Isolation and structural characterization of a novel galactomannan from Eremurus anisopterus (Ker. et Kir) Regel roots

Structural characteristics and immunostimulatory activities of a new polysaccharide from Dendrobium fimbriatum Hook

A new polysaccharide (cDFP-W1) with high immunostimulatory activities was isolated from the stems of Dendrobium fimbriatum Hook. The analysis of the physicochemical properties showed that cDFP-W1 consisted of mannose and glucose in a molar ratio of 1 : 3.84, and its relative molecular weight was 4.0 × 10⁴ Da. Structural analysis implied that the linear backbone of cDFP-W1 was composed of α-1,4-d-Glcp, β-1,4-d-Manp, 3-O-acetyl-α-1,4-d-Glcp and α-1,4,6-d-Glcp, and its branches were the terminal β-d-Manp that was attached to the C-6 position of α-1,4,6-d-Glcp. An in vivo immunostimulatory assay exhibited that cDFP-W1 at 200 mg kg^-1 could significantly increase the proportions of CD4⁺ T-cell subpopulations, B cells, natural killer cells and dendritic cells, decrease the proportion of CD8⁺ T-cell subpopulations, and upregulate the percentage of activated macrophages (p < 0.01) in the spleen of mice. An in vitro immunostimulatory assay revealed that cDFP-W1 could effectively promote the proliferation of spleen lymphocytes, enhance the proliferation and phagocytosis of macrophage RAW264.7 cells, and stimulate the mRNA expression and extracellular release of NO, TNF-α and IL-1β of RAW264.7 cells. The western blot experiment suggested that the immunostimulatory activities of cDFP-W1 were closely related to the activation of MAPKs, NF-κB and PI3K/Akt signaling pathways.

Isolation of secondary metabolites from the Iranian medicinal plant Eremurus persicus

Eremurus persicus (Jaub. & Spach) Boiss. belonging to Xanthorrhoeaceae family is an endemic medicinal plant widely distributed in Iran. Its leaves have been traditionally used as a food and also as medicinal plant. Regarding the widespread application of E. persicus in Iranian folk medicine, and the insignificant investigation of its components, this study aimed at the isolation and identification of major secondary metabolites of this plant. By applying various chromatographic techniques, corchoionoside A (1), 4-amino-4-carboxychroman-2-one (2), isoorientin (3), ziganein 5-methyl ether (4), auraptene (5), and imperatorin (6) were isolated from the EtOAc and CHCl₃ fractions of the crude extract. Except isoorientin (3), all the identified phytoconstituents were reported for the first time from Eremurus genus.

Extraction, purification and characterization of water soluble galactomannans from Mimosa pudica seeds

Water soluble galactomannans from seed endosperm of Mimosa pudica L. was extracted and characterized (Fig. 1). Nuclear magnetic resonance spectroscopy and Gas Chromatography results revealed the presence of 4-linked mannose backbone with galactose side chains linked at the C6 position. Scanning Electron Micrographs showed smooth, elongated and irregular granular structure of galactomannan. Structural analysis by Attenuated total reflection infrared spectroscopy presented the Mannose to Galactose ratio while the X-ray diffraction studies showed the presences of A-type crystalline pattern of the galactomannan. Thermo Gravitimetric Analysis showed the three steps weight loss event and determined the thermal stability. The results showed that the extracted polysaccharides are typically amorphous, thermally stable and have desirable properties for industrial applications.

Antiviral Activity of Sulfated Polysaccharide of Adenanthera pavonina against Poliovirus in HEp-2 Cells

Adenanthera pavonina, popularly known as red-bead tree, carolina, pigeon's eye, and dragon's eye, is a plant traditionally used in Brazil for the treatment of several diseases. The present study aimed at evaluating the activity of sulfated polysaccharide from the Adenanthera pavonina (SPLSAp) seeds against poliovirus type 1 (PV-1) in HEp-2 cell cultures. The SPLSAp presented a cytotoxic concentration (CC₅₀) of 500 μg/mL in HEp-2 cell cultures, evaluated by the dimethylthiazolyl-diphenyltetrazolium bromide method (MTT). The SPLSAp exhibited a significant antiviral activity, with a 50% inhibitory concentration (IC₅₀) of 1.18 µg/mL, determined by plaque reduction assay and a high selectivity index (SI) of 423. The maximum inhibition (100%) of PV replication was found when the SPLSAp treatment was concomitant with viral infection (time 0 h), at all tested concentrations. The maximal inhibition was also found when the SPLSAp was used 1 h and 2 h postinfection, albeit at 50 μg/mL and 100 μg/mL. Therefore, we demonstrated that the SPLSAp inhibited PV growth. We also suggested that SPLSAp inhibited PV in more than one step of the replication, as the mechanism of antiviral action. We, therefore, selected the compound as a potential candidate for further development towards the control of the infection.

Cytotoxic triterpenoids from Lysimachia parvifolia

Five new oleanane-type triterpenoids, including two aglycones, 13β-28-epoxy-3β,22α,23-trihydroxyolean-16-one (1) and 13β-28-epoxy-22α,23-dihydroxyolean-3,16-dione (2), and three glycosides, anagalligenone-3-O-α-L-arabinopyranoside (3), anagalligenone-3-O-[β-D-glucopyranosyl(1 → 4)-α-L-arabinopyranoside] (4) and anagalligenone-3-O-[β-D-xylopyranosyl(1 → 2)-β-D-glucopyranosyl(1 → 4)-α-L-arabinopyranoside] (5), were isolated from the aerial parts of Lysimachia parvifolia, together with three known oleanane-type triterpenoid glycosides (6-8). The structures of the new compounds were subsequently elucidated by spectroscopic analysis and their cytotoxicities evaluated against six human cancer cell lines. Compounds 5-8 exhibited significant cytotoxicities against all the cell lines tested, with IC50 values lower than 10 μM. The possible mechanism of action of compound 6 was also studied.