Determination of Lotus Leaf Alkaloids by Solid Phase Extraction Combined with High Performance Liquid Chromatography with Diode Array and Tandem Mass Spectrometry Detection

Lotus (nelumbo) is a traditional Chinese medical herb, and alkaloids are responsible for its pharmaceutical activities. Therefore, a rapid, validated method to determine alkaloids in lotus leaves is useful for its quality control. The goal of this work was to develop and validate an analytical method for the identification and quantitation of the bioactive alkaloids of extracts from lotus leaf and classification of lotus germplasm based on alkaloid concentrations. Solid-phase extraction was used prior to high-performance liquid chromatography coupled with photodiode array detection at 272 nm and tandem electrospray ionization triple quadrupole mass spectrometry for analysis. Nuciferine and O-nornuciferine were the dominant compounds in lotus used for seed production and some used for flower production. However, anonaine, roemerine, and N-nornuciferine were abundant only in some lotus flowers. All the lotuses were classified into four groups by principal component analysis of alkaloid content: 10 flower and three seed lotuses characterized by high nuciferine and O-nornuciferine content; 12 flower lotuses with high N-nornuciferine, roemerine, and anonaine content; two flower lotuses with a relatively high content of all five alkaloids; and cultivars with a low alkaloid content and without dominant alkaloids.     

Comparative Study of the Petal Structure and Fragrance Components of the Nymphaea hybrid,a Precious Water Lily

Nymphaea hybrid, a precious water lily, is a widely-cultivated aquatic flower with high ornamental, economic, medicinal, and ecological value; it blooms recurrently and emits a strong fragrance. In the present study, in order to understand the volatile components of N. hybrid and its relationship with petals structure characteristics, the morphologies and anatomical structures of the flower petals of N. hybrid were investigated, and volatile compounds emitted from the petals were identified. Scanning and transmission electron microscopy were used to describe petal structures, and the volatile constituents were collected using headspace solid-phase microextraction (HS-SPME) fibers and analyzed using gas chromatography coupled with mass spectrometry (GC-MS). The results indicated that the density and degree of protrusion and the number of plastids and osmiophilic matrix granules in the petals play key roles in emitting the fragrance. There were distinct differences in the components and relative contents of volatile compounds among the different strains of N. hybrid. In total, 29, 34, 39, and 43 volatile compounds were detected in the cut flower petals of the blue-purple type (Nh-1), pink type (Nh-2), yellow type (Nh-3) and white type (Nh-4) of N. hybrid at the flowering stage, with total relative contents of 96.78%, 97.64%, 98.56%, and 96.15%, respectively. Analyses of these volatile components indicated that alkenes, alcohols, and alkanes were the three major types of volatile components in the flower petals of N. hybrid. The predominant volatile compounds were benzyl alcohol, pentadecane, trans-α-bergamotene, (E)-β-farnesene, and (6E,9E)-6,9-heptadecadiene, and some of these volatile compounds were terpenes, which varied among the different strains. Moreover, on the basis of hierarchical cluster analysis (HCA) and principal component analysis (PCA), the N. hybrid samples were divided into four groups: alcohols were the most important volatile compounds for Nh-4 samples; esters and aldehydes were the predominant volatiles in Nh-3 samples; and ketones and alkenes were important for Nh-2 samples. These compounds contribute to the unique flavors and aromas of the four strains of N. hybrid.     

Volatiles emission patterns of different plant organs and pollen of Citrus limon

The volatiles emitted in vivo by different plant parts of Citrus limon (Rutaceae) have been identified by mean of head space-solid phase micro extraction (HS-SPME) and gas chromatography coupled with mass spectrometry (GC-MS) analyses. In particular, the profiles of flower buds, mature flowers, petals, stamens, gynaecium, pericarp of unripe and ripe fruits, young and adult leaves and pollen have been examined. Furthermore, the essential oil obtained from expression of ripe pericarp was studied. Volatiles were produced in distinctive amounts by the different plant organs, creating an interesting contrast, particularly within the flower parts: the highest amount of limonene (62.5%) was emitted by gynaecium, followed by stamens (22.9%) and petals (3.1%). Pollen did not produce limonene at all. The same compound is contained in higher amounts in the young leaves than in old ones (65.3% versus 30.1%). A possible defensive role of limonene and other volatiles, mainly terpene aldehydes, produced by young leaves has been hypothesized.     

Heterologous Expression of a <Emphasis Type="Italic">Nelumbo nucifera</Emphasis> Phytochelatin Synthase Gene Enhances Cadmium Tolerance in <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis>

Phytochelatin synthase (PCS) is a key enzyme involved in the synthesis of phytochelatins, which are thought to play important roles in heavy metal detoxification. The sacred lotus (Nelumbo nucifera), one of the most popular ornamental species, has been shown to be a potential phytoremediator of heavy metal polluted water. However, the phytochelatin synthase gene in N. nucifera has not been identified yet. Here, we report the isolation and function characterization of a N. nucifera homologue of phytochelatin synthase. The sequence obtained shares a high degree of similarity with PCSs from other plant species and was named as Nelumbo nucifera phytochelatin synthase1 (NnPCS1). By using quantitative RT-PCR, we found that the expression of NnPCS1 in leaves of N. nucifera was dramatically increased in response to Cadmium (Cd) treatment. We further showed that, when exposed to Cd stress, Arabidopsis transgenic plants heterologous expressing NnPCS1 accumulated more Cd when compared with wild type. These results suggest that NnPCS1 involved in the response of N. nucifera to Cd stress and may represent a useful target gene for the phytoremediation of Cd-polluted water.     

Simultaneous qualitative assessment and quantitative analysis of flavonoids in various tissues of lotus (Nelumbo nucifera) using high performance liquid chromatography coupled with triple quad mass spectrometry

Flavonoid composition and concentration were investigated in 12 different tissues of ‘Ti-1’ lotus (Nelumbo nucifera) by high performance liquid chromatography equipped with photodiode array detection tandem electrospray ionization mass spectrometry (HPLC-DAD-ESI-MSⁿ). A total of 20 flavonoids belonging to six groups (myricetin, quercetin, kaempferol, isohamnetin, diosmetin derivatives) were separated and identified. Myricetin 3-O-galactoside, myricetin 3-O-glucuronide, isorhamnetin 3-O-glucuronide and free aglycone diometin (3′,5,7-trihydroxy-4′-methoxyflavone) were first reported in lotus. Flavonoid composition varied largely with tissue type, and diverse compounds (5–15) were found in leaf and flower stalks, flower pistils, seed coats and embryos. Flower tissues including flower petals, stamens, pistils, and, especially, reproductive tissue fruit coats had more flavonoid compounds (15–17) than leaves (12), while no flavonoids were detectable in seed kernels. The flavonoid content of seed embryos was high, 730.95 mg 100 g⁻¹ DW (dry weight). As regards the other tissues, mature leaf pulp (771.79 mg 100 g⁻¹ FW (fresh weight)) and young leaves (650.67 mg 100 g⁻¹ FW) had higher total flavonoid amount than flower stamens (359.45 mg 100 g⁻¹ FW) and flower petals (342.97 mg 100 g⁻¹ FW), while leaf stalks, flower stalks and seed coats had much less total flavonoid (less than 40 mg 100 g⁻¹ FW).     

Molecular Cloning and Expression Analysis of an <Emphasis Type="Italic">Mn</Emphasis>-<Emphasis Type="Italic">SOD</Emphasis> Gene from <Emphasis Type="Italic">Nelumbo nucifera</Emphasis>

A rapid amplification cDNA end (RACE) assay was established to achieve the complete sequence of mitochondrial manganese-superoxide dismutase (Mn-SOD) cDNA in Nelumbo nucifera. The obtained full-length cDNA of Mn-SOD was 926 bp and contained a 699-bp open reading frame encoding an Mn-SOD precursor of 233 amino acids. The recombinant of Mn-SOD expressed by PET-32a vector in Escherichia coli BL21 was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blotting assays. A 3D structural model of the Mn-SOD was constructed by homology modeling. Real-time polymerase chain reaction analysis revealed that Mn-SOD mRNA was expressed in young leaves, blossom, stems, and terminal buds during reproductive stage but with the highest expression in young leaves. This significant difference demonstrated the differential expression of Mn-SOD in various organs of N. nucifera.     

Analysis of volatile compounds emitted from fresh Syringa oblata flowers in different florescence by headspace solid-phase microextraction-gas chromatography-mass spectrometry

In this study, a simple and solvent-free method was developed for determination of the volatile compounds from fresh flowers of Syringa oblata using headspace solid-phase microextraction and gas chromatography-mass spectrometry. The SPME parameters were studied, the optimum conditions of a 65 μm polydimethylsiloxan/divinylbenezene (PDMS/DVB), extraction temperature of 25 °C and extraction time of 30 min were obtained and applied to extraction of the volatile compounds emitted from fresh flowers of S. oblata. The volatile compounds released from fresh flowers of S. oblata were separated and identified by GC-MS. Lilac aldehyde A, lilac aldehyde B, lilac aldehyde C, lilac aldehyde D, lilac alcohol A, lilac alcohol B, lilac alcohol C, lilac alcohol D, α-pinene, sabinene, β-pinene, myrcene, d-limonene, eucalyptol, cis-ocimene, benzaldehyde, terpinolene, linalool, benzene acetaldehyde, α-terpineol, p-methoxyanisole, p-anisaldehyde, (Z,E)-α-farnesene and (E,E)-α-farnesene were the most abundant volatiles released from fresh flowers of S. oblata var. alba. The relative contents of main volatile fragrance were found to be different in emissions from two varieties of S. oblata flowers (white or purple in color). The four isomers of lilac alcohol and four isomer lilac aldehyde were the characteristic components of the scent of fresh flowers of S. oblata. The main volatile fragrance from fresh flowers of S. oblata var. alba in different florescence ((A) flower buds; (B) at the early stage of flower blooming; (C) during the flower blooming; (D) at the end of flower blooming; (E) senescence) were studied in this paper. The results demonstrated that headspace SPME-GC-MS is a simple, rapid and solvent-free method suitable for analysis of volatile compounds emitted from fresh flowers of S. oblata in different florescence.     

Creation of “Rose Petal” and “Lotus Leaf” Effects on Alumina by Surface Functionalization and Metal‐Ion Coordination

Functional differences between superhydrophobic surfaces, such as lotus leaf and rose petals, are due to the subtle architectural features created by nature. Mimicry of these surfaces with synthetic molecules continues to be fascinating as well as challenging. Herein, we demonstrate how inherently hydrophilic alumina surface can be modified to give two distinct superhydrophobic behaviors. Functionalization of alumina with an organic ligand resulted in a rose‐petal‐like surface (water pinning) with a contact angle of 145° and a high contact angle hysteresis (±69°). Subsequent interaction of the ligand with Zn²⁺ resulted in a lotus‐leaf‐like surface with water rolling behavior owing to high contact angle (165°) and low‐contact‐angle‐hysteresis (±2°). In both cases, coating of an aromatic bis‐aldehyde with alkoxy chain substituents was necessary to emulate the nanowaxy cuticular feature of natural superhydrophobic materials.     

Glebionis coronaria (L.) Cass. ex Spach (Asteraceae)- a new fabric dye with potential antibacterial properties

The paper elucidates first ever report on Glebionis coronaria (L.) Cass. ex Spach as a new dyeing agent with high antibacterial activity. Glebionis coronaria (L.) Cass. ex Spach which is also known as Garland/Crown Daisy belonging to the flowering plant family Asteraceae has been identified as a new precursor/candidate to produce highly efficient natural textile dye and a potential antibacterial agent. Natural dye from garland daisy was extracted from the dried petals using DCM and MeOH solvent system. Change in mordants yielded 12 different shades of colours. Spectroscopic analysis of these extracts revealed the presence of carotenoids and flavonoids pigments and hence giving varied shades of yellow, greenish yellow colours (Code No. is assigned to each colour). Alum and stannous chloride have been found to give bright colours while ferrous sulphate gave dark shades of colour. Antibacterial activity of the extracts was studied against non-pathogenic bacteria's, Staphylococcus aureus (Gram-positive bacteria) and for the first time for Aeromonas sp. (Gram-negative bacteria). Two different concentrations of 10 ​mg/ml DCM and methanol extracts using methanol as solvent were tested. Both DCM and methanol extracts have shown inhibition in Aeromonas sp. while only DCM extract was inhibiting S. aureus. The flower extracts has not been evaluated till date for its dyeing properties with different mordants along with their bactericidal activity. Therefore, our present work was to extract natural dye from the flowers of Glebionis Coronaria (L.) Cass. ex Spach. and to do a detailed study.     

Synthesis of polyfunctionalized methylphosphine oxides

N,N-Dialkylamino(diphenylphosphoryl)chloromethanes, a new type of organophosphorus compounds, were synthesized. On dissolving in polar and low polar solvents, N,N-dialkylamino(diphenylphosphoryl)chloromethanes dissociate spontaneously with the P??C bond cleavage to form the diphenylphosphinite anion Ph₂PO^?. This was confirmed by the reaction of N,N-dimethylamino(diphenylphosphoryl)chloromethane with electrophilic substrates to form the corresponding addition or substitution products of Ph₂PO^?. The capability of spontaneous generating the diphenylphosphinite anion considers accessible N,N-dimethylamino(diphenylphosphoryl)chloromethane as a synthetic equivalent of the diphenylphosphinite anion.     

Synthesis and crystal structure of the complex N,N-dimethylanilinium dicitratoborate monohydrate

N,N-Dimethylanilinium dicitratoborate monohydrate [C₆H₅NH(CH₃)₂][(C₆H₆O₇)₂B]·H₂O (I) was synthesized for the first time. Single crystals were obtained in an aqueous solution; the crystal structure was studied by X-ray crystallography. Crystals of I are triclinic, space group $P\bar 1$ , a = 9.7017(2) ?, b = 11.0475(2) ?, c = 12.6282(2) ?, ?? = 106.595(2)°, ?? = 106.931(1)°, ?? = 103.568(1)°, V = 1163.97(4) ?³, Z = 2, ??_calc = 1.516 g/cm³. The structural units of compound 1 are large complex dicitratoborate anions with a spiran structure, N,N-dimethylanilinium cations, and crystal water molecules. The crystal packing is a three-dimensional framework. A hydrogen-bond system is formed by seven independent contacts O(N)-H??O.     

Quercetin-3-O-glucuronide in the Ethanol Extract of Lotus Leaf (Nelumbo nucifera) Enhances Sleep Quantity and Quality in a Rodent Model via a GABAergic Mechanism

Current pharmacological treatments for insomnia carry several and long-term side effects. Therefore, natural products without side effects are warranted. In this study, the sleep-promoting activity of the lotus leaf (Nelumbo nucifera) extract was assessed using ICR mice and Sprague Dawley rats. A pentobarbital-induced sleep test and electroencephalogram analysis were conducted to measure sleep latency time, duration, and sleep architecture. The action mechanism of the extract was evaluated through ligand binding experiments. A high dose (300 mg/kg) of the ethanolic lotus leaf extract significantly increased sleep duration compared to the normal group (p < 0.01). Administration of low (150 mg/kg) and high doses (300 mg/kg) of the extract significantly increased sleep quality, especially the relative power of theta waves (p < 0.05), compared to the normal group. Furthermore, caffeine and lotus leaf extract administration significantly recovered caffeine-induced sleep disruption (p < 0.001), and the sleep quality was similar to that of the normal group. Additionally, ligand binding assay using [³H]-flumazenil revealed that quercetin-3-O-glucuronide contained in the lotus leaf extract (77.27 μg/mg of extract) enhanced sleep by binding to GABA_A receptors. Collectively, these results indicated that the lotus leaf extract, particularly quercetin-3-O-glucuronide, exhibits sleep quantity- and quality-enhancing activity via the GABAergic pathway.     

Nelumbo nucifera leaves as source of water-repellent wax: Extraction through polar and non-polar organic solvents

Nelumbo nucifera leaves are rich source of natural wax possessing super-hydrophobic properties. It provides protection to them from ecological turbulences and climatic wear and tear. In this study, various experiments have been conducted to observe the yield of extraction and the determination of various functional groups, which are present in natural wax, derived from Nelumbo nucifera leaves. The natural wax has been extracted from lotus leaves through non-polar (hexane) and polar (ethanol) solvent via different extraction methods. The superhydrophobic wax has been successfully extracted with hexane. Whereas, ethanol did not extract the water-repellent wax of lotus leaf. Considering the cumulative amount, i.e. (desired + undesired), the maceration shows the extraction of 2.9% (%w/w, through hexane) and 10.2% (%w/w, through ethanol), while it was found 2.5% (%w/w, cycle period 15 min) and 9.0% (%w/w, cycle period 26 min) respectively, in case of Soxhlet extraction technique. For this specific case of natural wax recovery from biomass (lotus leaf), the maceration (traditional method) resulted a little bit superior extraction yield in comparison to the Soxhlet extraction method for extraction of crude wax. In the case of non-polar solvent (hexane), an extraction yield of 1.97% (%w/w) through maceration method was observed while in the case of non-polar solvent (ethanol), an extraction yield of 1.62% (%w/w) through Soxhlet extraction was observed. The TLC analysis on both types of extracts was performed. For the detection of various hydrocarbon chains in the crude wax extracts, FTIR was also performed. Topography of wax surface and wax-coated waterproof fabric was compared through SEM.     

Water-soluble polymeric derivatives of β-cyclodextrin

On the basis of hydrophilic copolymers of N-vinylamides??N-vinylpyrrolidone and N-methyl-N-vinylacetamide??that contain carboxylic or activated ester groups, new polymeric ??-cyclodextrin derivatives are synthesized via polymer-analogous transformations. Their solubility in water depends on the content of ??-cyclodextrin and the types of hydrophilic and reactive comonomers.     

β-nitro- and β-bromo-β-nitrostyrenes in the reactions with aminonitroguanidine

The conditions for the reactions of ??-nitro- and ??-bromo-??-nitrostyrenes with 1-amino-2-nitroguanidine resulting in the amination products, 1-nitro- and 1-bromo-1-nitro-2-aryl-2-(2-nitroguanidinoamino) ethanes, were found. Under the action of the basic catalysts or prolonged boiling, the adducts derived from the gem-bromonitrostyrenes undergo decomposition to form N-arylmethylidene-N-(2-nitroguanidino)amines.     

Condensation of 2-naphthylamine or N-benzyl-2-naphthylamines with formaldehyde and methyl 2,2-dimethyl-4,6-dioxocyclohexane-3-carboxylate

Condensation of 2-naphthylamine with formaldehyde and methyl 2,2-dimethyl-4,6-dioxocyclohexanecarboxylate afforded depending on the reaction conditions methyl 9,9-dimethyl-11-oxo-8,9,10,12-tetrahydro-7H-benzo[a]acridine-10-carboxylate or 4-alkoxymethyl-1,4-dihydro-2??,6??-dioxo-4??,4??-dimethyl-2??H,3H,6??Hspirobenzo[f]quinoline-2,1??-cyclohexyl-3??-carboxylate. The condensation of N-benzyl-2-naphthylamines with formaldehyde and methyl 2,2-dimethyl-4,6-dioxocyclohexanecarboxylate provided with the quantitative yield the corresponding methyl 4-benzyl-1,4-dihydro-2??,6??-dioxo-4??,4??-dimethyl-2??H,3H,6??H-spirobenzo[f]quinoline-2,1??-cyclohexyl-3??-carboxylates.     

Features of the reactions of β-aryl(heteryl)-α-nitroacrylates with N,N-, N,O-, and N,S-binucleophiles

The reactions of ??-aryl(heteryl)-??-nitroacrylates with N,N-, N,O-, and N,S-binucleophiles proceed regiospecifically through the initial formation of the Ad_N products, among which only the product from o-aminothiophenol was isolated. The conditions of converting the S-adducts into 2-aryl(heteryl)benzothiazole were found. The N-adducts formed in the reaction with hydrazine, o-phenylenediamine, and o-aminophenol undergo immediately the spontaneous transformation into the linear (azine, azomethine) or heterocyclic (benzimidazole) structures.     

A three dimensional framework induced by �������� stacking of 2,2��-(Alkylene-1,6-diyl)diisoquinolinium from Q[6]-based Pseudorotaxane

A bromide salt of 2,2??-(hexane-1,6-diyl) diisoquinolinium (K6) was designed, synthesized and introduced to construct a novel framework induced by ??···?? stacking of 2,2??-(alkylene-1,??-diyl)diisoquinolinium from Q[6]-based pseudo-rotaxanes. The crystal structure of the compound revealed that the assembled framework based on the Q[6]-2,2??-(alkylene-1,6-diyl)diisoquinolinium pseudo-rotaxanes have stoichiometries of {(K6)@(Q[6])}²⁺·2Br^?·7(H₂O). The compound 1 has a novel three-dimensional framework constructed of two different channels?Done containing stacked isoquinolyl moieties from the K6@Q[6] pseudorotaxanes and the other containing the bromide anions. ¹H NMR spectra analysis was performed and confirmed the pseudorotaxane interaction model in which the 2,2??-(alkylene-1,6-diyl)diisoquinolinium guest threads into the cavity of Q[6] with the alkyl chain included inside the cavity and the two end isoquinolyl moieties protruding from the two opening portals. Absorption spectrophotometric and fluorescence spectroscopic analyses of the host?Cguest inclusion complex in aqueous solution found that the complexes were most stable at a host:guest mole ratio of 1:1. At this ratio, the complex has binding constants (K) ~10⁶.     

Pulse radiolysis studies of intermolecular charge transfers involving tryptophan and three-electron-bonded intermediates derived from methionine

The oxidation processes of the radiation-generated, three-electron-bonded intermediates AcMet₂ [S??S]⁺ and AcMet [S??Br] were investigated by pulse radiolysis via their reactions with tryptophan (TrpH). These intermediates were derived from N-acetyl-methionine amide (N-AcMetNH₂) and N-acetyl-methionine methyl ester (N-AcMetOMe). The bimolecular rate constant k of the reaction between each intermediate and l-tryptophan (TrpH) was measured. For N-AcMetNH₂, k for the reaction of AcMet₂ [S??S]⁺ with TrpH were 3.4?×?10⁸ and 2.2?×?10⁸?dm³?mol^?1?s^?1 at pH?=?1 and 4.5, respectively. For N-AcMetOMe, k for the reaction of AcMet₂ [S??S]⁺ with TrpH were 4.0?×?10⁸ and 2.8?×?10⁸?dm³?mol^?1?s^?1 at pH 1 and 4.5, respectively. The rate constants for the intermolecular transformation of Met [S??Br] into TrpH⁺ or Trp were also estimated. For N-AcMetNH₂, k for the reaction of AcMet₂ [S??Br] with TrpH were 2.6?×?10⁸ and 3.3?×?10⁸?dm³?mol^?1?s^?1 at pH 1 and 4.5, respectively. Related mechanisms were discussed.