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The cytosolic non-receptor protein kinase, spleen tyrosine kinase (SYK), is an attractive drug target in autoimmune, inflammatory disorder, and cancers indications. Here, we employed pharmacophore-based drug screening combined with biochemical assay and molecular dynamics (MD) simulations to identify and characterize inhibitors targeting SYK. The built pharmacophore model, phar-TanI, successfully identified tanshinone (TanI (IC50 = 1.72 μM)) and its analogs (TanIIA (IC50 = 3.2 μM), ST32da (IC50 = 46 μM), and ST32db (IC50 = 51 μM)) which apparently attenuated the activities of SYK in vitro. Additionally, the MD simulations followed by Ligplot analyses revealed that TanI and TanIIA interfered SYK activity through binding deeply into the active site. Besides, TanI and TanIIA mainly interact with residues L377, A400, V433, M448, M450, A451, E452, L453, G454, P455, and L501, which are functional hotspots for structure-based inhibitor optimization against SYK. The structure–activity relationships (SAR) study of the identified SYK inhibitors demonstrated that the pharmacophore model, phar-TanI is reliable and precise in screening inhibitors against SYK. This study disclosed the structure–function relationships of tanshinones from Traditional Chinese Medicine (Danshen), revealing their binding site and mode of action in inhibiting SYK and provides applicability in developing new therapeutic agents.

Chemical investigation of the dichloromethane extracts of the flowers of Dendranthema grandiflora cv. Yoko Ono afforded a new sesquiterpene lactone, grandiflorolide (1), 1,2-dilinoleoyl-3-linolenoylglycerol (2), a mixture of pseudotaraxasterol (3a), taraxasterol (3b), β-amyrin (3c), α-amyrin (3d), and lupeol (3e) in about 2:1:1:0.5:0.5 ratio, and another mixture of β-sitosterol (4a) and stigmasterol (4b) in about 2:1 ratio. The structure of 1 was elucidated by extensive 1D and 2D NMR spectroscopy, while those of 2–4b were identified by comparison of their NMR data with literature data.

Diabetic cardiomyopathy (DC) is one of the major lethal complications in patients with diabetes mellitus (DM); however, no specific strategy for preventing or treating DC has been identified.This study aimed to investigate the effects of β-lapachone (Lap), a natural compound that increases antioxidant activity in various tissues, on DC and explore the underlying mechanisms.As an in vivo model, C57BL/6 mice were fed with the high-fat diet (HF) for 10 weeks to induce type 2 DM. Mice were fed Lap with the HF or after 5 weeks of HF treatment to investigate the protective effects of Lap against DC.In the two in vivo models, Lap decreased heart weight, increased heart function, reduced oxidative stress, and elevated mitochondrial content under the HF. In the in vitro model, palmitic acid (PA) was used to mimic the effects of an HF on the differentiated-cardiomyoblast cell line H9c2. The results demonstrated that Lap reduced PA-induced ROS production by increasing the expression of antioxidant regulators and enzymes, inhibiting inflammation, increasing mitochondrial activity, and thus reducing cell damage. Via the use of specific inhibitors and siRNA, the protective effects of Lap were determined to be mediated mainly by NQO1, Sirt1 and mitochondrial activity.Heart damage in DM is usually caused by excessive oxidative stress. This study showed that Lap can protect the heart from DC by upregulating antioxidant ability and mitochondrial activity in cardiomyocytes. Lap has the potential to serve as a novel therapeutic agent for both the prevention and treatment of DC.

Cisplatin (CDDP) is a first-line chemotherapeutic drug for treating various cancers. However, CDDP also damages normal cells and causes many side effects. Recently, CDDP has been demonstrated to kill cancer cells by targeting mitochondria. Protecting mitochondria might be a potential therapeutic strategy for CDDP-induced side effects. β-Lapachone (β-lap), a recognized NADIn this study, the protective effects of β-lap on mitochondria against CDDP cytotoxicity in normal cells were evaluated.In vitro cell models were used in this study, including 3T3 fibroblasts, human dermal fibroblasts, MCF-7 breast cancer cells, and MDA-MB-231 breast cancer cells.Cells were treated with CDDP and β-lap, and cell survival, NADThe results demonstrated that β-lap significantly decreased CDDP cytotoxicity in normal fibroblasts. With various inhibitors and siRNAs, β-lap reduced CDDP-induced damage to normal fibroblasts by maintaining mitochondrial activity and increasing autophagy through the NQO1/NADβ-lap could be a good synergistic drug for reducing the side effects of CDDP without affecting the anticancer drug effect.

7,8-Dehydrorutaecarpine was a potent inhibitor of both CYP1A1 and CYP1A2. The introduction of methoxyl group reduced CYP1A1 inhibition and enhanced the relative inhibition selectivity to either CYP1A2 or CYP1B1. Among the synthesized derivatives, 2-methoxy-7,8-dehydrorutaecarpine had the best selectivity of CYP1A2 inhibition. In contrast, the introduction of 4-methoxyl group decreased the IC50 values for CYP1B1 and had the best selectivity of CYP1B1 inhibition. Results of molecular modeling showed that a hydrogen bond was formed between the 2-methoxyl group of 2-methoxy-7,8-dehydrorutaecarpine and Thr113 residue of CYP1A2. 2-Methoxy-7,8-dehydrorutaecarpine was a mixed type inhibitor of CYP1A2 with the inhibition constants of 9.5±2.6 and 6.7±2.6 nM for CYP1A2 and CYP1A2-substrate complex, respectively. For the 2-methoxyl derivatives of 7,8-dehydrorutaecarpine and rutaecarpine, the change of 2-methoxyl to an 2-ethoxyl group decreased and increased the IC50 values for CYP1A1 and CYP1A2, respectively. Our results demonstrated that introduction of alkoxyl modification to a heterocyclic compound, 7,8-dehydrorutaecarpine could change inhibitory selectivity among CYP1 enzymes. These results may provide important information for the interaction between CYP1 members and their inhibitors with a core structure of 7,8-dehydrorutaecarpine.

Danshen, the dried rhizome of Salvia miltiorrhiza Bunge is a widely used herb in traditional Chinese medicinal preparations to treat cardiovascular diseases, renal and liver diseases. Tanshinones and salvianolic acids are used as markers to survey the commercial available products. In this study, a convenient high-performance liquid chromatographic method was developed to simultaneously separate and identify six main polyphenolic components, caffeic acid (1), danshensu (2), lithospermic acid (3), rosmarinic acid (4), salvianolic acid B (5) and salvianolic acid A (6), and four major abietane-type diterpenes, 15,16-dihydrotanshinone I (7), cryptotanshinone (8), tanshinone I (9), and tanshinone IIA (10), with UV and MS detectors by comparing their retention time, MS and MS2 data with those data obtained from the authentic compounds. A good resolution of all the analytes was obtained by choosing methanol and 0.25% aqueous acetic acid (adjusted to pH 2.77 with 1N HCl) as the mobile phase. By using LC-UV (290 nm)-MS method, polyphenols (1-6) and tanshinones (7-10) were easily detected and unambiguously identified in commercial Danshen.

The alkaloid rutaecarpine exhibits antithrombotic and vasorelaxant effects. To characterize mouse cytochrome P450 (P450, CYP)-catalyzed rutaecarpine hydroxylations, the induction, inhibition, and kinetic properties of rutaecarpine hydroxylations were determined using liver microsomes of C57BL/6J mice. In untreated mice, rutaecarpine 10-, 11-, 12-, and 3-hydroxylation had K(subscript m) and V(subscript max) values ranging, respectively, between 11.6~16.7 μM and 62~197 pmol/min/mg protein. The formation rates of the four hydroxylated metabolites were inhibited by α-naphthoflavone and orphenadrine, but not by either sulfaphenazole or ketoconazole. 3-Methylcholanthrene-treatment increased rutaecarpine 11-, 12-, and 3-hydroxylation activities. Phenobarbital-treatment increased rutaecarpine 10-, 11-, 12-, and 3 -hydroxylation activities. Dexamethasone had no effect on these hydroxylation reactions in mice. These results indicated that CYP1A and CYP2B, but not CYP3A, play major roles in rutaecarpine hydroxylations in mice. Abbreviations: CYP, cytochrome P450; 3-MC, 3-methylcholanthrene; G6P, glucose-6-phosphate; α-NF, α-naphthoflavone; β-NADP(superscript +), β-nicotinamide adenine dinucleotide phosphate.

Billions of people have obesity-related metabolic syndromes such as diabetes and hyperlipidemia. Promoting the browning of white adipose tissue has been suggested as a potential strategy, but a drug still needs to be identified. Here, genetic deletion of activating transcription factor 3 (ATF3−/−) in mice under a high-fat diet (HFD) resulted in obesity and insulin resistance, which was abrogated by virus-mediated ATF3 restoration. ST32da, a synthetic ATF3 inducer isolated from Salvia miltiorrhiza, promoted ATF3 expression to downregulate adipokine genes and induce adipocyte browning by suppressing the carbohydrate-responsive element-binding protein–stearoyl-CoA desaturase-1 axis. Furthermore, ST32da increased white adipose tissue browning and reduced lipogenesis in HFD-induced obese mice. The anti-obesity efficacy of oral ST32da administration was similar to that of the clinical drug orlistat. Our study identified the ATF3 inducer ST32da as a promising therapeutic drug for treating diet-induced obesity and related metabolic disorders., Ching-Feng Cheng et al. find that expression of the transcription factor ATF3 in mice provides protection from obesity and insulin resistance under a high-fat diet. They show that expression of ATF3 can be induced by ST32da, a compound derived from the Chinese sage plant, Salvia miltiorrhiza.

Tyrosinase is an essential copper-containing enzyme required for melanin synthesis. The overproduction and abnormal accumulation of melanin cause hyperpigmentation and neurodegenerative diseases. Thus, tyrosinase is promising for use in medicine and cosmetics. Our previous study identified a natural product, A5, resembling the structure of the dipeptide WY and apparently inhibiting tyrosinase. Here, we comprehensively estimated the inhibitory capability of 20 × 20 dipeptides against mushroom tyrosinase. We found that cysteine-containing dipeptides, directly blocking the active site of tyrosinase, are highly potent in inhibition; in particular, N-terminal cysteine-containing dipeptides markedly outperform the C-terminal-containing ones. The cysteine-containing dipeptides, CE, CS, CY, and CW, show comparative bioactivities, and tyrosine-containing dipeptides are substrate-like inhibitors. The dipeptide PD attenuates 16.5% melanin content without any significant cytotoxicity. This study reveals the functional role of cysteine residue positional preference and the selectivity of specific amino acids in cysteine-containing dipeptides against tyrosinase, aiding in developing skin-whitening products.

Dysoxylum mollissimum Blume, the accepted name of the species known by more than a dozen names has been extensively studied for its chemical constituents under the name Dysoxylum hainanense Merr. Congruent with the observation that the chemical constituents of this species might be affected by its geographic distribution, the leaf samples of this species from Quezon Province, Philippines were investigated. The dichloromethane extract of the air-dried leaves of D. mollissimum Blume afforded four new glabretal-type triterpenoids ( 1a – 2b ) along with the known compounds, 24,25-epoxy-3β,23-dihydroxy-7-tirucallene ( 3 ), squalene, polyprenol, linoleic acid and lutein. The structures of 1a – 2b were elucidated by extensive 1D and 2D NMR spectroscopy and confirmed by mass spectrometry.

Euphorbiane (1), a novel triterpenoid exhibiting a unique skeleton, together with seven known compounds were isolated from the 95% EtOH extract of the fresh stems of Euphorbia tirucalli. The structure of 1 and relative stereochemistry were elucidated by extensive NMR and a single-crystal X-ray crystallographic analysis.

Silica gel chromatography of the dichloromethane extract of the seeds of Annona muricata afforded annoreticuin-9-one (1), while the flesh of the fruit yielded cis-annoreticuin (2) and sabadelin (3). The structures of 1-3 were elucidated by extensive 1 D and 2D NMR spectroscopy and confirmed by mass spectrometry. Acetogenins 1 and 2 were first isolated from A. reticulata and A. montana, respectively. Acetogenin 1 was reported to exhibit cytotoxic activities against the human pancreatic tumor cell line (PACA-2), human prostate adenocarcinoma (PC-3) and human lung carcinoma (A-549), while 2 was reported to exhibit cytotoxicity against human hepatoma carcinoma cell line (Hep G2).

Atalantia retusa Merr. is a rare Philippine endemic shrub which was reported to exhibit high antinociceptive and anti-inflammatory activities. The dichloromethane extract of the air-dried leaves of A. retusa afforded a new triterpene, retusenol (1), and friedelin (2), dischidiol (3), 5,7-dimethoxy-8- (3-methyl-2-oxybutyl)coumarin (4), humulene (5), and β-caryophyllene (6). The structures of 1 - 4 were elucidated by extensive 1D and 2D NMR experiments. Friedelin, a known analgesic and antiinflammatory drug, is an active principle of the shrub. Compounds 1 - 4 were tested for cytotoxicity against the human cancer lung adenocarcinoma A549, colon carcinoma HCT116 and the non-cancer Chinese hamster ovary AA8 using the MTT assay. Triterpenes 1 - 3 had no linear interpolation with HCT 116 and A549, thus the IC50 value could not be computed. This implied that these compounds did not exhibit any cytotoxic effect against these cell lines. Meanwhile, 4 exhibited moderate cytoxicity against A549, HCT 116 and AA8 with IC50 values of 47.5634, 42.4338 and 46:2751 μ g mL-1, respectively. Compounds 1, 2 and 4 were tested for their antimicrobial properties against seven microorganisms and exhibited the highest activity against B. subtilis, even surpassing the activity of the standard antibiotic Chloramphenicol. They also exhibited antimicrobial activities against P. aeruginosa, S. aureus, C. albicans, and T. mentagrophytes, but were inactive against A. niger and E. coli.

Neobavaisoflavone (NBIF) is an isoflavone isolated from Psoralea corylifolia L, a plant claimed to have osteogenic activity and used to treat bone fractures, osteomalacia and osteoporosis. The present results showed that NBIF concentration-dependently promoted osteogenesis in MC3T3-E1cells, demonstrated by notable enhancement of alkaline phosphatase (ALP) activity, increase of bone-specific matrix proteins expression including type I collagen (Col-I), osteocalcin (OCN) and bone sialoprotein (BSP), and formation of bone nodules. However, cell proliferation in the presence of NBIF was not affected. Results also demonstrated that NBIF up-regulated the expression of runt-related transcription factor 2 (Runx2) and Osterix (Osx), the bone-specific transcription factors participating in regulation of bone marker genes expression. Application of p38 inhibitor SB203580 repressed not only NBIF-induced activation of ALP, the expression of Col-I, OCN and BSP, but also the matrix proteins mineralization. Western blot analysis further revealed that NBIF increased the phosphorylated level of p38 concentration-dependently. Additionally, inhibition of p38 abolished the stimulatory effect of NBIF on the expression of Runx2 and Osx. Taken together, the osteogenic activity of NBIF might probably act through activation of p38-dependent signaling pathway to up-regulate the mRNA levels of Runx2 and Osx then stimulate bone matrix proteins expression. The beneficial effect of NBIF on mineralization demonstrated that NBIF represented as an active component existed in P. corylifolia and might be a potential anabolic agent to treat bone loss-associated diseases.

We evaluated the anti-inflammatory effects of cryptotanshinone and tanshinone IIA, two major tanshinones isolated from Salvia miltiorrhiza, on chemoattractant-induced cell migration in RAW264.7 macrophages. Results showed that cryptotanshinone inhibited cell migration toward complement 5a (C5a) and macrophage inflammatory protein-1alpha (MIP-1alpha) in a concentration-dependent manner. In contrast, tanshinone IIA displayed less or even no effect on cell migration evoked by these chemoattractants. Both C5a- and MIP-1alpha-induced migration were clearly inhibited by cytochalasin B (an inhibitor of actin polymerization), but not by colchicine (an inhibitor of microtubule polymerization). Fluorescence staining demonstrated that cryptotanshinone as well as cytochalasin B, effectively reversed cell polarization and filopodia extension induced by both chemoattractants. Furthermore, C5a-evoked increase in F-actin fluorescence intensity was significantly suppressed by cryptotanshinone. Based on these observations, we suggest that cryptotanshinone exerts anti-migrating activity possibly by impeding F-actin polymerization and filopodia formation.

Neovascularization is an essential process in tumor development, it is conceivable that anti-angiogenic treatment may block tumor growth. In angiogenesis, nitric oxide (NO) is an important factor which mediates vascular endothelial cell growth and migration. beta-Lapachone (3,4-dihydro-2,2-dimethyl-2H-naphtho-[1,2-b]pyran-5,6-dione), a natural product extracted from the lapacho tree (Tabebuia avellanedae), has been demonstrated to possess anti-cancer and anti-viral effects. Whether beta-lapachone can induce endothelial cell death or has an anti-angiogenic effect is still an enigma. We investigated the in vitro effect of beta-lapachone on endothelial cells, including human vascular endothelial cell line, EAhy926, and human umbilical vascular endothelial cells (HUVEC). Our results revealed that (1) the intracellular cGMP levels and the mitochondria membrane potential (MMP) decreased, and calpain and caspases were activated, during beta-lapachone-induced endothelial cell death; (2) co-treatment with calpain inhibitors (ALLM or ALLN) or the intracellular calcium chelator, BAPTA, but not the general caspase inhibitor, zVAD-fmk, provided significant protection against apoptosis by preventing the beta-lapachone-induced MMP decrease and cytoplasmic calcium increase; (3) addition of NO downregulated the beta-lapachone-induced cGMP depletion and protected the cells from apoptosis by blocking the MMP decrease and the calcium increase; and (4) exogenous NO protects endothelial cells against the cell death induced by beta-lapachone, but not the anti-angiogenic effect. From all the data above, we demonstrated that NO can attenuate the apoptotic effect of beta-lapachone on human endothelial cells and suggest that beta-lapachone may have potential as an anti-angiogenic drug.

Propofol, an intravenous anesthetic agent, is widely used for inducing and maintaining anesthesia during surgical procedures and for sedating intensive care unit patients. In the clinic, rapid elimination is one of the major advantages of propofol. Meanwhile, the biotransformation and drug interactions of propofol in rat livers are still little known. In this study, we evaluated the ring-oxidative metabolism of propofol in phenobarbital-treated rat livers and possible drug interactions. Administration of phenobarbital to male Wistar rats significantly increased levels of hepatic cytochrome P450 (CYP) 2B1/2 and microsomal pentoxyresorufinO-dealkylase (PROD) activity. Analyses by high-performance liquid chromatography and liquid chromatography mass spectroscopy revealed that propofol was metabolized by phenobarbital-treated rat liver microsomes into 4-hydroxypropofol. In comparison, PROD activity and 4-hydroxy-propofol production from propofol metabolism were suppressed by orphenodrine, an inhibitor of CYP2B1/2, and a polyclonal antibody against rat CYP2B1/2 protein. Furthermore, exposure of rats to propofol did not affect the basal or phenobarbital-enhanced levels of hepatic CYP2B1/2 protein. Meanwhile, propofol decreased the dealkylation of pentoxyresorufin by phenobarbital-treated rat liver microsomes in a concentration-dependent manner. Taken together, this study shows that rat hepatic CYP2B1/2 plays a critical role in the ring-oxidative metabolism of propofol into 4-hydroxypropofol, and this anesthetic agent can inhibit CYP2B1/2 activity without affecting protein synthesis.

As part of an ongoing study of traditional Chinese medicinal plants, the root tissue of Salvia miltiorrhiza was further investigated for its chemical constituents. Five naturally occurring products along with 13 known constituents were isolated from an ethyl acetate-soluble portion of its ethanol extract. Their structures were elucidated by means of spectroscopic methods. Some selected compounds were also evaluated for biological activity.

Rutaecarpine is the main active alkaloid of the herbal medicine, Evodia rutaecarpa. To identify the major human cytochrome P450 (P450) participating in rutaecarpine oxidative metabolism, human liver microsomes and bacteria-expressed recombinant human P450 were studied. In liver microsomes, rutaecarpine was oxidized to 10-, 11-, 12-, and 3-hydroxyrutaecarpine. Microsomal 10- and 3-hydroxylation activities were strongly inhibited by ketoconazole. The 11- and 12-hydroxylation activities were inhibited by alpha-naphthoflavone, quinidine, and ketoconazole. These results indicated that multiple hepatic P450s including CYP1A2, CYP2D6, and CYP3A4 participate in rutaecarpine hydroxylations. Among recombinant P450s, CYP1A1 had the highest rutaecarpine hydroxylation activity. Decreased metabolite formation at high substrate concentration indicated that there was substrate inhibition of CYP1A1- and CYP1A2-catalyzed hydroxylations. CYP1A1-catalyzed rutaecarpine hydroxylations had V(max) values of 1,388 to approximately 1,893 pmol/min/nmol P450, K(m) values of 4.1 to approximately 9.5 microM, and K(i) values of 45 to approximately 103 microM. These results indicated that more than one molecule of rutaecarpine is accessible to the CYP1A active site. The major metabolite 10-hydroxyrutaecarpine decreased CYP1A1, CYP1A2, and CYP1B1 activities with respective IC(50) values of 2.56 +/- 0.04, 2.57 +/- 0.11, and 0.09 +/- 0.01 microM, suggesting that product inhibition might occur during rutaecarpine hydroxylation. The metabolite profile and kinetic properties of rutaecarpine hydroxylation by human P450s provide important information relevant to the clinical application of rutaecarpine and E. rutaecarpa.

Rutaecarpine is an alkaloid isolated from the medicinal herb Evodia rutaecarpa. This study was to evaluate the elimination pathway of rutaecarpine in rat feces and urine. Rutaecarpine and its metabolites (3-, 10-, 11- and 12-hydroxyrutaecarpine) in urine were measured after incubation with beta-glucuronidase. After the rutaecarpine was administered (25 and 100 mg/kg) orally to rats, the urine and fecal samples were collected using a metabolic cage for five consecutive days. For determining rutaecarpine, the mobile phase consisted of acetontrile-10 mM NaH(2)PO(4) (60:40, v/v, pH 4.2 adjusted with orthophosphoric acid) with a flow rate of 1 mL/min. The calibration curve was linear in concentrations of 0.05-50 microg/mL in fecal and urine sample. The results indicated that more than 42% of the rutaecarpine was excreted by feces after oral administration (25 and 100 mg/kg), but only a small amount of rutaecarpine was detected in urine at a higher dose of rutaecarpine (100 mg/kg). After incubation with beta-glucuronidase, the hydroxyrutaecarpine in urine was eluted using methanol-acetonitrile-0.04% formic acid (6:30:64, v/v) with a flow rate of 1.2 mL/min. We conclude that the metabolic pathway of rutaecarpine went through phase I hydroxylation and phase II conjugation, and the major metabolite is 10-hydroxyrutaecarpine eliminated from urine of the rat.

Four new compounds were isolated from the basidiomata of the fungus Antrodia salmonea, a newly identified species of Antrodia (Aphyllophorales) in Taiwan. These new compounds are named as lanosta-8,24-diene-3beta,15alpha,21-triol (1), 24-methylenelanost-8-ene-3beta,15alpha,21-triol (2), 2,3-dimethoxy-5-(2',5'-dimethoxy-3',4'-methylenedioxyphenyl)-7-methyl-[1,4]-naphthoquinone (3), and 2,3-dimethoxy-6-(2',5'-dimethoxy-3',4'-methylenedioxyphenyl)-7-methyl-[1,4]-naphthoquinone (4), respectively. Their structures were elucidated by spectroscopic methods. An in vitro cellular functional assay was performed to evaluate their anti-oxidative burst activity in human leukocytes. They showed inhibitory effects against phorbol 12-myristate-13-acetate (PMA), a direct protein kinase C activator, induced oxidative burst in neutrophils (PMN) and mononuclear cells (MNC) with 50 % inhibitory concentration (IC(50)) ranging from 3.5 to 25.8 microM. The potency order of these compounds in PMA-activated leukocytes was as 1 > 3 > 4 > 2. They were relatively less effective in formyl-Met-Leu-Phe (fMLP), a G-protein coupled receptor agonist, induced oxidative burst, except for compounds 3 and 4 in fMLP-activated PMN. These results indicated that three (1, 3, and 4) of these four newly identified compounds displayed anti-oxidative effect in human leukocytes with different potency and might confer anti-inflammatory activity to these drugs.

The hepatotoxin, safrole is a methylenedioxy phenyl compound, found in sassafras oil and certain other essential oils. Recombinant cytochrome P450 (CYP, P450) and human liver microsomes were studied to investigate the selective inhibitory effects of safrole on human P450 enzymes and the mechanisms of action. Using Escherichia coli-expressed human P450, our results demonstrated that safrole was a non-selective inhibitor of CYP1A2, CYP2A6, CYP2D6, CYP2E1, and CYP3A4 in the IC(50) order CYP2E1 < CYP1A2 < CYP2A6 < CYP3A4 < CYP2D6. Safrole strongly inhibited CYP1A2, CYP2A6, and CYP2E1 activities with IC(50) values less than 20 microM. Safrole caused competitive, non-competitive, and non-competitive inhibition of CYP1A2, CYP2A6 and CYP2E1 activities, respectively. The inhibitor constants were in the order CYP1A2 < CYP2E1 < CYP2A6. In human liver microsomes, 50 microM safrole strongly inhibited 7-ethoxyresorufin O-deethylation, coumarin hydroxylation, and chlorzoxazone hydroxylation activities. These results revealed that safrole was a potent inhibitor of human CYP1A2, CYP2A6, and CYP2E1. With relatively less potency, CYP2D6 and CYP3A4 were also inhibited.

Rutaecarpine is a quinazolinocarboline alkaloid of the medicinal herb Evodia rutaecarpa and shows a variety of pharmacological effects. Four oxidation metabolites of rutaecarpine were prepared from 3-methylcholanthrene-treated rat liver microsomes. These metabolites had an [M + H]+ ion at m/z 304. The structures of metabolites were identified by comparison of their liquid chromatograms and mass, absorbance, and 1H NMR spectra with those of synthetic standards. Rutaecarpine was metabolized by microsomal enzymes to form 3-, 10-, 11-, and 12-hydroxyrutaecarpine. The formation of 10-hydroxyrutaecarpine was highly induced by a cytochrome P450 1A inducer, 3-methylcholanthrene.

Tanshinone IIA, a major component extracted from the traditional herbal medicine, Salvia miltiorrhiza Bunge, is known to exhibit potent cytotoxicity against various human carcinoma cells in vitro. However, the mechanism by which tanshinone IIA produces this anti-tumor effect remains unknown. Since anti-neovascularization has generally been regarded as an effective strategy for anti-cancer therapy, we decided to investigate the mechanism underlying tanshinone IIA-mediated death of human endothelial cells. In this study, we demonstrate that tanshinone IIA elicits human endothelial cell death independent of oxidative stress. These events are partially calcium-dependent and actually dependent upon NAD(P)H: quinone oxidoreductase (NQO1) activity. Tanshinone IIA induces an increase in intracellular calcium, which triggers the release of cytochrome c, thus causing loss of the mitochondrial membrane potential (MMP), resulting in the subsequent activation of caspases. Blocking the induction of Ca2+ perturbation with BAPTA-AM partially rescued cells from tanshinone IIA-induced cytotoxicity. Additionally, blocking NQO1 activity with dicoumoral or inhibiting caspase activities with the general caspase inhibitor, z-VAD-fmk, prevented cell death induced by tanshinone IIA. Therefore, our results imply that tanshinone IIA-mediated cytotoxicity against human endothelial cells may occur through activation of NQO1, which induces a calcium imbalance and mitochondrial dysfunction, thus stimulating caspase activity.

Safrole is a natural plant constituent, found in sassafras oil and certain other essential oils. The carcinogenicity of safrole is mediated through 1'-hydroxysafrole formation, followed by sulfonation to an unstable sulfate that reacts to form DNA adducts. To identify the main cytochrome P450 (P450) involved in human hepatic safrole 1'-hydroxylation (SOH), we determined the SOH activities of human liver microsomes and Escherichia coli membranes expressing bicistronic human P450s. Human liver (n = 18) microsomal SOH activities were in the range of 3.5-16.9 nmol/min/mg protein with a mean value of 8.7 +/- 0.7 nmol/min/mg protein. In human liver (n = 3) microsomes, the mean K(m) and V(max) values of SOH were 5.7 +/- 1.2 mM and 0.14 +/- 0.03 micromol/min/nmol P450, respectively. The mean intrinsic clearance (V(max)/K(m)) was 25.3 +/- 2.3 microL/min/nmol P450. SOH was sensitive to the inhibition by a CYP2C9 inhibitor, sulfaphenazole, and CYP2E1 inhibitors, 4-methylpyrazole and diethyldithiocarbamate. The liver microsomal SOH activity showed significant correlations with tolbutamide hydroxylation (r = 0.569) and chlorzoxazone hydroxylation (r = 0.770) activities, which were the model reactions catalyzed by CYP2C9 and CYP2E1, respectively. Human CYP2C9 and CYP2E1 showed SOH activities at least 2-fold higher than the other P450s. CYP2E1 showed an intrinsic clearance 3-fold greater than CYP2C9. These results demonstrated that CYP2C9 and CYP2E1 were the main P450s involved in human hepatic SOH.

Bioassay-directed fractionation of Saussurea lappa led to the isolation of a novel lappadilactone (1) and seven sesquiterpene lactones (2-8) as cytotoxic principles against selected human cancer cell lines. Lappadilactone (1), dehydrocostuslactone (2), and costunolide (5) exhibited the most potent cytotoxicity with CD50 values in the range 1.6-3.5 microg/mL in dose- and time-dependent manners. The cytotoxicities were not specific and showed similar activities against HepG2, OVCAR-3 and HeLa cell lines. The structure-activity relationship showed that the alpha-methylene-gamma-lactone moiety is necessary for cytotoxicity, and activity is reduced with the presence of a hydroxyl group. In addition, seven noncytotoxic compounds (9-15) were also isolated, including two novel sesquiterpenes, a guaianolide-type with a C17 skeleton, lappalone (13), and 1beta,6alpha-dihydroxycostic acid ethyl ester (14). The structures of the new compounds were elucidated from spectroscopic and/or X-ray data interpretations. Some representative compounds were also tested for antibacterial activity; however, only marginal activities were observed. Therefore, compounds 1-8 are potential cytotoxic agents but without significant antibacterial effect.

The cyclopentadienyl complex Cp*Ir(PMe3)Cl2 reacts with the dipotassium salt of phthalic acid in the presence of AgPF6 via chloride substitution to give the ortho-metalated compound Cp*Ir(PMe3)[C6H3(CO2)(CO2H)]. This new compound has been isolated by recrystallization and has been characterized in solution by 1H and 13C NMR spectroscopies, and the solid-state structure has been verified by X-ray crystallography. Cp*Ir(PMe3)[C6H3(CO2)(CO2H)] crystallizes in the monoclinic space group P21/c, a = 9.1010(6) A, b = 16.715(1) A, c = 14.3965(9) A, β = 108.24(1)°, V = 2080.0(2) A3, Z = 4, and dcalc = 1.813 mg/m3; R = 0.0276, Rw = 0.0810 for 2730 reflections with I > 2σ(I). Coordination of the benzene ring to the iridium center via one of the carboxylate groups and ortho-metalation of the C–H moiety that was α to the iridium-bound carboxylate group is confirmed.

Aim To investigate the chemical constituents of Glinus oppositifolius. Methods The compounds were isolated by silica gel chromatography. The structure of the new triterpene was elucidated by extensive 1D and 2D NMR spectroscopy. Results The dichloromethane extract of the air-dried leaves of Glinus oppositifolius afforded a new triterpene, oppositifolone ( 1 ), spinasterol ( 2 ), squalene ( 3 ) and lutein ( 4 ). The structure of 1 was elucidated by NMR spectroscopy, while 2 - 4 were identified by comparison of their 13 C NMR data with those reported in the literature. Conclusion A new triterpene was isolated from G. oppositifolius .

The reduction and oxidation properties of the arachno-heteropolynuclear metal clusters Fe2(CO)6(μ3-S)2PtL2, where L2 = bipyridine (1), phenanthroline (2), diphenylphosphinoethane (3), diphenylphosphinoferrocene (4), or cyclooctadiene (5), have been examined by electrochemistry, IR spectroscopy, and ESR spectroscopy. An electron-transfer series involving up to five electrons is observed. The common characteristics are a fully reversible one-electron oxidation process to a monocation (in the range 0.13−0.38 V vs ferrocene) and a chemically reversible but electrochemically quasi-reversible two-electron reduction process (range −1.9 to −2.4 V). Complexes 1 and 2 also display a fully reversible one-electron reduction at a potential less negative (ca. −1.8 V) than the subsequent two-electron reduction. The LUMOs of 1 and 2 are predicted by EHMO calculations to be primarily π*-diimine based. Spectral data from the monoanions 1- and 2- are consistent with this orbital assignment: very small shifts of the metal−c...

The compound herbal medicine Wu-chu-yu-tang is used for the treatment of migraine and vomiting accompanying a cold. To assess the interactions of herb and drug metabolism, effects of Wu-chu-yu-tang on hepatic and renal cytochrome P450 (CYP), UDP-glucuronosyl transferase (UGT) and glutathione S-transferase (GST) were studied in C57BL/6J mice. Treatment of mice with 5 g/kg per day Wu-chu-yu-tang for 3 days caused 2.5-fold and 2.9-fold increases of liver microsomal 7-ethoxyresorufin O-deethylation (EROD) and 7-methoxyresorufin O-demethylation activities, respectively. However, CYP activities toward 7-ethoxycoumarin, benzphetamine, N-nitrosodimethylamine, erythromycin and nifedipine, and conjugation activities of UGT and GST were not affected. In kidney, Wu-chu-yu-tang-treatment had no effects on Cyp, UGT and GST activities. Among the four component herbs of Wu-chu-yu-tang, only Evodiae Fructus (Wu-chu-yu) extract increased EROD activity and CYP1a2 protein level. In E. Fructus, rutaecarpine, evodiamine and dehydroevodiamine are the main active alkaloids. At the doses corresponding to their contents in Wu-chu-yu-tang, rutaecarpine-treatment increased hepatic EROD activity, whereas evodiamine and dehydroevodiamine had no effects. These results demonstrated that ingestion of Wu-chu-yu-tang elevated mouse hepatic Cyp1a2 activity and protein level. E. Fructus and rutaecarpine contributed at least in part to the CYP1a2 induction by Wu-chu-yu-tang. Patients should be cautioned about the drug interaction of Wu-chu-yu-tang and CYP1A2 substrates.

This study synthesized a series of hydroxyl-functionalized 2-arylbenzo[b]furans based on the structure of tournefolic acid A and evaluated them for antioxidant and α-glucosidase inhibitory activities. Compounds 5a, 5e, and 5n showed remarkable inhibition of α-glucosidase (IC50 values of 1.9–3.0 μM), and they appear to be even more potent than quercetin. A kinetic binding study indicated that compounds 5a and 5n used a mechanism of mixed-competition to inhibit α-glucosidase. This study also revealed that compounds 5a and 5n bind to either the α-glucosidase or α-glucosidase-4-NPGP complex. Using the crystal structure of the Saccharomyces cerevisiae α-glucosidase, the molecular docking study has predicted the binding of compounds 5a and 5n to the active site of α-glucosidase through both hydrophobic and hydrogen interactions. A DPPH radical scavenging assay further showed that most hydroxyl-functionalized 2-arylbenzo[b]furans possess antioxidant activity. The exception was compound 5p, which has only one hydroxyl group on the 2-phenyl ring of 2-arylbenzo[b]furan. Our results indicate that hydroxyl-functionalized 2-arylbenzo[b]furans possess both antidiabetic as well as antioxidant properties.

beta-Lapachone, a novel anti-neoplastic drug, induces various cancer cells to undergo apoptosis. In a previous report, we showed that beta-lapachone-induced apoptosis of HL-60 cells is mediated by oxidative stress. However, in the present study, we found that beta-lapachone-induced apoptosis of human prostate cancer (HPC) cells may be independent of oxidative stress. In contrast to the 10-fold beta-lapachone-induced increase in H(2)O(2) production seen in HL-60 cells, only a 2- to 4-fold increase was observed in HPC cells. N-acetyl-L-cysteine (NAC), a thiol antioxidant, inhibited the apoptosis in DU145 cells after 12 h exposure to beta-lapachone. Nonetheless, NAC, along with other antioxidants, failed to exert similar effect in HPC cells subjected to beta-lapachone treatment for 24 h. Under this premise, we suggest that the oxidative stress may not play a crucial role in beta-lapachone-mediated HPC cell apoptosis. Here we demonstrate that damage to genomic DNA is the trigger for the apoptosis of HPC cells induced by beta-lapachone. According to our results, beta-lapachone stimulates DNA dependent kinase expression and poly(ADP-ribose) polymerase cleavage in advance of significant morphological changes. beta-Lapachone promotes the expression of cyclin-dependent kinase (cdk) inhibitors (p21(WAF1) and p27(Kip1)), induces bak expression, and subsequently stimulates the activation of caspase-7 but not of caspase-3 or caspase-8 during the apoptosis of HPC cells. Taken together, these results suggest that the signaling pathway involving the beta-lapachone-induced apoptosis of HPC cell may be by DNA damage, induction of cdk inhibitors (p21 and p27), and then subsequent stimulation of caspase-7 activation.

Treatment of Fe2(CO)6(μ2-PPhH)2 with BuLi (2 equiv.), followed by the addition of PtCl2 (dppe), affords the phosphido-bridged cluster Fe2(CO)6(μ3-PPh)2Pt(dppe). The Fe2Pt cluster was isolated and characterized in solution by IR and 31P NMR spectroscopy, and the molecular structure of Fe2(CO)6(μ3-PPh)2Pt(dppe) determined by X-ray diffraction analysis. Fe2(CO)6(μ3-PPh)2Pt(dppe) crystallizes in the orthorhombic space group Pbca, a = 17.539(3) A, b = 21.490(2) A, c = 22.959(3) A, V = 8653.5(18) A3, Z = 8, dcalc = 1.670 g cm−3; R = 0.0644, Rw = 0.0389 for 5040 observed reflections with I > 3σ(I).

The reaction between the dianion [Fe2(CO)6(μ2-S)2]2− and NiCl2(dppf) occurs readily at room temperature to give the mixed-metal cluster Fe2(CO)6(μ3-S)2Ni(dppf) in moderate yield. Fe2(CO)6(μ3-S)2Ni(dppf) was isolated by preparative chromatography and its solid-state structure established by X-ray diffraction analysis. Fe2(CO)6(μ3-S)2Ni(dppf) crystallizes in the monoclinic space group C2/c, a = 20.320(6), b = 13.114(2), c = 15.622(2) A, β = 110.25(2)°, V = 3905.4(11) A3, Z = 4, and d calc = 1.630 g/cm.3 The X-ray structure of Fe2(CO)6(μ3-S)2Ni(dppf) exhibits an Fe2S2Ni arachno polyhedral core, with the pendant dppf ligand attached to an essentially square planar Ni center. The redox chemistry of Fe2(CO)6(μ3-S)2Ni(dppf) was investigated by cyclic voltammetry which showed a reversible, one-electron oxidation localized on the Fe2S2 core along with an irreversible, one-electron reduction that is antibonding with respect to the Fe—Fe and Fe—S bonds. The electrochemical assignments were confirmed by carrying out extended Huckel MO calculations on the model cluster Fe2(CO)6(μ3-S)2Ni(H4-dppf).

The replacement of the 1,5-cyclooctadiene (COD) ligand in the cluster Fe2(CO)6(μ3-S)2Pt(1,5-COD) (1) with the pyridylphosphine ligand Ph2PPy (2.0 equiv) occurs readily at room temperature to give the phosphine-substituted cluster Fe2(CO)6(μ3-S)2Pt(Ph2PPy)2 (2). Cluster 2 was isolated by preparative chromatography and characterized in solution by IR and 31P NMR spectroscopy. The solid-state structure was established by X-ray diffraction analysis. Fe2(CO)6(μ3-S)2Pt(Ph2PPy)2 crystallizes in the monoclinic space group C2/c, a = 19.8781(5) A, b = 13.4603(3) A, c = 16.3304(4) A, β = 108.828(2)°, V = 4135.6(2) A3, Z = 4, d calc = 1.711 g cm−3; R = 0.0232, R w = 0.0258 for 2212 observed reflections with I ≥ 3σ(I). The X-ray structure confirms the square planar geometry at the platinum center and coordination of the phosphorus centers to the platinum center in cluster 2. The arachno polyhedral shape adopted by cluster 2 is not consistent with PSEP theory, with the deviation from PSEP theory being attribut...

The antiviral activity in the roots of Rubia cordifolia was examined, and three naphthohydroquinones, furomollugin (1), mollugin (2), and rubilactone (3), were isolated from it. Compounds 1 and 2 strongly suppressed the secretion of hepatitis B surface antigen (HBsAg), both with IC50 = 2.0 micrograms/mL, in human hepatoma Hep3B cells while having little effect on the viability of the cells. Evaluation of structurally related derivatives of 1 and 2 revealed that a 6-hydroxy group and a pyran or furan ring contribute to this suppressive effect.

The reaction between the cyclopentadienyliridium complexes Cp∗ Ir(L)Cl2 (where L = PMe3, PPh3, CN-t-Bu) and disodium maleonitriledithiolate (Na2mnt) yields the corresponding mnt-substituted compounds Cp∗ Ir(PMe3)(mnt) (1), Cp∗ Cp∗ Ir(PPh3)(mnt) (2) and Cp∗ Ir(CN-t-Bu)(mnt) (3). All of these new compounds have been isolated in high yield and characterized in solution by IR and NMR spectroscopy. The solid state structures of 2 and 3 were determined by single-crystal X-ray diffraction analysis. 2 crystallizes in the triclinic space group P 1 with a = 10.4557(8) A , b = 10.630(1) A , c = 14.894(1) A , α = 91.382(8)°, β = 90.141(6)°, γ = 118.182(7)° , V = 1458.5(3) A 3 and Z = 2 . Full-matrix least-squares refinement yielded R = 0.0281 for 3425 (I > σ(I)) reflections. 3 crystallizes in the monoclinic space group P21/n with a = 8.9609(7) A , b = 20.343(1) A , c = 11.9115(9) A , β = 94.168(6)°, V = 2165.(6) A 3 and Z = 4. Full-matrix least-squares refinement yielded R = 0.0245 for 2266 (I> 3 σ (I)) reflections. The redox properties of 1–3 have been explored by cyclic and rotating disc electrode voltammetric techniques in MeCN and CH2Cl2 solvents. Each of these compounds exhibit a well-defined one-electron oxidation wave that is assigned to the 0/ + 1 redox couple, along with a + 1/ + 2 redox wave, the reversibility of which is highly dependent on the nature of the ancillary two-electron donor ligand (L) and the solvent. Extended Huckel calculations have been performed on the model compounds CpIr(PH3)(mnt) and CpIr(CNH)(mnt), with the results used in a discussion of the nature of the HOMO and LUMO levels in 1–3.

isolation, structure elucidation, cytotoxicity and antimicrobial properties of the new triterpene retusenol (I) and some known compounds, e.g. friedelin and dischidiol

The affiliations of the fourteenth author, Wen-Chin Yang, are incorrect. Wen-Chin Yang is affiliated with 1,2, and the Biotechnology Research Center, Academia Sinica and Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan.

The hydroformylation of 1 -pentene using the benzylidyne-capped cluster PhCCO3(CO)9 has been examined by cylindrical internal reflectance (CIR) spectroscopy. At 130°C, cluster fragmentation is observed and the formation of aldehydes is shown to coincide with fragmentation of PhCCO3(CO)9 by CIR spectroscopy. These results are discussed in relationship to the observations previously reported by Withers and Seyferth (Inorg. Chem. 22 (1983) 2931) on PhCCO3(CO)9 and its polymer-bound analogues. CIR spectral data for the CO2(CO)8-catalyzed hydroformylation of 1-pentene are also presented for comparative purposes.

Rubilactone (1), dihydromollugin (2), and mollugin (3) are naturally occurring products found in Rubia cordifolia, which is a famous Chinese herb with anti tumor, viral inhibition and other activities. Synthetic studies were carried out in these naphthoic acid esters starting from 1,4-dihydroxy-2-naphthoic acid. In this study, we finished the synthesis of rubilactone which has not been reported before and also synthesized dihydromollugin and mollugin with better yields with different approaches compared to those previously reported in the literature.

Plumbagin is found in many herbal plants and inhibits the growth of various bacteria. Escherichia coli strains are relatively resistant to this drug. The mechanism of resistance is not clear. Previous findings showed that plumbagin treatment triggered up-regulation of many genes in E. coli including ahpC, mdaB, nfnB, nfo, sodA, yggX and ygfZ. By analyzing minimal inhibition concentration and inhibition zones of plumbagin in various gene-disruption mutants, ygfZ and sodA were found critical for the bacteria to resist plumbagin toxicity. We also found that the roles of YgfZ and SodA in detoxifying plumbagin are independent of each other. This is because of the fact that ectopically expressed SodA reduced the superoxide stress but not restore the resistance of bacteria when encountering plumbagin at the absence of ygfZ. On the other hand, an ectopically expressed YgfZ was unable to complement and failed to rescue the plumbagin resistance when sodA was perturbed. Furthermore, mutagenesis analysis showed that residue Cys228 within YgfZ fingerprint region was critical for the resistance of E. coli to plumbagin. By solvent extraction and HPLC analysis to follow the fate of the chemical, it was found that plumbagin vanished apparently from the culture of YgfZ-expressing E. coli. A less toxic form, methylated plumbagin, which may represent one of the YgfZ-dependent metabolites, was found in the culture supernatant of the wild type E. coli but not in the ΔygfZ mutant. Our results showed that the presence of ygfZ is not only critical for the E coli resistance to plumbagin but also facilitates the plumbagin degradation.

Psoralidin has been reported to inhibit lipopolysaccharide (LPS)-induced nitric oxide (NO) production, but the mechanisms of the action remain unclear. Thus, the impact of psoralidin on signaling pathways known to be implicated in NO synthesis was explored in LPS-activated RAW264.7 macrophages by using RT-PCR and Western blotting. Consistent with NO inhibition, psoralidin suppressed LPS-induced expression of inducible NO synthase (iNOS) by abolishing IκB kinase (IKK) phosphorylation, IκB degradation and nuclear factor κB (NF-κB) nuclear translocation without effecting mitogen-activated protein kinases (MAPKs) phosphorylation. Exposure to wortmannin abrogated IKK/IκB/NF-κB-mediated iNOS expression, suggesting activation of such a signal pathway might also be phosphoinositide-3-kinase (PI3K) dependent. By using Src inhibitor PP2, Janus kinase 2 (JAK-2) inhibitor AG490, Bruton's tyrosine kinase (Btk) inhibitor LFM-A13 and spleen tyrosine kinase (Syk) inhibitor piceatannol, the results showed that piceatannol clearly repressed NO production more potently than the other inhibitors. Furthermore, piceatannol significantly repressed LPS-induced PI3K/Akt phosphorylation and the downstream IKK/IκB activation, suggesting that Syk is an upstream key regulator in the activation of PI3K/Akt-mediated signaling. In fact, transfection with siRNA targeting Syk obviously reduced iNOS expression. Interestingly, LPS-induced phosphorylations of Syk and PI3K-p85 were both significantly blunted by psoralidin treatment. The present results show that interfering with Syk-mediated PI3K phosphorylation might contribute to the NO inhibitory effect of psoralidin via blocking IKK/IκB signaling propagation in LPS-stimulated RAW 264.7 macrophages.