Ecological change predicts population dynamics and genetic diversity over 120 000 years

While ecological effects on short‐term population dynamics are well understood, their effects over millennia are difficult to demonstrate and convincing evidence is scant. Using coalescent methods, we analysed past population dynamics of three lizard species (Psammodromus hispanicus, P. edwardsianus, P. occidentalis) and linked the results with climate change data covering the same temporal horizon (120 000 years). An increase in population size over time was observed in two species, and in P. occidentalis, no change was observed. Temporal changes in temperature seasonality and the maximum temperature of the warmest month were congruent with changes in population dynamics observed for the three species and both variables affected population density, either directly or indirectly (via a life‐history trait). These results constitute the first solid link between ecological change and long‐term population dynamics. The results moreover suggest that ecological change leaves genetic signatures that can be retrospectively traced, providing evidence that ecological change is a crucial driver of genetic diversity and speciation.     

Behavioural and chemical evidence of a male‐produced aggregation pheromone in the flower thrips Frankliniella intonsa

The response of adult flower thrips Frankliniella intonsa (Trybom) (Thysanoptera: Thripidae) to conspecifics is investigated in Y‐tube olfactometer bioassays. The results show that both males and females are attracted to the odours of adult males, which indicates a male‐produced aggregation pheromone in this species. Gas chromatography‐mass spectroscopy analyses of headspace volatiles collected on solid‐phase microextraction fibres show that two major components and six minor components are present in volatiles from males but not in females. Further gas chromatography‐mass spectroscopy analyses reveal that the two major components in head‐space volatiles produced by F. intonsa males are the same compounds that are reported in volatiles of Frankliniella occidentalis males: (R)‐lavandulyl acetate and neryl (S)‐2‐methylbutanoate. However, the quantity of these two compounds in the volatiles differs between the species.     

Characterization of 22 microsatellite loci developed from the genome of the Woolly Lemur (Avahi laniger)

Twenty‐two polymorphic microsatellite loci were isolated and characterized from the Avahi laniger genome. All were polymorphic in both the Eastern Woolly Lemur (A. laniger) and the Western Woolly Lemur (A. occidentalis). One locus, WOOL157, harboured allele structures that were species‐specific. This marker suite will be used in future studies to establish the ranges and population structures of the two Avahi species on the island of Madagascar.     

Enantiomers of fuscumol acetate comprise the aggregation‐sex pheromone of the South American cerambycid beetle Psapharochrus maculatissimus,and likely pheromones of the cerambycids Eupromerella plaumanni and Hylettus seniculus

There is increasing evidence that pheromone chemistry within the large coleopteran family Cerambycidae is often highly conserved, with numerous related species sharing the same pheromone components. As a result, traps containing these components can attract multiple cerambycid species simultaneously. In the present study, we exploited this concept in the identification of the male‐produced aggregation‐sex pheromone of the South American species Psapharochrus maculatissimus (Bates) (Coleoptera: Cerambycidae, subfamily Lamiinae, tribe Acanthoderini). Initially, live adults of both sexes were caught using a trap baited with a lure containing a blend of known cerambycid pheromone components. Headspace volatiles were collected from live beetles and analyzed by coupled gas chromatography‐mass spectrometry. Males of P. maculatissimus sex‐specifically produced a 1:38 blend of (R)‐fuscumol acetate ([2R,5E]‐6,10‐dimethylundeca‐5,9‐dien‐2‐yl acetate) and (S)‐fuscumol acetate, which were both components of the pheromone lures to which they had been attracted. In more focused field trials, traps baited with the (S)‐enantiomer, or a blend approximating the natural 1:38 ratio of (R)‐ to (S)‐enantiomers, attracted adults of both sexes in approximately equal numbers. During bioassays, adults of the lamiine species Eupromerella plaumanni (Fuchs) (tribe Acanthoderini) and Hylettus seniculus (Germar) (Acanthocinini) also were attracted, but to different lures, with E. plaumanni being attracted to the racemic mixture of the two enantiomers of fuscumol acetate, whereas H. seniculus was attracted specifically to (R)‐fuscumol acetate. Our results suggest that differences between these sympatric species in the stereochemistry of fuscumol acetate impart species‐specificity to pheromone communication channels, similar to what has been found recently with lamiine species from other continents.     

Biotransformations of Terpenes by Fungi from Amazonian Citrus Plants

The biotransformations of (RS)‐linalool ( 1 ), (S)‐citronellal ( 2 ), and sabinene ( 3 ) with fungi isolated from the epicarp of fruits of Citrus genus of the Amazonian forest (i.e., C. limon, C. aurantifolia, C. aurantium, and C. paradisiaca) are reported. The more active strains have been characterized, and they belong to the genus Penicillium and Fusarium. Different biotransformation products have been obtained depending on fungi and substrates. (RS)‐Linalool ( 1 ) afforded the (E)‐ and (Z)‐furanlinalool oxides ( 7 and 8 , resp.; 39 and 37% yield, resp.) with Fusarium sp. (1D2), 6‐methylhept‐5‐en‐2‐one ( 4 ; 49%) with F. fujikuroi, and 1‐methyl‐1‐(4‐methypentyl)oxiranemethanol ( 6 ; 42%) with F. concentricum. (S)‐Citronellal ( 2 ) gave (S)‐citronellol ( 12 ; 36–76%) and (S)‐citronellic acid ( 11 ; 5–43%) with Fusarium species, while diastereoisomeric p‐menthane‐3,8‐diols 13 and 14 (20 and 50% yield, resp.) were obtained as main products with Penicillium paxilli. Finally, both Fusarium species and P. paxilli biotransformed sabinene ( 3 ) to give mainly 4‐terpineol ( 19 ; 23–56%), and (Z)‐ and (E)‐sabinene hydrates ( 17 (3–21%) and 18 (11–17%), resp.).     

Modulating the folding stability and ligand binding affinity of Pin1 WW domain by proline ring puckering

The pyrrolidine side chain makes proline play a unique role in protein structure and function. The C^γ ring pucker preference and the cis– trans peptidyl bond ratio can be mediated via stereoelectronic effects. Here we used a compact triple‐stranded antiparallel β‐sheet protein, the human Pin1 WW domain, to study the consequences of implanting a preorganized C^γ ring pucker on protein structure and function. The conserved Pro37 is a key residue involved in one hydrophobic core, plays an important role in the WW domain, and adopts a C^γ‐endo ring pucker in the native structure. Pro37 was replaced with C^γ‐exo biased pucker derivatives: (2S,4R)‐4‐hydroxyproline (4R‐Hyp), (2S,4R)‐4‐fluoroproline (4R‐Flp), (2S,4R)‐4‐methoxyproline (4R‐Mop), and C^γ‐endo biased pucker derivatives: (2S,4S)‐4‐hydroxyproline (4S‐hyp), (2S,4S)‐4‐fluoroproline (4S‐flp), (2S,4S)‐4‐methoxyproline (4S‐mop) to examine how a preorganized pucker affects the folding stability and ligand‐binding affinity. Circular dichroism measurements indicate that among the variants, only the one with 4S‐flp substitution (P37flp) is more stable than the wild type, suggesting that the stabilization effects originated from preorganization of the backbone conformation and the hydrophobicity of C? F group. Analysis of ligand‐binding affinity using isothermal titration calorimetry revealed that only P37flp has a stronger ligand affinity than the wild type, showing that 4S‐flp can stabilize the WW domain and increase its ligand affinity. Together we have used 4‐substituted proline derivatives and the WW domain to demonstrate that proline ring puckering can be a key factor in determining the folding stability of a protein but the choice of the derivative groups is also critical. Proteins 2014; 82:67–76. © 2013 Wiley Periodicals, Inc.     

Diastereoselective Synthesis of a Lilac Aldehyde Isomer and Its Electrophysiological Detection by a Moth

The monoterpene lilac aldehyde (=2‐(5‐ethenyl‐5‐methyloxolan‐2‐yl)propanal) is a widespread flower scent. Lilac aldehyde is emitted in high amounts from nocturnal plant species, and it is highly attractive to nocturnal moth pollinators, such as Hadena bicruris, the pollinating seed predator of Silene latifolia. Lilac aldehyde possesses three stereogenic centers and can occur in eight stereoisomers which induce different antennal responses in H. bicruris. The distribution pattern of stereoisomers differs among plant species, and if H. bicruris has different receptors for detecting different isomers, it may use these differences to discriminate flowers of S. latifolia hosts from flowers of non‐host plants. To investigate the question whether the moths have in their antennae one olfactory receptor or several different receptors for the detection of the single lilac aldehyde isomers, (2S,2′S,5′S)‐lilac aldehyde was diastereoselectively synthesized. (2S,2′S,5′S)‐Lilac aldehyde and its isomeric mixture were tested electrophysiologically on antennae of H. bicruris. The results displayed antennal responses, which are characteristic for a single receptor that detects the different lilac aldehyde isomers.     

Genetic variation in productivity of foundation riparian species at the edge of their distribution: implications for restoration and assisted migration in a warming climate

We examined the hypothesis that genotypic variation among populations of commonly co‐occurring phreatophytic trees (Populus fremontii, Salix gooddingii) and the shrub (Salix exigua) regulates aboveground net primary productivity (ANPP) at a hot site at the edge of the species’ distribution. We used a provenance trial in which replicated genotypes from populations varying in mean annual temperature were transplanted to a common garden adjacent to the Lower Colorado River in southeastern California. The garden environment represented an extreme maximum temperature for the study species. Four major findings emerged: (1) Genotypic variation in ANPP was significant for all species with broad‐sense heritability (H²) across populations of 0.11, 0.13, and 0.10 for P. fremontii, S. gooddingii, and S. exigua, respectively, and within‐population H² ranging from 0.00 to 0.25, 0.00 to 0.44, and 0.02 to 0.21, respectively. (2) Population ANPP decreased linearly as mean annual maximum temperature (MAMT) transfer distance increased for both P. fremontii (r² = 0.64) and S. gooddingii (r² = 0.37), whereas it did not change for S. exigua; (3) Populations with similar MAMT to that of the common garden were 1.5 and 1.2 times more productive than populations with 5.0 °C MAMT transfer distances for P. fremontii and S. gooddingii, respectively; and (4) Variation in regression slopes among species for the relationship between ANPP and MAMT indicate species‐specific responses to temperature. As these plant species characterize a threatened habitat type and support a diverse community that includes endangered species, ecosystem restoration programs should consider using both local genotypes and productive genotypes from warmer environments to maximize productivity of riparian ecosystems in the face of global climate change.     

Experimental and Calculated CPL Spectra and Related Spectroscopic Data of Camphor and Other Simple Chiral Bicyclic Ketones

UV, circular dichroism (CD), fluorescence and circularly polarized luminescence (CPL) spectra were recorded for a set of four related [2.2.1] bicyclic compounds ((1S,4S)‐and (1R,4R)‐1,7,7‐trimethylbicyclo[2.2.1]heptan‐2‐one, namely (1S)‐ and (1R)‐camphor ( 1 ), (1S,4R)‐4,7,7‐trimethylbicyclo[2.2.1]hept‐5‐en‐2‐one, (1S)‐dehydro‐epicamphor ( 2 ), (1S,4S)‐1,7,7‐trimethylbicyclo[2.2.1]heptane‐2,5‐dione, (1S)‐5‐oxocamphor ( 3 ), (1S,4R)‐ and (1R,4S)‐1,7,7‐trimethylbicyclo[2.2.1]heptane‐2,3‐dione, (1S)‐ and (1R)‐camphorquinone ( 4 )) and a set of three related [2.2.2] bicyclic compounds (1S,4S)‐bicyclo[2.2.2]octan‐2,5‐dione (saturated diketone ( 5 )), (1R,4R)‐bicyclo[2.2.2]oct‐7‐en‐2,5‐dione (unsaturated diketone ( 6 )), ((1S,4S)‐bicyclo[2.2.2]oct‐7‐en‐5(S)‐ol‐2‐one (which we refer to as unsaturated hydroxy‐ketone ( 7 )). For the latter three compounds also mid‐IR vibrational circular dichroism (VCD) spectra were recorded and are presented. Time‐Dependent Density Functional (TD‐DFT) calculations provide a satisfactory interpretation of both absorption and emission chiroptical spectra and permit insight into ground and excited state electronic properties. We discuss the applicability of the octant rule or of other approximated models to rationalize the observed sign of the CPL. Chirality 25:589–599, 2013. © 2013 Wiley Periodicals, Inc.     

Use of spinosad and predatory mites for the management of Frankliniella occidentalis in low tunnel‐grown strawberry

Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) is a major pest of strawberry. The efficacy of three species of predatory mites, Typhlodromips montdorensis (Schicha), Neoseiulus cucumeris (Oudemans) (both: Acari: Phytoseiidae), and Hypoaspis miles (Berlese) (Acari: Laelapidae), and their compatibility with spinosad for the control of this thrips was evaluated in commercial strawberry in spring. Low tunnel‐grown strawberry was treated with ‘water then mites’, ‘spinosad then mites’, or ‘mites then spinosad’. Predatory mites were released as single‐, two‐ and three‐species combinations. Overall, spinosad‐treated plants had fewer thrips than water‐treated plants (control). In all treatment regimes, each species of predatory mite reduced the number of thrips relative to those plants that received no mites. Predatory mites were most effective in reducing thrips when released after spinosad was applied. Any multiple‐species combination of predatory mites reduced thrips numbers more than single‐species releases. The two‐species combination of T. montdorensis (foliage inhabiting) and H. miles (soil dwelling) was the most effective in suppressing thrips. The next most effective combination was a three‐species release. Of multiple‐species combinations, the two‐species combination of T. montdorensis and N. cucumeris was the least effective in suppressing thrips numbers. The spinosad and mites only temporarily reduced the numbers of F. occidentalis. This suggests that further application of predatory mites, spinosad, or both is required to maintain F. occidentalis populations below an economically damaging level.     

Trap colour and aggregation pheromone dose affect the catch of western flower thrips in blackberry crops

Frankliniella occidentalis causes significant damage to berry crops in Mexico. Traps may be used for monitoring or mass-trapping thrips populations. Generally, colour traps are used for monitoring thrips, but sometimes a chemical stimulus can be added to the traps. However, there is conflicting information about what colour is the most attractive and efficient for capturing F. occidentalis. In this study, we first evaluated six colours of adhesive traps for catching F. occidentalis in blackberries grown in tunnels or in an open field. Subsequently, using the most attractive trap colour, we assessed the biological activity of neryl (S)-2-methylbutanoate and (R)-lavandulyl acetate, components of the pheromone aggregation of F. occidentalis. Finally, we examined the effect of neryl (S)-2-methylbutanoate dosage rates on the number of captured thrips. We found that blue (tunnel) and yellow (open field) followed by violet traps captured a significantly greater number of F. occidentalis compared with the white, black and green traps. Our results confirm that neryl (S)-2-methylbutanoate is the only component necessary for enhancing the performance of coloured traps. Blue and yellow traps baited with 200–400 µg of neryl (S)-2-methylbutanoate increased the capture 2.5–3 times compared to unbaited traps. In all experiments, traps captured more females than males in blackberries grown in tunnels, whereas the opposite was found in blackberries cultivated in the open field. These results constitute the first step in the development of a monitoring system for F. occidentalis in soft fruit crops in Mexico.     

Kairomonal response of the parasitoid Anagyrus spec. nov. near pseudococci to the sex pheromone of the vine mealybug

The occurrence of a kairomonal response of the parasitoid Anagyrus spec. nov. near pseudococci (Hymenoptera: Encyrtidae) to (+)‐(1R,3R)‐cis‐2,2‐dimethyl‐3‐isopropenyl‐cyclobutanemethanol acetate (PcA, namely, planococcyl acetate) and (S)‐(+)‐lavandulyl senecioate (LS), the respective female sex pheromones of its hosts, the citrus mealybug, Planococcus citri (Risso) and the vine mealybug, Planococcus ficus (Signoret) (Homoptera: Pseudococcidae) was investigated. Attraction to the pheromones was tested by employing pheromone traps in field trials and by static air olfactometer bioassays in the laboratory. Female wasps showed a significant response to LS, in both field and olfactometer experiments. No significant response was registered to the sex pheromone of P. citri. Despite the similarity between the structures of LS and its analogue (S)‐(+)‐lavandulyl isovalerate (LI), no significant response to the latter compound was observed. It seems that differences between the structures of the carboxylate moiety of the respective molecules (LS and LI) markedly affect the kairomonal attractiveness to the parasitoid. The kairomonal response of Anagyrus spec. nov. near pseudococci was neither influenced by the host habitat nor by the host species on which it developed. This suggested innate behaviour of Anagyrus spec. nov. near pseudococci, possibly derived from evolutionary relationships between the parasitoid and P. ficus. The practical implications of the results are discussed.     

Isolation of Ceramides from Tagetes patula L. Yellow Flowers and Nematicidal Activity of the Fractions and Pure Compounds against Cyst Nematode,Heterodera zeae

Investigation of yellow flower extract of Tagetes patula L. led to the identification of an aggregate of five phytoceramides. Among them, (2R)‐2‐hydroxy‐N‐[(2S,3S,4R,8E)‐1,3,4‐trihydroxyicos‐8‐en‐2‐yl]icosanamide, (2R)‐2‐hydroxy‐N‐[(2S,3S,4R,8E)‐1,3,4‐trihydroxyicos‐8‐en‐2‐yl]heneicosanamide, (2R)‐2‐hydroxy‐N‐[(2S,3S,4R,8E)‐1,3,4‐trihydroxyicos‐8‐en‐2‐yl]docosanamide, and (2R)‐2‐hydroxy‐N‐[(2S,3S,4R,8E)‐1,3,4‐trihydroxyicos‐8‐en‐2‐yl]tricosanamide were identified as new compounds and termed as tagetceramides, whereas (2R)‐2‐hydroxy‐N‐[(2S,3S,4R,8E)‐1,3,4‐trihydroxyicos‐8‐en‐2‐yl]tetracosanamide was a known ceramide. A steroid (β‐sitosterol glucoside) was also isolated from the subsequent fraction. The structures of these compounds were determined on the basis of spectroscopic analyses, as well as chemical method. Several other compounds were also identified by GC/MS analysis. The fractions and some commercial products, a ceramide HFA, β‐sitosterol, and stigmasterol were evaluated against an economically important cyst nematode, Heterodera zeae. Ceramide HFA showed 100 % mortality, whereas, β‐sitosterol and stigmasterol were 40–50 % active, at 1 % concentration after 24 h of exposure time, while β‐sitosterol glucoside revealed no activity against the nematode.     

Structural Confirmation of a Unique Carotenoid Lactoside,P457, in Symbiodinium sp. Strain nbrc 104787 Isolated from a Sea Anemone and its Distribution in Dinoflagellates and Various Marine Organisms

The molecular structure of the carotenoid lactoside P457, (3S,5R,6R,3′S,5′R,6′S)‐13′‐cis‐5,6‐epoxy‐3′,5′‐dihydroxy‐3‐(β‐d ‐galactosyl‐(1→4)‐β‐d ‐glucosyl)oxy‐6′,7′‐didehydro‐5,6,7,8,5′,6′‐hexahydro‐β,β‐caroten‐20‐al, was confirmed by spectroscopic methods using Symbiodinium sp. strain NBRC 104787 cells isolated from a sea anemone. Among various algae, cyanobacteria, land plants, and marine invertebrates, the distribution of this unique diglycosyl carotenoid was restricted to free‐living peridinin‐containing dinoflagellates and marine invertebrates that harbor peridinin‐containing zooxanthellae. Neoxanthin appeared to be a common precursor for biosynthesis of peridinin and P457, although neoxanthin was not found in peridinin‐containing dinoflagellates. Fucoxanthin‐containing dinoflagellates did not possess peridinin or P457; green dinoflagellates, which contain chlorophyll a and b, did not contain peridinin, fucoxanthin, or P457; and no unicellular algae containing both peridinin and P457, other than peridinin‐containing dinoflagellates, have been observed. Therefore, the biosynthetic pathways for peridinin and P457 may have been coestablished during the evolution of dinoflagellates after the host heterotrophic eukaryotic microorganism formed a symbiotic association with red alga that does not contain peridinin or P457.     

Phytotoxic potential of Senna occidentalis (L.) Link extracts on seed germination and oxidative stress of Ipê seedlings

• Senna occidentalis is an invasive plant producing a series of allelochemicals that might inhibit the development of other plants. The objective of this study was to assess the phytotoxic effect of S. occidentalis extracts on the germination, development and antioxidant defence of the native species Tabebuia chrysotricha, T. pentaphylla, T. roseoalba and Handroanthus impetiginosus (Ipê species).
• We evaluated the effects of chemicals extracted from S. occidentalis on the germination rate, germination speed index (GSI) and biometric parameters of the test species under controlled conditions. The effect of the extracts on the pigment content, amount of H₂O₂ and malondialdehyde (MDA), and the activity of the antioxidant enzymes in roots and leaves were also tested.
• Alkaloids, coumarins, phenols, saponins, free steroids and condensed tannins were present in all extracts of S. occidentalis, while catechins were present only in leaf and stem extracts. Stem and root extracts caused a growth reduction in all Ipê species and total inhibition of seed germination in T. chrysotricha and T. roseoalba. All target species showed an increase in H₂O₂ and MDA in radicles and leaves. Oxidative stress contributed strongly to the morphological changes, such as seed blackening, thinning and darkening of radicle tips and reduction of biomass allocation in all Ipê species.
• Although there was activation of antioxidant defence mechanisms, such as an increase in activity of ascorbate peroxidase (APX) and peroxidase (POD) enzymes, the joint action of the allelochemicals caused phytotoxicity, leading to cell dysfunction in all Ipê species.

     

Stereoselective Formation and Metabolism of 20(S)‐Protopanaxadiol Ocotillol Type Epimers in Vivo and in Vitro

(20S,24S)‐epoxy‐dammarane‐3,12,25‐triol (24S‐epimer) and (20S,24R)‐epoxy‐ dammarane‐3,12,25‐triol (24R‐epimer), a pair of ocotillol type epimers, were identified as the main metabolites of 20(S)‐protopanaxadiol (PPD). The aim of this study was to systematically investigate the formation and metabolism of this pair of epimers in vivo and in vitro and to elucidate the isoforms of cytochrome P450 enzymes responsible for the stereoselective metabolism of both epimers. The result showed that 24S‐epimer was a more predominant ingredient in rat plasma after oral administration of PPD with higher area under the curve (AUC) values. Both the enzyme kinetic evaluations of the formation and elimination of 24S‐epimer and 24R‐epimer in rat liver microsomes (RLM) and human liver microsomes (HLM) indicated that 24S‐epimer had a higher formation rate and a lower oxygenation metabolism rate than 24R‐epimer, and the stereoselective differences were more obvious in HLM than in RLM. The chemical inhibition and recombinant human P450 isoforms assay showed that CYP3A4 was the predominant isoform responsible for the further metabolism of 24R‐epimer in HLM. The biliary excretion ratio of the 24S‐epimer glucuronide was more than 28‐fold higher than that of 24R‐epimer glucuronide after intravenous administration to rats, which also indicated 24S‐epimer was more preferential to be metabolized as the glucuronide conjugate than 24R‐epimer. Chirality 27:170–176, 2015. © 2014 Wiley Periodicals, Inc.     

PCR-RFLP analysis of the IGS region of rDNA: a useful tool for the practical discrimination between species of the genus Debaryomyces

The amplification by PCR of the intergenic spacer region (IGS) of rDNA followed by restriction fragment length polymorphism (RFLP) analysis was evaluated as a potential method for discriminating the 16 species belonging to the genus Debaryomyces. The digestion of this region with some or all the enzymes used in this study (HapII, HhaI and MboI) produced species-specific patterns that permitted differentiation of the species in the genus. With the exception of Debaryomyces vanrijiae, the technique was also efficient for␣distinguishing the varieties in the species Debaryomyces hansenii (var. hansenii, var. fabryi), Debaryomyces occidentalis (var. occidentalis, var. persoonii) and Debaryomyces polymorphus (var. africanus, var. polymorphus), respectively. PCR-RFLP analysis of the IGS region of rDNA is proposed as a clear and reproducible technique for the practical discrimination of species of the yeast genus Debaryomyces.     

Absolute configuration of phomactatriene diterpenoids obtained by Wagner‐Meerwein rearrangement of epimeric verticillols

The epimeric diterpenes (+)‐(1S,3E,7E,11S,12S)‐verticilla‐3,7‐dien‐12‐ol ( 1 ), isolated from Bursera suntui, and (+)‐(1S,3E,7E,11S,12R)‐verticilla‐3,7‐dien‐12‐ol ( 2 ), isolated from Bursera kerberi, gave the same Wagner‐Meerwein rearrangement product (?)‐(1E,4Z,8Z,11S,12R)‐phomacta‐1,(15)4,8‐triene ( 3 ). The Et₂O:BF₃‐induced transformations evidence that verticillenes and phomactanes, both containing the bicyclo[9.3.1]pentadecane skeleton, are biogenetically related through the verticillen‐12‐yl cation ( A ⁺ ), which also is a key intermediate in the biosynthetic pathways to generate antitumor taxanes. Molecular modeling using the Monte Carlo protocol, followed by density functional theory (DFT) geometry optimization employing the hybrid functionals B3LYP and B3PW91, both with the DGDZVP basis set, secured the configuration of 3 as followed from the good agreement between the calculated and experimental vibrational circular dichroism spectra. Similar DFT calculations allowed determining the absolute configuration of (+)‐(1R,4R,5R,8S,9S,11S,12R,15R)‐1,15:4,5:8,9‐triepoxyphomactane ( 9 ), which surprisingly derives from epoxidation of the second minimum energy conformer of 3 .     

Enantioselective liquid‐liquid extraction of 3‐chloro‐phenylglycine enantiomers using (S,S)‐DIOP as extractant

(S,S)‐DIOP, a common catalyst used in asymmetric reaction, was adopted as chiral extractant to separate 3‐chloro‐phenylglycine enantiomers in liquid‐liquid extraction. The factors affecting extraction efficiency were studied, including metal precursors, organic solvents, extraction temperature, chiral extractant concentration, and pH of aqueous phase. (S,S)‐DIOP‐Pd exhibited good ability to recognize 3‐chloro‐phenylglycine enantiomers, and the operational enantioselectivity (α) is 1.836. The highest performance factor (pf) was obtained under the condition of extraction temperature of 9.1°C, (S,S)‐DIOP‐Pd concentration of 1.7 mmol/L, and pH of aqueous phase of 7.0. In addition, the possible recognition mechanism of (S,S)‐DIOP‐Pd towards 3‐chloro‐phenylglycine enantiomers was discussed.     

Multilocus species delimitation in Mesoamerican Scaptotrigona stingless bees (Apidae: Meliponini) supports the existence of cryptic species

Accelerating taxonomic knowledge and making accurate species identifications are critically important given the current biodiversity crisis, particularly in biodiversity hotspots such as Mesoamerica. Objective species delimitation that reduces investigator‐driven bias is fundamental to the establishment of appropriate conservation strategies, above all in managed species. Previous morphological and molecular studies on three managed stingless bee species of the genus Scaptotrigona distributed in Mexico (S. mexicana, S. pectoralis and S. hellwegeri) suggested that both S. mexicana and S. hellwegeri are cryptic species complexes. Herein we tested species delimitation by analysing sequence information of five markers (two mitochondrial: cox1 and 16S, and three nuclear: ITS1, EF1‐α, ArgK) within a Bayesian coalescent framework to test the putative species. We obtained two different hypotheses using a Generalized Mixed Yule Coalescent (GMYC) model: four (cox1) and six (16S) species. After the species validation step with the Bayesian species‐delimitation analysis (BPP), we suggest that only S. mexicana is a complex of two species with different distribution (along the Pacific and the Atlantic coasts, respectively). We highly recommend avoiding colony exchange between geographical regions in order to conserve the genetic integrity of both taxa.