Climate, host and geography shape insect and fungal communities of trees.

Non-native pests, climate change, and their interactions are likely to alter relationships between trees and tree-associated organisms with consequences for forest health. To understand and predict such changes, factors structuring tree-associated communities need to be determined. Here, we analysed the data consisting of records of insects and fungi collected from dormant twigs from 155 tree species at 51 botanical gardens or arboreta in 32 countries. Generalized dissimilarity models revealed similar relative importance of studied climatic, host-related and geographic factors on differences in tree-associated communities. Mean annual temperature, phylogenetic distance between hosts and geographic distance between locations were the major drivers of dissimilarities. The increasing importance of high temperatures on differences in studied communities indicate that climate change could affect tree-associated organisms directly and indirectly through host range shifts. Insect and fungal communities were more similar between closely related vs. distant hosts suggesting that host range shifts may facilitate the emergence of new pests. Moreover, dissimilarities among tree-associated communities increased with geographic distance indicating that human-mediated transport may serve as a pathway of the introductions of new pests. The results of this study highlight the need to limit the establishment of tree pests and increase the resilience of forest ecosystems to changes in climate.

Carvacrol Derivatives as Antifungal Agents: Synthesis, Antimicrobial Activity and in Silico Studies on Carvacryl Esters.

Chemical modifications of natural monoterpenoids to various derivatives have been reported to result in enhancement of biological activities when compared to parent compounds. In this context a well-known biocide and food additive, carvacrol, served as a basic scaffold onto which a phenolic functionality transformation by introducing acyl groups was performed. By using this simple methodology, we obtained a small series of 25 esters. For each of the obtained compounds we have performed structural characterization, in vitro antimicrobial testing and in silico calculation of physico-chemical, pharmacokinetic and toxicological properties. Despite numerous data on the synthesis and bioactivity of carvacryl ester lower homologues, there are scarce data on esters with acid components higher than C9, so that among 25 compounds, 10 were reported for the first time (spectral characterization for 12 are herein the first reported). Our research is also the first comprehensive study of carvacryl esters antifungal and of medium/long chain fatty acid esters antibacterial activities. Interesting result is that all the synthesized esters, regardless the nature of the R residue, have shown activity on fungal strain Aspergilus niger and on yeast Candida albicans comparable to carvacrol. Besides presented experimental data, implementation of in silico calculation of physico-chemical, pharmacokinetic and toxicological properties on the prepared compounds, may be valuable information in further research.

Worldwide diversity of endophytic fungi and insects associated with dormant tree twigs.

International trade in plants and climate change are two of the main factors causing damaging tree pests (i.e. fungi and insects) to spread into new areas. To mitigate these risks, a large-scale assessment of tree-associated fungi and insects is needed. We present records of endophytic fungi and insects in twigs of 17 angiosperm and gymnosperm genera, from 51 locations in 32 countries worldwide. Endophytic fungi were characterized by high-throughput sequencing of 352 samples from 145 tree species in 28 countries. Insects were reared from 227 samples of 109 tree species in 18 countries and sorted into taxonomic orders and feeding guilds. Herbivorous insects were grouped into morphospecies and were identified using molecular and morphological approaches. This dataset reveals the diversity of tree-associated taxa, as it contains 12,721 fungal Amplicon Sequence Variants and 208 herbivorous insect morphospecies, sampled across broad geographic and climatic gradients and for many tree species. This dataset will facilitate applied and fundamental studies on the distribution of fungal endophytes and insects in trees.

Evaluation of the radical scavenging activity of some representative isoprenoid and aromatic cytokinin ribosides (N6-substituted adenosines) by in vitro chemical assays.

Cytokinins are naturally occurring adenine derivatives whose physiological role is that of growth regulators in plants and that show also many other activities either in plants and in mammalian cells. In plants, they can be found mainly as free bases ((N6-substituted adenines, CKs), but also as the corresponding N9- ribosides (N6-substituted adenosines, CKRs). In mammalian cells, CKRs are, in general, more active than CKs. In order to evaluate the intrinsic in vitro antioxidant capacity of some significant CKRs, their scavenging activity against synthetic radicals that are at the basis of well-established antioxidant assays (ORAC, TEAC, DPPH) has been evaluated. The results of the in vitro scavenging activity of biologically relevant radicals such as hydroxyl (HO•), superoxide (O2.-) and lipid peroxides (R-OO.) are reported and discussed.

Lipid peroxidation inhibition study: A promising case of 1,3-di([1,1'-biphenyl]-3-yl)urea.

In the present study eighteen inhibitors of the hydrolytic enzymes of the endocannabinoid system were investigated for antioxidant activity using lipid peroxidation (LP) method. Among the assayed compounds ten belong to carbamates with phenyl [1,1'-biphenyl]-3-ylcarbamate (6), reported for the first time, and eight are retro-amide derivatives of palmitamine. Interestingly, results indicated that most of the tested compounds have good antioxidant properties. In particular, 1,3-di([1,1'-biphenyl]-3-yl)urea (3) shows IC50 = 26 ± 6 µM comparable to ones obtained for standard antioxidants trolox and quercetin (IC50 = 22 ± 6 µM and 23 ± 6 µM, respectively). Compound 3 was investigated further by means of DFT calculations, to clarify a possible mechanism of the antioxidant action. In order to estimate the capability of 3 to act as radical scavenger the structure was optimized at B3LYP/6-311++G** level and the respective bond dissociation enthalpies were calculated. The calculations in non-polar medium predicted as favorable mechanism a donation of a hydrogen atom to the free radical and formation of N-centered radical, while in polar solvents the mechanism of free radical scavenging by SPLET dominates over HAT H-abstraction. The possible radical scavenging mechanisms of another compound with potent antioxidant properties (IC50 = 53 ± 12 µM), the retro-amide derivative of palmitamine (compound 18), was estimated computationally based on the reaction enthalpies of a model compound (structural analogue to 18). The computations indicated that the most favorable mechanisms are hydrogen atom transfer from the hydroxyl group in meta-position of the benzamide fragment in nonpolar medium, and proton transfer from the hydroxyl group in ortho-position of the benzamide fragment in polar medium.

Rutin as Deoxyribonuclease I Inhibitor.

DNase I inhibitory potential of water extract of nine Hypericum species (H. umbellatum, H. barbatum, H. rumeliacum, H. rochelii, H. perforatum, H. tetrapterum, H. olympicum, H. hirsutum, H. linarioides) and the most important Hypericum secondary metabolites (hypericin, hyperforin, quercetin, and rutin) was investigated. All examined Hypericum extracts inhibited DNase I with IC50 below 800 µg/ml, whereby H. perforatum was the most potent (IC50 =391.26±68.40 µg/ml). Among the investigated Hypericum secondary metabolites, rutin inhibited bovine pancreatic DNase I in a non-competitive manner with IC50 value of 108.90±9.73 µm. DNase I inhibitory ability of rutin was further confirmed on DNase I in rat liver homogenate (IC50 =137.17±16.65 µm). Due to the involvement of DNase I in apoptotic processes the results of this study indicate the importance of frequent rutin and H. perforatum consumption in daily human nutrition. Rutin is a dietary component that can contribute to male infertility prevention by showing dual mechanism of sperm DNA protection, DNase I inhibition and antioxidant activity.

An Overview, Advantages and Therapeutic Potential of Nonpeptide Positive Allosteric Modulators of Glucagon-Like Peptide-1 Receptor.

Due to uncomfortable injection regimens of peptidic agonists of glucagon-like peptide-1 receptor (GLP-1R), orally available nonpeptide positive allosteric modulators (PAMs) of GLP-1Rs are foreseen as the possible future mainstream therapy for type 2 diabetes. Herein, current GLP-1R PAMs are reviewed. Based on the effectiveness and in silico predicted physicochemical properties, pharmacokinetics, and toxicity, possible candidates for further development as oral drugs were selected. The suggestion is that GLP-1R PAMs might be used orally alone or in combination with dipeptidyl peptidase-4 (DPP-4) inhibitors, which could offer an optimal treatment option next to metformin monotherapy in type 2 diabetes mellitus, or in a wider spectrum of indications. Quercetin acts as a GLP-1R PAM and DPP-4 inhibitor, and therefore, might be considered as a pioneering agent with a dual mechanism of action, in terms of GLP-1R positive allosteric modulation and DPP-4 inhibition for potentiating GLP-1 dependent effects.

Mechanisms and pathways of anti-inflammatory activity of DPP-4 inhibitors in cardiovascular and renal protection.

Dipeptidyl peptidase-4 (DPP-4) cleaves N-terminal dipeptides, with Pro, Ala or Ser at the penultimate position, and, in that way, modulates biological activity of certain polypeptides. Due to its ubiquitous distribution, many pathological processes are associated with altered DPP-4 expression and activity. Besides the regulation of glucose metabolism, DPP-4 also exhibits many other systemic effects, and the inhibition of its activity might lead to cardiovascular and renal protection. Mechanisms underlying these protective effects of DPP-4 inhibition are ascribed to elevated bioavailability of its substrates, to impacts on mediators and signaling pathways that ameliorate cardiovascular and renal function through the suppression of oxidative stress, inflammation, fibrosis and apoptosis, improved endothelial function and tissue reparation. Inflammation contributes to and promotes progression of cardiovascular and renal disorders. Herein, we discuss cellular and molecular mechanisms mediating the anti-inflammatory activity of clinically used DPP-4 inhibitors in cardiovascular and renal protection.

Synthesis, Antimicrobial Activity and in silico Studies on Eugenol Eters.

The results presented herein represent our continued study based on the modification of phenolic functionality in molecules originated from natural sources by acylation. A small focused library of nineteen eugenyl esters, with four of which are new compounds, is reported. All compounds were subjected to in vitro antimicrobial testing. In silico studies were carried out calculating physico-chemical, pharmacokinetic and toxicological properties, providing more data as additional guidance for further research.

Synthesis, Antimicrobial Activity and in silico Studies on Thymol Esters.

Derivatisation of parent structure in terpenoids often results in enhancement of biological activity of newly obtained compounds. Thymol, a naturally occurring phenol biosynthesized through the terpene pathway, is a well known biocide with strong antimicrobial attributes and diverse therapeutic activities. We have aimed our study on a single modification of phenolic functionality in thymol in order to obtain a small focused library of twenty thymyl esters, ten of which were new compounds. All compounds were involved in in vitro antimicrobial testing. Another important aspect of current study was implementation of in silico calculation of physico-chemical, pharmacokinetic and toxicological properties, which could be helpful by giving an additional guidance in further research.

Determination of the serine palmitoyl transferase inhibitor myriocin by electrospray and Q-trap mass spectrometry.

Myriocin is a potent inhibitor of serine-palmitoyl-transferase, the first and rate-determining enzyme in the sphingolipids biosynthetic pathway. This study developed, validated and applied a LC-MS/MS method to measure myriocin in minute specimens of animal tissue. The chemical analog 14-OH-myriocin was used as the internal standard. The two molecules were extracted from the tissue homogenate by solid-phase extraction, separated by gradient reversed-phase liquid chromatography and measured by negative ion electrospray mass spectrometry in the triple quadrupole. Detection was accomplished by multiple reaction monitoring, employing the most representative transitions, 400@104 and 402@104 for myriocin and 14-OH-myriocin, respectively. The typical limit of detection and lower limit of quantitation of the optimized method were 0.9 pmol/mL (~0.016 pmol injected) and 2.3 pmol/mL, respectively, and the method was linear up to 250 pmol/mL range (r2 = 0.9996). The intra- and between-day repeatability afforded a coefficient of variation ≤7.0%. Applications included quantification of myriocin in mouse lungs after 24 h from administration of ~4 nmol by intra-tracheal delivery. Measured levels ranged from 4.11 (median; 2.3-7.4 IQR, n = 4) to 11.7 (median; 7.6-22.7 interquartile range (IQR), n = 6) pmol/lung depending on the different formulations used. Myriocin was also measured in retinas of mice treated by intravitreal injection and ranged from 0.045 (less than the limit of detection) to 0.35 pmol/retina.

An overview of recent dipeptidyl peptidase-IV inhibitors: linking their structure and physico-chemical properties with sar, pharmacokinetics and toxicity.

Dipeptidyl peptidase-IV (DPP-IV) (EC 3.4.14.5) is а member of the broad class of hydrolytic enzymes which is responsible for degradation of the incretin peptide hormones regulating blood glucose levels. In this article we review the literature on natural and synthetic DPP-IV inhibitors, focusing their chemical structure and mechanism of action. Further, physico-chemical, pharmacokinetic and toxicological properties of DPP-IV inhibitors are calculated and compared. On the basis of literature data we selected the DPP-IV inhibitors with IC50 values below 1 nM and discussed their possible application in therapy of type 2 diabetes mellitus.

Chemical and biological evaluation of Hypericum maculatum Crantz essential oil.

The chemical composition and the antimicrobial activity of the essential oil isolated from the aerial parts of Hypericum maculatum Crantz were determined. In total, 109 compounds were identified, with germacrene D (21.5%), nonane (6.5%), (E)-ß-farnesene (5.3%), δ-cadinene (4.5%), and ledol (4.4%) as the main constituents. The chemical compositions of this oil and of four previously studied H. maculatum oils were compared using multivariate statistical analyses, viz., agglomerative hierarchical cluster and principal component analyses. Based on the results, the interrelationship among the hitherto studied H. maculatum oil samples, including the oil characterized here, was discussed. The study of the antimicrobial potential of the oil against five bacterial and two fungal strains showed that the oil had mainly moderate antimicrobial effects.

Antimicrobial activity and cytotoxicity of some 2-amino-5-alkylidene-thiazol-4-ones.

We report a small, focused library of 30 diverse 2-amino-5-alkylidene-thiazol-4-ones that was assayed in a whole-cell antibacterial screen against a panel of several bacterial strains and a yeast. Most of the compounds exhibited modest to significant antibacterial activity against Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus, and no activity against Salmonella typhimurium and Escherichia coli. The antibacterial activity depends markedly upon substituents on the thiazol-4-one core, and the most potent compound assayed ([Formula: see text]-4-((2-(4-methylpiperidin-1-yl)-4-oxothiazol-5(4H)-ylidene)methyl)benzonitrile) reached a minimal inhibitory concentration (MIC) value of [Formula: see text] on P. aeruginosa strain. An important feature of the tested compounds is their low influence on cell viability, as determined in a HEK-293 metabolic activity assay. In light of the encouraging in vitro antimicrobial assay results against several bacterial strains, we have generated a pharmacophore model using the Discovery studio 3.0 package (Accelrys Inc., San Diego, USA), which exposed the spatial arrangement of key molecular properties responsible for our observed MIC results. Considering the absence of a defined target and the limitation of the described approach to pool different scaffolds, the calculated pharmacophore model could be used for library enrichment to identify compounds with a thiazolidinone scaffold with improved antimicrobial potency and physico-chemical properties.

Chemical composition and antimicrobial activity of the essential oil of Stachys officinalis (L.) Trevis. (Lamiaceae).

Characterization by GC-FID and GC/MS analyses of the Stachys officinalis (L.) Trevis. essential oil obtained by hydrodistillation of the aerial parts allowed the identification of 190 components that represented 97.9% of the total oil content. The main constituents identified were germacrene D (19.9%), ß-caryophyllene (14.1%), and α-humulene (7.5%). Terpenoids were by far predominant (89.4%), with sesquiterpene hydrocarbons (69.1%) and oxygenated sesquiterpenes (14.8%) being the most abundant compounds detected in the oil. Based on the present and previously published results, multivariate statistical comparison of the chemical composition of the essential oils was performed within the species. Principal component analysis (PCA) and agglomerative hierarchical clustering (AHC) of the data on the volatile profiles of S. officinalis taxa revealed no pronounced differences among the samples originated from the Balkan Peninsula. Additionally, the oil was screened for in vitro antibacterial and antifungal activity using the broth microdilution assay. The oil's best antimicrobial activities were obtained against the mold Aspergillus niger (minimal inhibitory (MIC) and minimal fungicidal (MFC) concentrations of 2.5 and 5.0 mg/ml, resp.) and the yeast Candida albicans (MIC and MFC of 5.0 mg/ml).

The case of Hypericum rochelii Griseb. & Schenk and Hypericum umbellatum A. Kern. essential oils: chemical composition and antimicrobial activity.

The chemical composition and antimicrobial activity studies on the essential oils of Hypericum rochelii Griseb. & Schenk and Hypericum umbellatum A. Kern. have been carried out for the first time. Seventy-nine compounds were identified in the essential oil of H. rochelii with n-nonane (24.7%), ß-pinene (22.4%), germacrene D (7.5%), n-undecane (6.8%) and α-pinene (5.8%) as main constituents. One hundred and twenty-six compounds were identified in H. umbellatum essential oil with germacrene D (6.1%), (E)-nerolidol (4.4%), n-nonane (4.0%), (E)-caryophyllene (3.0%) and caryophyllene oxide (3.0%) as the most abundant components. Both oils were characterized by the presence of many components which could have numerous applications in food, pharmaceutical and perfume industries. Taxa studied herein belong to the section Drosocarpium Spach, and their intrasectional placement based on the essential oil profiles was discussed. The oils were tested in a broth microdilution assay against five bacterial and two fungal strains and found to have mainly moderate antimicrobial effects.

Chemical composition and antioxidant and antimicrobial activities of essential oil of Allium sphaerocephalon L. subsp. sphaerocephalon (Liliaceae) inflorescences.

BACKGROUND: Allium sphaerocephalon is a wild-growing plant commonly used as an onion substitute. In this study the essential oil obtained from A. sphaerocephalon subsp. sphaerocephalon inflorescences was analysed by gas chromatography and gas chromatography/mass spectrometry and also evaluated for in vitro antioxidant and antimicrobial activities. The obtained results are reported for the first time and discussed with respect to the sulfur compounds detected in the essential oil. RESULTS: Ninty-one compounds were identified, representing 91.6% (w/w) of the total oil. Major constituents of the analysed sample were shyobunol (15.3%), ß-caryophyllene (8.1%), α-cadinol (7.8%), 3,5-diethyl-1,2,4-trithiolane (isomer II, 5.9%) and δ-cadinene (5.2%). The diluted oil had an antioxidant capacity of 160 000 ± 111 micromol α-tocopherol acetate equivalents g(-1). Its antimicrobial activity was evaluated against five bacterial and two fungal strains using the broth microdilution assay. Among the micro-organisms tested, the most susceptible strains were Pseudomonas aeruginosa (minimal inhibitory/bactericidal concentration = 0.08/2.5 mg mL(-1)) and Aspergillus niger (minimal inhibitory/fungicidal concentration = 0.31/0.63 mg mL(-1)). CONCLUSION: The results showed that the examined species had strong antioxidant and antimicrobial properties and are in accordance with the popular use of plants belonging to the genus Allium in traditional medicine, emphasising the necessity of further detailed study of the active principles in Allium species.

Hyaluronan binding assay (HBA) vs. sperm penetration assay (SPA): Can HBA replace the SPA test in male partner screening before in vitro fertilization?

OBJECTIVE: To determine if a less expensive, easier, and faster to perform HBA test is clinically equal to the more complicated, technically challenging and expensive SPA test as a reliable indicator of sperm fertilizing capacity. DESIGN: Prospective study. SETTING: Andrology laboratory within In Vitro Fertilization Program. PATIENT(S): Semen samples from 26 infertility couples were analyzed. Both, normal and male factor patients were included. INTERVENTION(S): Male partner screening with the HBA and the SPA tests. MAIN OUTCOME MEASURE(S): Relationship between HBA and SPA test results. RESULT(S): The data obtained in this study showed no statistically significant relationship between the HBA and SPA results. The mean HBA scores 76.3%, 61.3% and 76.8% were statistically not significantly different as compared to patients with negative (<5), grey zone (5-8) and for positive (>8) sperm capacitation index values. CONCLUSION(S): The HBA is not predictive of the results of the SPA. Therefore, HBA test does not reduce the need for and cannot replace the SPA test in male partner screening prior to infertility treatment.

Composition of Achillea distans Willd. subsp. distans root essential oil.

Gas chromatography and gas chromatography/mass specteometry analyses of root volatiles of Achillea distans Willd. subsp. distans, collected from wild populations in Serbia, enabled the identification of 185 constituents, accounting for 93.6% of the total oil. Main constituents of the oil were tau-cadinol (17.6%), alismol (14.1%), alpha-cadinol (9.1%) and caryophyllene oxide (5.0%). The root oil was additionally characterised by the presence of five different amides containing the olefinic C(10) acid moieties. This is the first report on A. distans subsp. distans root volatiles and on the occurrence of piperidides and piperideides as essential oil constituents.