| structure of alkaloid 275a, a novel 1-azabicyclo[5.3.0]decane from a dendrobatid frog, dendrobates lehmanni: synthesis of the tetrahydrodiastereomers. | the principal alkaloid 275a in skins of the colombian poison frog dendrobates lehmanni has been identified as the pyrrolo[1,2-a]azepane (1), the first occurrence in nature of this "izidine" system. tetrahydro-1 proved identical to one of the four synthetic diastereomers, 2a--2d, thereby establishing that 1 has the 5z,10e relative stereochemistry. alkaloid 1 is often accompanied by other congeners, in particular a 5z,10z diastereomer 15, a dihydro analogue 16, and a ketone 17. such izidines in fr ... | 2001 | 11325220 |
| stream noise, hybridization, and uncoupled evolution of call traits in two lineages of poison frogs: oophaga histrionica and oophaga lehmanni. | according to the acoustic adaptation hypothesis, communication signals are evolutionary shaped in a way that minimizes its degradation and maximizes its contrast against the background noise. to compare the importance for call divergence of acoustic adaptation and hybridization, an evolutionary force allegedly promoting phenotypic variation, we compared the mate recognition signal of two species of poison frogs (oophaga histrionica and o. lehmanni) at five localities: two (one per species) along ... | 2013 | 24194888 |
| alkaloids from dendrobatid frogs: structures of two omega-hydroxy congeners of 3-butyl-5-propylindolizidine and occurrence of 2,5-disubstituted pyrrolidines and a 2,6-disubstituted piperidine. | forty alkaloids were detected and characterized from skin extracts of high- and low-elevation populations of the poison frog dendrobates histrionicus from northwestern colombia. combined gc/ms with nh3 or nd3 in a chemical ionization mode detected protonated parent ions and determined the number of exchangeable nh and oh hydrogens. six previously unknown dendrobatid alkaloids were characterized. two were 2,5-disubstituted pyrrolidines, which included pyrrolidine 197b, a trans-2-butyl-5-pentylpyr ... | 2006 | 3734811 |
| complex patterns of differentiation and gene flow underly the divergence of aposematic phenotypes in oophaga poison frogs. | hybridization and introgression can have complex consequences for both species evolution and conservation. here, we investigated the origin and characteristics of a putative hybrid zone between two south american poison dart frog species, oophaga anchicayensis and the critically endangered oophaga lehmanni, which are heavily sought after on the illegal pet market. using a combination of phenotypic (49 traits) and genomic (ddradseq) data, we found that the putative hybrids are morphologically dis ... | 2020 | 31971303 |