (compounds 2) in good yield. The rearrangement of 22S-23-acetylsapogenins (compounds 4) afforded novel disubstituted dihydropyran furostanol frameworks. Exhaustive NMR characterization of the obtained compounds is provided. Additionally, the structures of the critical compounds (6a and 7a) were unequivocallyconfirmed by single crystal X-ray diffraction studies.

Antiepileptic geissoschizine methyl ether is an inhibitor of multiple neuronal channels.

Geissoschizine methyl ether (GM) is an indole alkaloid isolated from Uncaria rhynchophyll (UR) that has been used for the treatment of epilepsy in traditional Chinese medicine. An early study in a glutamate-induced mouse seizure model demonstrated that GM was one of the active ingredients of UR. In this study, electrophysiological technique was used to explore the mechanism underlying the antiepileptic activity of GM. We first showed that GM (1-30 µmol/L) dose-dependently suppressed the spontaneous firing and prolonged the action potential duration in cultured mouse and rat hippocampal neurons. Given the pivotal roles of ion channels in regulating neuronal excitability, we then examined the effects of GM on both voltage-gated and ligand-gated channels in rat hippocampal neurons. We found that GM is an inhibitor of multiple neuronal channels: GM potently inhibited the voltage-gated sodium (NaV), calcium (CaV), and delayed rectifier potassium (IK) currents, and the ligand-gated nicotinic acetylcholine (nACh) currents with IC50 values in the range of 1.3-13.3 µmol/L. In contrast, GM had little effect on the voltage-gated transient outward potassium currents (IA) and four types of ligand-gated channels (γ-amino butyric acid (GABA), N-methyl-D-aspartate (NMDA), α-amino-3-hydroxy-5-methylisoxazole-4-propionate/kainite (AMPA/KA receptors)). The in vivo antiepileptic activity of GM was validated in two electricity-induced seizure models. In the maximal electroshock (MES)-induced mouse seizure model, oral administration of GM (50-100 mg/kg) dose-dependently suppressed generalized tonic-clonic seizures. In 6-Hz-induced mouse seizure model, oral administration of GM (100 mg/kg) reduced treatment-resistant seizures. Thus, we conclude that GM is a promising antiepileptic candidate that inhibits multiple neuronal channels.

Asymmetric Synthesis of the C15⁻C32 Fragment of Alotamide and Determination of the Relative Stereochemistry.

Alotamide is a cyclic depsipetide isolated from a marine cyanobacterium and possesses a unique activation of calcium influx in murine cerebrocortical neurons (EC50 4.18 µM). Due to its limited source, the three stereocenters (C19, C28, and C30) in its polyketide fragment remain undetermined. In this study, the first asymmetric synthesis of its polyketide fragment was achieved. Four relative possible diastereomers were constructed with a boron-mediated enantioselective aldol reaction and Julia⁻Kocienski olefination as the key steps. Comparison of 13C NMR spectra revealed the relative structure of fragment C15⁻C32 of alotamide.

Metabolism, pharmacokinetics, and hepatic disposition of xanthones and saponins on Zhimu treatments for exploratively interpreting the discrepancy between the herbal safety and timosaponin A3-induced hepatotoxicity.

Timosaponin A3, a saponin in Zhimu, elicited hepatotoxicity via oxidative stress. However, the clinical medication of Zhimu has been historically regarded as safe, probably associated with the antioxidants it contains. However, the related information on the in vivo levels of timosaponin A3 and antioxidants remained unclear on Zhimu treatments. Therefore, a combination of the in vitro metabolism, including microbiota-mediated and liver-mediated metabolism, and in vivo pharmacokinetics and hepatic disposition, was conducted for three xanthones (neomangiferin, mangiferin, and norathyriol) and three saponins (timosaponin B2, timosaponin B3, and timosaponin A3) on Zhimu treatments. Consequently, following oral administration of Zhimu decoction to rats, those saponins and xanthones were all observed in the plasma with severe liver first-pass effect, where mangiferin was of the maximum exposure. Despite the ignorable content in the herb, timosaponin A3 elicited sizable hepatic exposure as the microbiota-mediated metabolite of saponins in Zhimu. The similar phenomenon also occurred to norathyriol, the microbiota-mediated metabolite of xanthones. However, the major prototypes in Zhimu were of limited hepatic exposure. We deduced the hepatic collection of norathyriol, maximum circulating levels of mangiferin, and timosaponin B2 and mangiferin interaction may directly or indirectly contribute to the whole anti-oxidation of Zhimu, and then resisted the timosaponin A3-induced hepatotoxicity. Thus, our study exploratively interpreted the discrepancy between herbal safety and timosaponin A3-induced hepatotoxicity. However, given the considerable levels and slow eliminated rate of timosaponin A3 in the liver, more attention should be paid to the safety on the continuous clinical medication of Zhimu in the future.

Diagnosis and therapeutic monitoring of inborn errors of metabolism in 100,077 newborns from Jining city in China.

BACKGROUND: Mandatory newborn screening for metabolic disorders has not been implemented in most parts of China. Newborn mortality and morbidity could be markedly reduced by early diagnosis and treatment of inborn errors of metabolism (IEM). Methods of screening for IEM by tandem mass spectrometry (MS/MS) have been developed, and their advantages include rapid testing, high sensitivity, high specificity, high throughput, and low sample volume (a single dried blood spot). METHODS: Dried blood spots of 100,077 newborns obtained from Jining city in 2014-2015 were screened by MS/MS. The screening results were further confirmed by clinical symptoms and biochemical analysis in combination with the detection of neonatal deficiency in organic acid, amino acid, or fatty acid metabolism and DNA analysis. RESULTS: The percentages of males and females among the 100,077 infants were 54.1% and 45.9%, respectively. Cut-off values were established by utilizing the percentile method. The screening results showed that 98,764 newborns were healthy, and 56 out of the 1313 newborns with suspected IEM were ultimately diagnosed with IEM. Among these 56 newborns, 19 (1:5267) had amino acid metabolism disorders, 26 (1:3849) had organic acid metabolism disorders, and 11 (1:9098) had fatty acid oxidation disorders. In addition, 54 patients with IEM were found to carry mutations, and the other 2 patients had argininemia. CONCLUSIONS: Fifty-six cases of metabolic disorders in Jining were confirmed via newborn screening (NBS) by MS/MS. Early diagnosis and treatment are crucial for the survival and well-being of affected children. A nationwide NBS program using MS/MS is recommended, especially in poor areas of China.

Timosaponin derivative YY-23 acts as a non-competitive NMDA receptor antagonist and exerts a rapid antidepressant-like effect in mice.

AIM: N-methyl-D-aspartic acid (NMDA) receptor modulators have shown promising results as potential antidepressant agents, whereas timosaponins extracted from the Chinese herb Rhizoma Anemarrhenae exhibit antidepressant activities. In the present study we examined whether YY-23, a modified metabolite of timosaponin B-III, could affect NMDA receptors in rat hippocampal neurons in vitro, and evaluated its antidepressant-like effects in stressed mice. METHODS: NMDA-induced currents were recorded in acutely dissociated rat hippocampal CA1 neurons using a whole-cell recording technique. C57BL/6 mice were exposed to a 6-week chronic mild stress (CMS) or a 10-d chronic social defeat stress (CSDS). The stressed mice were treated with YY-23 (20 mg·kg(-1)·d(-1)) or a positive-control drug, fluoxetine (10 mg·kg(-1)·d(-1)) for 3 weeks. Behavioral assessments were carried out every week. RESULTS: In acutely dissociated rat hippocampal CA1 neurons, YY-23 selectively and reversibly inhibited NMDA-induced currents with an EC50 value of 2.8 µmol/L. This inhibition of NMDA-induced currents by YY-23 was non-competitive, and had no features of voltage-dependency or use-dependency. Treatment of the stressed mice with YY-23 not only reversed CMS-induced deficiency of sucrose preference and immobility time, and CSDS-induced reduction of social interaction, but also had faster onset as compared to fluoxetine. CONCLUSION: YY-23 is a novel non-competitive antagonist of NMDA receptors with promising rapid antidepressant-like effects in mouse models of CMS and CSDS depression.

Organic anion-transporting polypeptides contribute to the hepatic uptake of berberine.

1. The purpose of this study was to investigate the mechanism of hepatic uptake of berberine. Berberine accumulation in hepatocytes was found to be highly dependent on active uptake, which could not be explained by liver organic cation transporter (OCT) alone. 2. Our studies indicated that berberine uptake was significantly suppressed by rifampicin, cyclosporine A and glycyrrhizic acid, which act as specific inhibitors of different Oatp isoforms (Oatp1a1, Oatp1a4 and Oatp1b2) in rat hepatocytes. The combination of OCT and OATP inhibitors further reduced berberine accumulation in both rat and human hepatocytes. The uptake of berberine could be increased in human HEK293-OATP1B3 but not in OATP1B1-transfected HEK 293 cells. 3. Rifampicin could reduce the berberine liver extraction ratio (ER) and double its concentration in the effluent in isolated rat livers. Further in vivo study indicated that berberine plasma exposure could be significantly increased by co-administration of the OATP inhibitor rifampicin or the substrate rosuvastatin. 4. In conclusion, this study demonstrated that both OCT and OATP contribute to the accumulation of berberine in the liver. OATPs may have important roles in berberine liver disposition and potential clinically relevant drug--drug interactions.

Timosaponin A3 induces hepatotoxicity in rats through inducing oxidative stress and down-regulating bile acid transporters.

AIM: To investigate the mechanisms underlying the hepatotoxicity of timosaponin A3 (TA3), a steroidal saponin from Anemarrhena asphodeloides, in rats. METHODS: Male SD rats were administered TA3 (100 mg·kg(-1)·d(-1), po) for 14 d, and the blood and bile samples were collected after the final administration. The viability of a sandwich configuration of cultured rat hepatocytes (SCRHs) was assessed using WST-1. Accumulation and biliary excretion index (BEI) of d8-TCA in SCRHs were determined with LC-MS/MS. RT-PCR and Western blot were used to analyze the expression of relevant genes and proteins. ROS and ATP levels, and mitochondrial membrane potential (MMP) were measured. F-actin cytoskeletal integrity was assessed under confocal microscopy. RESULTS: TA3 administration in rats significantly elevated the total bile acid in serum, and decreased bile acid (BA) component concentrations in bile. TA3 inhibited the viability of the SCRHs with an IC50 value of 15.21±1.73 µmol/L. Treatment of the SCRHs with TA3 (1-10 µmol/L) for 2 and 24 h dose-dependently decreased the accumulation and BEI of d8-TCA. The TA3 treatment dose-dependently decreased the expression of BA transporters Ntcp, Bsep and Mrp2, and BA biosynthesis related Cyp7a1 in hepatocytes. Furthermore, the TA3 treatment dose-dependently increased ROS generation and HO-1 expression, decreased the ATP level and MMP, and disrupted F-actin in the SCRHs. NAC (5 mmol/L) significantly ameliorated TA3-induced effects in the SCRHs, whereas mangiferin (10-200 µg/mL) almost blocked TA3-induced ROS generation. CONCLUSION: TA3 triggers liver injury through inducing ROS generation and suppressing the expression of BA transporters. Mangiferin, an active component in Anemarrhena, may protect hepatocytes from TA3-induced hepatotoxicity.

Anti-diabetic effects of TongGuanWan, a Chinese traditional herbal formula, in C57BL/KsJ-db/db mice.

In the present study, the anti-diabetic effects of a traditional Chinese medicinal formula extract, TongGuanWan, were investigated in type 2 diabetic animals. It was orally administered to C57BL/KsJ-db/db mice once a day for 4 weeks at the doses of 62, 125, and 250 mg/kg body weight. TongGuanWan significantly lowered the blood glucose and glycosylated haemoglobin levels as well as improved the glucose tolerance in db/db mice. The serum triglyceride levels in the db/db mice were significantly decreased, whereas the high-density lipoprotein cholesterol levels were significantly increased, after treatment with this herbal formula. TongGuanWan also markedly decreased the animals' body weights compared to those of the control db/db group but did not alter food intake. The effects of TongGuanWan were compared to those of the drug rosiglitazone. In addition, five main constituents of TongGuanWan, mangiferin, berberine, cinnamic aldehyde, timosaponin BII, and timosaponin AIII, were quantified using high performance liquid chromatography coupled with a diode array and an evaporative light scattering detector (HPLC-DAD-ELSD). These results suggest that TongGuanWan may be useful for the treatment of type 2 diabetes.

Mangiferin, an anti-HIV-1 agent targeting protease and effective against resistant strains.

The anti-HIV-1 activity of mangiferin was evaluated. Mangiferin can inhibit HIV-1(Ⅲ)(B) induced syncytium formation at non-cytotoxic concentrations, with a 50% effective concentration (EC50) at 16.90 µM and a therapeutic index (TI) above 140. Mangiferin also showed good activities in other laboratory-derived strains, clinically isolated strains and resistant HIV-1 strains. Mechanism studies revealed that mangiferin might inhibit the HIV-1 protease, but is still effective against HIV peptidic protease inhibitor resistant strains. A combination of docking and pharmacophore methods clarified possible binding modes of mangiferin in the HIV-1 protease. The pharmacophore model of mangiferin consists of two hydrogen bond donors and two hydrogen bond acceptors. Compared to pharmacophore features found in commercially available drugs, three pharmacophoric elements matched well and one novel pharmacophore element was observed. Moreover, molecular docking analysis demonstrated that the pharmacophoric elements play important roles in binding HIV-1 protease. Mangiferin is a novel nonpeptidic protease inhibitor with an original structure that represents an effective drug development strategy for combating drug resistance.

[Screening for neonatal inborn errors of metabolism by electrospray ionization-tandem mass spectrometry and follow-up].

OBJECTIVE: To determine the impact of expanded newborn screening using tandem mass spectrometry (MS/MS) on the overall detection rate of inborn errors of metabolism in Zhejiang province and to assess the outcome of the patients who were diagnosed. METHOD: Blood spots were collected between days 3 and 6 of life from the newborns. All samples were subjected to MS/MS analysis using Waters Quattro API. Confirmation tests included amino acid analysis, urinary organic acids by GC-MS, routine blood analysis, biochemistry, blood gas analysis, blood glucose and ammonia tests, blood homocysteine, lactate and pyruvate tests, urine acetone tests, biotin and biotin enzyme profile and DNA analysis. Standard treatment protocol was given to the patients. Protein restricted diet, special powdered formula and medicines recommended for the patients with amino acidemias. Protein restricted diet and L-carnitine, folic acid and Vitamin B12 supplementation were given for the patients with organic acidemia. L-carnitine was given to the patients with primary carnitine deficiency. The overall epidemiology, prognosis, follow-up of the screening program were also investigated in the neonates. RESULT: A total of 129 415 neonates were investigated for 26 inborn errors of metabolism during the period. Twenty-three newborns were confirmed as having inborn errors of metabolism, including 13 with amino acidemias, 6 with organic acidemias and 4 with fatty acid oxidation disorders. The prevalence was 1:5626. Positive predictive value was 2.10%, specificity was 99.72% and sensitivity 100%. Seventeen children remain asymptomatic during the follow-up. Five patients had motor and mental developmental delay. One patient presented metabolic disorders during the follow-up. No death occurred in this series of patients. CONCLUSION: This strategy represents a valuable preventive medicine approach by enabling diagnosis and treatment before the onset of symptoms.

Characterization of the multiple absorbed constituents in rats after oral administration of Chai-Huang decoction by liquid chromatography coupled with electrospray-ionization mass spectrometry.

A rapid, sensitive, and specific method by high-performance liquid chromatography (HPLC) coupled to diode-array detection (DAD) and tandem mass spectrometry (MS) techniques was developed for the identification of absorbed constituents and their metabolites in rats after the oral administration of a Chai-Huang decoction (CHD), which consists of Bupleurum chinense and Scutellaria baicalensis in the proportion 1 : 1 (w/w). By comparing their retention times and MS data with those of authentic compounds and published data, a total of 14 compounds were identified in the CHD samples. In addition, eleven and seven compounds were characterized in the urine and serum samples of the rats, respectively. The results indicated that the main absorbed constituents were chrysin-6-C-arabinosyl-8-C-glucoside, chrysin-6-C-glucosyl-8-C-arabinoside, baicalin, wogonin-5-O-glucoside, oroxylin A-7-O-glucuronide, wogonoside, saikosaponin A, saikosaponin C, saikosaponin D, baicalein, and wogonin. These compounds might be responsible for the curative effects of the CHD. The findings demonstrated that the proposed method could be used to rapidly and simultaneously analyze and screen the multiple absorbed bioactive constituents in a formula of traditional Chinese medicines (TCM). This is very important not only for the pharmaceutical discovery process and the quality control of crude drugs but also to explain the mechanisms of action of TCM.

Compounds from Acorus tatarinowii: determination of absolute configuration by quantum computations and cAMP regulation activity.

A new cadinane-type sesquiterpenoid, tatarinowin A (1), two phenylpropanoids, tatarinoids A (2) and B (3), and a trinorlignan, tatarinoid C (4), along with 15 known compounds including two pairs of mixtures were isolated from the rhizome of Acorus tatarinowii. The absolute configurations of 1-4 were established by computation of specific rotation values. The isolated compounds were evaluated for their cAMP regulatory activity by the AlphaScreen assay.

Characterization of anti-Coxsackie virus B3 constituents of Radix Astragali by high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry.

To profile the anti-Coxsackie virus B3 constituents of Radix Astragali, an HPLC-DAD-MS(n) analytical method, combined with an in vivo test, has been developed to identify the constituents of the active part, which has been demonstrated to have potency to inhibit the proliferation of virus in cardiac muscle, alleviate infraction in heart and elevate the survival rate of the animal. By comparing their retention time and MS data with those obtained from the authentic compounds and the published data, a total of 19 compounds, including 11 isoflavonoids and eight saponins, were identified, among which one pterocarpane glucoside was reported for the first time. The present study provides an approach to rapidly screening bioactive constituents in traditional Chinese medicines.

Complete NMR spectral assignments of two new iridoid diastereoisomers from the flowers of Plumeria rubra L. cv. acutifolia.

Two new iridoid diastereoisomers (1, 2), together with five known compounds, were isolated from the flowers of Plumerian rubra L. cv. acutifolia. Their structures were elucidated by the means of in-depth spectroscopic and mass-spectrometric analyses, particularly 1D and 2D NMR spectroscopy.

Cytotoxic triterpenoid saponins from Vaccaria segetalis.

By the guidance of bioassay, one new cytotoxic triterpenoid saponin, 3-O-[beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl] quillaic acid 28-O-beta-D-glucopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-[beta-D-fucopyranosyl-(1-->4)]-beta-D-fucopyranoside (1), and five known cytotoxic triterpenoid saponins, vaccaroside E (2), vaccaroside G (3), vaccaroside B (4), segetoside H (5) and segetoside I (6), were isolated from Vaccaria segetalis. Their structures were established on the basis of ESI-MS, IR, extensive NMR ((1)H NMR, (13)C NMR, TOCSY, (1)H-(1)H COSY, DEPT, HMQC, HMBC and ROESY) analyses, chemical degradation, and by comparing with previously reported data. Compounds 1-6 showed moderate cytotoxic activities against LNcap, P-388 and A-549 cell lines with IC(50) values in the range 0.1-12.9 microM.