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1.
Douglas E. Soltis 《Biochemical Systematics and Ecology》1980,8(2):149-151
Sullivantia species were found to produce quercetin 3-O-glycosides, several of which contain glucuronic acid, as well as pedalitin (6-hydroxy-7-O-methyl luteolin), pedalitin 6-O-glycosides, and small amounts of luteolin. Sullivantia has a unique combination of compounds that distinguishes it from other genera in the Saxifraginae for which flavonoid data are available. The nature of the flavonoid compounds is in accordance with a general trend within the Saxifragaceae of reduction and replacement of flavonols by flavones. 相似文献
2.
Nabiel A.M. Saleh Zeinab A.R. El-karemy Ragaa M.A. Mansour Abdel-Aziz A. Fayed 《Phytochemistry》1983,22(11):2501-2505
The flavonoids of five Geranium, fourteen Erodium and four Monsonia species were studied. Quercetin was the most common aglycone with lesse 相似文献
3.
An examination of four species of Cirsium disclosed the presence of two new flavonoids in C. lineare. The structure of one was 5,4′-dihydroxy-6,7,3′-trimethoxyflavone (cirsilineol) 4′-monoglucoside and the other 5,3′,4′-trihydroxy-6,7-dimethoxyflavone (cirsiliol) 4′-monoglucoside. Luteolin 7-glucoside was found in C. suffultum, and pectolinarin and linarin in C. kamtschaticum and C. pectinellum. 相似文献
4.
Cardiac glycoside transport was investigated on the organ and whole plant level. Uptake experiments were carried out with shoot and root cultures of Digitalis lanata. In both systems primary cardenolides, i.e., those with a terminal glucose in their oligosaccharide side chain, were taken up against their concentration gradient, whereas the glucose-free secondary cardenolides were not. Active uptake of primary cardenolides was further evidenced by KCN inhibition of uptake. Using plantlets grown in vitro the long-distance transport of primary cardenolides from the leaves to the roots was demonstrated. Cardenolides were also detected in etiolated leaves, induced on plants with green leaves, which are supposed to be unable to synthezise cardenolides de novo, providing further evidence for long-distance transport. Several primary cardenolides were detected in the honeydew excreted by aphids fed on Digitalis lanata leaves, indicating that the phloem is a transporting tissue for cardenolides. On the other hand, the xylem sap obtained by applying the pressure-chamber technique was cardenolide-free. It was concluded that in Digitalis primary cardenolides serve as both the transport and the storage form of cardenolides. After their synthesis they are either stored in the vacuoles of the source tissue or loaded into the sieve tubes, from which they are unloaded at other sites where they are trapped in the vacuoles of the respective sink tissue. 相似文献
5.
Flavonoids of the Hydrangeaceae Dumortier 总被引:3,自引:0,他引:3
Fourteen species representing nine genera of the Hydrangeaceae Dumortier were surveyed for their flavonoid pigments. All taxa exhibited profiles based upon common flavonols. Myricetin was seen in two genera: Jamesia and Decumaria. Jamesia was further distinguished by the absence of kaempferol or its glycosides. A complex array of 3-O-mono-, 3-O-di- and 3-O-triglycosides was observed, although not all species had all levels of glycosylation. Decumaria barbara was unique within the species studied in its possession of 3,7-di- and 3,7-triglycosides. The overall pattern of flavonol glycosides observed for the Hydrangeaceae closely resembles that found in herbaceous genera of Saxifragaceae. The comparatively low frequency of myricetin contrasts with its high occurrence in herbaceous genera. 相似文献
6.
A procedure for the culture in vitro of isolated small berries of Vitis vinifera L. cv. Muscat of Alexandria in a Murashige and Skoog basal medium supplemented with N6 -benzyladenine and indoleacetic acid is described. Berries developed well in culture during 60 days and tripled in size, but remained green and smaller than normal berries grown in vivo. Some callus formed on the distal end of the berry, and where major skin damage occurred, callus emerged from the cracked berries. In order to examine their biosynthetic competency, berries which were previously cultured in vitro for 60 days were incubated for 48 h in a Murashige and Skoog medium containing a [14 C]-labelled water-soluble fraction. This fraction was isolated from grape berries located adjacent to a leaf that had been exposed to gaseous 14 CO2 in full sunlight for 5 h. The berries were then recultured for 48 h after which a glycosidic fraction was isolated on a C18 reversed phase column and further separated by thin layer chromatography (TLC). The major labelled band corresponded to the geranyl-β-rutinoside marker, indicating that grape berries have the ability to synthesize monoterpene glycosides. This band also consisted of other monoterpene glycosides as revealed by the gas chromatography-mass spectrometry (GC-MS) analysis of their aglycones (released by enzymatic hydrolysis). 相似文献
7.
乌奴龙胆中五个新的环烯醚萜甙 总被引:4,自引:0,他引:4
从藏药乌奴龙胆(GentianaurnulaSmith)(龙胆科)的全草中分离到5个新的环烯醚萜甙,命名为乌奴龙胆甙(gentioumoside)A-E;它们的结构主要通过光谱分析得以确定。其中,乌奴龙胆A-C是二聚环烯醚萜甙,而乌奴龙胆甙D和E为马钱素型的环烯醚萜甙,所有这些化合物的分子中都具有一个2,3-二羟基苯甲酰基或其衍生物的取代基。 相似文献
8.
Christoph Theurer Hans-Joachim Treumann Thomas Faust Ursula May Wolfgang Kreis 《Plant Cell, Tissue and Organ Culture》1994,38(2-3):327-335
The glycosylation and deglycosylation of cardiac glycosides was investigated using cell suspension cultures and shoot cultures, both established from Digitalis lanata EHRH. plants, as well as isolated enzymes. Shoots were capable of glucosylating digitoxigenin, evatromonoside, digiproside, glucodigitoxigenin and digitoxin. Suspension cultured Digitalis cells glucosylated all the substrates mentioned but digiproside, whereas the UDP-glucosedependent cardinolide glucosyltransferase isolated from that source did not accept digitoxigenin and digiproside as substrates. It is concluded that at least three different glucosyltransferases are involved in cardiac glycoside formation in Digitalis. Similar experiments carried out with glucosylated cardenolides which were administered to cultured cells, shoots and a cardenolide -glucosidase isolated from young leaves revealed that at least two different glucosidases occur in Digitalis lanata, albeit in different tissues or during different phases of development. The biotransformation of glucoevatromonoside was investigated using unlabelled compound and [14C-glucose]-glucoevatromonoside synthesized enzymatically. After 7 d of incubation almost no radioactivity could be recovered from the cardenolide fraction, indicating that the terminal glucose of glucoevatromonoside was now incorporated into volatile, hydrophilic and insoluble compounds. Since, on the other hand, large amounts of cardenolides were found in the experiments with unlabelled glucoevatromonoside it is assumed that steady state or pool size regulation is achieved by the coordinated action of a cardenolide glucosidase and a glucosyltransferase.Abbreviations Acdox
D-acetyldigitoxose
- dgen
digoxigenin
- dox
D-digitoxose
- dten
digitoxigenin
- dtl
D-digitalose
- fuc
D-fucose
- gten
gitoxigenin
- qun
D-quinovose
- CGH
cardenolide 16-O-glucohydrolase
- DFT
UDP-fucose:digitoxigenin 3-O-fucosyltransferase
- DGT
UDP-glucose:Digitoxin 16-O-glucosyltransferase
- DQT
UDP-quinovose:digitoxigenin 3-O-quinovosyltransferase 相似文献
9.
Twenty-one flavonoid glycosides were isolated from the leaves of 22 North AmericanVitis L. taxa, representing two subgenera and five series. Three chemical groups were evident: one producing flavonols, flavones, and C-glycosylflavones, a second producing flavonols and flavones, and a third producing only flavonols. These three chemical groups did not correspond to any of the subgeneric groupings based on morphology. However, flavonoid distributions within series in each subgenus correlate well with morphological data. Parallel flavonoid evolution within each series is thought to account for this lack of subgeneric and interserial flavonoid distinction. The flavonoid data indicate that seriesCordifoliae of subgenusVitis, particularlyV. vulpina L., is the most closely related group to subgenusMuscadinia (Planch.)Rehder, and represents an evolutionary link between the two subgenera. 相似文献
10.
Marco Moracci Maria Ciaramella Roberto Nucci Laurence H. Pearl Ian Sanderson Antonio Trincone Mos Rossi 《Biocatalysis and Biotransformation》1994,11(2):89-103
The Sulfolobus solfataricus β-glycosidase (Sβgly) is a thermostable and thermophilic glycosyl-hydrolase with broad substrate specificity. The enzyme hydrolizes β-D-gluco-, fuco-, and galactosides, and a large number of /Winked glycoside dimers and oligomers, linked β1-3, β1-4, and β1-6, It is able to hydrolize oligosaccharides with up to 5 glucose residues. Furthermore, it is also able to promote transglycosylation reactions. The corresponding gene has been cloned and overexpressed both in yeast and Escherichia coli. Based on sequence and functional data, the Sβgly has been assigned to the so-called BGA family of glycosyl-hydrolases, including β-glycosidases, β-galactosidases and phosho-β-galactosidases from mesophilic and thermophilic organisms of the three domains. The Sβgly has been crystallized and the resolution of its structure is in progress. Because of its special properties, the enzymes has considerable biotechnological potential. 相似文献