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The reaction of complexes [Pt(μ‐Cl)(arylolefin)]2 with various either weak σ‐donor LN,S,O ligands or strong σ‐donor NHCs ligands results in [PtCl(arylolefin)(LN,S,O)] with LN,S,O in a cis position to the C=C group (series A) or [PtCl(arylolefin)(NHC)] with NHC in a trans position to the C=C group (series B), respectively. The reaction directions are decided by the nature of the reactants, and not by the reaction conditions. Analyses of NMR spectra, XRD and DFT results indicate that the formation of series B is strongly dominated by electronic properties, while steric factors direct the reaction to form series A. The chemical shifts of ethylenic protons and carbons as well as the values of 2JPtH, 3JPtH for the allyl protons and the 3JPtH value for H6 in the aryl group are unambiguously different for series A and series B. In addition, one complex [Pt(μ‐Cl)(EtEug)]2 and five complexes [PtCl(arylolefin)(NHC)] have been characterized by single crystal XRD. [ABSTRACT FROM AUTHOR]

Interaction of [Pt(µ -Cl)(arylolefin)] 2 with either quinoline (Q) or four derivatives (N , O H) afforded 2 – 10. The N atom of Q and (N , O) are at the cis position with respect to the allyl group in all the complexes. The cytotoxicity of 4 against Lu and 5 against KB cell lines are approximately 6 and 4 times lower than cisplatin, respectively. [Display omitted] Nine new cyclometalated platinum(II) complexes of the formula [PtCl(arylolefin)(Q)] (2 , 3) and [Pt(arylolefin)(N , O)] (4 – 10) (arylolefinH: eugenoxyacetic acid, isopropyl eugenoxyacetate; Q: quinoline; (N , O H): quinolin-8-ol, 2-methylquinolin-8-ol, 5,7-dichloroquinloin-8-ol and quinoline-2-carboxylic acid] were synthesized and fully characterized by EA, ESI mass spectrometry, IR and NMR spectroscopy and single-crystal X-ray diffraction for 3 , 7 and 10. The results show that the arylolefin binds with PtII via the C5 atom of the phenyl ring and the C C allyl in all the synthesized complexes. Quinoline coordinates with PtII via its N atom in 2 , 3 , while deprotonated (N , O H) coordinates with PtII via both the N and O atoms in 4 – 10. The N atom of Q and (N , O) in all complexes are at the cis position with respect to the allyl group of the arylolefin. The XRD confirms the square-planar coordination of PtII and trans position of the arylolefin and quinoline ligands. The results of in vitro cytotoxicity tests against human cancer cell lines KB and Lu of 2, 4 – 8 indicate that 4 and 5 exhibit the highest activities against Lu and KB cell lines with the IC 50 values of 7.1 and 4.1 µM, respectively, which are approximately 6 and 4 times lower than cisplatin. [ABSTRACT FROM AUTHOR]

The Asian box turtles of the Cuora galbinifrons complex (C. galbinifrons, C. bourreti, and C. picturata) rank among the most endangered chelonian species in the world. Despite several previous studies, the phylogenetic relationships and species boundaries of this complex remain a matter for dispute due to a shortage of field-collected samples for genetic validation, observed discordance between mitochondrial and nuclear markers, and reported intergradation zones combined with a strong tendency of hybridization in the genus. Here, we re-investigate the relationships and potential hybridization between the species of the C. galbinifrons complex based on the most comprehensive dataset to date consisting of 394 morphologically identified specimens (136 C. galbinifrons, 200 C. bourreti, 49 C. picturata, and nine individuals allegedly from Hainan). The turtles mainly came from assurance colonies as well as from zoological and private collections across the USA and Europe. Bayesian and Maximum Likelihood analyses of a concatenated mitochondrial dataset (COI and ND4 plus adjacent tRNA genes) yielded almost identical topologies, supporting three major clades corresponding to C. galbinifrons, C. bourreti, and C. picturata, respectively. In accordance with previous studies, C. bourreti represented the sister clade to C. galbinifrons and these two clades together were sister to C. picturata. Haplotype networks revealed pronounced mitochondrial divergences between the taxa. STRUCTURE and PCA analyses using 12 microsatellite loci also confirmed three distinct clusters that are in agreement with the recognized species. Only a few specimens with admixed ancestry (hybrids) or mismatched mitochondrial identity were revealed, suggesting extremely limited gene flow among the three species. However, this pattern could also reflect the separate captive management of the individual taxa and an underrepresentation of geographic contact zones in our sampling. [ABSTRACT FROM AUTHOR]

Terrestrial species from the Lao People's Democratic Republic (PDR) are under high threat due to deforestation and overhunting. Previous studies have even defined these forests as subjected to an "empty forest syndrome", a condition in which forests that are apparently well preserved are instead almost deprived of vertebrate faunas due to extreme exploitation by local communities. Forest specialists, including several primates, are among the most threatened species in the country. The Laotian langur (Trachypithecus laotum) is endemic to Lao PDR, is listed as Endangered by the IUCN Red List, and it is one of the least studied species in the region. A survey on the local distribution, life history and conservation status of the Laotian langur was carried out in Phou Hin Poun National Protected Area, Khammouane Province of Lao PDR. The survey consisted of an initial phase with interviews to select key informants on the Laotian langur and the other primate species of the area. Then, a phase of field surveys along forest transects, totaling 64.1 km of 21 transects, yielded a record of 35 individuals in 9 groups. The highest encounter/detection rate of the Laotian langur was 1 group per km at one sector of the park. In contrast, it was much lower (0.18–0.34 groups/km) in the rest of the protected area. The group sizes were much lower than those observed in the same area between 1994 and 2010, thus suggesting a decline in the population size of langurs. This decline may be linked to habitat loss (timber extraction and mining). Still, also overhunting, as signs of poaching were observed during our field surveys. This was also supported by the reports of our interviewees. Laotian langurs were observed to be sympatric and interact while foraging with the Assamese macaque (Macaca assamensis). In the cases of sympatric occurrence between the two species, we observed that subtle mechanisms of niche partitioning may occur to reduce interspecific competition for food. Further research on the population and ecology of this endangered langur should be conducted to understand the species and aid its conservation. [ABSTRACT FROM AUTHOR]