Antioxidant and antibacterial properties of ethanolic pot-pollen extract of Melipona beecheii and determination of the major components by GC-MS.

Melipona beecheii pot-pollen is a natural product that has barely been studied, unlike other hive products such as honey and propolis. Its application has been reported since ancient times in traditional Mayan medicine, and it is also a functional food with high nutritional value. In the present study, samples of ethanolic pot-pollen extracts from five locations in the Yucatán Peninsula were analyzed to determine their antibacterial and antioxidant properties. All the extracts showed activity against five medically important bacteria; Pseudomonas aeruginosa and Listeria monocytogenes were the most susceptible bacteria in all samples. The evaluated antioxidant activity was higher than that reported by other studies. Palmitic, linoleic, and linolenic fatty acids and their respective ethyl ethers were detected by Gas Chromatography-Mass Spectrometry (GC-MS) in all samples in different concentrations. Based on these results, pot-pollen extract from Mama, Yucatán exhibited the best biological activities (Minimum Inhibitory Concentrations (MICs) between 6 and 40 mg/mL, EC50 DPPH 28 µg/mL, EC50 RP 30 µg/mL), which could be related to a higher content of unsaturated fatty acids and their ethyl esters. The present study demonstrates that M. beecheii pot-pollen has therapeutic potential in addition to its benefits as a nutritional supplement.

1H-NMR Metabolomic Study of the Mushroom Pleurotus djamor for the Identification of Nematocidal Compounds.

Due to the increasing populations of anthelmintic-resistant gastrointestinal nematodes and as a consequence of the adverse effects of synthetic drugs, this study focuses on the search for secondary metabolites with nematocidal activity from the edible mushroom Pleurotus djamor using The proton nuclear magnetic resonance (1H-NMR) metabolomics. The highest activity was shown by the ethyl acetate fractions of mycelium (EC50 290.8 µg/mL) and basidiomes (EC50 282.7 µg/mL). Principal component analysis (PCA) and hierarchical data analysis (HCA) of the 1H-NMR metabolic profiles data showed that the ethanolic extracts, the ethyl acetate, butanol, and water fractions from mycelium have different metabolic profiles than those from basidiomes, while low polarity (hexane) fractions from both stages of fungal development show similar profiles. Orthogonal partial least squares discriminant analysis (OPLS-DA) allowed the identification of signals in the 1H-NMR metabolic profile associated with nematocidal activity. The signals yielded via OPLS-DA and bidimensional NMR analysis allowed the identification of uracil as a component in the ethyl acetate fraction from basidiomes, with an EC50 of 237.7 µg/mL. The results obtained showed that chemometric analyses of the 1H-NMR metabolic profiles represent a viable strategy for the identification of bioactive compounds from samples with complex chemical profiles.

Characterization of cement mortars with regional organic and inorganic additives.

The present investigation establishes the basis for future studies in the southeast of México for the improvement of building materials by combining regional organic and inorganic nanoparticles in admixtures to formulate cement mortars with durability potential in structures of concrete. The characterization of the organic extract of Albzia tomentosa by nuclear magnetic resonance (NMR) revealed the presence of epicatechin (tannin related) and sucrose. Calcium zinc hydroxide dihydrate nanoparticles (CZ NPs) showed the highest surface area of 60.7 m2 g-1. The electrical resistivity, propagation of ultrasound velocity and water absorption by capillarity properties were individually evaluated for the organic extract, the inorganic nanoparticles and their admixtures in cement mortars, at a curing time of 7, 28 and 96 days with and optimal concentration of 5 mg mL-1 of the added additives. The best results were obtained at 96 days showing slightly but clear improvement of the electrical resistivity (23.40 ± 0.022 kΩ cm, 22.40 ± 0.004 kΩ cm and 22.29 ± 0.013 kΩ cm), propagation of ultrasound velocity (1370 ± 10 m s-1, 1345 m s-1 ± 6, 1310 ± 9 m s-1) and capillary coefficient (0.0044 kg m-2s-1/2, 0.0045 kg m-2s-1/2 and 0.0049 kg m-2s-1/2) properties of the cement mortars with CZ NPs, extraction Albizia solution (EAS) and CZ NPs + EAS respectively when compared to the mortar control (19.91 ± 0.036 kΩ cm, 1266 ± 15 m s-1 and 0.0082 kg m-2s-1/2).

Intra- and Interspecies Differences of Two Cecropia Species from Tabasco, Mexico, Determined through the Metabolic Analysis and 1H-NMR-Based Fingerprinting of Hydroalcoholic Extracts.

The genus Cecropia is used in the traditional medicine of Tabasco, Mexico, in diabetes and hypertension treatments, mainly without distinction of the species. This contribution aimed to carry out the metabolic analysis and Proton Nuclear Magnetic Resonance (1H-NMR) spectroscopy-based fingerprinting of the hydroalcoholic leaf extracts of Cecropia peltata (Cp) and Cecropia obtusifolia (Co) collected in five sub-regions of the State of Tabasco (Cp1, "Centro"; Cp2, "Chontalpa"; Cp3, "Pantanos"; Cp4, "Ríos" and Co5, "Sierra"). Firstly, the extracts were evaluated for their Total Phenol Content (TPC) and Total Flavonoid Content (TFC) by spectrophotometric methods. In addition, metabolic analysis was performed using High-Performance Liquid Chromatography with Diode-Array Detection HPLC-DAD, which allowed the quantification of the chemical markers: chlorogenic acid, isoorientin, and orientin, as well as a vitexin analog. Finally, metabolomic analysis was carried out based on the 1H-NMR spectra. The Cp4 extract (C. peltata from the "Ríos" sub-region) presented the highest values of TPC (155 ± 9.1 mg GAE/g E) and TFC (724 ± 22.2 mg RE/g E). The metabolic analysis was similar among the five samples; the highest concentrations of the four chemical markers were found in Cp3 (C. peltata from the "Pantanos" sub-region) for chlorogenic acid (39.8 ± 2.3 mg/g) and isoorientin (51.5 ± 2.9 mg/g), in Cp4 for orientin (49.9 ± 0.6 mg/g), and in Cp2 (C. peltata from the "Chontalpa" sub-region) for the vitexin analog (6.2 ± 0.2 mg/g). The metabolic analysis and the 1H-NMR fingerprint analysis showed intraspecies differences among the C. peltata samples and interspecies between C. peltata and C. obtusifolia, which were attributed to variations in the metabolite groups as well as in the proportion of sugars such as glucose and xylose.

Metabolic changes in antennal glands of Caribbean spiny lobsters Panulirus argus infected by Panulirus argus virus 1 (PaV1).

Panulirus argus virus 1 (PaV1) (Family Mininucleoviridae) causes chronic and systemic infection in wild juvenile spiny lobsters Panulirus argus (Latreille, 1804), ending in death by starvation and metabolic wasting. In marine decapods, the antennal gland is involved in osmoregulation and excretion. In this compact organ, fluid is filtered from the hemolymph, and ions are reabsorbed to produce a hypotonic urine. Although PaV1 is released with the urine in infected individuals, little is known regarding the metabolic effect of PaV1 in the antennal gland. The objective of this study was to perform a comparative evaluation of the metabolic profile of the antennal gland of clinically PaV1-infected lobsters versus those with no clinical signs of infection, using proton nuclear magnetic resonance analysis. Overall, 48 compounds were identified, and the most represented metabolites were those involved in carbohydrate, amino acid, energy, and nucleotide metabolism. Most of the metabolites that were down-regulated in the infected group were essential and non-essential amino acids. Some metabolites involved in the urea cycle and carbohydrate metabolism were also altered. This study represents a first approach to the metabolic evaluation of the antennal gland. We broadly discuss alterations in the content of several proteinogenic and non-proteinogenic amino acids and other key metabolites involved in energetic and nucleotide metabolism.

An Insight to the Composition of Pre-Hispanic Mayan Funerary Pigments by 1H-NMR Analysis.

The funerary rites of particular members of the pre-Hispanic Mayan society included the pigmentation of the corpse with a red color. In order to understand this ritual, it is first necessary to identify the constituents of the pigment mixture and then, based on its properties, analyze the possible form and moment of application. In the present approach, 1H-NMR analysis was carried to detect organic components in the funerary pigments of Xcambó, a small Maya settlement in the Yucatan Peninsula. The comparison of the spectra belonging to the pigment found in the bone remains of seven individuals, and those from natural materials, led to the identification of beeswax and an abietane resin as constituents of the pigment, thus conferring it agglutinant and aromatic properties, respectively. The 1H-NMR analysis also allowed to rule out the presence of copal, a resin found in the pigment cover from paramount chiefs from the Mayan society. Additionally, a protocol for the extraction of the organic fraction from the bone segment without visible signs of analysis was developed, thus broadening the techniques available to investigate these valuable samples.

Design, Synthesis, and In Silico Multitarget Pharmacological Simulations of Acid Bioisosteres with a Validated In Vivo Antihyperglycemic Effect.

Substituted phenylacetic (1-3), phenylpropanoic (4-6), and benzylidenethiazolidine-2,4-dione (7-9) derivatives were designed according to a multitarget unified pharmacophore pattern that has shown robust antidiabetic activity. This bioactivity is due to the simultaneous polypharmacological stimulation of receptors PPARα, PPARγ, and GPR40 and the enzyme inhibition of aldose reductase (AR) and protein tyrosine phosphatase 1B (PTP-1B). The nine compounds share the same four pharmacophore elements: an acid moiety, an aromatic ring, a bulky hydrophobic group, and a flexible linker between the latter two elements. Addition and substitution reactions were performed to obtain molecules at moderated yields. In silico pharmacological consensus analysis (PHACA) was conducted to determine their possible modes of action, protein affinities, toxicological activities, and drug-like properties. The results were combined with in vivo assays to evaluate the ability of these compounds to decrease glucose levels in diabetic mice at a 100 mg/kg single dose. Compounds 6 (a phenylpropanoic acid derivative) and 9 (a benzylidenethiazolidine-2,4-dione derivative) ameliorated the hyperglycemic peak in a statically significant manner in a mouse model of type 2 diabetes. Finally, molecular dynamics simulations were executed on the top performing compounds to shed light on their mechanism of action. The simulations showed the flexible nature of the binding pocket of AR, and showed that both compounds remained bound during the simulation time, although not sharing the same binding mode. In conclusion, we designed nine acid bioisosteres with robust in vivo antihyperglycemic activity that were predicted to have favorable pharmacokinetic and toxicological profiles. Together, these findings provide evidence that supports the molecular design we employed, where the unified pharmacophores possess a strong antidiabetic action due to their multitarget activation.

NMR Metabolic Profiling of Sargassum Species Under Different Stabilization/Extraction Processes.

The genus Sargassum is well represented by benthic and pelagic species, some of which form massive aggregates that can travel long distances due to the force of the ocean currents. Although they constitute an essential habitat for fish and invertebrate species, large accumulations of Sargassum in coastal areas generate several economic, environmental, and health impacts. It is important to recognize the species forming these aggregates, and identify the metabolites they produce, allowing for its exploitation, and therefore, better management practices. NMR metabolic profiling is a technique that can discriminate samples while detecting their unique or differential chemical features, and has been successfully used in the study and classification of several algal species. The present investigation studied the metabolic profiling of Sargassum species found on strandings at Puerto Morelos (Quintana Roo) east coast of the Mexican Caribbean. PCA of the 1 H-NMR profiles corresponding to S. natans, S. natans (morphotype VIII), S. fluitans, and a benthic Sargassum buxifolium allowed the discrimination of samples amongst them. Furthermore, discrimination between the two forms of S. natans was also possible. The PCA loading plot revealed that glutamine and glutamate have the highest influence in the clustering of the benthic Sargassum, while a high abundance of lactate, Myo-inositol, and trimethylamine is a unique feature from the S. natans morphotype VIII. Additional PLS-DA models showed that a heat-drying process improved the extraction of metabolites. Maceration and microwave-assisted extraction with water-ethanol led to similar profiles and thus any of them could be used in future investigations.

The Influence of Drying Temperatures on the Metabolic Profiles and Antioxidant Activity of Manilkara zapota Leaves.

In the present study, the leaves of Manilkara zapota (L.) P. Royen (Sapotaceae), an evergreen tree recognized for its medicinal properties in Southern Mexico, were used as a model to study the effect of different drying temperatures on its metabolic profile and therefore, its antioxidant potential. For this purpose, a methanol extraction of leaves dried at room temperature (25 °C) or by heat convection (50, 75 and 100 °C) were compared in terms of drying efficiency, yield of extraction, total phenol content, 1H-NMR metabolic profile, and DPPH antioxidant activity. The drying curves enabled the fact to be uncovered that drying efficiency improves with increase of temperature, as does the level of total phenols and antioxidant activity. A metabolomics approach using principal component analysis (PCA) and orthogonal projections to latent structures discriminant analysis (OPLS-DA) of the corresponding 1H-NMR profiles allowed the impact of the drying temperature on their metabolic profile to be documented and also, caffeic acid and epicatechin as main secondary metabolites contributing to the antioxidant activity of M. zapota to be identified.

Natural Products from the Yucatecan Flora: Structural Diversity and Biological Activity.

The Yucatan Peninsula possesses a unique climate, geology, landscape, and biota that includes a distinct flora of over 2300 species; of these, close to 800 plants are used in what is known as Mayan traditional medicine, and about 170 are listed as native or endemic. Even though the flora of the Yucatan peninsula has been widely studied by naturalists and biologists, to date, phytochemical and pharmacological knowledge of most of the plants, including the medicinal plants, is limited. Presently, phytochemical studies carried out on plants from the Yucatecan flora have resulted in the identification of a wide variety of natural products that include flavonoids, terpenoids, polyketides, and phenolics with cytotoxic, antiprotozoal, antibacterial, anti-inflammatory, analgesic, antioxidant, and antifungal activities. This review describes the main findings in over 20 years (1992 to 2018) of exploring the natural product diversity of the Yucatecan flora.