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.
The ergot alkaloid biosynthesis system has become an excellent model to study evolutionary diversification of specialized (secondary) metabolites. This is a very diverse class of alkaloids with various neurotropic activities, produced by fungi in several orders of the phylum Ascomycota, including plant pathogens and protective plant symbionts in the family Clavicipitaceae. Results of comparative genomics and phylogenomic analyses reveal multiple examples of three evolutionary processes that have generated ergot-alkaloid diversity: gene gains, gene losses, and gene sequence changes that have led to altered substrates or product specificities of the enzymes that they encode (neofunctionalization). The chromosome ends appear to be particularly effective engines for gene gains, losses and rearrangements, but not necessarily for neofunctionalization. Changes in gene expression could lead to accumulation of various pathway intermediates and affect levels of different ergot alkaloids. Genetic alterations associated with interspecific hybrids of Epichloë species suggest that such variation is also selectively favored. The huge structural diversity of ergot alkaloids probably represents adaptations to a wide variety of ecological situations by affecting the biological spectra and mechanisms of defense against herbivores, as evidenced by the diverse pharmacological effects of ergot alkaloids used in medicine.  相似文献   

2.
Several fungi in two different families––the Clavicipitaceae and the Trichocomaceae––produce different profiles of ergot alkaloids, many of which are important in agriculture and medicine. All ergot alkaloid producers share early steps before their pathways diverge to produce different end products. EasA, an oxidoreductase of the old yellow enzyme class, has alternate activities in different fungi resulting in branching of the pathway. Enzymes beyond the branch point differ among lineages. In the Clavicipitaceae, diversity is generated by the presence or absence and activities of lysergyl peptide synthetases, which interact to make lysergic acid amides and ergopeptines. The range of ergopeptines in a fungus may be controlled by the presence of multiple peptide synthetases as well as by the specificity of individual peptide synthetase domains. In the Trichocomaceae, diversity is generated by the presence or absence of the prenyl transferase encoded by easL (also called fgaPT1). Moreover, relaxed specificity of EasL appears to contribute to ergot alkaloid diversification. The profile of ergot alkaloids observed within a fungus also is affected by a delayed flux of intermediates through the pathway, which results in an accumulation of intermediates or early pathway byproducts to concentrations comparable to that of the pathway end product.  相似文献   

3.
Ergot is a disease of cereals and grasses caused by fungi in the genus Claviceps. Of particular concern are Claviceps purpurea in temperate regions, C. africana in sorghum (worldwide), and C. fusiformis in pearl millet (Africa, Asia). The fungi infect young, usually unfertilized ovaries, replacing the seeds by dark mycelial masses known as sclerotia. The percentage of sclerotia in marketable grain is strictly regulated in many countries. In winter rye, ergot has been known in Europe since the early Middle Ages. The alkaloids produced by the fungus severely affect the health of humans and warm-blooded animals. In sorghum and pearl millet, ergot became a problem when growers adopted hybrid technology, which increased host susceptibility. Plant traits reducing ergot infection include immediate pollination of receptive stigmas, closed flowering (cleistogamy), and physiological resistance. Genetic, nonpollen-mediated variation in ergot susceptibility could be demonstrated in all three affected cereals. Fungicides have limited efficacy and application is weather dependent. Sorting out the sclerotia from the harvest by photocells is expensive and time consuming. In conclusion, molecular-based hybrid rye breeding could improve pollen fertility by introgressing effective restorer genes thus bringing down the ergot infection level to that of conventional population cultivars. A further reduction might be feasible in the future by selecting more resistant germplasm.  相似文献   

4.
Philippe Guerre 《Toxins》2015,7(3):773-790
The development of fungal endophytes of the genus Epichloë in grasses results in the production of different groups of alkaloids, whose mechanism and biological spectrum of toxicity can differ considerably. Ergot alkaloids, when present in endophyte-infected tall fescue, are responsible for “fescue toxicosis” in livestock, whereas indole-diterpene alkaloids, when present in endophyte-infected ryegrass, are responsible for “ryegrass staggers”. In contrast, peramine and loline alkaloids are deterrent and/or toxic to insects. Other toxic effects in livestock associated with the consumption of endophyte-infected grass that contain ergot alkaloids include the “sleepy grass” and “drunken horse grass” diseases. Although ergovaline is the main ergopeptine alkaloid produced in endophyte-infected tall fescue and is recognized as responsible for fescue toxicosis, a number of questions still exist concerning the profile of alkaloid production in tall fescue and the worldwide distribution of tall fescue toxicosis. The purpose of this review is to present ergot alkaloids produced in endophyte-infected grass, the factors of variation of their level in plants, and the diseases observed in the mammalian species as relate to the profiles of alkaloid production. In the final section, interactions between ergot alkaloids and drug-metabolizing enzymes are presented as mechanisms that could contribute to toxicity.  相似文献   

5.
The epichloae (Epichloë and Neotyphodium species), a monophyletic group of fungi in the family Clavicipitaceae, are systemic symbionts of cool-season grasses (Poaceae subfamily Poöideae). Most epichloae are vertically transmitted in seeds (endophytes), and most produce alkaloids that attack nervous systems of potential herbivores. These protective metabolites include ergot alkaloids and indole-diterpenes (tremorgens), which are active in vertebrate systems, and lolines and peramine, which are more specific against invertebrates. Several Epichloë species have been described which are sexual and capable of horizontal transmission, and most are vertically transmissible also. Asexual epichloae are mainly or exclusively vertically transmitted, and many are interspecific hybrids with genomic contributions from two or three ancestral Epichloë species. Here we employ genome-scale analyses to investigate the origins of biosynthesis gene clusters for ergot alkaloids (EAS), indole-diterpenes (IDT), and lolines (LOL) in 12 hybrid species. In each hybrid, the alkaloid-gene and housekeeping-gene relationships were congruent. Interestingly, hybrids frequently had alkaloid clusters that were rare in their sexual ancestors. Also, in those hybrids that had multiple EAS, IDT or LOL clusters, one cluster lacked some genes, usually for late pathway steps. Possible implications of these findings for the alkaloid profiles and endophyte ecology are discussed.  相似文献   

6.
7.
Ergot alkaloids are nitrogen-containing natural products belonging to indole alkaloids. The best known producers are fungi of the phylum Ascomycota, e.g., Claviceps, Epichloë, Penicillium and Aspergillus species. According to their structures, ergot alkaloids can be divided into three groups: clavines, lysergic acid amides and peptides (ergopeptines). All of them share the first biosynthetic steps, which lead to the formation of the tetracyclic ergoline ring system (except the simplest, tricyclic compound: chanoclavine). Different modifications on the ergoline ring by specific enzymes result in an abundance of bioactive natural products, which are used as pharmaceutical drugs or precursors thereof. From the 1950s through to recent years, most of the biosynthetic pathways have been elucidated. Gene clusters from several ergot alkaloid producers have been identified by genome mining and the functions of many of those genes have been demonstrated by knock-out experiments or biochemical investigations of the overproduced enzymes.  相似文献   

8.
Ergot alkaloids are mycotoxins formed by fungi of the Claviceps genus, which are some of the most common contaminants of food and feed worldwide. These toxins are a structurally heterogeneous group of compounds, sharing an ergoline backbone. Six structures and their corresponding stereoisomers are typically quantified by either HPLC-FLD or HPLC-MS/MS and the values subsequently summed up to determine the total ergot alkaloid content. For the development of a screening method targeting all ergot alkaloids simultaneously, the alkaloids need to be transferred to one homogeneous structure: a lysergic acid derivative. In this study, two promising cleaving methods—acidic esterification and hydrazinolysis—are compared, using dihydroergocristine as a model compound. While the acidic esterification proved to be unsuitable, due to long reaction times and oxidation sensitivity, hydrazinolysis reached a quantitative yield in 40‒60 min. Parallel workup of several samples is possible. An increasing effect on the reaction rate by the addition of ammonium iodide was demonstrated. Application of hydrazinolysis to a major ergot alkaloid mix solution showed that all ergopeptines were cleaved, but ergometrine/-inine was barely affected. Still, hydrazinolysis is a suitable tool for the development of a sum parameter screening method for ergot alkaloids in food and feed.  相似文献   

9.
Ergotism is a common and increasing problem in Saskatchewan’s livestock. Chronic exposure to low concentrations of ergot alkaloids is known to cause severe arterial vasoconstriction and gangrene through the activation of adrenergic and serotonergic receptors on vascular smooth muscles. The acute vascular effects of a single oral dose with high-level exposure to ergot alkaloids remain unknown and are examined in this study. This study had two main objectives; the first was to evaluate the role of α1-adrenergic receptors in mediating the acute vasocontractile response after single-dose exposure in sheep. The second was to examine whether terazosin (TE) could abolish the vascular contractile effects of ergot alkaloids. Twelve adult female sheep were randomly placed into control and exposure groups (n = 6/group). Ergot sclerotia were collected and finely ground. The concentrations of six ergot alkaloids (ergocornine, ergocristine, ergocryptine, ergometrine, ergosine, and ergotamine) were determined using HPLC/MS at Prairie Diagnostic Services Inc., (Saskatoon, SK, Canada). Each ewe within the treatment group received a single oral treatment of ground ergot sclerotia at a dose of 600 µg/kg BW (total ergot) while each ewe in the control group received water. Animals were euthanized 12 h after the treatment, and the pedal artery (dorsal metatarsal III artery) from the left hind limb from each animal was carefully dissected and mounted in an isolated tissue bath. The vascular contractile response to phenylephrine (PE) (α1-adrenergic agonist) was compared between the two groups before and after TE (α1-adrenergic antagonist) treatment. Acute exposure to ergot alkaloids resulted in a 38% increase in vascular sensitivity to PE compared to control (Ctl EC50 = 1.74 × 10−6 M; Exp EC50 = 1.079 × 10−6 M, p = 0.046). TE treatment resulted in a significant dose-dependent increase in EC50 in both exposure and control groups (p < 0.05 for all treatments). Surprisingly, TE effect was significantly more pronounced in the ergot exposed group compared to the control group at two of the three concentrations of TE (TE 30 nM, p = 0.36; TE 100 nM, p < 0.001; TE 300 nM, p < 0.001). Similar to chronic exposure, acute exposure to ergot alkaloids results in increased vascular sensitivity to PE. TE is a more potent dose-dependent antagonist for the PE contractile response in sheep exposed to ergot compared to the control group. This study may indicate that the dry gangrene seen in sheep, and likely other species, might be related to the activation of α1-adrenergic receptor. This effect may be reversed using TE, especially at early stages of the disease before cell death occurs. This study may also indicate that acute-single dose exposure scenario may be useful in the study of vascular effects of ergot alkaloids.  相似文献   

10.
Pastures are key feed sources for dairy production and can be contaminated with several secondary metabolites from fungi and plants with toxic or endocrine-disrupting activities, which possess a risk for the health, reproduction and performance of cattle. This exploratory study aimed to determine the co-occurrences and concentrations of a wide range of mycotoxins, phytoestrogens and other secondary metabolites in grazing pastures. Representative samples of pastures were collected from 18 Austrian dairy farms (one sample per farm) between April to October 2019. After sample preparation (drying and milling) the pastures were subjected to multi-metabolite analysis using LC-MS/MS. In total, 68 metabolites were detected, including regulated zearalenone and deoxynivalenol (range: 2.16–138 and 107–505 μg/kg on a dry matter (DM) basis, respectively), modified (3-deoxynivalenol-glucoside, HT-2-glucoside) and emerging Fusarium mycotoxins (e.g., enniatins), ergot alkaloids and Alternaria metabolites along with phytoestrogens and other metabolites. Aflatoxins, fumonisins, T-2 toxin, HT-2 toxin and ochratoxins were not detected. Of the geo-climatic factors and botanical diversity investigated, the environment temperature (average of 2 pre-sampling months and the sampling month) was the most influential factor. The number of fungal metabolites linearly increased with increasing temperatures and temperatures exceeding 15 °C triggered an exponential increment in the concentrations of Fusarium and Alternaria metabolites and ergot alkaloids. In conclusion, even though the levels of regulated mycotoxins detected were below the EU guidance levels, the long-term exposure along with co-occurrence with modified and emerging mycotoxins might be an underestimated risk for grazing and forage-fed livestock. The one-year preliminary data points out a dominant effect of environmental temperature in the diversity and contamination level of fungal metabolites in pastures.  相似文献   

11.
Ergot sclerotia effect cereal crops intended for consumption. Ergot alkaloids within ergot sclerotia are assessed to ensure contamination is below safety standards established for human and animal health. Ergot alkaloids exist in two configurations, the R and S-epimers. It is important to quantify both configurations. The objective of this study was to validate a new ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method for quantification of six R and six S-epimers of ergot alkaloids in hard red spring wheat utilizing deuterated lysergic acid diethylamide (LSD-D3) as an internal standard. Validation parameters such as linearity, limit of detection (LOD), limit of quantification (LOQ), matrix effects, recovery and precision were investigated. For the 12 epimers analyzed, low LOD and LOQ values were observed, allowing for the sensitive detection of ergot epimers. Matrix effects ranged between 101–113% in a representative wheat matrix. Recovery was 68.3–119.1% with an inter-day precision of <24% relative standard deviation (RSD). The validation parameters conform with previous studies and exhibit differences between the R and S-epimers which has been rarely documented. This new sensitive method allows for the use of a new internal standard and can be incorporated and applied to research or diagnostic laboratories.  相似文献   

12.
Ergot alkaloid mycotoxins interfere in many functions associated with serotonergic neurotransmitters. Therefore, the objective was to evaluate whether the association of serotonin (5-hydroxytryptamine, 5-HT) and ergot alkaloids during a 24 h pre-incubation could affect the vascular contractile response to ergot alkaloids. To evaluate the effects of 24 h exposure to 5-HT and ergot alkaloids (ergovaline, ERV), two assays were conducted. The first assay determined the half-maximal inhibitory concentration (IC50) following the 24 h pre-exposure period, while the second assay evaluated the effect of IC50 concentrations of 5-HT and ERV either individually or in combination. There was an interaction between previous exposure to 5-HT and ERV. Previous exposure to 5-HT at the IC50 concentration of 7.57 × 10−7 M reduced the contractile response by more than 50% of control, while the exposure to ERV at IC50 dose of 1.57 × 10−10 M tended to decrease (p = 0.081) vessel contractility with a response higher than 50% of control. The 24 h previous exposure to both 5-HT and ERV did not potentiate the inhibitory response of blood vessels in comparison with incubation with each compound alone. These results suggest receptor competition between 5-HT and ERV. More studies are necessary to determine the potential of 5-HT to treat toxicosis caused by ergot alkaloids.  相似文献   

13.
Standardization of herbal drugs based on their chemical and biological activity profile is an important prerequisite for acquiring the herbal market. The main problem encountered in standardization of Ayurvedic drugs is proper identification of the source plant. The present study was aimed to establish identification characters, quality control parameters, chemical and biological parameters for roots of three plants Cissampelos pareira, Cyclea peltata and Stephania japonica (Fam. Menispermaceae) which are being used as source of Patha, in the market. All the three plant were subjected for evaluation of quality control parameters as per WHO guidelines and root extracts and total alkaloidal fractions were subjected for HPTLC and HPLC fingerprinting analysis using a marker compound Bebeerine isolated from roots of Cissampelos pareira. The parameters studied clearly indicated the significant differences among the three plant materials. The roots of Cissampelos pareira can be distinguished from other two plants by presence of high concentration of alkaloids especially the presence of high concentration of pharmacologically active alkaloid bebeerine, which was found to be present in very low concentration in Stephania japonica and absent in roots of Cyclea peltata. The roots of Cyclea peltata were found to contain high concentration of saponins and comparatively in low concentration in Cissampelos pareira where as it was found to be absent in roots of Stephania japonica.  相似文献   

14.
The alkaloid content and the composition of the alkaloid complex of thirteen samples of ergot sclerotia from different gramineous host species collected in The Netherlands were investigated. Two samples collected in France were also examined. Ergot ofGlyceria fluitans (L.) R.Br. did not contain alkaloids. The total alkaloid content of ergot found on the other wild grasses was more than 0.2%. The ratio between the contents of water soluble and water insoluble alkaloids of the investigated ergot sclerotia varies between 1∶10 and 1∶20. The composition of the alkaloid complex in the sclerotia was studied by quantitative thin-layer chromatography. The sclerotia could be grouped into three main categories:
  • sclerotia ofLolium perenne L.,Festuca arundinacea Schreb. andArrhenatherum elatius (L.) P.B. ex J. et C. Presl, containing predominantly ergocornine, α- and β-ergokryptine and ergosine;
  • sclerotia ofDactylis glomerata L.,Phalaris arundinacea L.,Alopecurus geniculatus L. andHolcus mollis L., containing predominantly ergosine, ergocristine and ergotamine;
  • sclerotia ofMolinia caerulea (L.) Moench, containing predominantly ergocristine, ergosine and ergqmetrine.
  • A great similarity was found between the composition of the alkaloid complex in ergot ofLolium perenne L. from different locations and also in ergot ofMolinia caerulea (L.) Moench from different locations. This similarity was less in ergot ofDactylis glomerata L. collected from different locations.  相似文献   

    15.
    Following pending new legislation in the European Union setting a maximum of 20 ng g−1 for the total sum of ergot alkaloids in dry cereal-based baby food, a new UHPLC-MS/MS method was developed. It is suitable for the quantification of six ergot alkaloids: Ergocornine, ergocristine, ergometrine, ergosine, ergotamine, α-ergocryptine, and their corresponding epimers. The method is able to reliably detect individual ergot alkaloids at a level as low as 0.5 ng g−1. The method uses a modified QuEChERS extraction approach before UHPLC-MS/MS analysis. The method showed good sensitivity, accuracy, and precision. It has been applied to 49 samples from the Belgian market. In 26 samples, not a single ergot alkaloid was detected while in 23 out of 49 samples at least one ergot alkaloid was detected with 2 samples containing 12 ergot alkaloids. Ergometrine was the alkaloid most frequently detected i.e., 16 out of 49 samples. Only one sample, testing positive for all 12 ergot alkaloids, would be non-conforming to the newly proposed Maximum Residue Level (MRL).  相似文献   

    16.
    The leaves extracts of two indigenous plants of Ethiopia: Clematis longicauda steud ex A. Rich. and Clematis burgensis Engl. are used in Southwestern Ethiopia to treat otorrhoea and eczema. Antimicrobial activity and MIC of crude extracts were determined by disk diffusion and broth dilution. Phytochemical screening was performed on the extracts. The methanol and petroleum ether extracts of both plants showed antibacterial and antifungal activity. Sensitivity of reference strains was concentration dependent. Methanol and petroleum ether extracts of C. burgensis leaves exerted greater inhibitory effects than C. longicauda extracts whereas aqueous extracts of both plants were inactive. The MIC study revealed a concentration of 0.78 mg/ml on bacteria and 3.125 mg/ml on fungi for methanol extract and 1.56 mg/ml on both fungi and bacteria for petroleum ether extract. Phytochemical screening results indicated the presence of proteins, fixed oils, carbohydrates, tannins, saponins, flavonoids, and steroids. Preliminary chromatographic investigation showed fluorescing spots with Rf values that ranged from 0.05 to 0.96 for phenolic compounds and saponins. As the study is one of the first reports on the two indigenous species of Clematis; isolation, purification and characterization of the different primary and secondary metabolites may further yield alternative options to the microbial chemotherapy.  相似文献   

    17.
    ABSTRACT

    Sixty-three male sprague Dawley rats were randomly assigned to dietary treatments containing 1) N-formylloline alkaloid (NFL), 2) N-acetylloline alkaloid (NAL), 3) NFL + NAL, 4) NFL + a mixture of ergot alkaloids, 5) NAL + a mixture of ergot alkaloids, 6) NFL + NAL + a mixture of ergot alkaloids, 7) a mixture of ergot alkaloids, 8) endophyte-free tall fescue seed (EFTF), and 9) endophyte-infected tall fescue (EITF) seed (negative control). All diets were prepared by mixing the prepared treatments and Laboratory Chow® (1:1 ratio) and were fed at a maximum of 15 g per rat per day. All rats were killed at termination (d 18). Rats fed the EITF consumed less (P < .05) than those fed all other treatments. Feed intake for rats fed the NFL + ergot alkaloids was lower than for those fed NAL, NAL + ergot alkaloids, NFL + NAL + ergot alkaloids, ergot alkaloids, and EFTF treatments. Average daily weight gains (ADG) followed a trend similar to feed intake with some exceptions. Rats fed the NFL + NAL treatments had higher (P < .05) ADG than those fed all other treatments except the NFL + NAL + ergot alkaloid treatment. Rats fed the EITF had lower (P < .05) ADG than those fed all other treatments except those fed ergot alkaloids and NAL + ergot alkaloids. Epididymides, testes, hypothalamus, corpus striatum weights, prolactin and alkaline phosphatase content were not altered by dietary treatments. Results suggest that loline alkaloids may have a slight depressing effect on feed intake  相似文献   

    18.
    Epichloë endophytes are filamentous fungi (family Clavicipitaceae) that live in symbiotic associations with grasses in the sub family Poöideae. In New Zealand, E. festucae var. lolii confers significant resistance to perennial ryegrass (Lolium perenne) against insect and animal herbivory and is an essential component of pastoral agriculture, where ryegrass is a major forage species. The fungus produces in planta a range of bioactive secondary metabolites, including ergovaline, which has demonstrated bioactivity against the important pasture pest black beetle, but can also cause mammalian toxicosis. We genetically modified E. festucae var. lolii strain AR5 to eliminate key enzymatic steps in the ergovaline pathway to determine if intermediate ergot alkaloid compounds can still provide insecticidal benefits in the absence of the toxic end product ergovaline. Four genes (dmaW, easG, cloA, and lpsB) spanning the pathway were deleted and each deletion mutant was inoculated into five different plant genotypes of perennial ryegrass, which were later harvested for a full chemical analysis of the ergot alkaloid compounds produced. These associations were also used in a black beetle feeding deterrence study. Deterrence was seen with just chanoclavine present, but was cumulative as more intermediate compounds in the pathway were made available. Ergovaline was not detected in any of the deletion associations, indicating that bioactivity towards black beetle can be obtained in the absence of this mammalian toxin.  相似文献   

    19.
    Bioactivity-guided fractionation was used to determine the cytotoxic alkaloids from the toxic plant Peganum harmala. Two novel indole alkaloids, together with ten known ones, were isolated and identified. The novel alkaloids were elucidated to be 2-(indol-3-yl)ethyl-α-l-rhamnopyranosyl-(1 → 6)-β-d-glucopyranoside (2) and 3-hydroxy-3-(N-acetyl-2-aminoethyl)-6-methoxyindol-2-one (3). The cytotoxicity against human leukemia cells was assayed for the alkaloids and some of them showed potent activity. Harmalacidine (compound 8, HMC) exhibited the highest cytotoxicity against U-937 cells with IC50 value of 3.1 ± 0.2 μmol/L. The cytotoxic mechanism of HMC was targeting the mitochondrial and protein tyrosine kinase signaling pathways (PTKs-Ras/Raf/ERK). The results strongly demonstrated that the alkaloids from Peganum harmala could be a promising candidate for the therapy of leukemia.  相似文献   

    20.
    Sarpagandha ghanvati is a classical Ayurvedic formulation widely prescribed for anxiety and insomnia. It contains Sarpagandha (roots of Rauwolfia serpentina L. (Benth.) Ex Kurz; Family: Apocyanaceae), Khurasani ajowan (Hyocyamus niger L.; Family: Solanaceae) seeds, Jatamansi (Nardostachys jatamansi DC. Family: Valerianaceae) roots and Pipplamul (root of Piper longum L.; Family: Piperaceae). The objective of this study was to make a comparative evaluation of Ghanvatis and tablets of this formulation. Two tablet formulations were prepared; one incorporating only powders of all ingredients; the other with ethanol extracts of the first three ingredients and powder of Piper longum root. Similarly, two types of Sarpagandha ghanvati pills were prepared; one as per Ayurvedic Formulary of India; the other with ethanol extracts of the first three ingredients and powder of Piper longum root. Alcohol extracted 0.22% w/w of total alkaloids as against 0.061% w/w extracted by water. Tablets prepared with powders of all the ingredients had friability more than 3.0% where as those prepared with ethanol extract had very low friability. Ghanvatis, prepared as per the Ayurvedic formulary, did not show reserpine although other alkaloids were present. They showed less content uniformity and lower drug release. Ethanol extracted reserpine along with other alkaloids. Ghanvatis made with the alcoholic extracts exhibited better content uniformity and drug release than the traditional formulation. Tablets prepared with powders or extracts of the ingredients exhibited good content uniformity but the release of alkaloids from the tablets of powders was only 80%. Tablets of the extracts had good content uniformity with 90% release of the total alkaloids. Tablets prepared with alcoholic extracts using 1% polyvinylpyrrolidone as binder and 5% dried starch powder as disintegrating agent confirmed to all the requirements. Thus, the study shows tablets made with the extracts are superior to Ghanvatis and powder tablets.  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