Spirostanol Sapogenins and Saponins from Convallaria majalis L. Structural Characterization by 2D NMR, Theoretical GIAO DFT Calculations and Molecular Modeling.

Two new spirostanol sapogenins (5ß-spirost-25(27)-en-1ß,2ß,3ß,5ß-tetrol 3 and its 25,27-dihydro derivative, (25S)-spirostan-1ß,2ß,3ß,5ß-tetrol 4) and four new saponins were isolated from the roots and rhizomes of Convallaria majalis L. together with known sapogenins (isolated from Liliaceae): 5ß-spirost-25(27)-en-1ß,3ß-diol 1, (25S)-spirostan-1ß,3ß-diol 2, 5ß-spirost-25(27)-en-1ß,3ß,4ß,5ß-tetrol 5, (25S)-spirostan-1ß,3ß,4ß,5ß-tetrol 6, 5ß-spirost-25(27)-en-1ß,2ß,3ß,4ß,5ß-pentol 7 and (25S)-spirostan-1ß,2ß,3ß,4ß,5ß-pentol 8. New steroidal saponins were found to be pentahydroxy 5-O-glycosides; 5ß-spirost-25(27)-en-1ß,2ß,3ß,4ß,5ß-pentol 5-O-ß-galactopyranoside 9, 5ß-spirost-25(27)-en-1ß,2ß,3ß,4ß,5ß-pentol 5-O-ß-arabinonoside 11, 5ß-(25S)-spirostan-1ß,2ß,3ß,4ß,5ß-pentol 5-O-galactoside 10 and 5ß-(25S)-spirostan-1ß,2ß,3ß,4ß,5ß-pentol 5-O-arabinoside 12 were isolated for the first time. The structures of those compounds were determined by NMR spectroscopy, including 2D COSY, HMBC, HSQC, NOESY, ROESY experiments, theoretical calculations of shielding constants by GIAO DFT, and mass spectrometry (FAB/LSI HR MS). An attempt was made to test biological activity, particularly as potential chemotherapeutic agents, using in silico methods. A set of 12 compounds was docked to the PDB structures of HER2 receptor and tubulin. The results indicated that diols have a higher affinity to the analyzed targets than tetrols and pentols. Two compounds (25S)-spirosten-1ß,3ß-diol 1 and 5ß-spirost-25(27)-en-1ß,2ß,3ß,4ß,5ß-pentol 5-O-galactoside 9 were selected for further evaluation of biological activity.

Steroidal Glycosides from Convallaria majalis Whole Plants and Their Cytotoxic Activity.

Phytochemical examination of Convallaria majalis (Liliaceae) whole plants yielded 15 steroidal glycosides (1-15), including nine new compounds (4-6, 10-15) with a lycotetrose unit. The structures of the new compounds were determined using two-dimensional Nuclear magnetic resonance (NMR) analyses and chemical methods. The isolated compounds were evaluated for cytotoxicity against HL-60 human promyelocytic leukemia cells, A549 human lung adenocarcinoma cells, and HSC-4 and HSC-2 human oral squamous cell carcinoma cell lines. Of these, (25S)-spirost-5-en-3ß-yl O-ß-d-glucopyranosyl-(1→2)-O-[ß-d-xylopyranosyl-(1→3)]-O-ß-d-glucopyranosyl-(1→4)-ß-d-galactopyranoside (1) exhibited cytotoxic activity against HL-60, A549, HSC-4, and HSC-2 cells with IC50 values ranging from 0.96 to 3.15 µM. The corresponding furostanol glycoside of 1, (25S)-26-[(ß-d-glucopyranosyl)oxy]-22α-hydroxyfurost-5-en-3ß-yl O-ß-d-glucopyranosyl-(1→2)-O-[ß-d-xylopyranosyl-(1→3)]-O-ß-d-glucopyranosyl-(1→4)-ß-d-galactopyranoside (8), was cytotoxic to the adherent cell lines of A549, HSC-4, and HSC-2 cells with IC50 values of 2.97, 11.04, and 8.25 µM, respectively. The spirostanol lycotetroside (1) caused necrotic cell death in A549 cells in a dose-dependent manner. Alternatively, the furostanol lycotetroside (8) induced apoptotic cell death in A549 cells in a time-dependent manner, as was evident by morphological observations and flow cytometry analyses.

Adonis sp., Convallaria sp., Strophanthus sp., Thevetia sp., and Leonurus sp. - Cardiotonic Plants with Known Traditional Use and a Few Preclinical and Clinical Studies.

Plants have been always a fruitful source of active metabolites against many human disorders, where cardiovascular (CV) diseases have been one of the major health problems all over the world. There are some clinically proved medicinal plants with cardioprotective effects such as Crataegus monogyna and C. oxyacantha (hawthorn) from Rosaceae. On the other hand, cardiac glycosides, present in a number of plant species, are wellknown for their cardiotonic activity. However, we encountered such a fact that very less number of studies are available on the source plants; e.g. Adonis vernalis, Convallaria majalis, Strophanthus kombe, Thevetia peruviana, Leonurus cardiaca, etc. Consequently, we herein aimed to cover all available data consisting of in vitro, in vivo, and human studies (if any) on cardiotonic effects of the aforementioned species through a wide literature search using Scopus, Web of Science as well as Pubmed.

Convallaria keiskei as a novel therapeutic alternative for salivary gland cancer treatment by targeting myeloid cell leukemia-1.

BACKGROUND: Various chemotherapeutic agents have been used largely for the treatment of salivary gland cancer. However, results are disappointing, and these agents can cause some serious side effects. Therefore, recent studies have focused on the possible roles of natural products to overcome these limitations. METHODS: Salivary gland cancer cells treated with or without Convallaria keiskei (MECK) for 24 hours. Apoptotic changes were evaluated by live/dead assay, immunoblotting, and expression levels of caspase-3 and B-cell lymphoma-2 family member. RESULTS: MECK significantly inhibited salivary gland cancer growth. At the molecular level, MECK dramatically reduced myeloid cell leukemia-1 (Mcl-1) in a translation-dependent manner and thereby induced apoptosis through Bax/Bid. Furthermore, we found that Mcl-1 could be a potential therapeutic target of MECK-induced apoptosis and its stability is regulated by extracellular signal-regulated kinases 1/2 (ERK1/2) signaling CONCLUSION: MECK can be used as a safe and efficient therapeutic alternative for the treatment of salivary gland cancer. © 2015 Wiley Periodicals, Inc. Head Neck 38: E761-E770, 2016.

Synthesis and olfactory characterization of silicon-containing derivatives of the acyclic lily-of-the-valley odorant 5,7,7-trimethyl-4-methylideneoctanal.

5-Methyl-4-methylidene-6-(trimethylsilyl)hexanal (1b), a sila analog of the acyclic lily-of-the-valley odorant 5,7,7-trimethyl-4-methylideneoctanal (1a), and the Si-containing derivatives 2-6 were prepared in multistep syntheses, starting from Cl3 SiH and Cl2 SiMe2 , respectively. Compounds 1b, 2-6, and their new precursors were characterized by elemental analyses (C, H, N) and NMR spectroscopic studies ((1) H, (13) C, (15) N, and (29) Si). To gain more information about the structureodor correlation in the family of lily-of-the-valley or 'muguet' odorants, C/Si analogs 1a/1b and derivatives 2-6 were evaluated for their olfactory properties.

On the suitability of SIFT technique to deal with image modifications specific to confocal scanning laser microscopy.

Computer vision tasks such as recognition and classification of objects and structures or image registration and retrieval can provide significant information when applied to microscopy images. Recently developed techniques for the detection and description of local features make the extraction and description of local image features that are invariant to various changes possible. The invariance and robustness of feature detection and description techniques play a key role in the design and implementation of object recognition, image registration, or image mosaicing applications. The scale-invariant feature transform (SIFT) technique is a widely used method for the detection, description, and matching of image features. In this article we present the results of our experiments regarding the repeatability of SIFT features, and to the precision of the SIFT feature matching, under image modifications specific to confocal scanning laser microscopy (CSLM). We have analyzed the behavior of SIFT while changing the pinhole aperture, photomultiplier gain, laser beam power, and electronic zoom. Our experiments, conducted on CSLM images, show that the SIFT technique is able to match detected key points between images acquired at different values of the acquisition parameters with good precision and represents a consistent tool for computer vision applications in CSLM.

Imaging fluorescence detected linear dichroism of plant cell walls in laser scanning confocal microscope.

Anisotropy carries important information on the molecular organization of biological samples. Its determination requires a combination of microscopy and polarization spectroscopy tools. The authors constructed differential polarization (DP) attachments to a laser scanning microscope in order to determine physical quantities related to the anisotropic distribution of molecules in microscopic samples; here the authors focus on fluorescence-detected linear dichroism (FDLD). By modulating the linear polarization of the laser beam between two orthogonally polarized states and by using a demodulation circuit, the authors determine the associated transmitted and fluorescence intensity-difference signals, which serve the basis for LD (linear dichroism) and FDLD, respectively. The authors demonstrate on sections of Convallaria majalis root tissue stained with Acridin Orange that while (nonconfocal) LD images remain smeared and weak, FDLD images recorded in confocal mode reveal strong anisotropy of the cell wall. FDLD imaging is suitable for mapping the anisotropic distribution of transition dipoles in 3 dimensions. A mathematical model is proposed to account for the fiber-laminate ultrastructure of the cell wall and for the intercalation of the dye molecules in complex, highly anisotropic architecture.

Rapid hyperspectral fluorescence lifetime imaging.

We report a rapid hyperspectral fluorescence lifetime imaging (FLIM) instrument that exploits high-speed FLIM technology in a line-scanning microscope. We demonstrate the acquisition of whole-field optically sectioned hyperspectral fluorescence lifetime image stacks (with 32 spectral bins) in less than 40 s and illustrate its application to unstained biological tissue.

Convallasaponin A, a new 5beta-spirostanol triglycoside from the rhizomes of Convallaria majalis.

The rhizomes of Convallaria majalis have been analyzed for their steroidal glycoside constituents, resulting in the isolation of a new 5beta-spirostanol triglycoside, named convallasaponin A, along with two known cardenolide glycosides and a known cholestane glycoside. The structure of convallasaponin A was determined on the basis of extensive spectroscopic analysis, including 2D NMR data, and the results of hydrolytic cleavage. The cardenolide glycosides showed tumor specific cytotoxic activity.

The positive inotropic effect of the aqueous extract of Convallaria keiskei in beating rabbit atria.

The positive inotropic effect of the aqueous extract of Convallaria keiskei (ACK) and the possible mechanisms responsible for this effect were investigated in beating rabbit atria. ACK significantly increased atrial stroke volume, pulse pressure, and cAMP efflux in beating rabbit atria. The effects were not altered by pre-treatment with staurosporine and diltiazem, a non-selective protein kinase inhibitor and an L-type Ca2+ channel blocker, respectively. In addition, ACK markedly increased the K+ concentration in the beating atria-derived perfusate. Convallatoxin, a well-known digitalis-like cardiac glycosidic constituent of ACK, also increased atrial stroke volume and pulse pressure but did not alter the cAMP efflux level. The increases in atrial stroke volume and pulse pressure induced by convallatoxin were not also altered by pre-treatment with diltiazem. These results suggest that the ACK-induced positive inotropic effect in beating rabbit atria may, at least in part, be due to the digitalis-like activity of convallatoxin.

Anti-angiogenic activity of convallamaroside, the steroidal saponin isolated from the rhizomes and roots of Convallaria majalis L.

Angiogenesis plays a pivotal role in tumor growth and represents a key target for chemopreventive intervention. Despite the large number of existing angiogenesis inhibitors, there is still a great demand for new anti-angiogenic compounds. The objective of this study is to investigate the effect of administration of convallamaroside, a steroidal saponin isolated from the lily of the valley (Convallaria majalis L.) to mice on tumor angiogenesis reaction induced by tumor cells. Angiogenic activity was evaluated by mice intradermal test. Convallamaroside showed a significant inhibitory effect on the number of new vessels induced in mice by human kidney tumor cells (p < 0.001). Similarly, administration of convallamaroside to mice decreased the number of new vessels induced by sarcoma mice cells (p < 0.001).

[Determination of the azetidine-2-carboxylic acid from lily of the valley].

This paper reports the separation and determination of the azetidine-2-carboxylic acid in lily of the valley by high performance liquid chromatography (HPLC) with post-column derivatization and fluorescence detection. The operating conditions were cation exchange resin column (30 cm x 0.4 cm i.d.) with buffer solution A [1.96% (mass fraction) sodium citrate solution pH 3.10 +/- 0.02] and B [2.1% (mass fraction) sodium nitrate solution pH 9.60 +/- 0.02] as mobile phase at flow-rate of 0.4 mL/min, gradient elution, column temperature 65 degrees C, detection wavelength lambda ex = 338 nm and lambda em = 425 nm. The retention time of azetidine-2-carboxylic acid was 5.86 minutes. The recovery was 96.4% and coefficient of variation was 0.94%. This method is simple, rapid and sensitive.