First Report on the Synergistic Interaction between Essential Oils against the Pinewood Nematode .

Control of the pinewood nematode (PWN), the causal agent of pine wilt disease, can be achieved through the trunk injection of nematicides; however, many pesticides have been linked to environmental and human health concerns. Essential oils (EOs) are suitable alternatives due to their biodegradability and low toxicity to mammals. These complex mixtures of plant volatiles often display multiple biological activities and synergistic interactions between their compounds.

Evaluation of an Imine-Linked Polymer Organic Framework for Storage and Release of HS and NO.

Hydrogen sulfide (HS) and nitric oxide (NO) are especially known as toxic and polluting gases, yet they are also endogenously produced and play key roles in numerous biological processes. These two opposing aspects of the gases highlight the need for new types of materials to be developed in addition to the most common materials such as activated carbons and zeolites. Herein, a new imine-linked polymer organic framework was obtained using the inexpensive and easy-to-access reagents isophthalaldehyde and 2,4,6-triaminopyrimidine in good yield (64%) through the simple and catalyst-free Schiff-base reaction.

Development of a Library of Thiophene-Based Drug-Like Lego Molecules: Evaluation of Their Anion Binding, Transport Properties, and Cytotoxicity.

The anion-binding and transport properties of an extensive library of thiophene-based molecules are reported. Seventeen bis-urea positional isomers, with different binding conformations and lipophilicities, have been synthesized by appending α- or β-thiophene or α-, β-, or γ-benzo[b]thiophene moieties to an ortho-phenylenediamine central core, yielding six subsets of positional isomers. Through H NMR, X-ray crystallography, molecular modelling, and anion efflux studies, it is demonstrated that the most active transporters adopt a pre-organized binding conformation capable of promoting the recognition of chloride, using urea and C-H binding groups in a cooperative fashion.

Bioactivity of Ruta graveolens and Satureja montana Essential Oils on Solanum tuberosum Hairy Roots and Solanum tuberosum Hairy Roots with Meloidogyne chitwoodi Co-cultures.

As a nematotoxics screening biotechnological system, Solanum tuberosum hairy roots (StHR) and S. tuberosum hairy roots with Meloidogyne chitwoodi co-cultures (StHR/CRKN) were evaluated, with and without the addition of the essential oils (EOs) of Satureja montana and Ruta graveolens. EOs nematotoxic and phytotoxic effects were followed weekly by evaluating nematode population density in the co-cultures as well as growth and volatile profiles of both in vitro cultures types.

Antiparasitic Activity of Diterpenoids Against Trypanosoma cruzi.

Twenty-seven diterpenes, including abietanes, labdanes, abeoabietanes, halimanes, and pimaranes, have been evaluated against epimastigote and intracellular amastigote forms of and also against LC5 and NCTC cell lines. Royleanones (, and ) and a further abietane (), obtained by purification of spp. extracts, were the most active compounds on epimastigotes, showing IC values similar (1.

Larvicidal activity against Aedes aegypti of Foeniculum vulgare essential oils from Portugal and Cape Verde.

Dengue is a potentially fatal mosquito-borne infection with 50 million cases per year and 2.5 billion people vulnerable to the disease. This major public health problem has recurrent epidemics in Latin America and occurred recently in Cape Verde and Madeira Island.

Recognition of bio-relevant dicarboxylate anions by an azacalix[2]arene[2]triazine derivative decorated with urea moieties.

A new dichloroazacalix[2]arene[2]triazine receptor (1) with two chiral urea binding moieties is reported. The binding affinity of this macrocycle was evaluated by (1)H NMR titrations in CDCl3 for the dicarboxylate anions oxalate (ox(2-)), malonate (mal(2-)), succinate (suc(2-)), glutarate (glu(2-)), diglycolate (dg(2-)), fumarate (fum(2-)), maleate (male(2-)), and (R,R)- and (S,S)-tartarate (tart(2-)) enantiomers. Among the first five linear anions, the higher association constants were calculated for the larger anions glu(2-) and dg(2-) and for the smallest anion ox(2-), with Kass values following the sequence dg(2-) > glu(2-) > ox(2-) > suc(2-) > mal(2-).

Essential oil characterization of two Azorean Cryptomeria japonica populations and their biological evaluations.

Essential oils from foliage, bark and heartwood of Cryptomeriajaponica D. Don from Azores Archipelago (Portugal) were analyzed by GC and GC-MS. Two populations, of black and reddish heartwood color, were studied.

Azacalix[2]arene[2]triazine-based receptors bearing carboxymethyl pendant arms on nitrogen bridges: synthesis and evaluation of their coordination ability towards copper(II).

For functional nitrogen-bridged calix(hetero)aromatic platforms to be further used in the design of more sophisticated receptors, the azacalix[2]arene[2]triazine nitrogen bridges were functionalised with methyl bromoacetate. Three new macrocycles with four N-methyl ester pendant arms were straightforwardly prepared in good yields from the undecorated azacalix[2]arene[2]triazine precursors with chlorine, dimethylamine or dihexylamine substituted triazines. These intermediate macrocycles exhibited different reactivity towards the nucleophilic replacement, which was rationalized from the computed electrostatic potential for these molecules.

Evaluation of the structure-activity relationship of rifabutin and analogs: a drug-membrane study.

This work focuses on the influence of rifabutin and two novel analogs, namely, N'-acetyl-rifabutin and N'-butanoyl-rifabutin, on the biophysical properties of lipid membranes. Monolayers and multilamellar vesicles composed of egg L-α-phosphatidylcholine:cholesterol in a molar ratio of 4:1 are chosen to mimic biological membranes. Several accurate biophysical techniques are used to establish a putative relationship between the chemical structure of the antimycobacterial compounds and their activity on the membranes.

Interactions of N'-acetyl-rifabutin and N'-butanoyl-rifabutin with lipid bilayers: a synchrotron X-ray study.

This work focuses on the interaction of N'-acetyl-rifabutin (RFB2) and N'-butanoyl-rifabutin (RFB3) with human and bacterial cell membrane models under physiological conditions. The effect of RFB2 and RFB3 on human cell membrane models was assessed using multilamellar vesicles (MLVs) composed of 1,2-dimyristoyl-rac-glycero-3-phosphocholine (DMPC). In order to mimic the bacterial cell membrane, MLVs of 1,2-dimyristoyl-sn-glycero-3-phospho-rac-(1-glycerol) (DMPG) and a mixture of 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE) and 1,2-dipalmitoyl-sn-glycero-3-phospho-rac-(1-glycerol) (DPPG) (8:2 molar ratio) were chosen.

The influence of rifabutin on human and bacterial membrane models: implications for its mechanism of action.

This work focuses on the interaction of the antibiotic Rifabutin (RFB) with phospholipid membrane models using small- and wide-angle X-ray scattering (SAXS and WAXS) to assess drug-membrane interactions. The effect of different concentrations of RFB on human and bacterial cell membrane models was studied using multilamellar vesicles (MLVs) at the physiological pH (7.4).

Effects of a novel antimycobacterial compound on the biophysical properties of a pulmonary surfactant model membrane.

In this work, the interactions of a novel rifabutin's analogue (N'-acetyl-rifabutin, RFB2) with two-dimensional (Langmuir monolayers) and three-dimensional (large unilamellar and multilamellar vesicles) membrane models of the pulmonary surfactant (PS) were evaluated. The main purpose of this study is to obtain detailed information at the molecular level between the interactions of RFB2 with the phospholipids of the PS, under physiological conditions. Therefore, the effects of RFB2 in the monolayer phase behaviour at the air-water interface and in the lipid bilayer of membrane models composed of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) have been systematically compared.

Drug-membrane interaction studies applied to N'-acetyl-rifabutin.

This work aims the systematic study of the biophysical interactions of a novel antimycobacterial compound (N'-acetyl-rifabutin, RFB2) with membrane models of different lipid composition and surface charge. Membrane mimetic models were used to evaluate the RFB2's membrane partition, its preferential location across the membrane, and the effect of RFB2 on the biophysical properties of the membrane, which ultimately might be related with the antimycobacterial compound bioavailability and the membrane toxicity. According to the aforementioned, liposomes of dimyristoyl-sn-glycero-phosphocholine (DMPC) and 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol (DMPG) were, respectively, used as mimetic models of human and bacterial cell membranes.

Differential interactions of rifabutin with human and bacterial membranes: implication for its therapeutic and toxic effects.

This work focuses on the interaction of rifabutin (RFB), a naphthalenic ansamycin, with membrane models. Since the therapeutic and toxic effects of this class of drugs are strongly influenced by their lipid affinity, we concerned specifically on the ability of this antibiotic to affect the membrane biophysical properties. The extent of the interaction between RFB and membrane phospholipids was quantified by the partition coefficient (K(p)), using membrane model systems that mimic the human (liposomes of 1,2-dimyristoyl-sn-glycero-phosphocholine, DMPC) and the bacterial (liposomes of 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol, DMPG) plasma membranes.

Interplay of mycolic acids, antimycobacterial compounds and pulmonary surfactant membrane: a biophysical approach to disease.

This work focuses on the interaction of mycolic acids (MAs) and two antimycobacterial compounds (Rifabutin and N'-acetyl-Rifabutin) at the pulmonary membrane level to convey a biophysical perspective of their role in disease. For this purpose, accurate biophysical techniques (Langmuir isotherms, Brewster angle microscopy, and polarization-modulation infrared reflection spectroscopy) and lipid model systems were used to mimic biomembranes: MAs mimic bacterial lipids of the Mycobacterium tuberculosis (MTb) membrane, whereas Curosurf® was used as the human pulmonary surfactant (PS) membrane model. The results obtained show that high quantities of MAs are responsible for significant changes on PS biophysical properties.

Molecular interaction of Rifabutin on model lung surfactant monolayers.

Tuberculosis is one of the most relevant problems for global health care. The design of new drugs against tuberculosis is aimed at maximizing impact against the disease, as well as minimizing the toxicological effect on the lung surfactant. In this work, the antituberculosis drug Rifabutin is studied in combination with phospholipid Langmuir monolayers as models of the lung surfactant monolayer.

Pharmacophore insights into rpoB gene mutations in Mycobacterium tuberculosis rifampicin resistant isolates.

This paper reports the susceptibility profile to rifabutin (RFB) 1 and six recently synthesized RFB analogs 3-8, of either rifampicin (RFP) susceptible Mycobacterium tuberculosis and resistant clinical isolates from two sources: Mexico and Brazil. Taking into account that about 95% of M. tuberculosis strains resistant to RFP present mutations in the rpoB gene, with some of these mutations being determinant also to RFB resistance, the RFB analogs were screened for activity against a set of known RFP susceptible and resistant strains.

Antimycobacterial metabolites from Plectranthus: royleanone derivatives against Mycobacterium tuberculosis strains.

The antimycobacterial activities of eight diterpenes, 1-8, isolated previously from Plectranthus and eleven esters, 9-19, of 7alpha-acetoxy-6beta,12-dihydroxyabieta-8,12-diene-11,14-dione (5) were evaluated against the MTB strains H(37)Rv and MDR. Only diterpenoids with a quinone framework revealed anti-MTB activity. Abietane 5 and its 6,12-dibenzoyl, 12-methoxybenzoyl, 12-chlorobenzoyl, and 12-nitrobenzoyl esters, 9, 11, 12, and 13, respectively, showed potent activities against the MDR strain with MIC values between 3.

Influence of soil fertility on dye flavonoids production in weld (Reseda luteola L.) accessions from Portugal.

A HPLC-diode array detector (DAD) methodology was developed to allow the simultaneous identification and quantification of Reseda luteola L. (weld) dye flavonoids, luteolin, apigenin, luteolin 7-O-glucoside, apigenin 7-O-glucoside, luteolin 3',7-O-diglucoside and luteolin 4'-O-glucoside. The method was validated with excellent results in linearity, sensibility, accuracy and precision.

Synthesis and evaluation of rifabutin analogs against Mycobacterium avium and H(37)Rv, MDR and NRP Mycobacterium tuberculosis.

Clinical utility of rifabutin 1 (RBT), a potent antibiotic used in multidrug regimens for tuberculosis (TB) as well as for infections caused by Mycobacterium avium complex (MAC), has been hampered due to dose-limiting toxicity. RBT analogs 2-11 were synthesized and evaluated against M. avium 1581 and Mycobacterium tuberculosis susceptible and resistant strains in vitro.

HPLC quantification of dye flavonoids in Reseda luteola L. from Portugal.

A HPLC method was developed for the simultaneous identification of Reseda luteola L. (weld) flavonoids and quantification of the main compounds responsible for the yellow color. This method was applied to a large number of wild Portuguese weld to evaluate its potential application as dyestuff for textile factories, as a substitute for the synthetic dyes currently used.

Biovalorization of friedelane triterpenes derived from cork processing industry byproducts.

Here, we describe the synthesis, bioactivity screening, and structure-activity relationships of various synthetic triterpenoids prepared from the cork processing byproducts friedelin (1) and 3-hydroxyfriedel-3-en-2-one (2) via oxidative procedures. The synthesis of compounds 2alpha-trimethylsiloxyfriedelan-3-one (17), friedelin-2,3-lactone (18), friedelin-3-oxime (19), and friedelin-3,4-lactam (20) is also described. We have studied the insecticidal and phytotoxic potential of these compounds, their selective cytotoxic effects on insect and mammalian cells, and their antiparasitic effects.

Hemisynthetic secofriedelane triterpenes with inhibitory activity against the growth of human tumor cell lines in vitro.

Seco acids 7 and 9 and hydroxylated analogues 5 and 6 derived from friedelane triterpenes were synthesized stereoselectively in high yields. Compounds 5-9 were evaluated for their ability to inhibit in vitro the growth of three human tumor cell lines, MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer), and SF-268 (CNS cancer). Only compounds 7 and 9 were found to possess significant growth inhibitory effects, exhibiting GI(50) values that range from 24.