Structural Characterization and Anti-Proliferation Activities Against Tumor Cells of an Arabinogalactan from Juniperus convallium

Influence of Reduction with NaBH4 and HCl in Obtaining Amino Derivatives of Cashew Gum and Cytotoxic Profile

Tree-exuded gums are natural polymers that represent an abundant raw material in the food and pharmaceutical industries. The cashew gum can be obtained by exudation of trees of the genus Anacardium, a native species of the Brazilian northeast; its polymer consists of monosaccharide units propitious to the action of chemical reactions that tend to improve their intrinsic characteristics among them, as the degree of hydro-solubility. The objective of this work was to modify the exudate gum of Anacardium occidentale (cashew gum (CG)) through an amine reaction. The modification was confirmed by Nuclear Magnetic Resonance (¹H NMR), infrared spectroscopy (FTIR), gel permeation chromatography (GPC), zeta potential, and thermogravimetric analysis (TG). In addition, the chemical modification altered the molar mass and surface charge of the CG, and the amino group binding to the CG polymers was confirmed by FTIR spectra. In addition, cytotoxicity tests were performed where cell viability was estimated by an MTT assay on RAW 264.7 macrophages. Through these tests, it was found that the amine caused an increase in the thermal stability of the amino compounds and did not present cytotoxic potential at concentrations below 50.0 mg/L.

Extraction, structural characterization, and antioxidant activity of polysaccharides derived from Arctium lappa L

Introduction

Arctium lappa L. root has high nutritional and medicinal values and has been identified as a healthy food raw material by the Ministry of Health of the People's Republic of China.

Methods

In the present study, an aqueous two-phase system (ATPS) of polyethylene glycol (PEG)-(NH4)2SO4 was used to extract Arctium lappa L. polysaccharides (ALPs) from the Arctium lappa L. roots, the optimal extraction conditions of crude ALPs were optimized by using the single-factor experiment and response surface methodology. The structure and composition of ALPs were determined by fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and high-performance liquid chromatography (HPLC). At the same time, the antioxidant activity of ALPs was investigated by in vitro antioxidant experiment.

Results

The optimized extraction parameters for extraction ALPs were as follows: the PEG relative molecular weight of 6,000, a quality fraction of PEG 25%, a quality fraction of (NH4)2SO4 18%, and an extraction temperature of 80°C. Under these conditions, the extraction rate of ALPs could reach 28.83%. FTIR, SEM and HPLC results showed that ALPs were typical acidic heteropolysaccharides and had uneven particle size distribution, an irregular shape, and a rough surface. The ALPs were chiefly composed of glucose, rhamnose, arabinose, and galactose with a molar ratio of 70.19:10.95:11.16:6.90. In addition, the ALPs had intense antioxidant activity in vitro with IC50 values in the ·OH radical (1.732 mg/ml), DPPH radical (0.29 mg/ml), and superoxide anion (0.15 mg/ml) scavenging abilities.

Discussion

The results showed that ATPS was an efficient method to extract polysaccharides and could be used for the extraction of other polysaccharides. These results indicated that ALPs had great prospects as a functional food and could be exploited in multiple fields.

Molecular Identification Based on Chloroplast Sequences and Anti-complementary Activity Comparison of Juniperus Samples from the Qinghai-Tibet Plateau

Juniperus (Cupressaceae, Pinales) plants are widely distributed in the Qinghai-Tibet Plateau of China. The leaves and twigs of at least 8 Juniperus species (J. pingii, J. pingii var. wilsonii, J. squamata, J. recurva var. coxii, J. saltuaria, J. indica, J. tibetica and J. convallium var. microsperma) have been used as the Tibetan medicine Xuba. At present, it is difficult to distinguish among the original species of Xuba based only on their similar morphological characteristics. However, in our previous studies, 4 Xuba samples from different Juniperus species exhibited significant differences in both anticomplementary activity in vitro and anti-inflammatory effects on acute lung injury in vivo. To identify the effective original species of Xuba reliably, in this study, we developed a sequencing-based DNA molecular technology to distinguish 14 populations of 8 Juniperus species collected from Tibet region, using trnS-G, trnD - T, and petN-psbM genomic regions to build phylogenetic trees. In addition, their anticomplementary activities were evaluated. The results showed that combined sequence of these 3 genomic regions could identify 8 Juniperus species clearly and clustered individuals of one species but from different locations, whichever phylogenetic tree was constructed. Moreover, the anticomplementary activities of the 8 species were clustered into 2 groups. Among them, J. saltuaria and J. recurva var. coxii, which formed an independent branch apart from the other 6 species in phylogenetic trees, were the most potent (CH₅₀: 0.029 - 0.032 mg/mL). Consequently, DNA identification of Juniperus using the combined sequence could provide beneficial guidance for further efficacy evaluation and quality control of Xuba.