ABSTRACT
Emotions are important for social animals because animals' emotions function as beneficial cues to identify valuable resources such as food or to avoid danger by providing environmental information. Emotions also enable animals to predict individuals' behavior and determine how to behave in a specific context. Recently, several studies have reported that dogs are highly sensitive to not only conspecific but also human emotional cues. These studies suggest that domestication may have affected such sensitivity. However, there are still few studies that examine whether other domesticated animals, in addition to dogs, exhibit sensitivity to human emotional cues. In this study, we used a gaze-following task to investigate whether horses (Equus caballus) are sensitive to human emotional cues (happy, neutral, disgust) and if they adjust their behavior accordingly. In the study, the experimenter suddenly turned her head to either right or left and showed emotional cues. The results revealed that horses significantly decreased the frequency with which they followed the experimenter's gaze and the total looking time during the gaze-emotional cue presentation in the Disgust condition compared to the Neutral condition. These results suggest the possibility that horses are sensitive to human emotional cues and behave on the basis of the meaning implied by negative human emotional cues.
ABSTRACT
Two new phenanthrenes, and one new phenylpropanoid, named ephemeranthoquinone C (1), and marylaurencinols C (2) and D (3), were isolated from the roots of Cymbidium Great Flower 'Marylaurencin', respectively. These structures were determined on the basis of 2D NMR experiments. The compounds were tested for antimicrobial activity against Bacillus subtilis, Klebsiella pneumoniae, and Trichophyton rubrum.
Subject(s)
Anti-Infective Agents/chemistry , Orchidaceae/chemistry , Phenanthrenes/chemistry , Phenylpropionates/chemistry , Anti-Infective Agents/isolation & purification , Anti-Infective Agents/pharmacology , Flowers/chemistry , Phenanthrenes/isolation & purification , Phenanthrenes/pharmacology , Phenylpropionates/isolation & purification , Phenylpropionates/pharmacology , Plant Roots/chemistry , Quinones/chemistryABSTRACT
One new phenolic compound, sapnol A (1), and two new aromatic sophorosides, named saposides A (2) and B (3) were isolated from sugar maple sap. In addition, seven known phenolic compounds 4-10 were isolated. These structures were determined on the basis of NMR experiments as well as chemical evidence. Furthermore, all the isolated compounds 1-10 were tested for antioxidative activity by the superoxide dismutase (SOD)-like assay.
Subject(s)
Acer/chemistry , Lignans/chemistry , Phenols/chemistry , Antioxidants/administration & dosage , Antioxidants/chemistry , Canada , Humans , Lignans/isolation & purification , Magnetic Resonance Spectroscopy , Molecular Structure , Phenols/isolation & purificationABSTRACT
A new phenanthrendione, ephemeranthoquinone B (1), two phenanthrenes, marylaurencinols A (2) and B (3), and a phenanthrene glucoside, marylaurencinoside A (4), were isolated from the roots of Cymbidium Great Flower Marie Laurencin, along with six known phenanthrenes, 5-10. The structures of these compounds were established by a combination of extensive NMR spectroscopy and/or X-ray crystallographic analysis and chemical degradation. The compounds were tested for antibacterial activities against Bacillus subtilis and Klebsiella pneumoniae and for cytotoxic activity against the human promyelocytic leukemia (HL-60) cell line. Compounds 1, 3, and 6 showed antibacterial activities with minimum inhibitory concentration (MIC) values in the range of 4.88 to 65.10 µM. Notably, ephemeranthoquinone B (1) had a strong antibacterial effect on B. subtilis. Furthermore, 1 exhibited moderate cytotoxic activity (IC(50) 2.8 µM) against HL-60 cells. Compounds 4-9 also showed weak cytotoxic activity against the HL-60 cell line with IC(50) values of 19.3-52.4 µM.
Subject(s)
Antineoplastic Agents, Phytogenic/isolation & purification , Antineoplastic Agents, Phytogenic/pharmacology , Orchidaceae/chemistry , Phenanthrenes/isolation & purification , Phenanthrenes/pharmacology , Antineoplastic Agents, Phytogenic/chemistry , Crystallography, X-Ray , Drug Screening Assays, Antitumor , HL-60 Cells , Humans , Inhibitory Concentration 50 , Japan , Molecular Conformation , Molecular Structure , Phenanthrenes/chemistry , Plant Roots/chemistryABSTRACT
We have prepared novel ionic liquids of bis(N-2-ethylhexylethylenediamine)silver(I) nitrate ([Ag(eth-hex-en)(2)]NO(3) and bis(N-hexylethylenediamine)silver(I) hexafluorophosphate ([Ag(hex-en)(2)]PF(6)), which have transition points at -54 and -6 degrees C, respectively. Below these transition temperatures, both the silver complexes assume amorphous states, in which the extent of the vitrification is larger for the eth-hex-en complex than for the hex-en complex. The diffusion coefficients of both the complex cations, measured between 30 (or 35) and 70 degrees C, are largely dependent on temperature; the dependence is particularly large in the case of the eth-hex-en complex cation below 40 degrees C. Small-angle X-ray scattering studies showed that the bilayer structure of the metal complex is formed in the liquid state for both the silver complexes. A direct observation of the yellowish [Ag(eth-hex-en)(2)]NO(3) liquid by transmission electron microscopy (TEM) indicates the presence of nanostructures, as a microemulsion, of less than 5 nm. Such structures were not clearly observed in the [Ag(hex-en)(2)]PF(6) liquid. Although the [Ag(eth-hex-en)(2)]NO(3) liquid is sparingly soluble in bulk water, it readily incorporates a small amount of water up to [water]/[metal complex] = 7:1. Homogeneous and uniformly sized silver(0) nanoparticles in water were created by the reduction of the [Ag(eth-hex-en)(2)]NO(3) liquid with aqueous NaBH(4), whereas silver(0) nanoparticles were not formed from the [Ag(hex-en)(2)]PF(6) liquid in the same way.
