首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Tanacetum L. species traditionally used for insecticidal purposes as well as in folk medicine for their antitumor, antimicrobial, antifungal activities. In our previous study a novel sesquiterpene lactone and triterpene lactone together with 12 known flavonoids, coumarin and a triterpene were isolated from T. chiliophyllum var. oligocephalum and T. chiliophyllum var. monocephalum extracts which have insecticidal and antimicrobial activity. In this study, cytotoxic, antimicrobial activities and acetylcholinesterase (AChE), butyrylcholinesterase (BChE) inhibitory effects of pure compounds isolated from these plants were investigated. The tested compounds showed AChE and BChE inhibition which ranged between 7.20–80.37% and 9.19%–76.99% respectively. The highest AChE and BChE inhibition was observed for ulubelenolide which afforded 80.37% and 76.99% inhibition respectively. The cytotoxic effect of the compounds ranged between 22.34–49.77 μg/mL IC50 values. Highest cytotoxic activity was observed against MCF-7 and HEK 293 cell line by 5–hydroxy-3′,4′,7-trimethoxy flavone and 5-hydroxy-3′,4′,6,7-tetramethoxyflavone that produced 25.80 ± 0.17 and 22.34 ± 0.70 IC50 values respectively. Compounds eupatilin, cirsilineol, 5–hydroxy-3′,4′,7-trimethoxy flavone and ulubelenolide showed significant antimicrobial effect on C. albicans with 7.8 μg/mL MIC. The new compound ulubelenolide afforded high AChE and BChE inhibition as well as high antifungal activity. In our opinion activity of this substance should be evaluated further against other fungal species.  相似文献   

13.
14.
15.
16.
17.
18.
19.
Twenty-two ornamental flowers from different Adenium obesum, Mandevilla sanderi, and Nerium oleander cultivars/seedlings were analyzed for the presence of anthocyanins, flavonols, and chlorogenic acid using nuclear magnetic resonance (NMR) and mass spectrometry (MS). Cyanidin 3-O-[6-O-(rhamnosyl)-galactoside] and cyanidin 3-O-(galactoside) were identified as the major and minor anthocyanins, respectively, in three A. obesum seedlings that had red and red-purple flowers.Cyanidin 3-O-[2-O-(xylosyl)-galactoside] was identified as the major anthocyanin, whereas cyanidin 3-O-[6-O-(rhamnosyl)-galactoside] and cyanidin 3-O-(galactoside) were identified as the minor anthocyanins in 8 M. sanderi cultivars that had red and red-purple flowers. Cyanidin 3-O-[6-O-(rhamnosyl)-galactoside] and cyanidin 3-O-(galactoside) were identified as the major anthocyanins, whereas cyanidin 3-O-[2-O-(xylosyl)-galactoside] was identified as the minor anthocyanin in 8 N. oleander cultivars with red and red-purple flowers. Low levels of anthocyanins were detected in the N. oleander and M. sanderi cultivars that had white flowers, and there were no anthocyanins detected in the N. oleander cultivars with yellow flowers. Chlorogenic acid and four flavonols, quercetin 3-O-[6-O-(rhamnosyl)-galactoside], quercetin 3-O-[6-O-(rhamnosyl)-glucoside], kaempferol 3-O-(galactoside), and kaempferol 3-O-[6-O-(rhamnosyl)-galactoside], were identified in the flowers from all 22 cultivars/seedlings investigated.  相似文献   

20.
Summary With two combs and one or a small number of workers it was found that the comb itself without brood was less attractive than a comb with cocoon caps or larvae, but single workers were equally attracted to combs with a large or small number of larvae, or queen or non-queen larvae. A worker walked at random when off a comb and tended, when on a comb, to stay with the first group of larvae that it found.Observations in the field showed that adults formed a group at night at the bottom of the nest.Records from six observation nests of whole or almost whole colonies have been collected over a period of three years. In all cases a dominant comb, which carried a larger percentage of the workers than any other comb and usually the queen if present, was soon established. The dominant comb always contained brood, was nearest or one of the combs nearest the entrance, received most foragers, and workers grouped on it more frequently than other combs.The grouping behaviour of workers on a comb can be related to background temperature and caused comb temperature to increase to 29° C–32.5° C.The worker attention a larva received increased as the number of workers on its comb increased.Reasons for and the consequences of grouping behaviour, the appearance of a dominant comb and the position of the latter in the nest, are discussed.
Résumé Au cas où il y a deux rayons et soit un seul, soit un petit nombre d'ouvrières, on constate que le rayon sans couvain attire moins les ouvrières que celui operculé (cocons ou larves). Pour ce qui est d'un petit nombre ou d'un grand nombre de larves, ou encore des larves de reines ou de non-reines, l'attraction est égale pour chaque ouvrière. L'ouvrière ne se trouvant pas sur le rayon se déplace au hasard. De plus, quand elle est sur un rayon elle a tendance à rester avec le premier groupe de larves qu'elle trouve.L'examen des observations effectuées sur le terrain montre que les adultes se groupent la nuit, au fond du nid.Six nids, contenant des colonies entières ou presque entières, ont fait l'objet de plusieurs observations pendant une période de trois ans. Durant la même période, les résultats ont été enregistrés. Dans tous les cas, un rayon dominant s'est établi dans un bref délai. Ce rayon avait un plus grand pourcentage d'ouvrières que tout autre, et comportait généralement la reine. Le rayon dominant contenait toujours du couvain; il se trouvait le plus près de l'entrée du nid (ou bien était parmi les plus près); il recevait le plus grand nombre de butineuses, et des ouvrières s'y groupaient plus fréquemment que sur d'autres rayons.Il est possible d'établir un rapport entre le comportement des ouvrières lorsqu'elles se groupent sur un rayon, et la température ambiante. En effet, ce comportement a entrainé une hausse allant jusqu'à 29° C–32,5° C sur le rayon.L'attention que prêtait une ouvrière à la larve augmentait à mesure que le nombre d'ouvrières sur son rayon augmentait.On traite dans cet article du comportement observé lors d'un groupement, les raisons et les conséquences; ainsi que de l'apparition d'un, rayon dominant et de la position de celui-ci dans le nid.
  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号