New AZT analogues having 5'-alkylsulfonyl groups: synthesis and anti-HIV activity

New derivatives of azidothymidine (AZT) substituted by alkyl and alkylsulphonyl groups at N-3 and C-5', respectively, have been synthesized. The new synthesized derivatives showed remarkable anti-HIV-1 and HIV-2 activity in MT-4 cells. Compounds 8 and 10 have IC(50) values of 0.83 and 0.31 microg/mL against HIV-1 with therapeutic index of 83 and 403, respectively, and IC(50) values of 0.93 and 0.29 microg/mL against HIV-2 with therapeutic index of 74 and 431, respectively. This means that compounds 8 and 10 were cytotoxic to MT-4 cells at CC(50) of 69.2 microg/mL and 125 microg/mL, respectively.     

Antimicrobial activity of the extract and isolated compounds from Baccharis dracunculifolia D. C. (Asteraceae)

Baccharis dracunculifolia D.C. (Asteraceae) is the most important plant source of the Brazilian green propolis. Since propolis is known for its antimicrobial activity, the aim of this work was to evaluate the antimicrobial activities of B. dracunculifolia and some of its isolated compounds. The results showed that the leaves extract of B. dracunculifolia (BdE) presents antifungal and antibacterial activities, especially against Candida krusei and Cryptococcus neoformans, for which the BdE showed IC50 values of 65 microg mL(-1) and 40 microg mL(-1), respectively. In comparison to the BdE, it was observed that the green propolis extract (GPE) showed better antimicrobial activity, displaying an IC50 value of 9 microg mL(-1) against C. krusei. Also, a phytochemical study of the BdE was carried out, affording the isolation of ursolic acid (1), 2a-hydroxy-ursolic acid (2), isosakuranetin (3), aromadendrin-4'-methylether (4), baccharin (5), viscidone (6), hautriwaic acid lactone (7), and the clerodane diterpene 8. This is the first time that the presence of compounds 1, 2, and 8 in B. dracunculifolia has been reported. Among the isolated compounds, 1 and 2 showed antibacterial activity against methicillin-resistant Staphylococcus aureus, displaying IC50 values of 5 microg mL(-1) and 3 microg mL(-1), respectively. 3 was active against C. neoformans, showing an IC50 value of 15 microg mL(-1) and a MIC value of 40 microg mL(-1), while compounds 4-8 were inactive against all tested microorganisms. The results showed that the BdE, similar to the GPE, displays antimicrobial activity, which may be related to the effect of several compounds present in the crude extract.     

Protein glycation inhibitory activities of Lawsonia inermis and its active principles

The protein glycation inhibitory activity of ethanolic extract of Lawsonia inermis (henna) plant tissues was evaluated in vitro using the model system of bovine serum albumin and glucose. Protein oxidation and glycation are posttranslational modifications that are implicated in the pathological development of many age-related disease processes. This study investigated the effects of Lawsonia inermis ethanolic extract and its components, on protein damage induced by a free radical generator in in vitro assay system. We found that alcoholic extract of Lawsonia inermis can effectively protect against protein damage and showed that its action is mainly due to Lawsone. In addition, the presence of gallic acid also plays an important role in the protective activity against protein oxidation and glycation. Two known compounds, namely, Lawsone and gallic acid previously isolated from this plant were subjected to glycation bioassay for the first time. It was found that the alcoholic extract, lawsone (1) and gallic acid (2) showed significant inhibition of Advanced Glycated End Products (AGEs) formation and exhibit 77.95%, 79.10% and 66.98% inhibition at a concentration of 1500 microg/mL, 1000 microg/mL and 1000 microM respectively. Lawsonia inermis, compounds 1 and 2 were found to be glycation inhibitors with IC(50) 82.06 +/- 0.13 microg/mL, 67.42 +/- 1.46 microM and 401.7 +/- 6. 23 microM respectively. This is the first report on the glycation activity of these compounds and alcoholic extract of Lawsonia inermis.     

Total synthesis and bioactivity of unique flavone desmosdumotin B and its analogs

The first total synthesis of a unique flavone natural product, desmosdumotin B (1), was accomplished. Furthermore, three novel flavonoids, 6-8, and a novel chalcone, 9, were synthesized. The new compounds were evaluated as in vitro inhibitors of human cancer cell growth. The synthetic 1 showed significant cytotoxic activity against a multi-drug resistant cell line (KB-VIN) with an ED50 value of 2.0 microg/mL compared to >40 microg/mL against the parental KB cell line. Flavone 7 displayed selective activity against 1A9 ovarian carcinoma with an ED50 value of 0.7 microg/mL. Selected 1-analogs and synthetic intermediates were also screened for antitumor-promoting effects as inhibitors of EBV-EA activation. Among them, trihydroxyacetophenone derivatives 11 and 14 showed good activity.     

Phytoecdysteroids of Silene guntensis and their in vitro cytotoxic and antioxidant activity

Phytoecdysteroids from aerial parts of Silene guntensis B. Fedtsch were investigated and three phytoecdysteroids were isolated: 2,3-diacetate-22-benzoate-20-hydroxyecdysone (1), 2-deoxy-20-hydroxyecdysone (2), and 20-hydroxyecdysone (3). Their chemical structures were elucidated by DEPT, COSY, 1H and 13C NMR spectroscopy. The isolated compounds 1-3 and crude extracts were evaluated for their antiproliferative and antioxidant activities. They exhibited substantial inhibition of cell growth against human cervix adenocarcinoma (HeLa), hepatocellular carcinoma (HepG-2), and breast adenocarcinoma (MCF-7) cells. The chloroform extract showed potent cytotoxic effects [IC50 values (26.58 +/- 1.88) microg/mL, (20.99 +/- 1.64) microg/mL, and (18.89 +/- 2.36) microg/mL, respectively]. The new compound 1 was mildly cytotoxic compared to extracts [(127.97 +/- 11.34), (106.76 +/- 7.81), and (203.10 +/- 19.56) microg/mL, respectively]. Water and n-butanol extracts exhibited good antioxidant activities [IC50 values of (68.90 +/- 6.45) microg/mL and (69.12 +/- 5.85) microg/mL, respectively].     

Thio-sugars VII. Effect of 3-deoxy-4-S-(beta-D-gluco- and beta-D-galactopyranosyl)-4-thiodisaccharides and their sulfoxides and sulfones on the viability and growth of selected murine and human tumor cell lines

The first conversion of (1-->4)-thiodisaccharides into corresponding sulfoxides and sulfones by conventional oxidation with m-chloroperoxybenzoic acid (MCPBA) is reported. The effects of alpha-(1-->4)-3'-deoxythiodisaccharides (8-9) and their sulfoxide (14-15) and sulfone (16-17) derivatives on murine leukemia and human colon and pancreatic carcinoma cell viability were studied. Concentrations of thio-sugars that decreased tumor cell line viability by 50% (IC(50)), measured via the MTT assay, ranged from 6.4 to 38.3 microg/mL. The effect of alpha-(1-->4)-3'-deoxythiodisaccharide derivatives were most profound on human pancreatic epithelial carcinoma (PANC-1) cells with compounds 8 and 9 having IC(50) values of 6.4 microg/mL and 8.2 microg/mL, respectively. Sulfone derivatives 16 and 17 also had pronounced effects on PANC-1 cell viability (IC(50)=10.2 microg/mL and 9.6 microg/mL, respectively). These results indicate that deoxythio-disaccharide analogs generated by functionalization of the universal chiral precursor levoglucosenone may have cytotoxic properties and therapeutic potential as anticancer agents.     

Antimalarial halorosellinic acid from the marine fungus Halorosellinia oceanica.

Three known compounds, 2-hexylidene-3-methylsuccinic acid (1), cytochalasin Q (2), and 5-carboxymellein (3), together with two new derivatives, 2-hexylidene-3-methylsuccinic acid 4-methyl ester (4) and an ophiobolane sesterterpene named halorosellinic acid (5), were isolated from culture broth of the marine fungus Halorosellinia oceanica BCC 5149. Compounds 1-3 exhibited moderate cytotoxicity against KB and BC-1 cell lines with IC(50) values of 1-13 microg/mL, while compounds 2, 3, 5, and 6 showed antimalarial activity with respective IC(50) values of 17, 4, 13, and 19 microg/mL. Halorosellinic acid (5) possessed only weak antimycobacterial activity with the minimum inhibitory concentration of 200 microg/mL.     

Antiprotozoal and antimicrobial activities of O-alkylated and formylated acylphloroglucinols

In the present article, we examined the antileishmanial, antimalarial, antibacterial, and antifungal activities of several newly synthesized O-alkylated phloroglucinol compounds (11-19) which are analogues of the naturally occurring antimalarial compound 1. Analogues 12 and 16 exhibited antileishmanial activity against, Leishmania donovani promastigotes with IC(50)s of 5.3 and 4.2microg/mL, respectively. Naturally occurring monomeric formylated acylphloroglucinol compounds, grandinol (2), jensenone (3), and their analogues (29-37), were also synthesized and evaluated for antileishmanial, antimalarial, antibacterial, and antifungal activities. Amongst these, both grandinol and jensenone showed mild to moderate antibacterial, antifungal, and antileishmanial activities. Jensenone (3) was effective against Candida albicans with an IC(50) of 5.5microg/mL but was ineffective against Cryptococcus neoformans and methicillin-resistant Staphylococcus aureus. Among the analogues, 34 was the most active against C. albicans and C. neoformans with IC(50)s of 2.0 and 2.5microg/mL, respectively, and was fungicidal toward Candida albicans.     

枳实提取物及其药效组分对OX—LDL损伤的人脐静脉内皮细胞ICAM-1表达和NO释放的影响

目的：研究枳实提取物及其药效组分橙皮苷和新橙皮苷对氧化低密度脂蛋白（oxidized lowd ensity lipoprotein,Ox—LDL）损伤的人脐静脉内皮细胞（human umbilical vein endothelial cells line,HUVEC）细胞间黏附分子-1（intercellular adhesion molecule-1,ICAM-1）表达和一氧化氮（nitric oxide,NO）释放的影响。方法：体外培养HUVEC,50μg／mLOX—LDL制造HUVEC损伤模型。以MTS染色法检测细胞毒性确定用药浓度。细胞ELISA法测定细胞表面ICAM-1的含量,试剂盒测定细胞培养上清液中NO含量。结果：①枳实提取物小于等于2mg／mL时,橙皮苷浓度小于等于0．03125mg／mL时,新橙皮苷浓度小于等于0．25mg／mL时,HUVEC存活率分别大于80％。②2．0mg／mL和1．0mg／mL两个浓度的枳实提取物、15．625μg／mL的橙皮苷和0．2500mg／mL新橙皮苷对OX—LDL诱导的HUVEC的ICAM-1表达有显著抑制作用。③2．0mg／mL枳实提取物显著提高OX—LDL诱导的HUVEC和正常HUVEC培养液中的NO含量;7．813ixg／mL、15．625μg／mL和31．250μg／mL 3个浓度的橙皮苷能显著提高OX—LDL诱导的HUVEC培养液中的NO含量,31．250μg／mL的橙皮苷能促进正常HUVEC的NO释放;0．2500mg／mL和0．1250mg／mL 2个浓度的新橙皮苷能显著提高OX—LDL诱导的HUVEC培养液中的NO含量。结论：枳实提取物及其药效组分橙皮苷、新橙皮苷能抑制Ox-LDL诱导的HUVEC的ICAM-1表达,促进Ox-LDL诱导的HUVEC的NO释放。     

Antileishmanial, antimalarial and antimicrobial activities of the extract and isolated compounds from Austroplenckia populnea (Celastraceae)

Austroplenckia populnea (Celastraceae), known as "marmelinho do campo", is used in Brazilian folk medicine as antimicrobial, anti-inflammatory, and antitumoural agent. The aim of the present work was to evaluate the antimicrobial, antileishmanial and antimalarial activities of the crude hydroalcoholic extract of A. populnea (CHE) and some of its isolated compounds. The phytochemical study of the CHE was carried out affording the isolation of methyl populnoate (1), populnoic acid (2), and stigmast-5-en-3-O-beta-(D-glucopyranoside) (3). This is the first time that the presence of compound 3 in A. populnea is reported. The results showed that the CHE presents antifungal and antibacterial activities, especially against Candida glabrata and Candida albicans, for which the CHE showed IC50 values of 0.7 microg mL(-1) and 5.5 microg mL(-1), respectively, while amphotericin B showed an IC50 value of 0.1 microg mL(-1) against both microorganisms. Compounds 1-3 were inactive against all tested microorganisms. In the antileishmanial activity test against Leishmania donovani, the CHE showed an IC50 value of 52 microg mL(-1), while compounds 2 and 3 displayed an IC50 value of 18 microg mL(-1) In the antimalarial assay against Plasmodium falciparum (D6 and W2 clones), it was observed that all evaluated samples were inactive. In order to compare the effect on the parasites with the toxicity to mammalian cells, the cytotoxicity activity of the isolated compounds was evaluated against Vero cells, showing that all evaluated samples exhibited no cytotoxicity at the maximum dose tested.     

S-Euglobals: biomimetic synthesis, antileishmanial, antimalarial, and antimicrobial activities

Several new euglobal analogues (named as S-euglobals) were synthesized from phloroglucinol via a biomimetic three-component reaction involving Knoevenagel condensation followed by [4+2]-Diels-Alder cycloaddition with monoterpene. Newly synthesized euglobal analogues involve monoterpenes that have not yet been encountered in natural euglobals. S-Euglobals along with previously synthesized robustadial A and B were evaluated for in vitro antileishmanial, antimalarial, antimicrobial, and cytotoxic activities. Out of 16, nine analogues were found to exhibit antileishmanial activity against Leishmania donovani promastigotes. Analogue 7 was the most potent with IC(50) of 2.4 microg/mL and IC(90) of 8 microg/mL, followed by analogues 8 and 11 (IC(50) 5.5 and 9.5 microg/mL). Antileishmanial activity of robustadial A (5) and B (6) was moderate with IC(50) of 20 and 16 microg/mL, respectively. Robustadial A and B and S-euglobal 8 exhibited weak antimalarial activity against Plasmodium falciparum (IC(50) of 2.7-4.76 microg/mL). Few of the euglobal analogues showed antibacterial activity against methicillin-resistant Staphylococcus aureus. Amongst these, analogue 11 was the most potent with IC(50) of 1.0 microg/mL and MIC of 5.0 microg/mL. Most of the compounds were not cytotoxic up to 25 microg/mL in a panel of cell lines consisting of both cancer (SK-MEL, KB, BT-549, and SK-OV-3) as well as non-cancer kidney (Vero and LLC-PK11) cells.     

Chemical structures and biological activities of rhamnolipids produced by Pseudomonas aeruginosa B189 isolated from milk factory waste

The aim of this work was to study chemical structures and biological activities of rhamnolipids produced by Pseudomonas aeruginosa B189 isolated from milk factory waste. The culture produced two biosurfactants, a and b, which showed strong activity and were identified as L-rhamnopyranosyl-L-rhamnopyranosyl-beta-hydroxydecanoyl-beta-hydroxydecanoate or Rha-Rha-C10-C10 and L-rhamnopyranosyl-L-rhamnopyranosyl-beta-hydroxydecanoyl-beta-hydroxydodecanoate or Rha-Rha-C10-C12, respectively. Both compounds exhibited higher surfactant activities tested by the drop collapse test than several artificial surfactants such as SDS and Tween 80. Rhamnolipid a showed significant antiproliferative activity against human breast cancer cell line (MCF-7) at minimum inhibitory concentration (MIC) at 6.25 microg/mL while rhamnolipid b showed MIC against insect cell line C6/36 at 50 microg/mL.     

Chemical structures and biological activities of rhamnolipids produced by Pseudomonas aeruginosa B189 isolated from milk factory waste

The aim of this work was to study chemical structures and biological activities of rhamnolipids produced by Pseudomonas aeruginosa B189 isolated from milk factory waste. The culture produced two biosurfactants, a and b, which showed strong activity and were identified as L-rhamnopyranosyl-L-rhamnopyranosyl-beta-hydroxydecanoyl-beta-hydroxydecanoate or Rha-Rha C10-C10 and L-rhamnopyranosyl-L-rhamnopyranosyl-beta-hydroxydecanoyl-beta-hydroxydodecanoate or Rha-Rha C(10)-C(12), respectively. Both compounds exhibited higher surfactant activities tested by the drop collapse test than several artificial surfactants such as SDS and Tween 80. Rhamnolipid a showed significant antiproliferative activity against human breast cancer cell line (MCF-7) at minimum inhibitory concentration (MIC) at 6.25 microg/mL while rhamnolipid b showed MIC against insect cell line C6/36 at 50 microg/mL.     

Compounds from Kadsura heteroclita and related anti-HIV activity

Phytochemical investigation of the stems of Kadsura heteroclita led to isolation of 16 compounds, including the triterpenoid named longipedlactone J (2), and two dibenzocyclooctadiene type lignans named heteroclitin I and J (3, 4). Compounds 8-10, 14, and 15 were weakly active as anti-HIV agents, whereas compounds 6 and 12 exhibited moderate anti-HIV activity with EC50 values of 1.6 microg/mL, and 1.4 microg/mL, therapeutic index (TI) values of 52.9, and 65.9, respectively. Their structures were established by spectroscopic methods, including application of 2D NMR techniques and CD spectra.     

Synthesis and in vitro anti-hepatitis B virus activities of some ethyl 5-hydroxy-1H-indole-3-carboxylates

A series of ethyl 5-hydroxy-1H-indole-3-carboxylates 6A-10T were synthesized and evaluated for their anti-hepatitis B virus (HBV) activities in 2.2.15 cells. The IC50 and selective index of inhibition on replication of HBV DNA of compounds 10(L) (1.52 microg/ml, 9.38) and 10(P) (2.00 microg/ml, 8.85) were higher than those of the other evaluated compounds including lamivudine (7.02). Compounds 7E and 10J exhibited significant anti-HBV activities, and the IC50 values on replication of HBV DNA of these compounds were 24.90 and 15.41 microg/ml, respectively, which were far more potent than the positive control lamivudine 228.00 microg/ml.     

Larvicidal activities against Aedes aegypti of some Brazilian medicinal plants

Larvicidal activities against Aedes aegypti have been determined in the ethanolic extracts obtained from 51 Brazilian medicinal plants. Eleven of the 84 extracts studied showed significant (LC50 < 100 microg mL(-1)) activities against larvae, with extracts from Annona crassiflora (root bark, LC50 = 0.71 microg mL(-1); root wood, LC50 = 8.94 microg mL(-1)) and Annona glabra (seed, LC50 = 0.06 microg mL(-1)) showing the highest activities. The results obtained should be of value in the search for new natural larvicidal compounds.     

Effects of mycophenolate mofetil on key pattern of coronary restenosis: a cascade of in vitro and ex vivo models

Background

Mycophenolate mofetil (MMF), the prodrug of mycophenolic acid (MPA), is a rationally designed immunosuppressive drug. The current study investigates the effect of MMF on key pattern of restenosis in a cascade of in vitro and ex vivo models.

Methods

Part I of the study investigated in northern blot and cytoflow studies the effect of MMF (50, 100, 150, 200, 250, and 300 μg/mL) on TNF-α induced expression of intercellular adhesion molecule 1 (ICAM-1) in human coronary endothelial cells (HCAEC) and human coronary medial smooth muscle cells (HCMSMC). Part II of the study applied a human coronary 3D model of leukocyte attack, the 3DLA-model. HCAEC and HCMSMC were cultured on both sides of a polycarbonate filters, mimicking the internal elastic membrane. Leukocyte attack (LA) was carried out by adding human monocytes (MC) on the endothelial side. The effect of MMF (50 μg/mL) on adhesion and chemotaxis (0.5, 1, 2, 3, 4, 6, and 24 h after LA) and the effect on proliferation of co-cultured HCMSMC (24 h after LA) was studied. In part III of the study a porcine coronary organ culture model of restenosis (POC-model) was used. After ex vivo ballooning MMF (50 μg/mL) was added to the cultures for a period of 1, 2, 3, 4, 5, 6, and 7 days. The effect on reactive cell proliferation and neointimal thickening was studied at day 7 and day 28 after ballooning.

Results

Expression of ICAM-1 in northern blot and cytoflow studies was neither clearly inhibited nor stimulated after administration of MMF in the clinical relevant concentration of 50 μg/mL. In the 3DLA-model 50 μg/mL of MMF caused a significant antiproliferative effect (p < 0.001) in co-cultured HCMSMC but had no effect on MC-adhesion and MC-chemotaxis. In the ex vivo POC-model neighter reactive cell proliferation at day 7 nor neointimal hyperplasia at day 28 were significantly inhibited by MMF (50 μg/mL).

Conclusion

Thus, the data demonstrate a significant antiproliferative effect of clinical relevant levels of MMF (50 μg/mL) in the 3DLA-model. The antiproliferative effect was a direct antiproliferative effect that was not triggered via reduced expression of ICAM-1 or via an inhibition of MC-adhesion and chemotaxis. Probably due to technical limitations (as e.g. the missing of perfusion) the antiproliferative effect of MMF (50 μg/mL) could not be reproduced in the coronary organ culture model. A cascade of focused in vitro and ex vivo models may help to gather informations on drug effects before large experimental studies are initiated.     

Synthesis and antiviral/antitumor evaluation of 2-amino- and 2-carboxamido-3-arylsulfonylthiophenes and related compounds as a new class of diarylsulfones

Based on general SARs previously described for anti-HIV-1 diarylsulfone derivatives, a series of 2-amino- and 2-carboxamido-3-arylsulfonylthiophenes has been prepared and evaluated as potential antiviral and antitumor agents. In cell culture, some of the 2-aminothiophenes exhibited moderate and selective activity against HIV-1, with 2-amino-3-(2-nitrophenylsulfonyl)thiophene (7e) being most attractive (EC(50)=3.8 microg/mL, CC(50)=>100 microg/mL). In broad-spectrum antiviral assays, the 3-arylsulfonyl-2-(trifluoroacetamido)thiophenes (8c-g) and 2-acetamido-3-arylsulfonyl-5-nitrothiophenes (9f-g) proved considerably active (IC(50)=0.1-10 microg/mL) against human cytomegalovirus (CMV) and/or varicella zoster virus (VZV). Based on the activity of the trifluoroacetamides, ring-modified furan, N-(substituted)pyrrole, phenyl, and 3,4-thiophene analogues were prepared, and these compounds were also active against CMV and/or VZV, with the notable exception of the 3,4-thiophene derivative. In contrast to other amines, the 2-aminopyrrole precursors (13a-d) also exhibited potent activity against CMV. Unfortunately, most of these compounds displayed significant cytotoxicity against human fibroblasts, the cells supporting CMV and VZV replication, and thus selectivity indices were low. The most notable exception to this was the naphthyl-substituted aminopyrrole 13d, which exhibited both potent (IC(50)=0.3 microg/mL) and selective (CC(50)=>50 microg/mL) activity against CMV. Finally, thiophene aryl amides 8i-k displayed moderate in vitro activity against certain leukemia, breast, and colon cancer cell lines.     

Antileishmanial activity, cytotoxicity and QSAR analysis of synthetic dihydrobenzofuran lignans and related benzofurans

A series of synthetic dihydrobenzofuran lignans and related benzofurans were evaluated for their cytotoxicity in a screening panel consisting of various human tumour cell lines, and for their antiprotozoal activity against L. donovani (axenic amastigotes), chloroquine resistant Plasmodium falciparum (strain K1), Trypanosoma brucei rhodesiense and T. cruzi, and for cytotoxicity on L6 cells. No promising cytotoxicities against human tumour cell lines were observed for newly synthesised compounds, but the dimerisation product of some lipophylic esters of caffeic acid, such as compound 2g, showed a high activity against chloroquine-resistant P. falciparum (strain K1) (IC50 0.43 microg/mL) and L. donovani (axenic amastigotes) (IC50 0.12 microg/mL), which was confirmed in an infected macrophage assay (IC50 0.19 microg/mL). QSAR models for the cytotoxic and antileishmanial activity were generated using Quasar receptor surface modelling.