Derek J. McPhee
Editorial: Molecules Best Paper Award 2012
Molecules 2012, 17(2), 1795-1796; doi:10.3390/molecules17021795 - published online 10 February 2012
Show/Hide AbstractAbstract: Molecules start to institute the “Best Paper” award to recognize these outstanding papers in the area of natural products, medicinal chemistry and molecular diversity published in Molecules. We are pleased to announce the first “Molecules Best Paper Award” for 2012. Nominations were selected by the editor-in-chief and selected editorial board members from all the papers published in 2008. [...]

Seung Ha Kim and Monica H. Lamm
Review: Multiscale Modeling for Host-Guest Chemistry of Dendrimers in Solution
Polymers 2012, 4(1), 463-485; doi:10.3390/polym4010463 - published online 10 February 2012
Show/Hide AbstractAbstract: Dendrimers have been widely used as nanostructured carriers for guest species in a variety of applications in medicine, catalysis, and environmental remediation. Theory and simulation methods are an important complement to experimental approaches that are designed to develop a fundamental understanding about how dendrimers interact with guest molecules. This review focuses on computational studies aimed at providing a better understanding of the relevant physicochemical parameters at play in the binding and release mechanisms between polyamidoamine (PAMAM) dendrimers and guest species. We highlight recent contributions that model supramolecular dendrimer-guest complexes over the temporal and spatial scales spanned by simulation methods ranging from all-atom molecular dynamics to statistical field theory. The role of solvent effects on dendrimer-guest interactions and the importance of relating model parameters across multiple scales is discussed.

Abhishek Srivastava , Nehaya Al-Karablieh , Shaunak Khandekar , Arifa Sharmin , Helge Weingart and Matthias S. Ullrich
Article: Genomic Distribution and Divergence of Levansucrase-Coding Genes in Pseudomonas syringae
Genes 2012, 3(1), 115-137; doi:10.3390/genes3010115 - published online 10 February 2012
Show/Hide AbstractAbstract: In the plant pathogenic bacterium, Pseudomonas syringae, the exopolysaccharide levan is synthesized by extracellular levansucrase (Lsc), which is encoded by two conserved 1,296-bp genes termed lscB and lscC in P. syringae strain PG4180. A third gene, lscA, is homologous to the 1,248-bp lsc gene of the bacterium Erwinia amylovora, causing fire blight. However, lscA is not expressed in P. syringae strain PG4180. Herein, PG4180 lscA was shown to be expressed from its native promoter in the Lsc-deficient E. amylovora mutant, Ea7/74-LS6, suggesting that lscA might be closely related to the E. amylovora lsc gene. Nucleotide sequence analysis revealed that lscB and lscC homologs in several P. syringae strains are part of a highly conserved 1.8-kb region containing the ORF, flanked by 450-452-bp and 49-51-bp up- and downstream sequences, respectively. Interestingly, the 450-452-bp upstream sequence, along with the initial 48-bp ORF sequence encoding for the N-terminal 16 amino acid residues of Lsc, were found to be highly similar to the respective sequence of a putatively prophage-borne glycosyl hydrolase-encoding gene in several P. syringae genomes. Minimal promoter regions of lscB and lscC were mapped in PG4180 by deletion analysis and were found to be located in similar positions upstream of lsc genes in three P. syringae genomes. Thus, a putative 498-500-bp promoter element was identified, which possesses the prophage-associated com gene and DNA encoding common N-terminal sequences of all 1,296-bp Lsc and two glycosyl hydrolases. Since the gene product of the non-expressed 1,248-bp lscA is lacking this conserved N-terminal region but is otherwise highly homologous to those of lscB and lscC, it was concluded that lscA might have been the ancestral lsc gene in E. amylovora and P. syringae. Our data indicated that its highly expressed paralogs in P. syringae are probably derived from subsequent recombination events initiated by insertion of the 498-500-bp promoter element, described herein, containing a translational start site.

Wen Jie Li , Xian Long Cheng , Jing Liu , Rui Chao Lin , Gang Li Wang , Shu Shan Du and Zhi Long Liu
Article: Phenolic Compounds and Antioxidant Activities of Liriope muscari
Molecules 2012, 17(2), 1797-1808; doi:10.3390/molecules17021797 - published online 10 February 2012
Show/Hide AbstractAbstract: Five phenolic compounds, namely N-trans-coumaroyltyramine (1), N-trans-feruloyltyramine (2), N-trans-feruloyloctopamine (3), 5,7-dihydroxy-8-methoxyflavone (4) and (3S)3,5,4′-trihydroxy-7-methoxy-6-methylhomoisoflavanone (5), were isolated from the fibrous roots of Liriope muscari (Liliaceae). Compounds 2–5 were isolated for the first time from the Liriope genus. Their in vitro antioxidant activities were assessed by the DPPH and ABTS scavenging methods with microplate assays. The structure-activity relationships of compounds 1–3 are discussed.

Javier V. Gómez , Frode E. Sandnes and Borja Fernández
Article: Sunlight Intensity Based Global Positioning System for Near-Surface Underwater Sensors
Sensors 2012, 12(2), 1930-1949; doi:10.3390/s120201930 - published online 10 February 2012
Show/Hide AbstractAbstract: Water monitoring is important in domains including documenting climate change, weather prediction and fishing. This paper presents a simple and energy efficient localization strategy for near surface buoy based sensors. Sensors can be dropped randomly in the ocean and thus self-calibrate in terms of geographic location such that geo-tagged observations of water quality can be made without the need for costly and energy consuming GPS-hardware. The strategy is based on nodes with an accurate clock and light sensors that can regularly sample the level of light intensity. The measurements are fitted into a celestial model of the earth motion around the sun. By identifying the trajectory of the sun across the skies one can accurately determine sunrise and sunset times, and thus extract the longitude and latitude of the sensor. Unlike previous localization techniques for underwater sensors, the current approach does not rely on stationary or mobile reference points.

Joseph R. Coelho , Jon M. Hastings and Charles W. Holliday
Article: Near-Optimal Foraging in the Pacific Cicada Killer Sphecius convallis Patton (Hymenoptera: Crabronidae)
Insects 2012, 3(1), 133-140; doi:10.3390/insects3010133 - published online 10 February 2012
Show/Hide AbstractAbstract: This study evaluated foraging effectiveness of Pacific cicada killers (Sphecius convallis) by comparing observed prey loads to that predicted by an optimality model. Female S. convallis preyed exclusively on the cicada Tibicen parallelus, resulting in a mean loaded flight muscle ratio (FMR) of 0.187 (N = 46). This value lies just above the marginal level, and only seven wasps (15%) were below 0.179. The low standard error (0.002) suggests that S. convallis is the most ideal flying predator so far examined in this respect. Preying on a single species may have allowed stabilizing selection to adjust the morphology of females to a nearly ideal size. That the loaded FMR is slightly above the marginal level may provide a small safety factor for wasps that do not have optimal thorax temperatures or that have to contend with attempted prey theft. Operational FMR was directly related to wasp body mass. Smaller wasps were overloaded in spite of provisioning with smaller cicadas, while larger wasps were underloaded despite provisioning with larger cicadas. Small wasps may have abandoned larger cicadas because of difficulty with carriage.