HPLC-PDA Method for Quantification of Bioactive Compounds in Crude Extract and Fractions of Aucklandia costus Falc. and Cytotoxicity Studies against Cancer Cells.

Aucklandia costus Falc. (Synonym: Saussurea costus (Falc.) Lipsch.) is a perennial herb of the family Asteraceae. The dried rhizome is an essential herb in the traditional systems of medicine in India, China and Tibet. The important pharmacological activities reported for Aucklandia costus are anticancer, hepatoprotective, antiulcer, antimicrobial, antiparasitic, antioxidant, anti-inflammatory and anti-fatigue activities. The objective of this study was the isolation and quantification of four marker compounds in the crude extract and different fractions of A. costus and the evaluation of the anticancer activity of the crude extract and its different fractions. The four marker compounds isolated from A. costus include dehydrocostus lactone, costunolide, syringin and 5-hydroxymethyl-2-furaldehyde. These four compounds were used as standard compounds for quantification. The chromatographic data showed good resolution and excellent linearity (r2 ˃ 0.993). The validation parameters, such as inter- and intraday precision (RSD < 1.96%) and analyte recovery (97.52-110.20%; RSD < 2.00%),revealed the high sensitivity and reliability of the developed HPLC method. The compounds dehydrocostus lactone and costunolide were concentrated in the hexane fraction (222.08 and 65.07 µg/mg, respectively) and chloroform fraction (99.02 and 30.21 µg/mg, respectively), while the n-butanol fraction is a rich source of syringin (37.91 µg/mg) and 5-hydroxymethyl-2-furaldehyde (7.94 µg/mg). Further, the SRB assay was performed for the evaluation of anticancer activity using lung, colon, breast and prostate cancer cell lines. The hexane and chloroform fractions show excellent IC50 values of 3.37 ± 0.14 and 7.527 ± 0.18 µg/mL, respectively, against the prostate cancer cell line (PC-3).

5-Hydroxymethyl-2-furaldehyde induces developmental toxicology and decreases bone mineralization in zebrafish larvae.

In this study, we aimed to assess the developmental toxicity and effects of 5-HMF in zebrafish as a model organism for toxicology studies. To this end, we treated zebrafish embryos with 1-100 µg/ml 5-HMF and observed bone staining, gene expression, and reactive oxygen species levels in order to investigate the toxicological effects of 5-HMF. The results showed that high concentrations of 5-HMF caused increased mortality and deformity rates in zebrafish larvae, inhibited cartilage development, reduced bone mineralization, increased reactive oxygen species levels, and disrupted the expression of genes related to bone development and reactive oxygen species enzyme activity. The antioxidant N-acetyl-l-cysteine partially rescued the toxicological effects caused by the high concentrations of 5-HMF. Overall, these findings showed that high concentrations of 5-HMF induce reactive oxygen species production, leading to developmental toxicity and decreased bone mineralization. Our results provide a reference for understanding the toxic effects of 5-HMF.

Antioxidant activities and volatile compounds in longan (Dimocarpus longan Lour.) wine produced by incorporating longan seeds.

The seeds of dried longan, one of the major processed fruits in Thailand, contain several bioactive compounds. In this study, we developed longan wine by incorporating its seeds during juice preparation and evaluated the antioxidant activities and volatile compounds in different conditions. The results suggested that Saccharomyces cerevisiae EC-1118 was suitable for fermentation of longan juice supplemented with 50% seed and 20% initial soluble solids at an optimal temperature of 30 °C. Different yeast strains showed various extents of antioxidant activities; however, the fermentation temperature and initial soluble solids of longan juice had little effect on the inhibition of reactive species. Antioxidant activities were significantly increased with increasing seed content. Dominant volatile compounds, which were independent of the winemaking conditions, were found to be phenethyl alcohol, 2,3-butylene glycol, 5-hydroxymethyl-2-furaldehyde, ethyl hydrogen succinate, and 4-hydroxyphenethyl alcohol. These compounds highly influenced the antioxidant activities of longan wine produced by incorporating the seeds.

5-hydroxymethyl-2-furaldehyde purified from Japanese pear (Pyrus pyrifolia Nakai cv. Nijisseiki) juice concentrate inhibits melanogenesis in B16 mouse melanoma cells.

Pear juice concentrate prepared by boiling Japanese pear (Pyrus pyrifolia Nakai cv. Nijisseiki) juice can significantly inhibit the activity of tyrosinase, a key enzyme in melanin synthesis in human skin. Using the ethanol extract of pear juice concentrate, we homogeneously purified an active compound that was identified as 5-hydroxymethyl-2-furaldehyde (5-HMF) through 1H- and 13C-NMR and mass spectroscopy. We observed that 5-HMF inhibited the monophenolase and diphenolase activities of mushroom tyrosinase as a mixed-type inhibitor (K i values of 3.81 and 3.70 mmol/L, respectively). In B16 mouse melanoma cells, treatment with 170 µmol/L of 5-HMF significantly reduced α-melanocyte-stimulated melanin synthesis by suppressing the cyclic adenosine monophosphate-dependent signaling pathway involved in melanogenesis. The results of our study indicated that 5-HMF can be potentially used as a skin-lightening agent in the cosmetic industry. Abbreviations: AC: adenylate cyclase; CREB: cAMP response element-binding protein; dhFAME: S-(-)-10,11-Dihydroxyfarnesoic acid methyl ester; DMEM: dulbecco's modified eagle medium; l-DOPA: 3-(3,4-Dihydroxyphenyl)- l-alanine; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; HEPES: 4-(2-Hydroxyethyl)-1-piperazine ethane sulfonic acid; 5-HMF: 5-Hydroxymethyl-2-furaldehyde; MITF: microphthalmia-associated transcription factor; α-MSH: α-Melanocyte-stimulating hormone; PKA: protein kinase A; PVDF: polyvinylidene difluoride; SDS: sodium dodecyl sulfate; TRP1: tyrosinase-related protein 1; TRP2: tyrosinase-related protein 2.

Antioxidative Capacity of and Contaminant Concentrations in Processed Plum Products Consumed in Romania.

The bioactive compounds (total phenols, anthocyanins, and flavonoids) and antioxidant activity of plum-based products (prunes, jams, and marmalade) were evaluated based on spectrophotometric assays and acrylamide and 5-hydroxymethyl-2-furaldehyde concentrations to determine the quality and safety of these products in the Romanian marketplace. The total polyphenol concentrations in prunes, marmalade, and jams were 0.93 to 5.63 g of gallic acid equivalent per kg of dry matter, and the antioxidant activity was 3.0 to 17.2 mmol/kg. The concentrations of potentially harmful acrylamide in the plum products ranged from the limit of quantitation (<20 µg/kg) to 37.44 µg/kg, and the concentration was higher in prunes (26.66 to 163.72 µg/kg) than in jams. The 5-hydroxymethyl-2-furaldehyde concentrations in plum products were also variable, at 36 to 2,149 mg/kg. These data revealed a very low concentration of acrylamide in thermally processed plum products, and the results for total polyphenols and the antioxidant activity of prunes and plum jams may be relevant for evaluating these products as important sources of bioactive compounds.

Acid-catalysed glucose dehydration in the gas phase: a mass spectrometric approach.

Understanding on a molecular level the acid-catalysed decomposition of the sugar monomers from hemicellulose and cellulose (e.g. glucose, xylose), the main constituent of lignocellulosic biomass is very important to increase selectivity and reaction yields in solution, key steps for the development of a sustainable renewable industry. In this work we reported a gas-phase study performed by electrospray triple quadrupole mass spectrometry on the dehydration mechanism of D-glucose. In the gas phase, reactant ions corresponding to protonated D-glucose were obtained in the ESI source and were allowed to undergo collisionally activated decomposition (CAD) into the quadrupole collision cell. The CAD mass spectrum of protonated D-glucose is characterized by the presence of ionic dehydrated daughter ion (ionic intermediates and products), which were structurally characterized by their fragmentation patterns. In the gas phase D-glucose dehydration does not lead to the formation of protonated 5-hydroxymethyl-2-furaldehyde, but to a mixed population of m/z 127 isomeric ions. To elucidate the D-glucose dehydration mechanism, 3-O-methyl-D-glucose was also submitted to the mass spectrometric study; the results suggest that the C3 hydroxyl group plays a key role in the reaction mechanism. Furthermore, protonated levulinic acid was found to be formed from the monodehydrated D-glucose ionic intermediate, an alternative pathway other than the known route consisting of 5-hydroxymethyl-2-furaldehyde double hydration.

Two new furaldehyde compounds from the rhizomes of Gastrodia elata.

Two new compounds 5-[4'-(4″-hydroxybenzyl)-3'-hydroxybenzyloxymethyl]-furan-2-carbaldehyde (1) and 5-[4'-(4″-hydroxybenzyl)-3'-hydroxybenzyl]-furan-2-carbal-dehyde (2), together with two known 5-(4-hydroxbenzyloxymethyl)-furan-2-carbaldehyde] (3) and 5-(hydroxymethyl)-2-furaldehyde (4), were isolated from the rhizome of Gastrodia elata. Their structures were elucidated by spectroscopic analysis and comparison of their spectral data with those reported previously. All compounds exhibited weak or no cytotoxicity against human colon carcinoma cell line (HT-29) and human chronic myelogenous leukemia cell line (K-562).