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Role of flavonoids in plant interactions with the environment and against human pathogens — A review
Flavonoids are widely-distributed polyphenolic secondary metabolites with diverse biological activities in plants and benefit human health as protective dietary agents. They participate in plants' responses to harsh environmental conditions and effectively regulate the cell differentiation and growth. In plants, the majority of their functions are attributed to their strong antioxidative properties. Similarly, dietary flavonoids protect the human body against free radicals which are associated with the development of cancer and atherosclerosis. Plants rich in polyphenols have been used to cure various diseases because of their antibacterial, antiviral, antifungal and anticancer properties. This review summarizes the up-to-date research trends and development on flavonoids and its derivatives, working mechanisms and potential functions and applications particularly in relation to plant protection and human health. Towards the end, notable concluding remarks with a close-up look at the future research directions have also been presented briefly. 相似文献
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A R Feinstein 《Science (New York, N.Y.)》1988,242(4883):1257-1263
Many substances used in daily life, such as coffee, alcohol, and pharmaceutical treatment for hypertension, have been accused of "menace" in causing cancer or other major diseases. Although some of the accusations have subsequently been refuted or withdrawn, they have usually been based on statistical associations in epidemiologic studies that could not be done with the customary experimental methods of science. With these epidemiologic methods, however, the fundamental scientific standards used to specify hypotheses and groups, get high-quality data, analyze attributable actions, and avoid detection bias may also be omitted. Despite peer-review approval, the current methods need substantial improvement to produce trustworthy scientific evidence. 相似文献
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微波法提取山丹茎总黄酮的工艺优化 总被引:1,自引:0,他引:1
薛长晖 《青岛农业大学学报(自然科学版)》2009,26(1):70-72
采用微波提取法提取出了山丹茎中的总黄酮;对其中黄酮的种类进行了化学定性研究;对山丹茎中总黄酮的微波提取工艺进行了优化。结果表明:山丹茎中含有黄酮类化合物,并且可能是黄酮醇类化合物;影响山丹茎中总黄酮提取率的四大因素的次序为料液比>微波功率>微波提取时间>提取浓度;最后通过单因子实验确定了山丹茎黄酮微波提取的最佳微波功率为700W,微波加热90 s,乙醇浓度70%,料液比1:35,该工艺条件下总黄酮得率达1.06%,与传统提取方法相比,微波提取法具有节省时间、节约能量、提取效率高、控制方便等优点。 相似文献
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类黄酮在植物中大量存在并具有多种生理活性。具有C6-C3-C6骨架结构的类黄酮结构特征鲜明,对其结构与不同生理活性的构效关系研究是筛选和利用类黄酮的重要依据。随着类黄酮构效关系的研究方法不断地深入发展,从最初的定性构效关系研究,逐渐发展到依次出现的二维、三维和全息定量构效关系研究,极大地提高了对类黄酮活性研究的效率。本文从研究方法的角度,对近年来的类黄酮构效关系研究进展进行了综述。 相似文献
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黄酮类化合物是广泛存在于植物界的一类多酚类物质,具有多种生物活性与药理活性。在研究发现多种黄酮具有明显的抗辐射作用,其机制可能与对造血系统的保护作用、对免疫系统的保护作用、清除自由基、抗氧化、保护DNA等作用有关。本文就抗辐射活性机理,最近黄酮类化合物抗辐射试验研究状况进行了综述,并对其在食品中的应用提出了进一步的展望。 相似文献
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黄酮类化合物的活性研究进展 总被引:11,自引:1,他引:10
黄酮类化合物是植物经光合作用产生的,以2-苯基色原酮为母核的一类低分子天然物质,在母核上连接有羟基、羟氧基等结构不同的黄酮,具有抗氧化活性。文章综述了黄酮类化合物抗氧化活性大小与其结构的关系和测定黄酮类化合物抗氧化性的方法。 相似文献
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银杏叶中有效成分的研究 总被引:33,自引:1,他引:32
银杏叶中主要生物活性成分黄酮类和萜内酯是目前银杏叶提取物及植物药质量控制的有效。依据。本文详细综述了银杏叶中黄酮类和萜内酯有效成分,扼要讨论了它们的结构与活性关系,并简单概述了萜内酯的合成。 相似文献
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所谓功能性食品就是指在满足基本的营养需要的同时还能够发挥额外的生理作用,如预防或延迟慢性疾病的发作等。过去数十年的研究已经发现了大量的可以防止细胞氧化的营养物质。这些水果和蔬菜中的成分能够作为抗氧化剂清除体内的有害的能引起疾病的自由基。功能性食品在抗癌症方面有着广阔的应用前景。 相似文献
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Leishmaniasis and malaria: new tools for epidemiologic analysis 总被引:4,自引:0,他引:4
D F Wirth W O Rogers R Barker H Dourado L Suesebang B Albuquerque 《Science (New York, N.Y.)》1986,234(4779):975-979
Parasitic diseases are still prevalent in many parts of the world, causing both human suffering and economic loss. Recent developments in biotechnology, such as the use of monoclonal antibodies and recombinant DNA, have the potential for providing both more extensive and detailed information on the parasite in the infected human and in insect vectors. New methods of detection, both in man and insect vectors, have been developed for two parasitic diseases, leishmaniasis and malaria. These new methodologies will be important in epidemiologic studies on the prevalence and transmission of these parasitic diseases. 相似文献
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葎草及黄酮类化合物的研究进展 总被引:3,自引:0,他引:3
黄酮类化合物是一类具有广泛开发前景的天然药物,葎草中舍有丰富的黄酮类化合物。介绍了葎草的化学成分、药理活性及黄酮类化合物提取、分离和测定方法的研究进展,为开发利用葎草中黄酮类化合物提供一定的科学借鉴依据。 相似文献
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HIV-1 production from infected peripheral blood T cells after HTLV-I induced mitogenic stimulation 总被引:17,自引:0,他引:17
The human immunodeficiency virus type 1 (HIV-1) and human T-cell leukemia virus type I (HTLV-I) are two distinct human retroviruses that infect T cells. Recent epidemiologic studies have identified a cohort of individuals that are coinfected with both viruses. It is reported here that human peripheral blood leukocytes infected with HIV-1 in vitro can be induced to produce large quantities of HIV-1 after mitogenic stimulation by noninfectious HTLV-I virions. It is also shown that HTLV-I virions may exert this effect prior to, immediately following, or well after the cells are infected with HIV-1. These results provide further impetus for epidemiologic studies of dually infected individuals to determine whether HTLV-I may act as a cofactor for acquired immunodeficiency syndrome (AIDS). 相似文献
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利用70%的乙醇提取中华稻蝗黄酮,并用乙酸乙酯和正丁醇依次进行萃取,采用DPPH自由基、超氧阴离子、羟基自由基、鳌合亚铁离子和还原力、总抗氧化的反应体系,检测了中华稻蝗组分的体外抗氧化活性,并与化学合成抗氧化剂BHT进行比较.结果表明:在所测浓度范围内,水相残留物的清除能力、总抗氧化能力和总还原能力最好;IC50值,羟基自由基(25.16±0.64) μg/ml、超氧阴离子自由基(35.06±0.86) μg/ml、DPPH为(19.56±1.24) μg/ml、脂质过氧化(43.75±0.94) μg/ml,且均强于BHT. 其它几种萃取物与BHT相当,因此,稻蝗黄酮类组分具有很好的抗氧化能力. 相似文献