Recovery of Naringin-Rich Flavonoid Extracts from Agroresidues with Anxiolytic- and Antidepressant-like Effects in Mice.

Citrus paradisi species belong to the Rutaceae family, and it is commonly known as grapefruit. Grapefruit consumption involves a large amount of waste that goes to landfills and produces significant pollution affecting the human health. To examine this phenomenon, we designed an efficient chemical method that recovers naringin-rich flavonoid extracts from the fresh waste of grapefruits, by using the solvent impregnation resin method (SIR) with XAD-4 amberlite and either methanol or water as elution systems. Additionally, we focused on evaluating these extracts' anxiolytic- and antidepressant-like effects in behavioral predictive paradigms in mice. According to direct Principal Component Analysis (PCA) by NMR, and Direct Injection Electrospray Ionization-Mass Spectrometry (DIESI-MS), methanol extracts obtained after resin treatment were free of coumarin compounds and evinced had a high content of naringin. Poncirin, phenylalanine, chrysin 5,7-dimethyl ether, 5,7-dimethoxy-4'-hydroxyflavanone, 2,3-dihydro-2-(4-hydroxyphenyl)-5,6,7,8-tetramethoxy-4H-1-benzopyran-4-one, tetrahydrocurcumin, corchoionoside C, 6'-coumaroyl-1'-O-[2-(3,4-dihydroxyphenyl) ethyl]-ß-D-glucopyranoside were also detected. Naringin-rich methanol extract caused a clear anxiolytic-like effect in the Elevated Plus Maze (EPM) and the Hole-Board (HBT) Tests, increasing oral doses of this extract did not produce a sedative effect. A single oral dose caused an antidepressant-like effect in the Tail Suspension Test (TST), while repeated administrations of the methanol extract elicited a robust antidepressant effect in the Forced Swimming Test (FST) in mice. Our evidence highlights the importance of bioprospecting studies of organic waste with therapeutic potentials, such as anxiety and depression disorders.

Calea zacatechichi Schltdl. (Compositae) produces anxiolytic- and antidepressant-like effects, and increases the hippocampal activity during REM sleep in rodents.

ETHNOPHARMACOLOGICAL RELEVANCE: Calea zacatechichi is a plant with an extensive popular and ritual use in Mexico. In healthy volunteers, it induces well-being and tranquility senses, and facilitates superficial stages of sleep. However, anxiolytic, and antidepressant-like effects and changes on the sleep-waking stages have not been explored. AIM: To determine anxiolytic and antidepressant-like effects of an aqueous extract of C. zacatechichi (CZ) in rodents and to analyze their effects on hippocampal activity in the rat sleep-waking cycle. MATERIAL AND METHODS: CZ anxiolytic- and antidepressant-like effects were evaluated in several mice and rat behavioral paradigms. CZ effects on temporal distribution of sleep were described, and hippocampus EEG frequency patterns were analyzed during the sleep-waking cycle; absolute and relative powers were analyzed during Rapid Eye Movements (REM) and non-REM sleep stages. CZ chemical analysis was performed by UPLC-ESI-MS. RESULTS: CZ produced specific and robust anxiolytic- and antidepressant-like effects in mice and rats, similar to those of prototypical drugs, at doses ranging from 0.5 to 50 mg/kg. CZ at 100 mg/kg produced visible mild sedative effects in rats, associated with a significant increase in Slow Wave Sleep episodes during a 6 h recording, and enhanced fast frequencies of hippocampus (gamma-band:31-50 Hz) during REM sleep. CONCLUSION: Results could support the well-being and tranquility senses reported by healthy consumers, and to explain the oneiric content during dreams and some improvements in cognitive processes described by consumers. Anxiolytic- and antidepressant-like effects of this species, reported for first time in this study could improve some aspects of mental health.

Non-Cytotoxic Dibenzyl and Difluoroborate Curcuminoid Fluorophores Allow Visualization of Nucleus or Cytoplasm in Bioimaging.

Curcumin, the most important secondary metabolite isolated from Curcuma longa, is known for its numerous purported therapeutic properties and as a natural dye. Herein, based on curcumin's intrinsic fluorescence, a search for improved curcumin-based fluorophores was conducted. Within the set of semi-synthetic curcumin derivatives i.e. mono (1), di (2), tri (3), tetra (4) benzylated and dibenzyl-fluoroborate (5), the fluorescence properties of 2 and 5 in solution outstood with a two-fold quantum yield compared to curcumin. Furthermore, all benzylated derivatives showed a favorable minimal cytotoxic activity upon screening at 25 µM against human cancer and non-tumoral COS-7 cell lines, with a reduction of its cytotoxic effect related to the degree of substitution. Fluorophores 2 and 5 are versatile bioimaging tools, as revealed by Confocal Fluorescence Microscopy (CFM), and showed permeation of living cell membranes of astrocytes and astrocytomas. When 2 is excited with a 405- (blue) or 543-nm (green) laser, it is possible to exclusively and intensively visualize the nucleus. However, the fluorescence emission fades as the laser wavelength moves towards the red region. In comparison, 5 allows selective visualization of cytoplasm when a 560-nm laser is used, showing emission in the NIR region, while it is possible to exclusively observe the nucleus at the blue region with a 405-nm laser.

Reliable, high-quality suppression of NMR signals arising from water and macromolecules: application to bio-fluid analysis.

Analysis of metabolites in biofluids using nuclear magnetic resonance often requires the suppression of obscuring signals arising from water and macromolecules. This paper analyses the limitations of the pulse sequence most commonly used to achieve such suppression (presat-CPMG) and proposes new pulse sequences that do not share those limitations. The utility of these improved pulse sequences is demonstrated in a metabolomic study of multiple sclerosis (MS) patients.

Full Structural Characterization of Homoleptic Complexes of Diacetylcurcumin with Mg, Zn, Cu, and Mn: Cisplatin-level Cytotoxicity in Vitro with Minimal Acute Toxicity in Vivo.

At the present time, scientists place a great deal of effort worldwide trying to improve the therapeutic potential of metal complexes of curcumin and curcuminoids. Herein, the synthesis of four homoleptic metal complexes with diacetylcurcumin (DAC), using a ligand designed to prevent the interaction of phenolic groups, rendering metal complexes through the ß-diketone functionality, is reported. Due to their physiological relevance, we used bivalent magnesium, zinc, copper, and manganese for complexation with DAC. The resulting products were characterized by ultraviolet-visible (UV-Vis), fluorescence spectroscopy, infrared spectroscopy (IR), liquid and solid-state nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), magnetic moment, mass spectrometry (MS), single crystal, and powder X-ray diffraction (SCXRD and PXRD). Crystallization was achieved in dimethylsulfoxide (DMSO) or N,N-dimethylformamide (DMF) as triclinic systems with space group P-1, showing the metal bound to the ß-diketone function, while the 1H-NMR confirmed the preference of the enolic form of the ligand. Single crystal data demonstrated a 1:2 metal:ligand ratio. The inhibition of lipid peroxidation was evaluated using the thiobarbituric acid reactive substance assay (TBARS). All four metal complexes (Mg, Zn, Cu, and Mn) exhibited good antioxidant effect (IC50 = 2.03 ± 0.27, 1.58 ± 0.07, 1.58 ± 0.15 and 1.24 ± 0.10 µM respectively) compared with butylated hydroxytoluene (BHT) and α-tocopherol. The cytotoxic activity in human cancer cell lines against colon adenocarcinoma (HCT-15), mammary adenocarcinoma (MCF-7), and lung adenocarcinoma (SKLU-1) was found comparable ((DAC)2Mg), or ca. 2-fold higher ((DAC)2Zn) than cisplatin. The acute toxicity assays indicate class 5 toxicity, according to the Organization for Economic Co-operation and Development (OECD) guidelines at doses of 3 g/kg for all complexes. No mortality or changes in the behavior of animals in any of the treated groups was observed. A therapeutic potential can be envisaged from the relevant cytotoxic activity upon human cancer cell lines in vitro and the undetected in vivo acute toxicity of these compounds.

A New Family of Homoleptic Copper Complexes of Curcuminoids: Synthesis, Characterization and Biological Properties.

We report herein the synthesis and crystal structures of five new homoleptic copper complexes of curcuminoids. The scarcity of reports of homoleptic complex structures of curcuminoids is attributed to the lack of crystallinity of such derivatives, and therefore, their characterization by single crystal X-ray diffraction is rare. The ligand design suppressing the phenolic interaction by esterification or etherification has afforded a significant increase in the number of known crystal structures of homoleptic metal complexes of curcuminoids revealing more favorable crystallinity. The crystal structures of the present new copper complexes show four-fold coordination with a square planar geometry. Two polymorphs were found for DiBncOC-Cu when crystallized from DMF. The characterization of these new complexes was carried out using infrared radiation (IR), nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), and single crystal X-ray diffraction (SCXRD) and the antioxidant and cytotoxic activity of the obtained complexes was evaluated.

Heliopsis longipes: anti-arthritic activity evaluated in a Freund's adjuvant-induced model in rodents

ABSTRACT This study assesses the anti-arthritic effect of the affinin-enriched (spilanthol, main alkamide) hexane extract from the roots of Heliopsis longipes (A. Gray) S.F. Blake, Asteraceae, on a Freund adjuvant-induced arthritis model in rodents. The extract was orally administered at a dose of 2, 6.6, or 20 mg/kg; a significant edema-inhibitory activity in the acute and chronic phases was observed with a dose of 2 and 20 mg/kg, respectively. The extract showed higher anti-inflammatory and anti-arthritic effects than the reference drug phenylbutazone (80 mg/kg). Moreover, the extract prevented the occurrence of secondary lesions associated to this pharmacological model.

The influence of sulfur configuration in 1 H NMR chemical shifts of diasteromeric five-membered cyclic sulfites.

The effect of the stereochemistry of the sulfur atom on 1 H chemical shifts of the diasteromeric pair of cyclic sulfites of 4-[methoxy(4-nitrophenyl)methyl]-5-phenyl-1,3,2-dioxathiolan-2-oxide was investigated. The complete 1 H and 13 C NMR spectral assignment was achieved by the use of one-dimensional and two-dimensional NMR techniques in combination with X-ray data. A correlation of experimental data with theoretical calculations of chemical shift tensors using density functional theory and topological theory of atoms in molecules was made. Copyright © 2016 John Wiley & Sons, Ltd.

Retro-Curcuminoids as Mimics of Dehydrozingerone and Curcumin: Synthesis, NMR, X-ray, and Cytotoxic Activity.

Curcumin and its derivatives have been extensively studied for their remarkable medicinal properties, and their chemical synthesis has been an important step in the optimization of well-controlled laboratory production. A family of new compounds that mimic the structure of curcumin and curcuminoids, here named retro-curcuminoids (7-14), was synthesized and characterized using 1D ¹H- and 13C-NMR, IR, and mass spectrometry; the X-ray structure of 7, 8, 9, 10, 12, 13, and 14 are reported here for the first time. The main structural feature of these compounds is the reverse linkage of the two aromatic moieties, where the acid chloride moiety is linked to the phenolic group while preserving α, ß-unsaturated ketone functionality. The cytotoxic screening of 7, 8, 9, and 10 at 50 and 10 µg/mL was carried out with human cancer cell lines K562, MCF-7, and SKLU-1. Lipid peroxidation on rat brain was also tested for compounds 7 and 10. Compounds 7, 8, and 10 showed relevant cytotoxic activity against these cancer cell lines, and 10 showed a protective effect against lipid peroxidation. The molecular resemblance to curcuminoids and analogs with ortho substituents suggests a potential source of useful bioactive compounds.

Antidepressant-like and toxicological effects of a standardized aqueous extract of Chrysactinia mexicana A. Gray (Asteraceae) in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: C. mexicana A. Gray (Asteraceae) is a native of North America plant. In Mexico׳s folk medicine it is used for the fever, rheumatism and as a diuretic, antispasmodic, general tonic or adaptogenic herb, and as a stimulant agent. The aim of the study was to examine the antidepressant-like properties of an aqueous extract of C. mexicana (Cm), in order to scientifically describe its potential value in the management of depressive disorders. To evaluate the acute and subacute toxic effects of Cm and effects on hepatic and biochemical functions in mice. MATERIALS AND METHODS: Antidepressant-like effects of Cm were evaluated in the Forced swimming and suspension tail tests (FST and TST), the ambulatory activity was measure in the Open Field Test (OFT), motor coordination was evaluated in the inverted screen and gyratory roller (IST and Rota-rod), the biochemical and histopathological analysis were carried out. Phytochemical studies of organic and aqueous extracts of Cm were thoroughly conducted. RESULTS: Cm produced a significant reduction of the immobility time both FST and in TST, without affect the ambulatory activity of experimental mice. Cm did not produce any damage in the hepatic functions, nor produce any significant change in the morphological tissue of organs examined. CONCLUSIONS: Chrysactinia mexicana induces a clear antidepressant-like effect in mice, without affect any basic functions. The consumption of this medicinal plant does not represent risk for health. The chemical analysis showed the flavonoids free and glycosides mainly.

Minimising research bottlenecks by decluttering NMR spectra.

The lack of resolving power in everyday NMR produces ambiguous data, causing bottlenecks, lengthening multi-step projects and increasing the likelihood of making mistakes. Significant impacts can be made in many fields by minimising these problems with the aid of pure shift techniques.

Anti-depressant-like effect of kaempferitrin isolated from Justicia spicigera Schltdl (Acanthaceae) in two behavior models in mice: evidence for the involvement of the serotonergic system.

We evaluated the antidepressant-like effect of kaempferitrin (Km) isolated from the plant Justicia spicigera (Asteraceae), which is used in traditional medicine for relieving emotional disorders, such as "la tristeza" (sadness or dysthymia) and "el humor" (mood changes). The actions of Km were evaluated in a forced swimming test (FST) and a suspension tail test (TST) in mice. We explored the involvement of the serotonergic system and the hypothalamic-hypophysis-adrenal axis (HPA) in the antidepressant-like effect of Km. To evaluate nonspecific effects of Km on general activity, the open field test (OFT) was performed. Km at 5, 10, and 20 mg/kg induced an antidepressant-like effect. Sub-effective dose of Km (1 mg/kg) produced a synergistic effect with imipramine (6.25 mg/kg) and fluoxetine (10 mg/kg) but not with desipramine (3.12 mg/kg). Pretreatment with p-chlorophenylalanine methyl ester (PCPA), a serotonin synthesis inhibitor, N-{2-(4-(2-methoxyphenyl)-1-piperazinyl}-N-(2-pyridinyl)cyclohexecarboxamide (WAY-100635), a selective 5-HT1A receptor antagonist, and 8OH-DPAT, a selective 5-HT1A agonist, but not pindolol (10 mg/kg) blocked the anti- immobility effect induced by Km. Taken together, these results indicate that the antidepressant-like effect of Km is related to the serotonergic system, principally 5-HT1A. This effect was not related to changes in locomotor activity.

Oligomerization of 10,16-dihydroxyhexadecanoic acid and methyl 10,16-dihydroxyhexadecanoate catalyzed by lipases.

The main monomer of tomato cuticle, 10,16-dihydroxyhexadecanoic acid (10,16-DHPA) and its methyl ester derivative (methyl-10,16-dihydroxyhexadecanote; methyl-10,16-DHHD), were used to study their oligomerization reactions catalyzed by five lipases: Candida antarctica lipase B (CAL-B), Rhizomucor miehei lipase (RM), Thermomyces lanuginosus lipase (TL), Pseudomonas cepacia lipase (PCL) and porcine pancreatic lipase (PPL). For 10,16-DHPA, optimum yields were obtained at 60 °C using toluene and 2-methyl-2-butanol (2M2B) as solvent, while for methyl-10,16-DHHD the bests yields were obtained in toluene and acetonitrile. Both reactions leaded to linear polyesters according to the NMR and FT-IR analysis, and there was no data indicating the presence of branched polymers. Using optimized conditions, poly(10,16-DHPA) and poly(methyl-10,16-DHHD) with Mw = 814 and Mn = 1,206 Da, and Mw = 982 and Mn = 860 Da, respectively, were formed according to their MALDI-TOF MS and ESI-MS data. The self-assembly of the polyesters obtained were analyzed by AFM.

Anxiolytic-like and antinociceptive effects of 2(S)-neoponcirin in mice.

STUDY AIMS: 2(S)-neopincirin (NEO) is a constituent from of Clinopodium mexicanum, which is used in traditional Mexican herbal medicine for its tranquilizing and analgesic properties. This study investigated the anxiolytic-like, sedative and antinociceptive effects of NEO in several mice models. MATERIAL AND METHODS: The anxiolytic-like effect was evaluated in the hole-board (HBT) and Open Field Tests (OFT); sedative effect was evaluated in sleeping time induced by sodium pentobarbital, and its antinociceptive actions were measured in the hot plate test. To evaluate if the GABA receptor could be involved in the anxiolytic-like effect produced by NEO, in independent experiments, the effects produced by co-administration of NEO plus muscimol (MUS) and NEO plus Pitrotoxin (PTX) were evaluated in the HBT. RESULTS: NEO was isolated from Clinopodium mexicanum leaves. The NMR, MS and optic rotation data helped establish its identity as (2S)-5-hydroxy-4'-methoxyflavanone-7-O-{ß-glucopyranosyl-(1→6)-ß-rhamnoside}. NEO showed an anxiolytic-like effect and was able to counter the nociception induced by a thermal stimulus in a dose-dependent manner. PTX blocked the anxiolytic-like effect of NEO, while MUS was able to enhance it. CONCLUSIONS: The findings of present work demonstrated that NEO possesses anxiolytic-like and antinociceptive effects in mice. Such effects are not associated with changes in the locomotor activity. These results supported the notion that anxiolytic-like effect of NEO involves the participation of GABAergic system.

Decoupling two-dimensional NMR spectroscopy in both dimensions: pure shift NOESY and COSY.

An increase in the resolving power in 2D NMR spectra is obtained by collapsing 2D signals with multiplet structure into 2D singlets. This resolution gain is achieved by combining 2D experiments with pure shift techniques and covariance processing (see picture). The method should be of value in both manual and automated structure determination.

Flavonoid mixture analysis by matrix-assisted diffusion-ordered spectroscopy.

The structural similarity of flavonoids, often present in natural product mixtures, makes their analysis by NMR methods less than straightforward. This similarity is a dual problem for one of the most powerful NMR methods for mixture analysis, diffusion-ordered spectroscopy (DOSY), which relies both on well-resolved peaks and on differences in hydrodynamic radii for separating the signals from different components in a mixture. To overcome these limitations, we use a matrix-assisted DOSY approach that exploits differential chemical interactions with a slow diffusion matrix (here micellar sodium dodecyl sulfate) to resolve flavonoid mixtures in mixed solvents.

Resolving natural product epimer spectra by matrix-assisted DOSY.

High resolution diffusion-ordered NMR spectroscopy allows the separation of signals from different species based on their diffusion coefficients. In general this requires that the NMR spectra of the components do not have overlapping signals, and that the diffusion coefficients are significantly different. Modifying the solvent matrix in which a sample is dissolved can change the diffusion coefficients observed, allowing resolution ("matrix-assisted DOSY"). We show here that dissolving the two naturally-occurring epimers of naringin in an aqueous solution of ß-cyclodextrin causes both shift and diffusion changes, allowing the signals of the epimers to be distinguished. Chiral matrix-assisted DOSY has the potential to allow simple resolution and assignment of the spectra of epimers and enantiomers, without the need for derivatisation or for titration with a shift reagent.

Hydroxynitrile lyases from prunus seeds in the preparation of cyanohydrins.

The hydroxynitrile lyase (HNL) activity of nine defatted Prunus seeds was compared for catalyzing the addition of HCN to aromatic, heteroaromatic and α,ß-unsaturated aldehydes. Although the conversion and enantiomeric excess (ee) of the corresponding cyanohydrins were both influenced by the HNL source and the chemical structure of the aldehyde, Prunus HNLs were all suitable for the enantioselective preparation of cyanohydrins.

Biocatalytic oxidative kinetic resolution of (±)-4-(chlorophenyl)phenylmethanol by Nocardia corallina B-276

Chiral diarylmethanols are versatile building blocks for the preparation of biologically active substances, but they are difficult to obtain in enantiopure form. We used Nocardia corallina B-276 for the oxidative kinetic resolution of (+/-)-4-(chlorophenyl)phenylmethanol, 1. Two experimental methods were used: 1) Suspension of cells in a phosphate buffer solution and 2) Cells in the culture media, in a 3-L bioreactor. After 36 hrs using the first method, the ketone/alcohol ratio was 56/44 and the unoxidized alcohol had an enantiomeric ratio of 93/7, predominating the R-alcohol.

Comparative esterification of phenylpropanoids versus hydrophenylpropanoids acids catalyzed by lipase in organic solvent media

The esterification of phenylpropanoid and hydrophenylpropanoid acids, catalyzed by candida antarctica lipase B (CAL-B), with several alcohols has demonstrated that the substitution pattern on the aromatic ring has a very significant influence on the reactivity of the carboxyl group due, mainly, to electronic effects, when compared to the unsaturated acids with the hydrogenated acids. It is also clear that in the saturated acids there still remain some unclear effects related to the aromatic substituents.