Pheromone chirality of african palm weevil, Rhynchophorus phoenicis (F.) and palmetto weevil, Rhynthophorus crueniatus (F.) (Coleoptera: Curculionidae)

There are four stereoisomers of both 3-methyl-octan-4-ol, the aggregation pheromone of the African palm weevil,Rhynchophorus phoenicis (F.) and 5-methyl-octan-4-ol, the aggregation pheromone of the palmetto weevil,Rhynchophorus cruentatus (F.). Synthetic stereoisomers of 3-methyl-octan-4-ol and 5-methyl-octan-4-ol were baseline-separated on a Cyclodex-B fused silica column. Use of this column in gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometric (GC-MS) analyses revealed that only one stereoisomer, (3S,4S)-3-methyl-octan-4-ol and (4S,5S)-5-methyl-octan-4-ol, is produced by maleR. phoenicis and maleR. cruentatus, respectively, and elicits good antennal responses by conspecific male and female weevils. In field trapping experiments, withR. phoenicis in Côte d'Ivoire andR. cruentatus in Florida, (3S,4S)-3-methyl-octan-4-ol and (4S,5S)-5-methyl-octan-4-ol strongly enhanced attraction of fresh palm tissue, whereas other stereoisomers were behaviorally benign. Stereoisomeric 3-methyl-octan-4-ol and 5-methyl-octan-4-ol may be utilized to monitor and/or manage populations of these two palm weevils.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones en Productos Naturales (CIPRONA

Aggregation Pheromone of Coconut Rhinoceros Beetle, Oryctes rhinoceros (L.) (Coleoptera: Scarabaeidae)

Male coconut rhinoceros beetles,Oryctes rhinoceros (L.), produce three sex-specific compounds, ethyl 4-methyloctanoate, ethyl 4-methylheptanoate, and 4-methyloctanoic acid, the first of which is an aggregation pheromone. Synthesis of these compounds involving conjugate addition of organocuprates to ethyl acrylate is reported. In field trapping experiments, (4S)-ethyl 4-methyloctanoate and the racemic mixture were equally attractive and 10 times more effective in attracting beetles than ethyl chrysanthemumate, a previously recommended attractant. Ethyl 4-methylheptanoate was as attractive as ethyl chrysanthemumate and more attractive than 4-methyloctanoic acid, but further studies are required before it can be classed as an aggregation pheromone. Compared to ethyl 4-methyloctanoate alone, combinations of the three male-produced compounds did not increase attraction, whereas addition of freshly rotting oil palm fruit bunches to pheromone-baited traps significantly enhanced attraction. With increasing dose, captures of O. rhinoceros increased, but doses of 6, 9, and 18 mg/day were competitive with 30 mg/day lures. Newly designed vane traps were more effective in capturing beetles than were barrier or pitfall traps. Results of this study indicate that there is potential for using ethyl 4-methyloctanoate in operational programs to control O. rhinoceros in oil palm plantations.Chem Tica InternationalUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones en Productos Naturales (CIPRONA

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Minimal information for studies of extracellular vesicles 2018 (MISEV2018):a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines

The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Organic Acids without a Carboxylic Acid Functional Group

Publisher copyright policies & self-archiving: Author's Pre-print: archiving status unclear. Author's Post-print: author cannot archive post-print (ie final draft post-refereeing.). Publisher's Version/PDF: author cannot archive publisher's version/PDF. Documento privadoThis paper presents several organic molecules that have been labeled as acids but do not contain a carboxylic acid functional group. The rationale for the nomenclature and appropriate explanations for the apparent acidity are discussed. For each molecule, the structure is shown and the most acidic proton is highlighted. Various chemical principles such as pKa, tautomerization, aromaticity, conformation, resonance, and induction are explored.Universidad de Costa RicaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Químic

Sudoku Puzzles for First-Year Organic Chemistry Students

We use sudoku puzzles to help the students (i) learn the correspondence between the names of the amino acids, their abbreviations, and codes and (ii) learn the correspondence between the names of the functional groups, their structures, and their abbreviations. This representation of information can be a fun way to learn details in chemistry.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones en Productos Naturales (CIPRONA

Efficient syntheses of streptocarpone and (±)-a-dunnione

An efficient divergent synthesis of both streptocarpone and racemic α-dunnione from lawsone are described. A one-pot, formal [3+2] cyclization to form a furanonaphthoquinone directly provided a common intermediate.Universidad de Costa Rica (Project No. 809-A4-012)Ministry of Science and Technology of Costa Rica and the Costa Rican National Research and Technology Council (Project No. FV-032-03)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones en Productos Naturales (CIPRONA)UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Químic

Synthesis of 2-hydroxy-3-substituted naphthoquinones using the Heck reaction

An efficient Heck coupling of 2-hydroxy-3-iodo-naphthoquinone with a series of electron-deficient alkenes in aqueous solution has been accomplished. The method is characterized by simple conditions and facile work-up to isolate the products in good to excellent yields. The products contain the motif present in several naphthoquinone pigments but with enhanced polarity.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones en Productos Naturales (CIPRONA

Transformation of presumptive precursors to frontalin and exo-brevicomin by bark beetles and the West Indian sugarcane weevil (Coleoptera)

(Z)-6-Nonen-2-one (1) has recently been shown to be the biosynthetic precursor for the aggregation pheromone exo-brevicomin (2) in mountain pine beetle (MPB) males, Dendroctonus ponderosae (Hopkins). We tested the hypotheses that (1) 6-methyl-6-hepten-2-one (3) is the biosynthetic precursor for the aggregation pheromone frontalin (4) in the spruce beetle (SB), Dendroctonus rufipennis (Kirby), and (2) that frontalin and exo-brevicomin are produced from 3 and 1, respectively, only by beetles that utilize them as aggregation pheromones. Exposure of scolytids MPB, SB, pine engraver (PE), Ips pini (Say) and Ips tridens (Mannerheim) and West Indian sugar cane weevil (WISW), Metamasius hemipterus sericeus (Olivier) to deuterio- or protio-3 invariably resulted in the production of deuterio- or protio-4. Similarly, exposure of SB, WISW and I. tridens to 1 resulted in the production of 2. We were unable to demonstrate the presence of 3 in SB volatiles, nor were we able to demonstrate the conversion of 6-methyl-5-hepten-2-one to 3 by SB. Production of enantiomerically enriched frontalin and exo-brevicomin by all the beetles exposed to respective precursors reveals widespread occurrence of nonspecific polysubstrate monooxidases in the Coleoptera. Production of enantiomerically enriched frontalin and exo-brevicomin by all the beetles exposed to respective precursors represent nonspecific and nonselective biotransformations, and demonstrate widespread occurence of nonspecific polysubstrate monooxidases in the Coleoptera.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones en Productos Naturales (CIPRONA