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The promethea moth Callosamia promethea is one of three species of silkmoths from the genus Callosamia that occur in North America. Cross attraction of males to heterospecific calling females has been observed in the field, and hybrid progeny have been produced by pairing heterospecifics in captivity. These observations suggest that all three species share or have considerable overlap in the sex attractant pheromones produced by females, so that other prezygotic isolating mechanisms, such as diel differences in reproductive activity, limit hybridization in the field. Coupled gas chromatography-electroantennogram detection and gas chromatography- mass-spectrometry analyses of extracts of volatiles collected from female promethea moths supported the identification of (4 E ,6 E ,11 Z ,13 Z )-hexadeca-4,6,11,13-tetraenal [(4 E ,6 E ,11 Z ,13 Z )-16:Ald] as the compound in extracts that elicited the largest responses from antennae of males. The identification was confirmed by non-selective synthesis of several isomers as analytical standards, and stereoselective synthesis of (4 E ,6 E ,11 Z ,13 Z )-16:Ald for testing in field trials. Male moths were strongly attracted to synthetic (4 E ,6 E ,11 Z ,13 Z )-16:Ald, suggesting that this compound is the major and possibly the only component of the sex pheromone of these large saturniid moths. Based on the cross-attraction of heterospecifics, it is likely that this is also a major pheromone component of the other two North American Callosamia species as well.

The increase in multi-drug resistant pathogenic bacteria is making our current arsenal of clinically used antibiotics obsolete, highlighting the urgent need for new lead compounds with distinct target binding sites to avoid cross-resistance. Here we report that the aromatic polyketide antibiotic tetracenomycin (TcmX) is a potent inhibitor of protein synthesis, and does not induce DNA damage as previously thought. Despite the structural similarity to the well-known translation inhibitor tetracycline, we show that TcmX does not interact with the small ribosomal subunit, but rather binds to the large subunit, within the polypeptide exit tunnel. This previously unappreciated binding site is located adjacent to the macrolide-binding site, where TcmX stacks on the noncanonical basepair formed by U1782 and U2586 of the 23S ribosomal RNA. Although the binding site is distinct from the macrolide antibiotics, our results indicate that like macrolides, TcmX allows translation of short oligopeptides before further translation is blocked. Structural and biochemical analysis reveal that tetracenomycin X acts as an inhibitor of protein synthesis by binding within the exit tunnel in a large ribosomal unit to prevent the prolongation of the nascent polypeptide chain.

The basis for a quantum-mechanical description of matter is electron wave functions. For atoms and molecules, their spatial distributions and phases are known as orbitals. Although orbitals are very powerful concepts, experimentally only the electron densities and -energy levels are directly observable. Regardless whether orbitals are observed in real space with scanning probe experiments, or in reciprocal space by photoemission, the phase information of the orbital is lost. Here, we show that the experimental momentum maps of angle-resolved photoemission from molecular orbitals can be transformed to real-space orbitals via an iterative procedure which also retrieves the lost phase information. This is demonstrated with images obtained of a number of orbitals of the molecules pentacene (C22H14) and perylene-3,4,9,10-tetracarboxylic dianhydride (C24H8O6), adsorbed on silver, which are in excellent agreement with ab initio calculations. The procedure requires no a priori knowledge of the orbitals and is shown to be simple and robust.

An actinobacterial strain A23T, isolated from adult ant Camponotus vagus collected in Ryazan region (Russia) and established as tetracenomycin X producer, was subjected to a polyphasic taxonomic study. Morphological characteristics of this strain included well-branched substrate mycelium and aerial hyphae fragmented into rod-shaped elements. Phylogenetic analyses based on 16S rRNA gene and genome sequences showed that strain A23T was most closely related to Amycolatopsis pretoriensis DSM 44654T. Average nucleotide identity and digital DNA–DNA hybridization values between the genome sequences of isolate A23T and its closest relative, Amycolatopsis pretoriensis DSM 44654T, were 39.5% and 88.6%, which were below the 70% and 95–96% cut-off point recommended for bacterial species demarcation, respectively. The genome size of the isolate A23T was 10,560,374 bp with a DNA G + C content of 71.2%. The whole-cell hydrolysate contained meso-diaminopimelic acid and arabinose and galactose as main diagnostic sugars as well as ribose and rhamnose. It contained MK-9(H4) as the predominant menaquinone and iso-C16:0, iso-C15:0, anteiso-C17:0 and C16:0 as the major cellular fatty acids. Diphosphatidylglycerol and phosphatidylethanolamine prevailed among phospholipids. Mycolic acids were not detected. Based on the phenotypic, genomic and phylogenetic data, isolate A23T represents a novel species of the genus Amycolatopsis, for which the name Amycolatopsis camponoti sp. nov. is proposed, and the type strain is A23T (= DSM 111725T = VKM 2882T).

The synthesis of multiply substituted acenes is still a relevant research problem, considering their applications and future potential. Here we present an elegant synthetic protocol to afford tetra-peri-substituted naphthalene and tetracene from their tetrahalo derivatives by a Pd(0)-catalyzed C-C cross-coupling method in a single step. The newly synthesized tetracenes were characterized by NMR, HRMS, UV-vis spectrophotometry, and single-crystal X-ray diffraction (SCXRD). In addition, the first systematic computational study of the effect of chalcogenophenyl substitutions on the chiroptical properties of twistacenes was reported here. The gas phase computational studies using density functional theory (DFT) on a series of chalcogenophene-substituted tetracenes revealed that their chiroptical activity could be systematically increased via the atomistic tuning of peripheral substituents.

Doxorubicin (DOX) is one of the most effective cytotoxic agents against malignant diseases. However, the clinical application of DOX is limited, due to dose-related toxicity. The development of DOX nanoformulations that significantly reduce its toxicity and affect the metabolic pathway of the drug requires improved methods for the quantitative determination of DOX metabolites with high specificity and sensitivity. This study aimed to develop a high-throughput method based on high-performance liquid chromatography with fluorescence detection (HPLC-FD) for the quantification of DOX and its metabolites in the urine of laboratory animals after treatment with different DOX nanoformulations. The developed method was validated by examining its specificity and selectivity, linearity, accuracy, precision, limit of detection, and limit of quantification. The DOX and its metabolites, doxorubicinol (DOXol) and doxorubicinone (DOXon), were successfully separated and quantified using idarubicin (IDA) as an internal standard (IS). The linearity was obtained over a concentration range of 0.05–1.6 μg/mL. The lowest limit of detection and limit of quantitation were obtained for DOXon at 5.0 ng/mL and 15.0 ng/mL, respectively. For each level of quality control (QC) samples, the inter- and intra-assay precision was less than 5%. The accuracy was in the range of 95.08–104.69%, indicating acceptable accuracy and precision of the developed method. The method was applied to the quantitative determination of DOX and its metabolites in the urine of rats treated by novel nanoformulated poly(lactic-co-glycolic acid) (DOX-PLGA), and compared with a commercially available DOX solution for injection (DOX-IN) and liposomal-DOX (DOX-MY).

We have developed a simple, scalable, transfer-free, ecologically sustainable, value-added method to convert inexpensive coal tar pitch to patterned graphene films directly on device substrates. The method, which does not require an additional transfer process, enables direct growth of graphene films on device substrates in large area. To demonstrate the practical applications of the graphene films, we used the patterned graphene grown on a dielectric substrate directly as electrodes of bottom-contact pentacene field-effect transistors (max. field effect mobility ~0.36 cm 2 ·V −1 ·s −1 ), without using any physical transfer process. This use of a chemical waste product as a solid carbon source instead of commonly used explosive hydrocarbon gas sources for graphene synthesis has the dual benefits of converting the waste to a valuable product and reducing pollution.

A conformational search of 5,12-dihydro-5,12-ethanonaphthacene-13-carbaldehyde predicted the presence of twelve conformations. The geometry of the twelve conformations established at the B3LYP/6-31G* level showed only six unique ones. Vibrational frequencies were calculated at the B3LYP/6-31G* level. The calculated vibrational frequencies enabled us to interpret the appearance of two bands corresponding to the C=O stretching mode of 5,12-dihydro-5,12-ethanonaphthacene-13-carbaldehyde. The first band corresponded to the 5,12-dihydro-5,12-ethanonaphthacene-13-carbaldehyde structure where the aldehyde group O atom was above the benzene or naphthalene ring. The other band was due to the O atom of the aldehyde group pointing out of the benzene or naphthalene ring.

With the goal of mimicking the mechanisms of the biological effects of low energy laser irradiation, we have shown that infrared low intensity laser radiation causes oxygenation of the chemical traps of singlet oxygen dissolved in organic media and water saturated by air at normal atmospheric pressure. The photooxygenation rate was directly proportional to the oxygen concentration and strongly inhibited by the singlet oxygen quenchers. The maximum of the photooxygenation action spectrum coincided with the maximum of the oxygen absorption band at 1270 nm. The data provide unambiguous evidence that photooxygenation is determined by the reactive singlet (1)Delta(g )state formed as a result of direct laser excitation of molecular oxygen. Hence, activation of oxygen caused by its direct photoexcitation may occur in natural systems.

Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants. Some compounds belonging to this group are considered carcinogenic to people. In order to yield carcinogenic properties, these compounds must be metabolically transformed by enzymes of cytochrome P450 family to oxy-derivatives. In this study, the ability of the following six PAHs: anthracene (Ant), benz(a)anthracene (BA), naphthacene (Nap), benzo(a)pyrene (BaP), dibenz(a,c)anthracene (DB(a,c)A) and dibenz(a,h)anthracene (DB(a,h)A) to induce enzymes of cytochrome P450 (CYP450), in particular CYP1A1 and CYP1A2 in Mcf7 and HepG2 cells was studied. The induction of CYP1A enzymes was assessed at the level of enzymatic protein and enzymatic activity. The change in CYP1A1 and CYP1A2 protein level was assessed by means of confocal microscopy. The ethoxyresorufin-O-deethylase (EROD) and methoxyresorufin-O-deethylase (MROD) assays were applied to determine the CYP1A1 and CYP1A2 activity. The Induction Equivalency Factors (IEFs) were also determined. According to EROD and MROD assay and calculated IEFs the following order of the inducing potency was determined in HepG2 cells: DB(a,h)A > BaP > DB(a,c)A approximately BA > Nap > Ant, and in Mcf7 cells: DB(a,h)A > DB(a,c)A > BaP > Nap > BA > Ant. The assessment of the protein levels revealed that DB(a,h)A was also the strongest inducer of protein level, however the correlation between enzymatic activity and protein level induction by other PAHs was not always evident. The EROD and MROD activities were higher in Mcf7 than in HepG2 cells, however the CYP1A2 protein level was shown to be higher in HepG2 cells. The results obtained indicate possible catalytic enzymatic activity alterations induced by PAHs.