Chemical constituents from Nelumbo nucifera leaves and their anti-obesity effects

Nelumbo nucifera Gaertn. (Nymphaeaceae), commonly called lotus, is widely distributed throughout Eastern Asia. It has been used for food and medicine for a long time. A phytochemical investigation of N. nucifera leaves led to the isolation of 13 megastigmanes (1–13), including a new megastigmane, nelumnucifoside A (1), and a new eudesmane sesquiterpene, nelumnucifoside B (14), eight alkaloids (15–22), and 11 flavonoids (23–33). Their chemical structures were determined based on spectroscopic methods including 1D, 2D NMR and MS spectrometry. The relative and absolute stereochemistry of the compounds was determined by NOESY and CD spectrometry, respectively. Compounds 19 and 22 significantly inhibited pancreatic lipase, whereas compounds 15 and 16 showed a strong inhibitory effect on adipocyte differentiation. Therefore, the leaves of N. nucifera have potential as an anti-obesity agent by inhibiting pancreatic lipase and adipocyte differentiation.     

Alkaloids of Nelumbo nucifera

The alkaloids of leaves of Nelumbo nucifera Gaertn. were examined using combined GLC-MS. The occurrence of four new alkaloids, dehydroroemerine (XII), dehydronuciferine (XI), dehydroanonaine (XIII) and N-methylisococlaurine (III) were revealed, besides the known roemerine (V), nuciferine (VI), anonaine (VII), pronuciferine (IV), N-nornuciferine (VIII), nornuciferine (IX), amepavine (I) and N-methylcoclaurine (II).     

The Phloem of Nelumbo nucifera Gaertn

In common with other aquatic angiosperms, Nelumbo nucifera Gaertn.has a relatively strongly developed phloem tissue. The vascularsystem consists of discrete collateral bundles in which no cambiumdevelops and the phloem and xylem are separated by a narrowlayer of parenchyma cells. The phloem consists of sieve elements,companion cells, and phloem parenchyma cells. The sieve elementshave transverse end walls with simple sieve plates. The cellsattain considerable width in the late phloem (metaphloem). Thecompanion cells are in vertical strands. In the early phloem(protophloem) of large bundles the sieve tubes and companioncells are eventually obliterated. The parenchyma cells alsoform vertical strands which may contain tannin cells. Some parenchymacells and companion cells are binucleate. The sieve elementsshow ultrastructural features common for these cells in dicotyledons.At maturity, they lack nuclei, ribosomes, and tonoplasts, butretain a plasmalemma, mitochondria, and plastids. The latterare poorly differentiated and form starch. The endoplasmic reticulumis in part stacked, in part it forms a network next to the plasmalemma.The P-protein occurs in two forms. One consists of tubules notassembled in any specific type of array. The other, possiblycomposed of much extended tubules, is assembled in crystallineaggregates which are retained as such in mature cells. The sieveplate pores are lined with callose and plasmalemma. The lateralwalls are relatively thin and the nacreous layer varies in degreeof distinctness.     

Evaluation of Hypoglycemic Activity of Inorganic Constituents in Nelumbo nucifera Seeds on Streptozotocin-Induced Diabetes in Rats

The seeds of Nelumbo nucifera (Lotus) have been used in the traditional system of medicine for various ailments including diabetes. The present study was aimed at analyzing the levels of biologically important trace elements in the lotus seeds by atomic absorption spectroscopy and evaluating the hypoglycemic properties of seed ash on streptozotocin-induced diabetes in rats. Diabetic rats treated with lotus seed ash at a concentration of 200 mg/kg body weight orally for 30 days exhibited significant hypoglycemic activity. The presence of trace elements in appreciable amounts in the seeds may play a direct or indirect role on insulin secretion or its action in a synergetic manner. The hypoglycemic activity of the ash was comparable with glyclazide. The role of trace elements in disorders related to diabetes is also discussed briefly.     

莲藕的组织培养与快速繁殖

1　植物名称　莲藕 (Ｎｅｌｕｍｂｏｎｕｃｉｆｅｒａ)鄂莲 4号。2　材料类别　茎尖。3　培养条件　 ( 1 )芽分化培养基 :ＭＳ 6 ＢＡ1 .0～ 2 .0ｍｇ·Ｌ- 1 (单位下同 ) ＮＡＡ 0 .2 3.0 %蔗糖 ;( 2 )增殖培养基 :ＭＳ 6 ＢＡ 0 .5～ 1 .0 ＩＢＡ0 .2 3.0 %蔗糖 ;( 3)生根培养基 :ＭＳ ＩＢＡ 0 .5～1 .0 ＡＣ 1 50 0 蔗糖 5.0 %。以上各培养基加0 .6%琼脂 ,ｐＨ 5.8。 ( 4 )移栽用营养液 :1 /4ＭＳ。培养温度 2 5～ 2 8℃ ,每天光照 1 0ｈ ,光照度 1 0 0 0～ 1 50 0ｌｘ。4　生长与分化情况4.1　茎尖的切取与分化　切取健康…     

莲的离体快速繁殖技术

以莲(Nelumbo nucifera)授粉后18天的莲子胚芽为外植体,通过初代培养、继代培养和炼苗移栽,建立了莲离体快速繁殖体系。结果表明,将胚芽外植体诱导出无菌苗的最适初代培养基为MS固体培养基添加0.5 mg·L–1 6-BA、0.5 mg·L–1NAA、30 g·L–1蔗糖、0.5 g·L–1活性炭和0.8 g...     

Composition and structure study of natural Nelumbo nucifera fiber

Nelumbo nucifera (Nn.) fiber is the isolated secondary wall of the Nn. leafstalk Tracheary elements which has a unique shape. As the shape of the fiber may strongly affect the industrial uses especially for textile usage, the morphology and structure of Nn. fiber at different growth stages were investigated by several techniques in the present work. The Nn. fiber has spriral morphology with cellulose I structure. The diameter of mature fiber is about 4 μm and the cross-section shows elliptical or slightly oval shape without lumen. These findings aim to deeply understand the structure of Nn. fiber which is expected to be helpful to bring Nn. fiber into industrial use.     

Anti-HIV benzylisoquinoline alkaloids and flavonoids from the leaves of Nelumbo nucifera, and structure-activity correlations with related alkaloids

(+)-1(R)-Coclaurine (1) and (-)-1(S)-norcoclaurine (3), together with quercetin 3-O-beta-D-glucuronide (4), were isolated from the leaves of Nelumbo nucifera (Nymphaceae), and identified as anti-HIV principles. Compounds 1 and 3 demonstrated potent anti-HIV activity with EC50 values of 0.8 and <0.8 microg/mL, respectively, and therapeutic index (TI) values of >125 and >25, respectively. Compound 4 was less potent (EC50 2 microg/mL). In a structure-activity relationship study, other benzylisoquinoline, aporphine, and bisbenzylisoquinoline alkaloids, including liensinine (14), negferine (15), and isoliensinine (16), which were previously isolated from the leaves and embryo of Nelumbo nucifera, were evaluated for anti-HIV activity. Compounds 14-16 showed potent anti-HIV activities with EC50 values of <0.8 microg/mL and TI values of >9.9, >8.6, and >6.5, respectively. Nuciferine (12), an aporphine alkaloid, had an EC50 value of 0.8 microg/mL and TI of 36. In addition, synthetic coclaurine analogs were also evaluated. Compounds 1, 3, 12, and 14-16 can serve as new leads for further development of anti-AIDS agents.     

中国莲的偶线期核型分析

本研究建立了中国莲偶线期染色体的核型,为研究莲的减数分裂过程及分子细胞遗传学研究提供基础。     

Chemical evaluation and antibacterial activity of novel bioactive compounds from endophytic fungi in Nelumbo nucifera

The objective of this study was to characterize an endophytic fungi producing-bioactive compound from the aquatic plant, Nelumbo nucifera. All parts of such plant were cleaned with surface sterilization technique and cultured on potato dextrose agar to isolate endophytic fungi. The identification was characterized by morphological and molecular technique. Fungal isolates were screened to discover antimicrobial activities by disc diffusion method against Methicillin-resistant Staphylococcus aureus DMST20651 (MRSA). MIC and MBC for those crude fungal extracts were determined. Finally, the chemical profile of crude extract was determined by gas chromatography and mass spectrometry. Six endophytic fungi were isolated from the surface-satirized parts of N. nucifera. Based on disc diffusion assay, the highest antibacterial activity against MRSA was isolate ST9.1 identified as Aspergillus cejpii. Results demonstrated that the ethyl acetate extraction had more active fractions with MIC of 2.5 mg/ml and MBC concentration of 50.0 mg/ml. The crude extracts were developed to identify the chemical constituents by gas chromatography and mass spectrometry. The major component of crude extract of endophytic fungi was 5-(1H-Indol-3-yl)-4,5-dihydro-[1,2,4]triazin-3-ylamine (C₁₁H₁₁N₅). Thus, the plant could be used in the treatment of infectious diseases caused by bacterial pathogen.     

The Development of Embryo and Endosperm of Nelumbo nucifera Gaertn

The development of the embryo and endosperm of Nelumbo nucifera Gaertn can be summarized as follows: 1. Embryogenesis of N. nucifera belongs to Solanad type; the 1st mitotic division of the zygote takes place later than that of the primary endosperm nucleus. 2. The development of endosperm basically conforms to the Helobial endosperm. After fertilization, the primary endosperm nucleus divides first transversely. This division results in the formation of two cells. The wall of this division is a little oblique to the longitudinal axis of the embryo sac. In accordance with the character of the endospermic development, it can be divided into, three stages: (1) two-celled endosperm stage, (2) multicellular endosperm stage, and (3) the stage of the endospermic nutrition being absorbed and cells atrophy. The developments of the embryo and endosperm are well correlated. This relation is relatively stable. 3. The cotyledons of the mature embryo are comparatively developed, but the radicle is extremely reduced. 4. As the seed is ripening, a thin membrane remains outside the plumule, which is the remainder of the endosperm. Therefore, the seed of N. nucifera is exalbuminous.     

Laticifers in Nelumbo nucifera Gaertn.: Distribution and Structure

The laticifers of Nelumbo nucifera Gaertn. (Nelumbonaceae) occurin vascular bundles and separately from these in the groundparenchyma. In common with laticifers in some other plants,they pass through a stage when they contain numerous small vacuoles,or vesicles, which later merge with the central vacuole. Osmiophilicglobules are formed in the small vacuoles and later releasedinto the central one. Partial disintegration of protoplaststakes place in the central vacuole, apparently by autophagy.The globules are retained. The laticifers are long thin-walledcells. Many show single perforations in the end walls.     

Hepatoprotective and free radical scavenging effects of Nelumbo nucifera.

Ethanol extracts from Nelumbo nucifera (ENN) seeds were studied for possible antioxidative and hepatoprotective effects. Antioxidative effects were measured spectrophotometrically by reduction of 2,2'-Diphenyl-1-picrylhydrazyl (DPPH) radicals. Hepatoprotective effects were tested using carbon tetrachloride (CCl4) and aflatoxin B1 (AFB1)-induced hepatocyte toxicity models. ENN showed potent free radical scavenging effects with a median inhibition concentration of 6.49 microg/ml. Treatment of hepatocytes with ENN inhibited both the production of serum enzymes and cytotoxicity by CCl4. The genotoxic and cytotoxic effects of AFB1 were also inhibited by ENN in dose-dependent manners. These hepatoprotective effects of ENN against CCl4 and AFB1 might result from its potent antioxidative properties.     

Purification and characterization of 2S albumin from Nelumbo nucifera

The 2S albumins are a group of seed storage proteins that have recently attracted considerable attention in the field of allergen science due to their allergenic potential. A new 2S albumin from seeds of Nelumbo nucifera (Nn-2S alb) was purified to electrophoretic homogeneity by the combination of ammonium sulfate fractionation, gel filtration, and ion exchange chromatography. The protein has a molecular mass of about 12 kDa estimated by SDS–PAGE, in good agreement with 12.5 ± 0.01 kDa determined by ESI–MS. Circular dichroism data showed that protein contained about 66% α-helices as estimated by K2D3, indicating that the protein was predominantly helical. The sedimentation coefficient (s°_20,w) of the predicted model was 1.72 ± 0.21 S. The predicted 3-dimensional structure of the Nn-2S alb revealed that the protein has a region of 12 amino acids which largely corresponds to the conserved immuno-dominant epitope of 2S allergens.     

花莲种质资源形态性状多样性研究(英文)

对从国家种质资源圃中选取的40份花莲种质资源的19个形态性状进行了观察。结果发现花型、花瓣数、雌蕊是否瓣化、雌蕊瓣化程度和根茎颜色与花蕾形状呈显著正相关,其中花型、花瓣数和根茎颜色与花蕾形状呈极显著高度相关。通径分析表明现蕾期对花型有显著正向效应(0.552),其次是花瓣数(0.516)和根茎颜色(0.368)。与花型呈显著负相关的性状有花瓣长(-0.801)、现花期(-0.558)和叶宽(-0.451)。主成分分析显示前四个成分累计贡献率达65.68%。聚类分析将所有材料分为四组。     

Alkaloid constituents from flower buds and leaves of sacred lotus (Nelumbo nucifera,Nymphaeaceae) with melanogenesis inhibitory activity in B16 melanoma cells

Methanolic extracts from the flower buds and leaves of sacred lotus (Nelumbo nucifera, Nymphaeaceae) were found to show inhibitory effects on melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells. From the methanolic extracts, a new alkaloid, N-methylasimilobine N-oxide, was isolated together with eleven benzylisoquinoline alkaloids. The absolute stereostructure of the new alkaloid was determined from chemical and physicochemical evidence. Among the constituents isolated, nuciferine, N-methylasimilobine, (?)-lirinidine, and 2-hydroxy-1-methoxy-6a,7-dehydroaporphine showed potent inhibition of melanogenesis. Comparison of the inhibitory activities of synthetic related alkaloids facilitated characterization of the structure-activity relationships of aporphine- and benzylisoquinoline-type alkaloids. In addition, 3–30 μM nuciferine and N-methylasimilobine inhibited the expression of tyrosinase mRNA, 3–30 μM N-methylasimilobine inhibited the expression of TRP-1 mRNA, and 10–30 μM nuciferine inhibited the expression of TRP-2 mRNA.     

Management and use of Nelumbo nucifera Gaertn. in Thai wetlands

Management and use of Nelumbo nucifera Gaertn.—the lotus plant—was studied in 58 wetlands distributed throughout Thailand. Although traditionally harvested in extractive systems depending on natural wetlands, N. nucifera is now increasingly being managed. Two hundred eighty informants mentioned 20 different uses, mainly for food, medicine, and religious rites, in both subsistence and cash economies. The uses of N. nucifera appeared to be rather generalized throughout the country even if informants in the northern and central regions knew of more uses and ways of commercializing its products, possibly related to the abundance of wetlands and natural stand in those regions, and maybe also cultural differences.     

莲子长寿机制的研究进展

莲( Nelumbo nucifera Gaertn.)为莲科、莲属多年水生宿根草本植物。莲子生命力极强,在自然条件下的泥碳层中能存活千年,甚至在极端高温、高湿条件下仍能保持较高的萌发活力。随着莲基因组测序与基因注释的完善,莲子长寿机制的相关研究取得了一定进展。本文对莲子的结构形态、保护系统和基因组特性方面的研究进展进行了综述,阐明莲子的长寿机制,对后续研究方向进行了展望。