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1.
A survey of the biflavonyls in the leaves and branchlets of all three sections of the genus Dacrydium s.l. revealed a complex mixture of amentoflavone and its partial methyl ethers and hinokiflavone in most species. A group of three species in section C, however, were characterised by cupressuflavone derivatives as the major biflavone constituents. The results are used to discuss proposals for revised generic boundaries. 相似文献
2.
Banerjee T Valacchi G Ziboh VA van der Vliet A 《Molecular and cellular biochemistry》2002,238(1-2):105-110
The present study attempts to establish the isoforms of hyaluronidase enzyme and their possible role in the spreading of toxins during envenomation. Screening of venoms of 15 snakes belonging to three different families revealed varied hyaluronidase activity in ELISA-like assay, but with relatively similar pH and temperature optima. The zymograms of individual venoms showed varied activity banding patterns and indicated the presence of at least two molecular forms of the enzyme. During envenomation, activity of hyaluronidase is considered crucial for the spreading of toxins and is presumed to distort the integrity of extracellular matrix through the degradation of hyaluronic acid in it. This property has been addressed through localization of hyaluronic acid in human skin and muscle tissue sections using the probe, biotinylated hyaluronic acid binding protein. Faint and discontinuous staining pattern of hyaluronidase treated tissue sections over intense staining of untreated tissue sections confirm the selective degradation of hyaluronic acid in extracellular matrix and thus provide an evidence for the spreading property of the enzyme. 相似文献
3.
The formation of new capillaries from existing blood vessels is critical for tumor growth and metastasis. In this study we
report that amentoflavone, a biflavonoid from Biophytum sensitivum, could inhibit the process of angiogenesis. Amentoflavone at nontoxic concentrations (0.05–0.2 μg/ml) showed significant
inhibition in the proliferation, migration, and tube formation of endothelial cells, which are key events in the process of
angiogenesis. In vivo studies in C57BL/6 mice using amentoflavone showed remarkable inhibition (52.9%) of tumor directed capillary formation. Amentoflavone
showed inhibitory effect on the production of various endogenous factors such as IL-1β, IL-6, TNF-α, GM-CSF, and VEGF that
control the process of angiogenesis. Amentoflavone treatment could increase the production of IL-2 and TIMP-1, which could
successfully shift the equilibrium towards an angiostatic condition. The antiangiogenic activity of amentoflavone was supported
by its remarkable suppression in sprouting of microvessels from rat aorta. Our results also show that amentoflavone could
inhibit the production of VEGF mRNA in B16–F10 cells. These findings indicate that amentoflavone inhibits angiogenesis by
disrupting the integrity of endothelial cells and by altering the endogenous factors that are required for the process of
neovascularization.
Published in Russian in Biokhimiya, 2008, Vol. 73, No. 2, pp. 258–269. 相似文献
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Yasmin Silva Rizk Alice Fischer Marillin de Castro Cunha Patrik Oening Rodrigues Maria Carolina Silva Marques Maria de Fátima Cepa Matos M?nica Cristina Toffoli Kadri Carlos Alexandre Carollo Carla Cardozo Pinto de Arruda 《Memórias do Instituto Oswaldo Cruz》2014,109(8):1050-1056
This study is the first phytochemical investigation of Selaginella sellowii
and demonstrates the antileishmanial activity of the hydroethanolic extract
from this plant (SSHE), as well as of the biflavonoids amentoflavone and
robustaflavone, isolated from this species. The effects of these substances were
evaluated on intracellular amastigotes of Leishmania (Leishmania)
amazonensis, an aetiological agent of American cutaneous leishmaniasis.
SSHE was highly active against intracellular amastigotes [the half maximum inhibitory
concentration (IC50) = 20.2 µg/mL]. Fractionation of the extract led to the isolation
of the two bioflavonoids with the highest activity: amentoflavone, which was about
200 times more active (IC50 = 0.1 μg/mL) and less cytotoxic than SSHE (IC50 = 2.2 and
3 μg/mL, respectively on NIH/3T3 and J774.A1 cells), with a high selectivity index
(SI) (22 and 30), robustaflavone, which was also active against L.
amazonensis (IC50 = 2.8 µg/mL), but more cytotoxic, with IC50 = 25.5
µg/mL (SI = 9.1) on NIH/3T3 cells and IC50 = 3.1 µg/mL (SI = 1.1) on J774.A1 cells.
The production of nitric oxide (NO) was lower in cells treated with amentoflavone
(suggesting that NO does not contribute to the leishmanicidal mechanism in this
case), while NO release was higher after treatment with robustaflavone. S.
sellowii may be a potential source of biflavonoids that could provide
promising compounds for the treatment of cutaneous leishmaniasis. 相似文献
6.
Twenty species, including representatives of all 11 genera of the Callitroideae, were examined for biflavonoid content of the leafy twigs. The major biflavonoids are based on amentoflavone, cupressuflavone and hinokiflavone. Their uneven distribution amongst the genera allows the distinction of five groups. These do not correlate strongly with currently recognized tribal groupings. The affinities of these genera are discussed. 相似文献
7.
采用Diaion HP-20、Toyopearl HW-40、Sephadex LH-20和硅胶等多种柱色谱对蔓生卷柏的化学成分进行分离纯化,结合现代波谱技术分离鉴定了5个化合物,分别为邻羟基苯丙酸(1)、邻羟基肉桂酸(2)、5-羟基香豆素(3)、阿曼托双黄酮(4)和(4E,6Z)-2,7-二甲基-8-羟基-辛二烯酸(5)。这些成分均为首次从该植物中分离得到。 相似文献
8.
A chemosystematic survey has been made of the flavonoids in the three orders of Lycopsida (Lycopodiales, Isoetales, Selaginellales), and of the single order of Psilotopsida (Psilotales). On the basis of the flavonoid patterns observed, a phylogenetic scheme is proposed for these taxa and their origin from fossil Pteridophyta (Psilophytales, Protolepidodendrales, Lepidodendraceae, Sigillariaceae) is discussed. 相似文献
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Thirty species, representing all eight genera of the subfamily Cupressoideae, were examined for biflavonoid content of the leafy twigs. The major biflavonoid constituents are based on amentoflavone, cupressuflavone and hinokiflavone. The affinities suggested by biflavonyl distribution do not correlate with the currently recognized tribal groupings. There is evidence of closer links between northern and southern hemisphere genera than would be expected on the basis of the presently recognized subfamilies. 相似文献