Ion chromatography-ultra violet-hydride generation-Atomic Florescence Spectrometry was applied to detect 5 arsenic species in seafoods. The arsenic species studied include arsenobetaine(As B), arsenite(As(III)), dimet...Ion chromatography-ultra violet-hydride generation-Atomic Florescence Spectrometry was applied to detect 5 arsenic species in seafoods. The arsenic species studied include arsenobetaine(As B), arsenite(As(III)), dimethylarsinic acid(DMA), monomethylarsonic acid(MMA), and arsenate(As(V)), which were extracted from samples using 2% formic acid. Gradient elution using 33 mmol L^(-1) CH_3COONH_4 and 15 mmol L^(-1) Na_2CO_3 with 10 mL CH_3CH_2OH at pH 8.4 allowed the chromatographic separation of all the species on a Hamilton PRP-X100 anion-exchange column in less than 8 min. In this study, an ultrasound extraction method was used to extract arsenic species from seafood. The extraction efficiency was good and the recoveries from spiked samples were in the range of 72.6%–109%; the precision between sample replicates was higher than 3.6% for all determinations. The detection limits were 3.543 μg L^(-1) for As B, 0.4261 μg L^(-1) for As(III), 0.216 μg L^(-1) for DMA, 0.211 μg L^(-1) for MMA, and 0.709 μg L^(-1) for As(V), and the linear coefficients were greater than 0.999. We also developed an application of this method for the determination of arsenic species in bonito, Euphausia superba, and Enteromorpha with satisfactory results. Therefore, it was confirmed that this method was appropriate for the detection of arsenic species in seafood.展开更多
In this work,an electronic nose was used to evaluate the different cultivars and mature stages of melons,so as to establish a scientific method to accurately distinguish the maturity and varieties of melons. Principal...In this work,an electronic nose was used to evaluate the different cultivars and mature stages of melons,so as to establish a scientific method to accurately distinguish the maturity and varieties of melons. Principal component analysis (PCA) and linear discriminant analysis (LDA ) showed that immature melons could be well distinguished from mature melons using electronic nose. When PCA method was used to analyze,electronic nose could completely classify and identify the maturity of melons. Meanwhile,the electronic nose could distinguish different varieties of melons with high discrimination value. The flavor of samples under cut or no cut conditions would slightly change,leading to the variation of discrimination value among different varieties. The samples with similar flavor under no cut condition could be analyzed through cutting mode. The research built a rapid and accurate method to judge the maturity of melons instead of man sense.展开更多
Plants in genus Kadsura,belong to the Schisandraceae family including genus Schisandra and genus Kadsura,revealed folk efficacy and medicinal application in the treatment of rheumatoid arthritis and gastroenteric diso...Plants in genus Kadsura,belong to the Schisandraceae family including genus Schisandra and genus Kadsura,revealed folk efficacy and medicinal application in the treatment of rheumatoid arthritis and gastroenteric disorders for a long history.Previous study indicated that plants from genus Kadsura mainly contain lignans,triterpenoids and essential oils,and showed the active compounds were lignans and triterpenoids.Among all compounds from Schisandraceae family,the triterpenoids between the genus Schisandra and genus Kadsura had obvious differences.In this paper,we reviewed214triterpenoids and their pharmacological activities reported from genus Kadsura in the past30years(from1987to2017),aiming to provide reference for further study.展开更多
Health organizations worldwide recommend that adults and children minimize intakes of excess energy and salty, sweet, and fatty foods （all of which are highly preferred tastes） and eat diets richer in whole grains, ...Health organizations worldwide recommend that adults and children minimize intakes of excess energy and salty, sweet, and fatty foods （all of which are highly preferred tastes） and eat diets richer in whole grains, low- and non- fat dairy products, legumes, fish, lean meat, fruits, and vegetables （many of which taste bitter）. Despite such recommendations and the well-established benefits of these foods to human health, adults are not complying, nor are their children. A primary reason for this difficulty is the remarkably potent rewarding properties of the tastes and flavors of foods high in sweetness, saltiness, and fatness. While we cannot easily change children＇s basic ingrained biology of liking sweets and avoiding bitterness, we can modulate their flavor preferences by providing early exposure, starting in utero, to a wide variety of flavors within healthy foods, such as fruits, vegetables, and whole grains. Because the flavors of foods mothers eat during pregnancy and lactation also flavor amniotic fluid and breast milk and become preferred by infants, pregnant and lactating women should widen their food choices to include as many flavorful and healthy foods as possible. These experiences, combined with repeated exposure to nutritious foods and flavor variety during the weaning period and beyond, should maximize the chances that children will select and enjoy a healthier diet [Current Zoology 56 （6）： 834-841, 2010].展开更多
A new 18-norschiartane bisnortriterpenoid,12-angeloyl wuweizidilactone I(1)and nine known compounds,wuweizidilactone I(2),wuweizidilactone G(3),deoxychizandrin(4),sasanquin(5),orcinol-O-β-D-glucopyranoside(6),okanin-...A new 18-norschiartane bisnortriterpenoid,12-angeloyl wuweizidilactone I(1)and nine known compounds,wuweizidilactone I(2),wuweizidilactone G(3),deoxychizandrin(4),sasanquin(5),orcinol-O-β-D-glucopyranoside(6),okanin-4-methyl ether-3’-O-β-Dglucopyranoside(7),evemic acid(8),juglansol A(9)and 2-acetoxybenzyl benzoate(10),were isolated from the fruits of Schisandra Chinensis.Their structures were established by a combination of spectroscopic data analysis in addition to comparison with literature data.Compound 1 was new,and compounds 6–10 were isolated from Schisandrae Chinensis for the first time.展开更多
Toxic insects advertise their defended state to potential predators using warning displays. Frequently these displays use cues through more than one sensory modality, and combine color, smell and sound to produce a mu...Toxic insects advertise their defended state to potential predators using warning displays. Frequently these displays use cues through more than one sensory modality, and combine color, smell and sound to produce a multimodal warning display. Signalling through more than one sensory pathway may enhance the rate of avoidance learning, and the memorability of the learned avoidance. A common insect warning odor, pyrazine, has previously been shown to increase the rate of learned avoidance of unpalatable yellow prey by domestic chicks （GaUus gallus domesticus）, and the odor also improved memory of this learned avoidance. However, to date no research has examined this response to pyrazine odor using wild birds under natural conditions. This study used wild robins （Erithacus rubecula） to investigate whether wild birds avoided yellow baits that smelled of pyrazine more strongly than those presented with no odor. The results provide some evidence that pyrazine odor does increase the level of protection an aposematic insect gains from a wild avian predator, but that the effect of pyrazine on learned avoidance was much weaker than was found with domestic chicks .展开更多
Primates have been found to differ widely in their taste perception and studies suggest that a coevolution between plant species bearing a certain taste substance and primate species feeding on these plants may contri...Primates have been found to differ widely in their taste perception and studies suggest that a coevolution between plant species bearing a certain taste substance and primate species feeding on these plants may contribute to such between-species differences. Considering that only platyrrhine primates, but not catarrhine or prosimian primates, share an evolutionary history with the neotrop- ical plant Stevia rebaudiana, we assessed whether members of these three primate taxa differ in their ability to perceive and/or in their sensitivity to its two quantitatively predominant sweet- tasting substances. We found that not only neotropical black-handed spider monkeys, but also paleotropical black-and-white ruffed lemurs and Western chimpanzees are clearly able to perceive stevioside and rebaudioside A. Using a two-bottle preference test of short duration, we found that Ateles geoffroyi preferred concentrations as low as 0.05 mM stevioside and 0.01 mM rebaudioside A over tap water. Taste preference thresholds of Pan troglodytes were similar to those of the spider monkeys, with 0.05 mM for stevioside and 0.03 mM for rebaudioside A, whereas Varecia variegata was slightly less sensitive with a threshold value of 0.1 mM for both substances. Thus, all three primate species are, similar to human subjects, clearly more sensitive to both steviol glycosides compared to sucrose. Only the spider monkeys displayed concentration-response curves with both stevioside and rebaudioside A which can best be described as an inverted U-shaped function sug- gesting that Ateles geoffroyi, similar to human subjects, may perceive a bitter side taste at higher concentrations of these substances. Taken together, the results of the present study do not support the notion that a co-evolution between plant and primate species may account for between-species differences in taste perception of steviol glycosides.展开更多
基金funded by the National Major ScientificInstrument and Equipment Development Project of China (No.2012YQ090229)
文摘Ion chromatography-ultra violet-hydride generation-Atomic Florescence Spectrometry was applied to detect 5 arsenic species in seafoods. The arsenic species studied include arsenobetaine(As B), arsenite(As(III)), dimethylarsinic acid(DMA), monomethylarsonic acid(MMA), and arsenate(As(V)), which were extracted from samples using 2% formic acid. Gradient elution using 33 mmol L^(-1) CH_3COONH_4 and 15 mmol L^(-1) Na_2CO_3 with 10 mL CH_3CH_2OH at pH 8.4 allowed the chromatographic separation of all the species on a Hamilton PRP-X100 anion-exchange column in less than 8 min. In this study, an ultrasound extraction method was used to extract arsenic species from seafood. The extraction efficiency was good and the recoveries from spiked samples were in the range of 72.6%–109%; the precision between sample replicates was higher than 3.6% for all determinations. The detection limits were 3.543 μg L^(-1) for As B, 0.4261 μg L^(-1) for As(III), 0.216 μg L^(-1) for DMA, 0.211 μg L^(-1) for MMA, and 0.709 μg L^(-1) for As(V), and the linear coefficients were greater than 0.999. We also developed an application of this method for the determination of arsenic species in bonito, Euphausia superba, and Enteromorpha with satisfactory results. Therefore, it was confirmed that this method was appropriate for the detection of arsenic species in seafood.
基金Supported by National Natural Science Foundation of China(30870109)
文摘In this work,an electronic nose was used to evaluate the different cultivars and mature stages of melons,so as to establish a scientific method to accurately distinguish the maturity and varieties of melons. Principal component analysis (PCA) and linear discriminant analysis (LDA ) showed that immature melons could be well distinguished from mature melons using electronic nose. When PCA method was used to analyze,electronic nose could completely classify and identify the maturity of melons. Meanwhile,the electronic nose could distinguish different varieties of melons with high discrimination value. The flavor of samples under cut or no cut conditions would slightly change,leading to the variation of discrimination value among different varieties. The samples with similar flavor under no cut condition could be analyzed through cutting mode. The research built a rapid and accurate method to judge the maturity of melons instead of man sense.
基金funding support from Hunan Province Universities 2011 Collaborative Innovation Center of Protection and Utilization of Huxiang Chinese Medicine Resources, Hunan Provincial Key Laboratory of Diagnostics in Chinese Medicine, and National Natural Science Foundation of China (No. 81673579)
文摘Plants in genus Kadsura,belong to the Schisandraceae family including genus Schisandra and genus Kadsura,revealed folk efficacy and medicinal application in the treatment of rheumatoid arthritis and gastroenteric disorders for a long history.Previous study indicated that plants from genus Kadsura mainly contain lignans,triterpenoids and essential oils,and showed the active compounds were lignans and triterpenoids.Among all compounds from Schisandraceae family,the triterpenoids between the genus Schisandra and genus Kadsura had obvious differences.In this paper,we reviewed214triterpenoids and their pharmacological activities reported from genus Kadsura in the past30years(from1987to2017),aiming to provide reference for further study.
文摘Health organizations worldwide recommend that adults and children minimize intakes of excess energy and salty, sweet, and fatty foods （all of which are highly preferred tastes） and eat diets richer in whole grains, low- and non- fat dairy products, legumes, fish, lean meat, fruits, and vegetables （many of which taste bitter）. Despite such recommendations and the well-established benefits of these foods to human health, adults are not complying, nor are their children. A primary reason for this difficulty is the remarkably potent rewarding properties of the tastes and flavors of foods high in sweetness, saltiness, and fatness. While we cannot easily change children＇s basic ingrained biology of liking sweets and avoiding bitterness, we can modulate their flavor preferences by providing early exposure, starting in utero, to a wide variety of flavors within healthy foods, such as fruits, vegetables, and whole grains. Because the flavors of foods mothers eat during pregnancy and lactation also flavor amniotic fluid and breast milk and become preferred by infants, pregnant and lactating women should widen their food choices to include as many flavorful and healthy foods as possible. These experiences, combined with repeated exposure to nutritious foods and flavor variety during the weaning period and beyond, should maximize the chances that children will select and enjoy a healthier diet [Current Zoology 56 （6）： 834-841, 2010].
文摘A new 18-norschiartane bisnortriterpenoid,12-angeloyl wuweizidilactone I(1)and nine known compounds,wuweizidilactone I(2),wuweizidilactone G(3),deoxychizandrin(4),sasanquin(5),orcinol-O-β-D-glucopyranoside(6),okanin-4-methyl ether-3’-O-β-Dglucopyranoside(7),evemic acid(8),juglansol A(9)and 2-acetoxybenzyl benzoate(10),were isolated from the fruits of Schisandra Chinensis.Their structures were established by a combination of spectroscopic data analysis in addition to comparison with literature data.Compound 1 was new,and compounds 6–10 were isolated from Schisandrae Chinensis for the first time.
文摘Toxic insects advertise their defended state to potential predators using warning displays. Frequently these displays use cues through more than one sensory modality, and combine color, smell and sound to produce a multimodal warning display. Signalling through more than one sensory pathway may enhance the rate of avoidance learning, and the memorability of the learned avoidance. A common insect warning odor, pyrazine, has previously been shown to increase the rate of learned avoidance of unpalatable yellow prey by domestic chicks （GaUus gallus domesticus）, and the odor also improved memory of this learned avoidance. However, to date no research has examined this response to pyrazine odor using wild birds under natural conditions. This study used wild robins （Erithacus rubecula） to investigate whether wild birds avoided yellow baits that smelled of pyrazine more strongly than those presented with no odor. The results provide some evidence that pyrazine odor does increase the level of protection an aposematic insect gains from a wild avian predator, but that the effect of pyrazine on learned avoidance was much weaker than was found with domestic chicks .
文摘Primates have been found to differ widely in their taste perception and studies suggest that a coevolution between plant species bearing a certain taste substance and primate species feeding on these plants may contribute to such between-species differences. Considering that only platyrrhine primates, but not catarrhine or prosimian primates, share an evolutionary history with the neotrop- ical plant Stevia rebaudiana, we assessed whether members of these three primate taxa differ in their ability to perceive and/or in their sensitivity to its two quantitatively predominant sweet- tasting substances. We found that not only neotropical black-handed spider monkeys, but also paleotropical black-and-white ruffed lemurs and Western chimpanzees are clearly able to perceive stevioside and rebaudioside A. Using a two-bottle preference test of short duration, we found that Ateles geoffroyi preferred concentrations as low as 0.05 mM stevioside and 0.01 mM rebaudioside A over tap water. Taste preference thresholds of Pan troglodytes were similar to those of the spider monkeys, with 0.05 mM for stevioside and 0.03 mM for rebaudioside A, whereas Varecia variegata was slightly less sensitive with a threshold value of 0.1 mM for both substances. Thus, all three primate species are, similar to human subjects, clearly more sensitive to both steviol glycosides compared to sucrose. Only the spider monkeys displayed concentration-response curves with both stevioside and rebaudioside A which can best be described as an inverted U-shaped function sug- gesting that Ateles geoffroyi, similar to human subjects, may perceive a bitter side taste at higher concentrations of these substances. Taken together, the results of the present study do not support the notion that a co-evolution between plant and primate species may account for between-species differences in taste perception of steviol glycosides.
