The medicinal chemistry of Urtica dioica L.:from preliminary evidence to clinical studies supporting its neuroprotective activity

Urtica dioica is a perennial herb from the family of Urticaceae that is commonly known as stinging nettle.This plant is widespread in Europe,Africa,America,and a part of Asia,as it adapts to different environments and climatic condi-tions.The leaves,stalk,and bark of U.dioica found applications in the field of nutrition,cosmetics,textile,pest control and pharmacology.In this connection,bioactive chemical constituents such as flavonoids,phenolic acids,amino acids,carotenoids,and fatty acids have been isolated from the plant.With this review,we aim at providing an updated and comprehensive overview of the contributions in literature reporting computational,in vitro,pre-clinical and clini-cal data supporting the therapeutic applications of U.dioica.Experimental evidence shows that U.dioica constituents and extracts can provide neuroprotective effects by acting through a combination of different molecular mecha-nisms,that are discussed in the review.These findings could lay the basis for the identification and design of more effective tools against neurodegenerative diseases.

土壤水分对异株荨麻(Urtica dioica)保护酶和渗透调节物质的影响及其与叶片光合和生物量的相关性

通过对不同土壤水分处理下异株荨麻保护酶系(SOD、POD)活性、渗透调节物质(可溶性蛋白、可溶性糖和游离脯氨酸)和细胞膜脂过氧化产物(MDA)含量以及最大光合速率、生物量的测定,各项生理指标间线性相关性的分析,探讨异株荨麻对水分变化的响应特性和耐干旱适应能力。实验采用盆栽水分梯度法将异株荨麻扦插苗按土壤相对含水量93.58%、80.74%、67.90%、55.06%和42.22%分组,以充足水分93.58%为CK对照组,实验组水分由高到低为T1、T2、T3和T4共5组。结果表明,(1)异株荨麻体内SOD活性随水分含量下降而呈先上升后下降的变化趋势,POD活性与之成相似互补的变化趋势;可溶性蛋白、可溶性糖、游离脯氨酸和MDA含量随水分含量的下降而升高;(2)各保护酶系和渗透调节物质与土壤水分呈显著线性负相关,保护酶系、渗透调节物质与过氧化产物MDA线性正相关;(3)比较光合速率、生物量和各种酶系、渗透调节物质的关系发现,光合速率与各生理指标无明显相关性,渗透调节物质对生物量积累有显著负相关性。

异株荨麻(Urtica dioica)生长及光合特性对不同土壤水分含量的响应

异株荨麻是我国一种重要中药植物，如何对其进行人工定向培植具有重要意义。以异株荨麻扦插苗为实验材料，采用盆栽水分梯度法，按土壤相对含水量93．58％、80．74％、67．90％、55．06％和42．22％分为对照组CK，实验处理组T1，T2，T3和T4五个处理组，通过观测不同水分条件下，异株荨麻生长量、生物量变化和光合特征变化，试图探讨异株荨麻的水分适应性，寻找出适合其生长的水分范围及对生物量分配的影响，为北方地区种植栽培此类植物提供科学依据。结果发现：随土壤水分含量的降低，异株荨麻生长量和生物量积累呈先上升后下降趋势，在土壤相对含水量80．74％生长达到高峰，土壤相对含水量67．90％～80．74％为异株荨麻生长的适宜范围。净光合速率、蒸腾速率、气孔导度、气孔限制值及叶绿体色素含量的变化趋势与之相近似。在上述水分范围以外其光合功能下降、同化作用减弱，使异株荨麻生长衰退和干物质积累的减少。此外，土壤水分直接调控光合产物在地上和地下的分配以及植株个体形状，生产实践中，通过控水可以达到控制株形和根冠比的作用，用以诱导植株朝种植的预期方向生长，以达到获取植株不同部位产量的实际应用需求。

Hepatoprotective effects of Nigella sativa L and Urtica dioica L on lipid peroxidation, antioxidant enzyme systems and liver enzymes in carbon tetrachloride-treated rats

AIM： To investigate the effects of Nigella sativa 1 （NS） and Urtica dioica 1 （UD） on lipid peroxidation, antioxidant enzyme systems and liver enzymes in CCl4-treated rats. METHODS： Fifty-six healthy male Wistar albino rats were used in this study. The rats were randomly allotted into one of the four experimental groups： A （CCl4-only treated）, B （CCl4＋UD treated）, C （CCl4＋NS treated） and D （CCl4＋UD＋NS treated）, each containing 14 animals. All groups received CCl4 （0.8 mL/kg of body weight, sc, twice a week for 60 d）. In addition, B, C and D groups also received daily i.p. injections of 0.2 mL/kg NS or/and 2 mL/kg UD oils for 60 d. Group A, on the other hand, received only 2 mL/kg normal saline solution for 60 d. Blood samples for the biochemical analysis were taken by cardiac puncture from randomly chosen-seven rats in each treatment group at beginning and on the 60th d of the experiment. RESULTS： The CCl4 treatment for 60 d increased the lipid peroxidation and liver enzymes, and also decreased the antioxidant enzyme levels. NS or UD treatment （alone or combination） for 60 d decreased the elevated lipid peroxidation and liver enzyme levels and also increased the reduced antioxidant enzyme levels. The weight of rats decreased in group A, and increased in groups B, C and D. CONCLUSION： NS and UD decrease the lipid peroxidation and liver enzymes, and increase the antioxidant defense system activity in the CCl4-treated rats.

异株荨麻(Urtica dioica)种子萌发特性研究

运用双因素随机区组设计方案，系统研究了温度和稀土、温度和赤霉素对药用植物异株荨麻（Urtica dioica）种子萌发的影响。结果表明，异株荨麻种子在15～40℃恒温条件下均能发芽，但不同温度下种子发芽率和发芽势均差异显著（P〈0．05），温度过高或过低均不利于种子萌发，适宜的温度为30～35℃，最适温度约为30℃。稀土溶液在25～500mg／L范围内，均可有效促进种子萌发，浓度为100mg／L时，种子发芽势和发芽率均最高。赤霉素溶液浓度在25～600mg／L范围内，均可促进种子萌发，最适宜浓度为400mg／L。温度和稀土对异株荨麻种子发芽率无明显交互作用，而温度和赤霉素对促进种子发芽有显著的交互作用，各种组合中，以温度为30℃和35℃、赤霉素溶液浓度分别为400、500和600mg／L的6个组合的交互效应对种子发芽率的提高最为显著。异株荨麻种子在中性条件下最易发芽，随着酸碱度的增加，种子发芽率逐渐降低。

Antimicrobial Effectiveness on Selected Bacterial Species and Alkaloid and Saponin Content of <i>Rosa nutkana</i>C. Presl (Nootka Rose) and <i>Urtica dioica</i>L. (Stinging Nettle) Extracts

Nootka rose (Rosa nutkana C. Presl) and stinging nettle (Urtica dioica L.) have been traditionally used in the treatment of skin infection by Indigenous peoples of Vancouver Island, British Columbia, Canada. The main objective of this study was to examine the antibacterial efficacy of extracts of Nootka rose and stinging nettle against the common pathogenic skin bacteria Staphylococcus aureus, Micrococcus luteus, and Pseudomonas aeruginosa using Indigenous science and standard methods of analysis. The Indigenous science method of plant extraction by steeping as advised by the Traditional Knowledge keeper was performed to examine minimum inhibitory concentration (MIC) values and minimum bactericidal concentrations (MBC) by serial dilution and bacterial population counts. Soxhlet extractions and Kirby Bauer disc sensitivity testing showed that Nootka rose extracts possessed antibacterial effectiveness against all three bacterial species while stinging nettle extracts were effective against M. luteus. Results for MIC and MBC indicated antibacterial activity against M. luteus and S. aureus for the Nootka rose when using full-strength solutions;all three bacterial species exhibited growth when undiluted stinging nettle treatments were used. When considering bacterial population counts for S. aureus, results indicated that only the Nootka rose treatment offered effective inhibition. Chemical analysis showed that alkaloid percentage was greater in the stinging nettle (0.17%) than Nootka rose (0.07%), while saponin percentage was greater in the Nootka rose (0.87%) than stinging nettle (0.17%). Overall, Nootka rose showed a greater level of antibacterial effectiveness than stinging nettle by Indigenous and Western scientific methods of plant extract preparation.

The healing effects of herbal preparations from Sambucus ebulus and Urtica dioica in full-thickness wound models

Objective:To investigate the healing effects of two herbal preparations.Methods:For this purpose,106 wistar rats were divided into 9 groups including a control,eucerine,phenytoin,Urtica dioica(U.dioica)(2%),U.dioica(5%),Sambucus ebulus(S.ebulus)(2%),S.ebulus(5%),combination(2%),and combination(5%)groups.The control group remained untreated,the eucerin and phenytoin groups were considered as the negative and positive controls respectively,and the remaining groups received different concentrations of the ointments.Full thickness wounds were made.The healing process of the wounds was investigated on day 7,14 and 21 of the experiment.Several factors including the number of fibroblasts,new vessel formation(angiogenesis),thickness of the granulomatous tissues(GT),and the overlying epithelium were analyzed.Results:Among the studied groups,all of the treatment groups were significantly different from the control,eucerin,and phenytoin groups in a positive manner with regard to all studied factors(P 0.05).However,the best results were observed with the S.ebulus(2%) and the combination 2% groups(P 0.05).Conclusions:Topical ointments prepared from the extracts of U.dioica and S.ebulus and their combination possess strong wound healing properties.It is postulated that a synergistic effect may exist between the two extracts since the combination 2% showed better results than the sole extracts.

Effects of Urtica dioica extract on CA3 hippocampal pyramidal cell loss in young diabetic rats

BACKGROUND： Urtica dioica extract has been shown to play a protective role in the neurodegeneration associated with diabetes mellitus. OBJECTIVE： To verify the neuroprotective efficacy of nettle extract on pyramidal cell density in the CA3 hippocampal subfield following administration of Urtica dioica extract to young diabetic rats. DESIGN, TIME AND SETTING： A randomized, controlled, neurobiological study was performed at the Department of Histology and Embryology at the Gorgan University of Medical Sciences in Iran from 2006 to 2007. MATERIALS： Urtica dioica leaves were collected from a cultivated plant in the suburb of Gorgan （northem Iran） and taxonomically identified by the Department of Pharmacognosy, Mazandaran University of Medical Sciences. METHODS： A total of 20 male, albino, Wistar rats, aged 6-7 postnatal weeks, were randomly assigned to four groups： normal control, diabetic model, preventive, and treatment, with five rats in each group. Diabetes was induced by intraperitoneal injection of streptozotocin （80 mg/kg） in the diabetic and treatment groups. Rats from the preventive group received a hydroalcoholic extract of Urtica dioica （100 mg/kg per day） during the first 5 days, and then streptozotocin （80 mg/kg） was administered on day 6. One week following the streptozotocin injection, rats in the treatment group were intraperitoneally administered hydroalcoholic extract of Urtica dioica （100 mg/kg per day） for 4 weeks. MAIN OUTCOME MEASURES： Following administration of Urtica dioica extract, the dorsal hippocampal formation of the right cerebral hemispheres was stained with cresyl violet. Area densities of CA3 pyramidal cells were measured. RESULTS： The diabetic, preventive, and treatment groups exhibited reduced cell densities compared with the control group （P 〈 0.05）. Moreover, densities of CA3 pyramidal cells in the treatment group were significantly reduced compared with the diabetic model group （P 〈 0.05）. CONCLUSION： The Urtica dioica extract exhibited no significant neuroprotectJve benefits in diabetes-induced loss of pyramidal cells in the CA3 hippocampal subfields of young diabetic rats.

Estimation of Some Plant Secondary Products in Urtica dioica L., Viola odorata L. and Melissa officinalis L. Naturally Grown in Hawraman-Kurdistan Region of Iraq

The plant aerial parts of three species, Urtica dioica L., Viola odorata L. and Melissa officinalis L. were collected at randomly-different locations, according to altitudes in May 2010. The aerial parts of Urtica were collected within three replications from different locations： Biare 1,090 masl （meters above sea level）, Tawile 1,450 masl and Awiser 1,680 masl. The aerial parts of Viola and Melissa were collected randomly within three replications at different locations： Biare 1,090 masl, Degashikhan 1,250 masl and Tawile 1,450 masl. The extracts of the aerial parts of these species were purified by filtrations for several times in preparation for HPLC analyses. The chromatograms of Urtica indicated the presence of five major important alkaloid components （fragrine, benzylisoquinoline, scopoletin, glucoquinone and dotriacotaine） and ten major important phenolic compounds （formic acid, tannin, chlorogenic acid, caffeoylmalic acid, anthocyanine, quercetin, zeaxanthin, luetin epoxide, coumarine and vanillin）. All the concentrations of alkaloid and phenolic compounds were increased significantly due to higher altitudes, except that of alkaloid dotriacotaine. The chromatograms of Viola indicated the presence of four major important alkaloid components （violine, isoquinoline, cycloviolacin and luteolin-3-glucoronide） and ten major important phenolic compounds （formic acid, tannin, chlorogenic acid, caffeoylmalic acid, anthocyanine, quercetin, zeaxanthin, luetin epoxide, coumarine and vanillin）. The results of the influence of altitudes showed that the concentrations of all alkaloids and phenolic compounds were increased significantly due to higher altitudes, except that of the alkaloid luteolin-3-glucoronide and the phenolic compounds zeaxanthin and luetin epoxide. The chromatograms of Melissa indicated the presence of five major essential oils （pinene, linalool, citronellol, geraniol and rosmarinic acid）. Their quantitative evaluations were influenced by altitudes indicating that the concentrations of all oils were increased significantly due to the higher altitude, except that of the pinene.

Effect of nettle(Urtica dioica) extract on gentamicin induced nephrotoxicity in male rabbits

Objective:To investigate the antioxidant ef ect of an orally administered ethanol extract of nettle(Urtica dioica) and its protective role in preventing or ameliorating oxidative stress as a major factor in gentamicin-induced nephrotoxicity in male rabbits. Methods: Twenty rabbits were divided into 4 equal groups:(G1) control group,(G2) gentamicin treated group(100 mg/kg),(G3) nettle treated group(100 mg/kg),(G4) combination treated group with both gentamicin(100 mg/kg) and nettle(100 mg/kg) for 10 days. The antioxidant properties of nettle were evaluated using dif erent antioxidant tests, such as determination of glutathione and malondialdehyde levels and total phenolic content analysis. Results: Biochemical and histopathological study revealed that gentamicin caused nephrotoxicity observed clearly in the histopathological section of the kidney in the gentamicin treated group. Serum creatinine and blood urea nitrogen were biochemical indicators for nephrotoxicity which increased signii cantly in gentamicin treated group; other groups have no signii cant change in these two parameters. Nettle extract protected the rabbits from alteration in the level of blood urea nitrogen and serum creatinine when given after inducing of gentamicin nephrotoxicity. The nettle treated group showed a great ef ect as an antioxidant factor by increasing the glutathione level and reducing malondialdehyde level. No signii cant changes in biochemical parameters and no renal histopathological changes observed in the groups treated with nettle extract, which meant nettle had powerful antioxidant activity. Conclusions: Therefore, it can be assumed that the nephroprotective ef ect shown by nettle in gentamicin-induced nephrotoxicity can reserve intracellular levels of biological pathways and supportively enhance excretion of toxic levels of gentamicin.

Identification of SARS-CoV-2 Spike Protein Inhibitors from Urtica dioica to Develop Herbal-Based Therapeutics Against COVID-19

Objective: The high transmission rate and mutations of SARS-Co V-2 have made it a global pandemic, and the shortage of any effective clinical treatment has created such a commotion. There are some synthetic antiviral drugs, such as remdesivir and lopinavir that are being repurposed to treat SARS-Co V-2, but all of these demonstrate extreme side effects in humans. Hence, promoting herbal-based drug development has become crucial as they are cost-effective and have lesser or no side effects. Urtica dioica is abundant in the Himalayan region and the compounds present in it have shown significant antiviral and anti-SARS activity. Therefore, molecular docking studies were performed to identify SARS-Co V-2 spike protein inhibitors from U. dioica to combat the COVID-19 disease. Materials and Methods: Compounds from U. dioica were screened using the bioinformatic approach, and subsequently, these compounds were docked with the S1 subunit of the COVID-19 spike protein(PDB ID: 6YOR). Molecular docking was carried out using the Py Rx software(0.8 version) and further examined by employing the Discovery Studio Visualizer. Results: About all the selected compounds showed significant binding energy(e.g., beta-sitosterol:-10.3 kcal/mol) in contrast to the control chloroquine phosphate. This binding was observed with the spike protein residues that were common in the old strain and the more contagious newly modified B.1.1.7 strain of SARS-Co V-2. Conclusions: Thus, our study can be used in effective drug development against SARS-Co V-2 and its mutant strains also.

A Prospective, Observational Study of Use Combination Silodosin 8 mg Plus Serenoa Repens, Urtica Dioica, Cucurbita Pepo (Rotaprost) Compared With Silodosin 8 mg Alone in Treatment Patients with Benign Prostate Hyperplasia

Background:Benign prostatic hyperplasia(BPH)is one of the most common causes of lower urinary tract symp-toms(LUTS)in older men.Nowadays,there are several plant extracts used for the treatment of LUTS due to BPH.Objective:The aim of this study is to compare the effect of combining silodosin 8 mg with Serenoa repens,Urtica dioica,Cucurbita pepo(Rotaprost 530 mg)compared to silodosin 8 mg and Rotaprost 530 mg alone in patients with LUTS/BPH.Methods:Four hundred five men with symptomatic BPH were recruited for the study from June 2020 to Jan-uary 2021.Three hundred eighty-nine patients were followed up for 6 months.All participants provided writ-ten informed consent.This prospective study included analysis of three treatment groups:Group I patients(n=130)received a combination of silodosin 8 mg and Rotaprost 530 mg(containing a dry extract of Serenoa repens 80 mg,a dry extract of Urtica dioica 150 mg,a dry extract of Cucurbita pepo seeds 200 mg,zinc(in the form of zinc picolinate)0.105 mg,and selenium(as sodium selenite)22.5μg);the group II(n=129)re-ceived silodosin 8 mg alone,and the group III(n=130)received Rotaprost 530 mg alone.Outcomes were measured by changes from baseline in International Prostate Symptom Score(IPPS)total score,PSA value,prostate volume,residual urine after urination,and maximum flow rate.Statistical significance was set at P<0.05.Results:In group I,IPSS,prostate volume,and maximum urinary flow rate(Qmax)improved significantly(P<0.05)compared with groups II and III during follow-up.Prostate volume in group I showed a significant decrease only during 6 months of therapy(P<0.05).No serious adverse effects were registered in the three groups.Conclusion:Combination therapy with silodosin 8 mg significantly reduced LUTS/BPH,Qmax,and prostate volume compared with silodosin 8 mg alone.Rotaprost 530 mg can also reduce PSA by at least 20.6−25.7%after 6-months of treatment.

Expression of antioxidant genes in broiler chickens fed nettle(Urtica dioica)and its link with pulmonary hypertension

Nettle(Urtica dioica)contains a wide range of chemical constituents that confer a strong antioxidant capacity to the plant.The present study was to investigate the antioxidant gene expression and pulmonary hypertensive responses of broiler chickens to U.dioica.A total of 240 one-d-old broilers(Ross308)were randomly assigned to 4 dietary levels of U.dioica(0.0.5%.1% and 1.5%).Birds were reared for6 wk in a high altitude region(2.100 m).The results showed a significant relative overexpression(target gene/β-actin as the arbitrary unit)of catalase(CAT)and superoxide dismutase 1(SOD1)in the liver and lung of the chickens fed U.dioica.Lipid peroxidation was significantly suppressed,as reflected in reduced circulatory concentrations of malondialdehyde(MDA)in the birds fed U.dioica.These birds also had significantly(P<0.05)higher serum nitric oxide(NO)concentrations than those in the control group.Feeding U.dioica at 1% and 1.5% also attenuated the right ventricular hypertrophy(reflected in the lower right to total ventricular weight ratio),which was associated with a significant lower rate of mortality from pulmonary hypertension syndrome.Feeding U.dioica led to an upregulation of hepatic and pulmonary antioxidant genes.

遮荫对异株荨麻光合特性和荧光参数的影响

系统研究了全光照和不同程度的遮荫(43%,58%,73%,87%,97%)对异株荨麻光合特性和荧光参数的影响。结果表明,异株荨麻的光补偿点和光饱和点均较低,且随着遮荫程度的提高,其值以及暗呼吸速率均依次降低。净光合速率日变化曲线呈单峰型,光合速率高峰值和日平均光合速率均随着遮荫程度的提高而明显下降。蒸腾速率和气孔导度的日变化与光合速率的日变化趋势一致,遮荫对蒸腾作用和气孔导度均有显著的影响,随着遮荫程度的提高,蒸腾速率和气孔导度均显著下降。在各光照条件下,蒸腾速率与气孔导度呈显著正相关。蒸腾速率和气孔导度与光合速率的相关性随遮荫条件的不同而异,全光照条件下蒸腾速率与光合速率呈显著正相关,而所有遮荫条件下相关性不显著。气孔导度与光合速率在所有光照下相关性均不显著。各遮荫条件下叶片总叶绿素、叶绿素a、叶绿素b含量均显著高于全光照的,且随遮荫程度的提高叶绿素含量呈上升趋势,而叶绿素a/b的值则随着遮荫程度的提高而下降。叶绿素荧光参数PSⅡ内禀光能转化效率(Fv/Fm)和潜在活性(Fv/Fo)日变化呈单谷曲线。各遮荫条件下Fv/Fm和Fv/Fo值均高于全光照的,且随着遮荫程度的提高其值均依次增加。这说明,异株荨麻是一种耐荫性很强的植物,遮荫可使其降低光补偿点、光饱和点、净光合速率、暗呼吸速率以及叶绿素a/b,但增加总叶绿素、叶绿素a、叶绿素b含量、光能利用率以及PSⅡ原初光能转化效率和潜在活性,以增强在弱光条件下的生长发育能力。

大荨麻根提取物对前列腺增生小鼠的治疗作用

目的观察大荨麻根提取物对前列腺增生的治疗作用。方法采用皮下注射丙酸睾酮制作小鼠前列腺增生模型,观察各组前列腺指数的变化及镜下病理学改变。结果大荨麻根提取物可明显降低前列腺增生小鼠的前列腺湿重,前列腺体积和前列腺指数,明显改善其组织形态学结构。结论大荨麻根提取物具有良好的抗前列腺增生作用。

3个种源异株荨麻光合特性的比较

在盆栽条件下以3个异株荨麻(Urtica dioica L.)种源为对象,用Li-6400型便携式光合作用测定系统对其叶片光合作用日变化、光响应曲线和CO2的响应曲线进行了比较测定,阐述了光合作用对光和CO2浓度的响应特征。结果表明:异株荨麻叶片的净光合速率(Pn)日变化均呈双峰曲线型,峰值在9:00和15:00,中午有明显的"午休"现象,Pn的降低主要是由非气孔因素所致;浙江天台县异株荨麻的Pn值明显高于其他2个种,表现出显著的高光合效率特性;不同种源异株荨麻的光合生理特性参数有显著差异:浙江天台县异株荨麻的光补偿点比其他2个种源的异株荨麻低,而光饱和点比另2个种源的高,说明其光能利用区间较宽;浙江天台县异株荨麻的CO2补偿点和饱和点都低于其他2个种源,异株荨麻在CO2饱和点以下,Pn随CO2浓度的增加呈线性增长,说明增大CO2浓度可大大提高光合生产力。

异株荨麻不同炮制品中总黄酮和多糖的含量分析

目的测定异株荨麻不同炮制品中总黄酮和多糖等两种有效成分的含量,探讨不同炮制方法存在的差异。方法分光光度计法。结果各炮制品中总黄酮含量按如下顺序减少:自然晾干荨麻>炒荨麻>105℃杀青晾干荨麻>220℃烘荨麻>焦荨麻>120℃烘荨麻>170℃烘荨麻。各炮制品中多糖含量按如下顺序减少:炒荨麻>170℃烘荨麻>220℃烘荨麻>自然晾干荨麻>120℃烘荨麻>焦荨麻>105℃杀青晾干荨麻。结论不同炮制方法能使异株荨麻中总黄酮和多糖含量产生变化。

异株荨麻茎叶中黄酮类化合物含量测定方法的研究

目的研究异株荨麻茎叶中黄酮类化合物的测定方法。方法分别采用Al(NO3)3络合分光光度法和HPLC法测定异株荨麻茎叶中黄酮类化合物的含量,并对测定结果进行比较;同时以黄酮类化合物的含量为指标,优选出了超声波辅助法提取异株荨麻茎叶中黄酮类化合物的最佳条件。结果超声波辅助法的最佳提取条件:体积分数为80%的乙醇溶液、料液比为1∶30,提取温度为60℃;HPLC法同时测定异株荨麻中芦丁和槲皮素的高效液相色谱条件:色谱柱选用Dia-mosnilTM钻石C18(250 mm×4.6 mm,5μm),柱温25℃,流动相为甲醇:0.4%磷酸=55∶45,流速1.0 ml/min,检测波长370 nm。结论Al(NO3)3络合分光光度法操作方便,简单,快速;HPLC法可以同时准确地测定出样品中不同黄酮类化合物的含量,精确性和灵敏度高。两种方法测定的总黄酮含量相差甚微,应根据不同的测定目的,选择适当的测定方法。

大荨麻根、茎叶乙醇提取物化学成分的GC/MS研究

利用气相色谱—质谱联用技术对大荨麻根、茎叶乙醇提取物化学成分进行分析,结果表明,茎叶醇提物的19种化学成分主要以脂肪酸及其衍生物、硼烷配合物、杂环类化合物为主,其含量分别为51.05%、21.19%、13.18%,其中医药化工原料中间体残留物占52.51%;根醇提物的17种化学成分主要以脂肪酸及其衍生物、杂环类化合物、烃类化合物为主,分别含50.77%、30.71%、10.62%,其中农药残留物占29.68%。

水分胁迫对异株荨麻光响应特性的影响

采用盆栽试验研究了土壤饱和含水量为100%、70%、60%及40%条件下,异株荨麻的光合作用—光响应特性。结果表明:非直角双曲线模型能很好地拟合异株荨麻的光合作用—光响应曲线;净光合速率在同等光合有效辐射时基本上表现为T2>T3>T1>T4;异株荨麻叶片的表观量子效率、最大净光合速率、暗呼吸速率和光饱和点均在适度水分胁迫下达到最大,在重度干旱胁迫下最低,这说明适度水分胁迫有助于提高异株荨麻对光能的利用能力。