Anti-TMV Effects of Amaryllidaceae Alkaloids Isolated from the Bulbs of Lycoris radiata and Lycoricidine Derivatives

Fifteen known amaryllidaceae alkaloids were isolated from the bulbs of Lycoris radiata.Some of the compounds and lycoricidine derivatives had been screened for the activities against tobacco mosaic virus(TMV)by the conventional halfleaf method.Lycoricidine derivatives were also carried out the assay of effect on systemic infection of TMV by western-blot and RT-PCR analysis.The tested compounds showed moderate inactivation effect,whereas the lycoricidine derivatives showed good protective effect.The protective inhibitory activity of compounds L1(N-methyl-2,3,4-trimethoxyly-coricidine)(60.8%)and L3(N-methyl-2-methoxy-3,4-acetonidelycoricidine)(62.0%)was almost similar to the positive control,Ningnanmycin(66.4%).RT-PCR and Western-blot analysis displayed that compounds L1,L3,L5(N-allyl-2,3,4-triallyloxylycoricidine)exhibited antiviral activity,which was evidenced by reducing TMV-CP gene replication and TMV-CP protein expression.Additionally,defensive enzyme activities confirmed that compound L1 could increase the activity of PAL,POD,SOD to improve disease resistance of tobacco.

A new alkaloid from Lycoris aurea

A new alkaloid was isolated from the bulbs of Lycoris aurea （L＇Herit.） Herb. Its structure was established as 3-o-ethyltazettinol through chemical and spectroscopic studies including 2D NMR.

An LC-MS/MS Method for the Simultaneous Determination of Lycorine and Galanthamine in Rat Plasma and Its Application to Pharmacokinetic Study of Lycoris Radiata Extract in Rats

A rapid, sensitive, and selective liquid chromatography-tandem mass spectrometry was developed for the simultaneous determination of lycorine and galanthamine, two major constituents in Lycoris radiata extract, in rat plasma. Liquid-liquid extraction with ethyl ether was carried out using diphenhydramine as the internal standard The two bioactive alkaloids were separated on a Zorbax SB-C18 reserved-phase column （150 mm× 4.6 mm, i.d., 5 μm） by gradient elution using a mobile phase consisting of methanol with 0.1% formic acid （A） and water with 0.1% formic acid （B） at a flow rate of 0.6 mL/min. All analytes showed good linearity over a wide concentration range （r^2〉0.99） and the lower limit of quantification was 3.00 ng/mL for each analyte. The average extraction re- covery of the analytes from rat plasma was more than 82.15%, and the intra-day and inter-day accuracy and preci- sion of the assay were less than 12.6%. The validated method was successfully applied to monitoring the concen- trations and pharmacokinetic studies of two Amaryllidaceous alkaloids in rat plasma after an oral administration of Lycoris radiata extract.

Antimicrobial and Antioxidant Activities of Extracts from Bulbs of Lycoris aurea

[Objectives]To explore the antimicrobial and antioxidant activities of flavonoid and polysaccharide extracts from bulbs of Lycoris aurea.[Methods]The disc diffusion method was used to evaluate the antimicrobial activity of flavonoid and polysaccharide extracts from the bulbs of L.aurea.The antioxidant activity was determined by scavenging of hydroxyl and 1,1-diphenyl-2-picrylhydrazine(DPPH)free radicals,and reducing ability.[Results]Flavonoids were effective on 7 microorganisms,but polysaccharides had no effect.Flavonoids had better hydroxyl free radical scavenging activity and reducing capacity than polysaccharides,but weaker than ascorbic acid.However,flavonoids had similar DPPH free radical activity to ascorbic acid.The strong antibacterial and antioxidant activities of flavonoids were mainly attributed to the high content of total phenols in the extract,which was(76.71±4.42)mg/g.[Conclusions]The study shows that flavonoids from bulbs of L.aurea could be regarded as a new potential source of natural bacterial inhibitors and antioxidants.

Isolation and identification of alkaloids and anthocyanins from flower and bulb of Lycoris radiata using HPLC and LC-ESI-MS

Three anthocyanins (cyanidin 3-diglucoside, cyanidin 3-sambubioside and cyanidin 3-glucoside) together with eleven known alkaloids (lycoricidine, hipppeastrine,O-Demethyllycoramin, lycoricidinol, galanthine, lycorine, lycorenine, lycoramine, galanthamine, homolycorine and pretazettine) were identified in the flower and bulb of Lycoris radiata using high-performance liquid chromatography coupled with UV detection and electrospray ionization mass spectrometry. Anthocyanins play a major role in protecting plant’s DNA from the UV spectrum of sunlight and also in attracting insects for the purpose of pollination. Thus, knowledge on the contents and types of anthocyanins of L. radiata will help to evaluate the adaptive evolution of flowers and provide useful information for the ornamental breeding.

Knowledge Map and Topics Analysis on the Research of Lycoris Research based on the Perspective of Literature Metrology

[Objective]In order to reflect the relationship between literatures quickly and efficiently and reveal the evolutionary path and hotspot,and predict the future trend of Lycoris researches.[Methods]In 19902019,CiteSpace software was used for visual graphic analysis authors,institutes and key words related to Lycoris research based on data sources of WOS and CNKI.[Results](1)Domestic researchers have formed a core group of authors in East China,but the cooperation between the different teams is relatively dispersed.(2)From the perspective of international cooperation level,the cocontribution in China is the largest.Among them,the Chinese Academy of Sciences published has the largest number of papers,and higher research level.(3)The research on Lycoris has experienced three stages:slow accumulation period,rapid growth period and stable growth period.And its research direction develops along the route of“interspecific relationship within genuspropagation and cultivationpharmacology and pharmacodynamicscytology and molecular biologycross breeding”.[Conclusion]The research of Lycoris mainly distributed in Asian countries such as China and Japan.On the whole,its research direction is developing from macro to micro.

Enzyme-assisted Extraction and Enrichment of Galanthamine from Lycoris aurea

Objective To explore the optimum condition for complex enzyme-assisted extraction of galanthamine from Lycoris aurea by L_9（3~4） orthogonal array design and separation effect of cation exchange resin on galanthamine. Methods Cellulase and pectinase solution was used as the extraction solvent. The effects of p H value of enzyme, amount of complex enzyme, dissociation time, and enzymatic hydrolysis temperature on the extraction results were investigated. Results The optimal conditions were obtained as follows： ratio of solid to liquid（g：mL） 1：10, pH value 4.5, amount of complex enzymes 4%, enzymatic hydrolysis temperature 50oC, and reaction time 2.0 h. Under these conditions, the extraction yield of galanthamine was 0.0294%. In addition, D-001 cation exchange resin was selected for separation of galanthamine. The separation conditions were that adsorption flow rate was 3 BV/h with reagent of pH2 and the desorption flow rate was 3 BV/h with 70% ethanol solution containing 1.5 mol/L ammonia. After separation, the content of galanthamine was increased to 12.31%. Conclusion The results provide a reference for industrial production of galanthamine.

Benzylphenethylamine Alkaloids from the Bulbs and Flowers of Lycoris radiata

Objective To study the benzylphenethylamine alkaloids from the bulbs and flowers of Lycoris radiata.Methods Alkaloids were isolated by various column chromatographic methods and their structures were identified by spectral data.Results Fifteen known benzylphenethylamine alkaloids were isolated and identified as lycoramine(1),O-demethyllycoramine(2),N-demethyllycoramine(3),galanthamine(4),lycorine(5),caranine(6),ungminorine(7),narciclasine(8),5-hydroxy-10-O-demethyl-homolycorine(9),hippeastrine(10),ungerine(11),hippeastrine N-oxide (12),O-demethylhaemanthamine(13),haemanthidine(14),and 8-demethoxyhostasine(15).Conclusion Compound 15 is first isolated from the plants in Amaryllidaceae,compounds 3,6,9,and 11 are first reported from the plants in Lycoris Herb.,and compounds 2,7,and 14 are isolated from L.radiata for the first time.The1 3C-NMR data of compouds 3,7,and 12 are first reported in the present study.Furthermore,the galasine-type alkaloid is isolated from the plants of Lycoris Herb.for the first time.

Molecular Modeling and Docking of Mannose-binding Lectin from Lycoris radiata

Lycoris radiata mannose-binding lectin（LRL） is a protein which binds mannose residues specifically. The maturation peptide and three mannose-binding domains（residues 49-57, 80-88 and 113--121） of LRL were identified by sequence analysis. The 3D structure of LRL constructed by homology modeling shaped a flstular triangular prism. Three flanks of the prism are mainly composed of β-sheets and each flank has a mannose-binding domain. According to the docking and dynamics simulation, the bindings of residues 49--57 and 80--88 with mannose are more stable than that of residues 113--121 with it. The key residues for binding mannose are Gin80, Asp82, Ash84 and Tyr88. The study preliminarily analyzed the interaction sites and mechanism of LRL with mannoses, which could be useful for the study on insect-resistance and related drug discovery of LRL.

Identification and Expression Analysis of EST-based Genes in the Bud of Lycoris longituba

To obtain a primary overview of gene diversity and expression pattern inLycoris longituba, 4,992 ESTs (Expressed Sequence Tags) from L. longituba bud were se-quenced and4,687 cleaned ESTs were used for gene expression analysis. Clustered by the PHRAP program, 967contigs and 1,343 singlets were obtained. Blast search showed that 179 contigs and 227 singlets(totally 1,066 ESTs) had homologues in GenBank and 3,621 ESTs were novel.

湖北野生石蒜的驯化栽培初探

对驯化栽培3年的湖北野生石蒜(Lycoris radiata Herb)的生物学特性及形态解剖构造进行了研究。结果表明,由于驯化栽培石蒜与野生石蒜的生长环境存在显著的差异,从而使二者在生物学特性、外部形态和解剖构造方面产生了一定的差异,表现为驯化栽培3年后的野生石蒜抽薹期、盛花期和衰败期提前;叶面积缩小而叶的数目以及鳞茎直径和鲜重增加;叶上下表皮细胞、气孔直径明显减小,气孔密度明显增加。

忽地笑鳞片的组织培养和植株再生

忽地笑(Lycoris aurea)是一种多年生草本花卉。我们将径宽5cm的忽地笑鳞茎切去根系,洗净后剥去一层外围鳞片,经常规方法进行消毒后,将鳞茎切成宽0.4—0.6cm,长0.7cm,带有鳞茎盘或不带有鳞茎盘的鳞片切块,接种到MS基本培养基,附加不同浓度的6-BA、NAA,或IAA、IBA的固体培养基中。每天光照8—10小时,光强1000—1500lx,温度25±2℃。

不同温度对忽地笑光响应曲线及叶绿素荧光参数的影响

[目的]研究不同温度对忽地笑光合作用和叶绿素荧光参数的影响.[方法]将盆栽忽地笑依次置于5、10、15、20、25、30℃的恒温培养箱内培养0.5h,选取忽地笑的成熟叶片进行光响应曲线的测量;将盆栽忽地笑置于5、10、15、20、25、30℃的恒温培养箱内黑暗培养0.5 h,选取成熟叶片测量各项叶绿素荧光参数.[结果]在25 ℃条件下,忽地笑净光合速率、表观量子效率、最大光化学效率最高,光补偿点最低,其次为20℃＞10℃＞15℃＞5℃,在30℃条件下净光合速率最低.[结论]忽地笑在20～ 25℃范围内光能利用率最高.它对光照要求不严,对弱光和强光均可有效利用,适应性较强.

石蒜属植物切花品种的栽培技术研究

以石蒜属(Lycoris Herb.)切花品种忽地笑(Lycoris aurea)、红花石蒜(Lycoris radiata)、换锦花(Lycoris sprengeri)、长筒石蒜(Lycoris longituba)为试材,研究种源鳞茎、光、温、栽培基质等因素对石蒜属植物切花品质和产量的影响。结果表明,石蒜种源其种球大小和种球年限与切花品质、产量呈正相关。在不同的光照条件下,随着遮阴强度增大,则延迟开花且缩短花期;在45%遮阴条件下,可提高产量,提早开花期,增加花葶长度与粗度,切花品质普遍提高。温度对石蒜属植物开花时间有影响,随温度降低而延后,以20~26℃为开花的最佳温度。4个品种都喜温暖的气候,最高气温不超过30℃,旬平均气温24~26℃适宜石蒜生长,但从切花产量与品质来看,差异并不明显。3种栽培基质对石蒜切花品质、产量影响不显著。

石蒜有性生殖败育的原因探讨

采用石蜡切片法对石蒜(Lycoris radiata(L'Her.)Herb)小孢子、雄配子体和胚囊的发生发育过程进行了观察.结果表明,小孢子母细胞减数分裂过程存在滞后染色体、染色体桥、染色体片段和微核等现象;成熟花粉粒具有2核、3核和营养细胞中存在2核等异常现象;在胚囊的形成发育过程中,未见胚囊母细胞经减数分裂产生四分体的现象和7细胞8核结构的雌配子体产生,造孢细胞分裂产生2核后,细胞迅速变大并高度液泡化,其中的细胞质和细胞迅速解体消失.因此,石蒜有性生殖的败育原因,主要是由于其胚囊形成中的发育不良所致.

石蒜光合特性比较及其对温度胁迫的响应

为寻找适合林下栽培的石蒜种源,本研究通过比较19个种源石蒜光合参数,筛选出高光效种源,并进一步对该种源温度胁迫的响应机制进行分析。结果表明:在19个地理种源石蒜中,南京、黄山种源各项光合参数均处于优势水平,可作为高光效种源扩大生产。其中,南京种源在高温和低温胁迫下,Pn均降低,高温胁迫下Tr始终高于胁迫初期水平,在低温胁迫下Tr表现为不可逆的降低趋势。石蒜ACBP6基因受温度诱导,高温胁迫下的表达量显著高于低温胁迫下。在两种温度胁迫下,ABA含量均增加,但短期的胁迫中低温诱导的ABA浓度更高。石蒜的ACBP6基因和内源激素ABA可能参与了其对温度胁迫的防御反应。本研究为石蒜适宜种源筛选及温度胁迫响应机制研究提供理论依据。