Mesoionic pyrido[1,2-a]pyrimidinones: Discovery of dicloromezotiaz as a lepidoptera insecticide acting on nicotinic acetylcholine receptors1,2

A novel class of mesoionic pyrido[1,2-a]pyrimidinones has been discovered with exceptional insecticidal activity controlling a number of insect species. In this communication, we report the part of the optimization program that led to the identification of dicloromezotiaz as a potent insecticide to control a broad range of lepidoptera. Our efforts in discovery, synthesis, structure-activity relationship elucidation, and biological activity evaluation are also presented.     

Discovery,synthesis, and evaluation of N-substituted amino-2(5H)-oxazolones as novel insecticides activating nicotinic acetylcholine receptors

N-Substituted amino-2(5H)-oxazolones A are a novel class of insecticides acting as nicotinic acetylcholine receptor (nAChR) agonists and show potent activity against hemipteran insect species. Here we report the discovery and preparation of this class of chemistry. Our efforts in SAR elucidation, biological activity evaluation, as well as mode-of-action studies are also presented.     

Tomophagus cattienensis sp. nov., a new Ganodermataceae species from Vietnam: Evidence from morphology and ITS DNA barcodes

The polypore genus Tomophagus was created to segregate one peculiar species, Ganoderma colossum, from the genus Ganoderma. Recent molecular studies have established the validity of this monotypic genus. Here we report the discovery of a second species of Tomophagus, T. cattienensis sp. nov., from Cat Tien National Park in southern Vietnam, a lowland forest that has been designated as a Biosphere Reserve by the United Nations Educational, Scientific and Cultural Organization (UNESCO). Recognition of this new species is based on combined evidence from morphology, cultural characteristics, and ITS rDNA barcodes. The discovery of this new species may have implications for the discovery of novel bioactive compounds for pharmaceutical use and/or for the pulp industry.     

Chloramphenicol acetyl transferase activity in Brassica spp.

Upon discovery that Brassica campestris leaf extracts harbour some chloramphenicol acetyl transferase (CAT) activity, a systematic screening of plant tissue for this activity, so far only reported for prokaryotic microorganism, has been conducted. Results were negative for three solanaceous plants as well as for the Cruciferae Arabidopsis thaliana and Orychophragmus violaceus. By contrast, the three tested species of the Cruciferae genus Brassica exhibit significant CAT activity. The Brassica CAT activity is much more heat labile than the enzyme encoded by the bacterial transposon, Tn9, that is commonly used as a reporter in gene fusion experiments.     

Golden hamsters are nocturnal in captivity but diurnal in nature

Daily activity rhythms are nearly universal among animals and their specific pattern is an adaptation of each species to its ecological niche. Owing to the extremely consistent nocturnal patterns of activity shown by golden hamsters (Mesocricetus auratus) in the laboratory, this species is a prime model for studying the mechanisms controlling circadian rhythms. In contrast to laboratory data, we discovered that female hamsters in the wild were almost exclusively diurnal. These results raise many questions about the ecological variables that shape the activity patterns in golden hamsters and the differences between laboratory and field results.     

The patterns of vascular plant discoveries in China

Aim(1) To understand geographic patterns of species discovery by examining the effect of growth form, range size, and geographic distribution on discovery probability of vascular plant species in China; (2) to find out which taxa harbor the largest number of undiscovered species and where those species locate; and (3) to find out the determinants of province‐level mean discovery time and inventory completeness.LocationChina.MethodsWe compiled the discovery time and province‐level geographic distributions of ~31,000 vascular plant species described between 1753 and 2013 from Flora of China. We used a Cox proportional hazard model to determine the biological and geographic correlates of discovery probability. Accumulation curves of species discoveries were fitted by a logistic discovery model to estimate inventory completeness of different growth forms and of different provinces. We then used linear regression to identify the determinants of mean discovery time and beta regression to identify the determinants of inventory completeness.ResultsWe found that species with larger range size and distributed in northeastern part of China have a higher discovery probability. Coastal species were discovered earlier than inland species. Trees and shrubs of seed plants have the highest discovery probability while ferns have the lowest discovery probability. Herbs have the largest number of undiscovered species in China. Most undiscovered species will be found in southwest China, where three global biodiversity hot spots locate. Spatial patterns of mean discovery time and inventory completeness are mainly driven by the total number of species, human population density in an area, and latitude and longitude of a province.Main ConclusionsSocioeconomic factors primarily determine the discovery patterns of vascular plants in China. Undiscovered species are most likely to be narrow‐ranged, inconspicuous endemic species such as herbs and ferns, which are prone to extinctions and locate in biodiversity hot spots in southwestern China.     

The Ethnobotany and Ethnopharmacology of Wild Tomatillos, Physalis longifolia Nutt., and Related Physalis Species: A Review

The Ethnobotany and Ethnopharmacology of Wild Tomatillos, Physalis longifolia Nutt., and Related Physalis Species: A Review. The wild tomatillo, Physalis longifolia Nutt., and related species have been important wild-harvested foods and medicinal plants. This paper reviews their traditional use as food and medicine; it also discusses taxonomic difficulties and provides information on recent medicinal chemistry discoveries within this and related species. Subtle morphological differences recognized by taxonomists to distinguish this species from closely related taxa can be confusing to botanists and ethnobotanists, and many of these differences are not considered to be important by indigenous people. Therefore, the food and medicinal uses reported here include information for P. longifolia, as well as uses for several related taxa found north of Mexico. The importance of wild Physalis species as food is reported by many tribes, and its long history of use is evidenced by frequent discovery in archaeological sites. These plants may have been cultivated, or ??tended,?? by Pueblo farmers and other tribes. The importance of this plant as medicine is made evident through its historical ethnobotanical use, information in recent literature on Physalis species pharmacology, and our Native Medicinal Plant Research Program??s recent discovery of 14 new natural products, some of which have potent anti-cancer activity.     

Enantioselective synthesis of tetrahydrocarbazoles via trienamine catalysis and their anxiolytic-like activity

The first study about the anxiolytic activity of two chiral tetrahydrocarbazoles is presented. This new chiral compounds were prepared through an organocatalytic strategy via trienamine activation. The in situ ortho-quinodimethane species, formed by the condensation of the N-protected 2-methylindole acrylaldehyde with a sterically hindred diarylsilylprolinol ether derivative as catalyst, easily participate in a Diels–Alder reaction with the ethyl cyanophenyl acrylate as dienophile, in good yields and excellent stereoselectivity. These compounds showed activity against anxiety and mood disorders that can possibly contribute in the discovery of new drugs. In addition, the use of N-protected 2-methylindole acrylaldehyde will set a new base for the synthesis of medically and pharmacologically important tetrahydrocarbazoles via trienamine catalysis.     

Antibacterial Activity of Pseudoalteromonas in the Coral Holobiont

Corals harbor diverse and abundant prokaryotic populations. Bacterial communities residing in the coral mucus layer may be either pathogenic or symbiotic. Some species may produce antibiotics as a method of controlling populations of competing microbial species. The present study characterizes cultivable Pseudoalteromonas sp. isolated from the mucus layer of different coral species from the northern Gulf of Eilat, Red Sea, Israel. Six mucus-associated Pseudoalteromonas spp. obtained from different coral species were screened for antibacterial activity against 23 tester strains. Five of the six Pseudoalteromonas strains demonstrated extracellular antibacterial activity against Gram-positive—but not Gram-negative—tester strains. Active substances secreted into the cell-free supernatant are heat-tolerant and inhibit growth of Bacillus cereus, Staphylococcus aureus, and of ten endogenous Gram-positive marine bacteria isolated from corals. The Pseudoalteromonas spp. isolated from Red sea corals aligned in a phylogenetic tree with previously isolated Pseudoalteromonas spp. of marine origin that demonstrated antimicrobial activity. These results suggest that coral mucus-associated Pseudoalteromonas may play a protective role in the coral holobiont's defense against potential Gram-positive coral pathogens.     

Penoxsulam—Structure–activity relationships of triazolopyrimidine sulfonamides

The discovery of the sulfonamide herbicides, which inhibit the enzyme acetolactate synthase (ALS), has resulted in many investigations to exploit their herbicidal activity. One area which proved particularly productive was the N-aryltriazolo[1,5-c]pyrimidine sulfonamides, providing three commercial herbicides, cloransulam-methyl, diclosulam and florasulam. Additional structure–activity investigations by reversing the sulfonamide linkage resulted in the discovery of triazolopyrimidine sulfonamides with cereal crop selectivity and high levels of grass and broadleaf weed control. Research efforts to exploit these high levels of weed activity ultimately led to the discovery of penoxsulam, a new herbicide developed for grass, sedge and broadleaf weed control in rice. Synthetic efforts and structure–activity relationships leading to the discovery of penoxsulam will be discussed.     

Two new Agave species (Agavaceae) from central Arizona and their putative pre-Columbian domesticated origins

Recent fieldwork in central Arizona resulted in the discovery of two agaves that display low seed set, reproduce mainly by vegetative means, have restricted distributions, and cannot be readily assigned to any existing species. These agaves are closely associated with archaeological structures and features and can be found growing with other previously described pre-Columbian Agave domesticates. Herein we describe Agave verdensis and A. yavapaiensis, two species that can be placed within Gentry’s informal Ditepalae Agave group, and propose that they are clonal relict domesticates. The two species have affinities with A. chrysantha, A. shrevei, and A. delamateri, the latter also a central Arizona pre-Columbian domesticate. We provide a key to distinguish these species from other agaves in central Arizona and adjacent northern Mexico with which they may be confused. The discovery of these two new species brings the total number of putative Arizona Agave domesticates to five species.     

Spatio-temporal Foraging Dynamics in Two Coexisting Harvester Ants (Hymenoptera: Formicidae)

Different aspects of the foraging strategies of two harvester ant species, Messor wasmanni and M. minor, were investigated in a Mediterranean dry grassland area. Baits were used to evaluate the existence of a trade-off between resource discovery and domination as well as the effect of three variables (air temperature, relative humidity and distance) on the trade-off. Baits were also utilized to explore random vs non random use of time by colonies. Random vs non random utilization of space was instead evaluated by mapping the daily foraging area of colonies in a grid of 900 plots of 1 m² each. Results revealed that species coexistence is not preferentially supported by a trade-off in resource utilization with no overall effect of the examined variables. The foraging activity of the two species widely overlapped whilst a clear competition for space occurred. The observed space partitioning could represent an advantageous strategy for the coexistence of the two ant species.     

Review article: The meristem in indeterminate root nodules of Faboideae

In this review, the anatomy of indeterminate legume root nodule is briefly summarized. Next, the indeterminate nodule meristem activity, organization and cell ultrastructure are described in species with a distinct nodule meristem zonation. Finally, the putative primary endogenous factors controlling nodule meristem maintenance are discussed in the context of the well-studied root apical meristem (RAM) of Arabidopsis thaliana.     

Specific aspects of detection of peroxidase isozymes and their genetic control in barley

Identical specimens were separated by electrophoresis in two gels to detect and fix peroxidase isozymes. Both gels were stained by Coomassie brilliant blue for detecting proteins. One gel was previously incubated for detecting peroxidase activity. The differences in electrophoretic patterns between the gels indicate the zones of peroxidase activity. It has been shown that locus Prx 6H, controlling a low-mobility grain peroxidase (PRX 6H), is localized to barley chromosome 6. Two loci, Alb 4H and Alb 7H, controlling the biosyntheses of water-soluble proteins of barley endosperm, were localized to chromosomes 4 and 7. It has been demonstrated that barley species is polymorphic at multiple molecular forms of peroxidase.     

Comparison of Insect Gut Cellulase and Xylanase Activity Across Different Insect Species with Distinct Food Sources

Insect guts represent unique natural biocatalyst systems for biocatalyst discovery and biomass deconstruction mechanism studies. In order to guide the further research for enzyme discovery and biodiversity analysis, we carried out comprehensive xylanase and cellulase activity assays for the gut contents of three insect species representing different orders and food sources. The three insect species are grasshopper (Acrididae sp.), woodborer (Cerambycidae spp.), and silkworm (Bombyx mori) to represent the wood-consuming, grass-consuming, and leaf-consuming insects from Orthoptera, Coleoptera, and Lepidoptera orders, respectively. Generally speaking, the enzyme activity assays have shown that the cellulase and xylanase activities for grasshopper and woodborer guts are significantly higher than those of silkworm under various conditions. In addition, both pH and temperature have a significant impact on the enzyme activities in the gut contents. For the grasshopper gut, the means of xylanase and cellulase activities at pH 7 were 3,397 and 404 μM mg^?1 min^?1, which are significantly higher than the activities at pH 4 and 10 (P?<?0.05). However, woodborer guts have shown the highest cellulase activity at pH 10. The results suggested that systems similar to woodborer guts could be good resources for discovering alkaline-tolerant enzymes. Moreover, the enzyme activities in response to different substrate concentrations were also analyzed, which indicated that grasshopper gut had particularly high cellulase activity. The enzyme activities in response to the reaction time were also examined, and we found that the enzyme activities (micromolar per milligram per minute) of different insect gut juices in response to the increase of incubation time fit well to the power function equation (E _c = K ? t ^b ) with high coefficients (r ²?>?0.99). The newly developed model serves well to compare the characteristics of the enzyme mixtures among different insect species, which can be applied to other studies of natural biocatalyst systems for the future. Overall, the data indicated that grasshopper and woodborer guts are valuable resources for discovering the novel biocatalysts for various biorefinery applications.     

A New Species of Eagle Ray Aetobatus narutobiei from the Northwest Pacific: An Example of the Critical Role Taxonomy Plays in Fisheries and Ecological Sciences

Recent taxonomic and molecular work on the eagle rays (Family Myliobatidae) revealed a cryptic species in the northwest Pacific. This species is formally described as Aetobatus narutobiei sp. nov. and compared to its congeners. Aetobatus narutobiei is found in eastern Vietnam, Hong Kong, China, Korea and southern Japan. It was previously considered to be conspecific with Aetobatus flagellum, but these species differ in size, structure of the NADH2 and CO1 genes, some morphological and meristic characters and colouration. Aetobatus narutobiei is particularly abundant in Ariake Bay in southern Japan where it is considered a pest species that predates heavily on farmed bivalve stocks and is culled annually as part of a ‘predator control’ program. The discovery of A. narutobiei highlights the paucity of detailed taxonomic research on this group of rays. This discovery impacts on current conservation assessments of A. flagellum and these need to be revised based on the findings of this study.     

Interactions between ant species increase arrival rates of an ant parasitoid

Behaviours or traits associated with aggression and communication may increase an animal's conspicuousness to predators or parasitoids. Most examples of this come from instances of aggression or communication within a species. We tested whether interspecific encounters between ants enhance the host location success of a parasitoid (Diptera: Phoridae) that attacks ants in the genus Linepithema. At food resources recruited to by Linepithema, parasitoid discovery rates were lower when Linepithema was alone than when other ant species were present. In experimentally controlled encounters, parasitoid discovery rates were elevated when Linepithema confronted an ant species that elicited use of chemicals, but not when it confronted an ant species that primarily elicited physical aggression. These results indicate that phorid parasitoids of Linepithema use the ant's chemicals as host location cues. Because Linepithema is known to abandon food resources in the presence of its phorid parasitoids, its use of chemicals during interspecific encounters may diminish its competitive success when phorids are nearby. Copyright 2003 Published by Elsevier Science Ltd on behalf of The Association for the Study of Animal Behaviour.      

Malvaceous miscellany,including new species from Mexico and Brazil

Preliminary studies toward a treatment of the Malvaceae of Mexico have led to the discovery of four new taxa ofAbutilon and two new combinations inAllowissadula. In addition, a new Brazilian species ofPavonia is described.