柑橘中柠檬苦素类似物的研究新进展

柠檬苦素类似物是一类高度氧化的四环三萜类植物次生代谢物质。国外对柠檬苦素类似物的结构、性质、提取分离、分析鉴定、生物合成及分布、生物活性等方面均有深入研究,而我国对该类物质的研究报道相对较少。主要对柠檬苦素类似物的结构、分析方法和生物活性等方面进行探讨。     

The toxicity and physiological effect of neem limonoids on Cnaphalocrocis medinalis (Guenée) the rice leaffolder

The effect of neem (Azadirachta indica) limonoids azadirachtin, salannin, deacetylgedunin, gedunin, 17-hydroxyazadiradione, and deaceytlnimbin on gut enzyme activity of the rice leaffolder larvae was investigated. When fed a diet of rice leaves treated with limonoids in bioassays, gut tissue enzymes—acid phosphatases (ACP), alkaline phosphatases (ALP), and adenosine triphosphatases (ATPase) activities of rice leaffolder (Cnaphalocrocis medinalis) larvae are affected. Azadirachtin was most potent in all experiments. Larvae that were chronically exposed to limonoids showed a reduction in weight (59-89%) and exhibited a significant reduction in ACP, ALP, and ATPase activities. These results indicate neem limonoids affects gut enzyme activities. These effects are most pronounced in early instars.     

Essential Oils and Antioxidants Derived From Citrus By-Products in Food Protection and Medicine: An Introduction and Review of Recent Literature

After a brief overview of the general production, market value, and uses of citrus by-products, this literature review will focus on the most highly refined “pharmaceutical grade” citrus oils and antioxidants that have been derived from peels or other fruit parts. Citrus oils have been used as a part of the perfume industry and in the practice of alternative medicine for a long time, but now there is a great deal of mainstream food processing and drug industry interest in them owing to the rediscovery or confirmation of some of their beneficial properties, as well their development for entirely new applications. Their roles as antimicrobial, immunomodulatory, and cancer chemopreventive or chemotherapeutic agents appear promising.     

Antifungal activity of limonoids from Khaya ivorensis

Chemical investigation of the diethyl ether extract of the stem bark of Khaya ivorensis A Chev (Meliaceae) afforded ten limonoids of angolensates, ring D-opened limonoids and mexicanolides. The structures of the limonoids isolated were determined by comparison of their (1)H and (13)C NMR data with those reported in the literature. These compounds were evaluated for their antifungal activity against the plant pathogenic fungus Botrytis cinerea Pers. Methyl 6-hydroxyangolensate and 3,7-dideacetylkhivorin were also tested for their antifungal and antibacterial activities on several fungal and bacterial species. Methyl angolensate and 1,3,7-trideacetylkhivorin displayed the highest antifungal activity against B. cinerea, with respectively 62.8 and 64.0% mycelial growth inhibition at 1000 mg litre(-1), and 73.3 and 68.6% mycelial growth inhibition at 1500 mg litre(-1). 3,7-Dideacetylkhivorin showed stronger antifungal and antibacterial activities than methyl 6-hydroxyangolensate against all of the test fungi and bacteria except Penicillium expansum Link. This is the first report on the antifungal and antibacterial effects of these limonoids. Structure-antifungal activity relationships of the limonoids isolated are discussed.     

比色法测量印楝种仁提取物中柠檬苦素类物质

印楝素（Azadirachtin,C35H44O16)以及相似的柠檬苦素类物质（AZRL,azadirachtin related limonoids)与加入了硫酸的香兰素甲醇溶液有显色反应。以此为基础,通过选择比色波长及优化香兰素浓度、碳酸加入量、反应时间几个因素,得到一种用比色法测定印楝种仁提取物中AZRL含量的方法。并测定了3种印楝种仁提取物中的AZRL含量。     

常山胡柚与葡萄柚果实营养品质和功能成分对比研究

对常山胡柚和葡萄柚的果实外观性状（单果重、果形指数和果皮厚度）、主要营养品质指标（总可溶性固形物、总糖、还原糖、总酸、维生素C、矿物质和氨基酸含量）和功能成分含量（黄酮类物质、柠檬苦素类物质和精油）进行了对比测定和分析研究。研究结果表明：常山胡柚的苦味物质（柚皮苷和柠檬苦素类物质）和总酸含量比葡萄柚低,总糖、总可溶性固形物以及矿物质元素钙、铁、锌和硒含量较高。红肉型葡萄柚中的柚皮苷和柠檬苦素类物质含量比其他品种高,两种葡萄柚的精油含量均比胡柚高。在口感上,葡萄柚比常山胡柚偏苦、偏酸。总体上常山胡柚和葡萄柚都含有丰富的营养物质和功能性成分,具有较高的营养和保健价值。该研究对常山胡柚和葡萄柚的生产和消费具有一定的指导作用。     

类柠檬苦素的生物活性研究进展

类柠檬苦素是一类三萜类植物次生代谢产物,主要存在于芸香科或楝科植物中。人们探求柑橘类果汁苦味的原因时发现了该类物质,并对其进行了研究。其表现出来的多种生物活性,如抗肿瘤、抗疟疾、抗氧化等,对人类健康具有重要意义。就目前已发现的类柠檬苦素的各种生物活性进行综述,并讨论其开发利用前景。     

Identification of new limonoids from Swietenia and their biological activity against insects

BACKGROUND: Natural limonoids are one group of compounds being studied for their insecticidal properties. To discover new limonoids with better activities, analogs were prepared via acylation and hydrolysis, and bioassayed. RESULTS: Analogs were identified using one‐ and two‐dimensional (COSY, HMQC and HMBC) ¹H and ¹³C NMR, IR and MS. 3‐O‐Isovalerylswietenolide (13) and 3‐O‐isobutyrylswietenolide (14) showed excellent antifeedant activity, with DC₅₀ values of 0.19 and 0.009 mg L^?1 respectively, compared with the natural limonoid swietenolide (80.6 mg L^?1) against fourth‐instar Spodoptera frugiperda (JE Smith) larvae. CONCLUSION: This work shows that limonoid analogs prepared through semi‐synthesis can be used as lead compounds for the development of new insecticides. Copyright © 2010 Society of Chemical Industry     

Effect of fraxinellone on growth and digestive physiology of Asian corn borer, Ostrinia furnacalis Guenee

A limonoid, fraxinellone significantly reduced the relative growth rate, food consumption rate as well as the efficiency of conversion of ingested food of the Asian corn borer, Ostrinia furnacalis when incorporated into artificial diets at concentration of 10 ppm and above. After being fed with diets that contained fraxinellone for 24 h, the larval midguts of O. furnacalis possess significantly lower activities of α-amylase and non-specific proteases and higher activities of cytochrome P450s. In vitro, the compound did not inhibit the activities of α-amylase and non-specific proteases extracted from the larval midguts. The modes of action of fraxinellone against the insect were discussed.     

柑橘果实中柠檬苦素及类似物功能活性研究进展

柠檬苦素类似物是一类三萜系化合物,包括柠檬苦素、诺米林、奥巴叩酮等物质。主要存在于柑橘类果实的核、内果皮和囊衣等部位,尤其在种子中含量丰富。本文介绍柠檬苦素及类似物的化学结构,综述其抗肿瘤、抗氧化及防治植物病虫等功能活性的研究进展,展望在医疗、食品及农作物病虫害防治方面的应用前景,并提出今后的研究方向。