荆条蜂胶化学成分的研究

本文对荆条蜂胶乙醇提取物的化学成分进行了研究,为进一步的活性评价及建立标准化模型提供基础数据。蜂胶原胶经65%乙醇溶液80℃加热得到蜂胶提取物,将提取物采用石油醚、乙酸乙酯、正丁醇进行逐级溶剂分配、硅胶色谱柱层析、重结晶、制备液相等方法进行分离和纯化,从乙酸乙酯部分分离得到31个化合物,通过对化学物理性质分析以及红外、紫外、质谱、核磁共振波谱的测定解析,确定了化合物结构。其中黄酮类化合物14个,肉桂酸衍生物7个,咖啡酸酯类化合物6个,其它类4个。     

白鲜皮化学成分分离与鉴定

白鲜皮乙醇提取物乙酸乙酯萃取层采用反复硅胶柱色谱、凝胶柱色谱、制备HPLC分离得到单体化合物,通过光谱方法对其化学成分进行结构鉴定。从白鲜皮乙醇提取物的乙酸乙酯萃取层中分离得到6个化合物,分别鉴定为3-醛基吲哚(1),5-羟基-2-羟甲基吡啶(2),白鲜碱(3),大叶桉亭(4)邻苯二甲酸二丁酯(5),β-谷甾醇(6)。其中化合物1及化合物2为白鲜皮种内首次分离。     

决明子中降血脂化学成分的研究

研究决明子降血脂的化学成分,为确定决明子中降血脂有效成分提供依据。对决明子75%乙醇提取物采用硅胶柱分离方法进行分离,并运用核磁共振波谱等光谱法鉴定化合物结构。从石油醚和乙酸乙酯部位中共分离并鉴定了4个单体化合物。其中从石油醚部位获得2个单体化合物,分别为大黄酚(Chrysophanol,Ⅰ)、大黄素甲醚(Physcion,Ⅱ);从乙酸乙酯部位中分离并鉴定了2个单体化合物,分别为橙黄决明素(Aurantio-obtusin,Ⅲ)和钝叶素(Obtusifolin,Ⅳ)。     

鹿茸草化学成分研究

目的:研究鹿茸草的化学成分。方法:鹿茸草用95%的乙醇提取,提取物依次经石油醚和乙酸乙酯萃取,再经硅胶柱色谱法、聚酰胺柱色谱法反复进行分离纯化,并通过波谱技术及理化性质鉴定化合物结构。结果:从鹿茸草中分离得到3个化合物,分别为胆甾醇(1)、芹菜素(2)、木犀草素(3)。结论:此3个化合物均为首次从该植物中分离得到。     

黔产玄参化学成分研究

对黔产玄参的化学组分进行了研究。在超声辅助条件下,依次用二氯甲烷和甲醇对玄参中化学成分提取,再分别用乙酸乙酯和60%乙醇提取玄参,采用气质联用技术对提取浸膏进行成分分析。从二氯甲烷提取得到的玄参提取物中共鉴别出3种化合物,采用甲醇提取玄参得到的浸膏中共鉴别出30种化合物,采用乙酸乙酯提取玄参提取物中共计鉴别出7种化合物,采用60%乙醇提取得到的玄参提取物中共鉴别出3种化合物。研究结果可以为黔产玄参的综合开发与利用提供理论依据。     

帚梗柱孢霉属真菌Cyllndrocladium sp.YMF1.03662的化学成分研究

通过对帚梗柱孢霉属真菌Cyllndrocladiumsp.YMF1.03662发酵液的乙酸乙酯提取物及菌丝体的甲醇提取物进行化学成分研究,分离得到2个化合物,经波谱分析,鉴定为citrantifidiol和1-monoacylglycerol。     

五味子化学成分的分离和结构鉴定

目的研究五味子中木脂素类化学成分。方法应用正相硅胶柱色谱、ODS柱色谱、制备型和分析型HPLC及重结晶等方法对五味子提取物的乙酸乙酯部位的化学成分进行了系统研究。结果从五味子乙酸乙酯部位中分离得到了8个化合物,鉴定化合物为五味子醇甲(化合物1)、邻苯二甲酸二丁酯(化合物2)、五味子甲素(化合物3)、柠檬酸双甲酯(化合物4)、柠檬酸单甲酯(化合物5)、五味子酯丙(化合物6)、Schinlignan E(化合物7),当归酰戈米辛H(化合物8)。结论化合物2为首次从本植物中分离得到。     

地肤子抑菌活性成分筛选

以最小抑菌浓度为指标,采用二倍稀释法分别测试地肤子乙醇提取物中的石油醚相、乙酸乙酯相、正丁醇相和水相萃取物对4株细菌和5株植物病原菌的抑制作用;再对抑菌活性较强的萃取物进行分离纯化,通过二倍稀释法测试所分离化合物的抑菌活性,并对其结构进行表征。结果表明,正丁醇相萃取物的抑菌活性最强,从中分离得到3个化合物,其中化合物Ⅰ的抑菌活性较强,对大肠杆菌具有显著的抑制作用,其最小抑菌浓度为31.3μg·mL-1,经1 HNMR、IR及高分辨质谱等鉴定化合物Ⅰ为齐墩果酸。齐墩果酸有较强的抑菌活性,是地肤子抑菌活性的物质基础。     

黄皮果中农用成分的提取和分离

[目的]研究黄皮果中农用活性成分。[方法]利用硅胶柱层析对黄皮果的乙酸乙酯提取物进行分离,并对提取化合物进行农用活性测定。[结果]从黄皮果的乙酸乙酯提取物中分离得到7个化合物,分别为黄皮酰胺Ⅰ、黄皮酰胺B、黄皮酰胺C、(E)-N-甲基肉桂酰胺、N-(2-羟基-2-苯乙基)-N-甲基肉桂酰胺、N-(2-苯基环氧乙基)-N-甲基肉桂酰胺、苯乙基肉桂酰胺。其中N-(2-苯基环氧乙基)-N-甲基肉桂酰胺为首次从植物中分离得到。[结论]黄皮果中分离出的单体化合物均属于生物碱类化合物,具有一定的农用活性。     

白饭树枝叶的化学成分研究(Ⅱ)

综合运用硅胶柱层析、ODS柱层析、Sephadex LH-20凝胶柱层析以及制备型高效液相等色谱分离技术,对大戟科白饭树属植物白饭树(Flueggea virosa)枝叶的化学成分进行系统分离与纯化。结合理化性质和多种现代波谱技术,并通过与文献对照,鉴定了从白饭树枝叶90%乙醇提取物的乙酸乙酯萃取部位中分离得到8个化合物,分别为securitinine(1)、phyllanthidine(2)、4-epiphyllanthine(3)、epibubbiadine(4)、(+)-松脂酚(5)、8α-羟基松脂酚(6)、龙胆酸(7)和原儿茶酸(8)。化合物5~8为首次从白饭树中分离得到。     

Chemical composition of North American bee propolis and biological activity towards larvae of greater wax moth (Lepidoptera: Pyralidae)

Bee propolis is a sticky amalgamation of plant resins collected by honeybees (Apis mellifera L.) and used in the hive for filling cracks and repairing combs. Propolis contains a diversity of compounds of plant origin, and is reported to have medicinal, antimicrobial, insecticidal, and phytotoxic properties. We examined the physical and chemical composition of North American samples of bee propolis from several sites in North America and tested for bioactivity against larvae of the greater wax moth (Galleria mellonella L.), a common apiary pest. The amount of methanol-extractable resin in samples from Ohio and Georgia ranged from 24% to 79% by weight. Propolis collected from hives in Ohio was more chemically diverse (over 30 compounds detected by paper chromatography) than material from south Georgia (fewer than 10 major compounds) and contained a lower proportion of methanol-insoluble beeswax. The paper chromatographic surveys revealed little variation in the chemical profile of specific hives over a six-month period and no differences between propolis from adjacent hives. Four flavonoids were identified from propolis collected in Ohio: kaempferol, galangin, 3,3-dimethoxyquercetin and 3-methoxykaempferol. When mixed into artificial diet, fractionated propolis reduced larval growth of the greater wax moth, but not dramatically. An array of phenolics reported from propolis (caffeic acid, chrysin, ferulic acid, galangin, kaempferol, and quercetin) were bioassayed individually for effects on larvae, but none reduced larval growth at the concentrations tested, suggesting that wax moths are tolerant of some phenolics in their diet.     

The composition,active components and bacteriostatic activity of propolis in dietetics

The composition and bacteriostatic activities of fifteen propolis samples from various botanic and geographic origins were determined. Twenty-six phenolic components were identified by high-performance liquid chromatography with array photodiode detector. Acacetin and apigenin were most abundant. Pinocembrin, quercetin, rutin and vanillin were present in lesser quantities. Variance analysis shows significant differences (P≤0.05) in the contents of phenols, flavonoids and active components. The minimum inhibitory concentration of propolis is about 53 times higher than that reported for tetracycline againstBacillus subtilis andStaphylococcus aureus, and about 400 times higher againstEscherichia coli.     

Encapsulation of propolis flavonoids in a water soluble polymer using pressurized carbon dioxide anti-solvent crystallization

This study investigated the pressurized carbon dioxide anti-solvent co-precipitation process (abbr. PAS) on encapsulation of propolis with water soluble polyethylene glycol (PEG). The extent to which recovery of propolis flavonoids, total yield, amount of propolis (i.e. drug content) affects the precipitation was examined using a two-factor central composite schemed experimental design method. Analysis results indicated that the drug content and total yield of the precipitates are conversely related to each other in the PAS process. Additionally, micro-sized amorphous particulates of propolis encapsulated on the surface of PEG were generated, as evidenced by chromatography and X-ray diffraction analyses. Total yield of the PAS co-precipitation process reached 88%, and recovery of propolis flavonoids achieved 97%. Experimental results also indicated that the concentration ratio of propolis to PEG in the feed more significantly affects the drug content than that of the pressure factor. Moreover, nearly spherical and aggregated micro-sized co-precipitated particulates are more soluble in an aqueous solution than those of ethanol extracts.     

Synthesis,Characterization of Guar-Containing Polyurethane Films and their Non-enzymatic Caffeic Acid Sensor Applications

Stable voltammetric sensors were fabricated by dropping the guar-containing polyurethane films on a platinum electrode for the non-enzymatic determination of caffeic acid. The voltammetric responses of PU-G-1% toward caffeic acid have a linear concentration range from 1 to 15?mM with a correlation coefficient of 0.9938. The detection limit of PU-G-1% electrode was approximately 0.25?mM. PU-G-1% sensor showed the good sensitivity, selectivity, high R-value, low detection limit, and high reproducibility toward caffeic acid. Therefore, it is claimed that the polyurethane film containing 1% guar can be used as an excellent selective membrane for caffeic acid detection in the presence of interferent molecules.     

Hot-pressurized fluid extraction of flavonoids and phenolic acids from Brazilian propolis and their cytotoxic assay in vitro

This work has examined the hot-pressurized fluid extraction of seven flavonoids, caffeic acid phenethyl ester and four phenolic acids from Brazilian propolis lumps generating, during the process, fat- and water-soluble extracts. The solid content of water-soluble extract obtained by hot-pressurized water in the presence of 29% natural surfactant was 35.2 mg/mL and was 44% greater than that obtained without natural surfactant. Furthermore the amount of the seven flavonoids and caffeic acid phenethyl ester in the fat-soluble extract exceeded those in the water-soluble sample while, on the other hand, the amount of the four phenolic acids in the water-soluble extract was more than those in the fat-soluble extract. Our findings show that the total solid content and the amount of these 12 active compounds produced by the emulsified hot-pressurized water are 36% and 7% higher, respectively, than those produced by emulsified water at atmospheric pressure. The EC₅₀ value of the free radical scavenging activity of 1,1-diphenyl-2-picrylhydrazyl of the emulsified hot-pressurized water extract was the lowest, and presented the strongest anti-oxidation ability among all the extracts. In vitro cytotoxicity indicated that the water-soluble extract strongly suppressed the growth of leukemia (HL-60, U937), lung cancer (A549, CH27) and liver cancer (Hep G2, Hep 3B) cells in a concentration-dependent behavior.     

不同产地蜂胶中总黄酮的提取及含量测定

目的:测定不同产地蜂胶中总黄酮的含量,为蜂胶的质量控制提供更多依据。方法:通过正交设计试验,优选蜂胶中总黄酮的提取方法;以芦丁为对照品,用分光光度法测定不同产地蜂胶中总黄酮的含量。结果:国内主要产地的蜂胶中总黄酮含量均高于巴西蜂胶,且河南,山东产蜂胶中总黄酮含量大于20%。结论:该方法可靠,测定结果能反映客观实际,可作为蜂胶质量控制指标之一。     

Peroxyl and hydroxyl radical scavenging activity of some natural phenolic antioxidants

The autoxidation of linoleic acid dispersed in an aqueous media and the antioxidant effect of hydroxytyrosol, oleuropein, caffeic acid and tyrosol were studied. Linoleic acid autoxidation rate was estimated by the increase of conjugated diene level and by the decrease of linoleic acid content in the samples. The phenolic compounds exhibited an antioxidant activity which increased in the order: tyrosol < caffeic acid < oleuropein < hydroxytyrosol. The analysis of the hydroperoxide isomers pointed out that hydroxytyrosol, oleuropein and caffeic acid at a concentration of 10⁻⁴M inhibited the formation oftrans- trans isomers in the increasing order: caffeic acid < oleuropein < hydroxytyrosol. This inhibition could be related to the ability of phenolic compounds to scavenge peroxyl radical. Tyrosol did not inhibit the formation oftranstrans isomers. Phenolic compounds were degraded as a consequence of their antioxidant activity and their degradation rate was positively correlated to their antioxidant efficacy. These phenolic compounds, at a concentration of 6 × 10⁻³M, also scavenged hydroxyl radical, with an efficiency which increased in the order: tyrosol < hydroxytyrosol < oleuropein < caffeic acid. Polar substituents at the para position, such as in caffeic acid and oleuropein, were correlated with higher hydroxyl radical quenching ability.     

Zn2+配位双模板印迹聚合物的制备表征及同时萃取升麻中的阿魏酸和咖啡酸

以Zn²⁺-阿魏酸-咖啡酸配合物为模板制备了双分子印迹聚合物,优化了制备条件,用傅里叶红外光谱和扫描电镜对分子印迹聚合物进行结构表征,测试了分子印迹聚合物的吸附特性,探讨了分子印迹聚合物固相萃取应用效能并对萃取条件进行了优化.结果表明,当预反应混合液中金属离子、模板总量(阿魏酸-咖啡酸摩尔比为2:3)、功能单体及交联剂用量比为1:1:3:30(摩尔比)时,所得印迹聚合物对两种模板(阿魏酸和咖啡酸)均具有最好的吸附性能,吸附量分别达51.12mg/g和70.26mg/g.吸附动力学测试表明吸附3h,分子印迹聚合物可达到吸附平衡.用分子印迹聚合物进行固相萃取时,优化的淋洗过程为1.00mL H₂O、1.00mL甲醇-H₂O (3/7,体积比)及1.00mL甲醇-H₂O-ACN (4/4/2,体积比),洗脱溶剂为2.00mL甲醇.在优化条件下,分子印迹聚合物可同时选择富集升麻初提液中的阿魏酸和咖啡酸,二者回收率分别为92.67%和95.42%,而且产品中杂质少于用硅胶萃取所得产品.     

A first pilot study to produce a food antioxidant from sunflower seed shells (Helianthus annuus)

This article explains a laboratory procedure to produce an antioxidant from grinded, dehulled and partially defatted sunflower seeds. Initially, a solvent suitable to extract phenols was searched among different solutions of water mixed with ethanol, methanol and acetone at 40% (vol/vol) (each tested at pH 5, 7 and 9). Both the ethanol/water 60:40 (vol/vol) and the acetone/water 60:40 (vol/vol) mixtures proved to be suitable for the dephenolization of sunflower seed shells, but in the next steps of this research, the mixture ethanol/water 60:40 (vol/vol) at pH 5 was used. Secondly, the procedure to obtain the antioxidant product was defined, which consisted in hydrolysis of sunflower seed phenols with 1.25 N NaOH at room temperature for 60 min and finally the recovery of caffeic acid formed from chlorogenic acid with ethyl acetate. From 25 g of partially defatted sunflower shells, around 90 mg of powdery antioxidant product, consisting of 58% caffeic acid, was obtained. The antioxidant product, the caffeic acid standard and propyl gallate were added to different edible fats at the same dose of 240 AU (antioxidant units) per kg fat. A Rancimat test, at 130 °C and an air flow of 20 L h^?1, demonstrated that the effectiveness of the sunflower antioxidant product was essentially similar to that of the caffeic acid standard, but 15–20% lower than that of propyl gallate. In conclusion, dephenolization of sunflower seeds could be economically convenient, not only because a useful antioxidant can be produced, but also because the raw material composition can be improved for other uses.     

Effects of three phenolic acids on chlorophyll content and ions uptake in cowpea seedlings

This study was conducted to test the hypothesis that interfering with chlorophyll metabolism and ion uptake may be mechanisms through which some phenolic acids inhibit the growth of cowpea seedlings. Three concentrations (10^–4 M, 5 × 10^–4 M, and 10^–3 M) of each of syringic, caffeic, and protocatechuic acids were used to test their effects using sand-culture medium. It was found that seedling growth, chlorophyll a, total chlorophyll, chlorophyll a/b ratio, and the uptake of N, P, K, Fe, and Mo were significantly reduced by most of the test concentrations of the phenolic acids. However, chlorophyll b content and the Mg uptake were not significantly affected by all the phenolic acid concentrations. Calcium uptake was significantly inhibited by 5 × 10^–4 M and 10^–3 M of caffeic acid and 5 × 10^–4 M of protocatechuic acid. In most cases, the reduction in dry weight was parallel to the reduction in chlorophyll content and ion uptake, and the reduction in chlorophyll was also parallel to the reduction in ion uptake. The relationships among the inhibition of dry weights, chlorophyll content, and ion uptake are briefly discussed.