Search results for "glycoside"
showing 10 items of 296 documents
Triterpene Saponins from the Fruits of Phytolacca rugosa (Phytolaccaceae)
2010
Four known serjanic acid glycosides were isolated from the fruits of Phytolacca rugosa and characterized mainly by 2D NMR spectroscopy and mass spectrometry. This aglycon has a chemotaxonomic significance for the genus Phytolacca.
Antiproliferative oleanane saponins from Polyscias guilfoylei
2008
Three new oleanane saponins (1–3), together with four known ones (4–7), were isolated from the aerial parts of Polyscias guilfoylei. Their structures were elucidated by 1D and 2D NMR experiments, including 1D TOCSY, DQF-COSY, ROESY, HSQC, and HMBC spectroscopy, as well as ESIMS analysis. The antiproliferative activity of all compounds was evaluated using three murine and human cancer cell lines; J774.A1, HEK-293, and WEHI-164. All the compounds were inactive except for 3β- O-[β-D-glucopyranosyl-(1→2)-α-L-arabinopyranosyl]-echinocystic acid 28-[ O-β-D-glucopyranosyl-(1→6) O-β-D-glucopyranosyl] ester (3), which was active against all the cell lines.
New Diosgenin Glycosides from Costus afer
1997
Two new steroidal saponins, aferosides B (1) and C (2), together with the known saponins, dioscin (3) and paryphyllin C (4), were isolated from the roots of Costus afer. The known flavonoid glycoside, kaempferol 3-O-α-l-rhamnopyranoside (5), was obtained from the aerial parts. The structures of the new compounds were elucidated principally by 2D NMR spectral methods. A structural revision of the sugar sequence was made for the previously reported saponin aferoside A (6) on the basis of detailed spectroscopic analysis. Saponins 1−4 and 6 did not show any ability to potentiate in vitro cisplatin cytotoxicity in a human colon cancer cell line.
Two New Oleanane-type Saponins from Hydrocotyle multifida
2018
A phytochemical study of a Venezuelan species Hydrocotyle multifida led to the isolation of five oleanane-type glycosides: two previously undescribed and three known ones. Their structures were established by 2D NMR spectroscopic techniques and mass spectrometry as 3- O-β-D-galactopyranosyl-(1→2)-[α-L-arabinopyranosyl-(1→3)]-β-D-glucuronopyranosyloleanolic acid and 3- O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-(1→2)-β-D-glucuronopyrano-syloleanolic acid. These results represent a significative contribution to the chemotaxonomy of the Hydrocotyle genus.
Efficacy of three drugs for protecting against gentamicin-induced hair cell and hearing losses
2012
BACKGROUND AND PURPOSE Exposure to an ototoxic level of an aminoglycoside can result in hearing loss. In this we study investigated the otoprotective efficacy of dexamethasone (DXM), melatonin (MLT) and tacrolimus (TCR) in gentamicin (GM)-treated animals and cultures. EXPERIMENTAL APPROACH Wistar rats were divided into controls (treated with saline); exposed to GM only (GM); and three GM-exposed groups treated with either DXM, MLT or TCR. Auditory function and cochlear surface preparations were studied. In vitro studies of oxidative stress, pro-inflammatory cytokine mRNA levels, the MAPK pathway and caspase-3 activation were performed in organ of Corti explants from 3-day-old rats. KEY RESU…
Innovative technologies for the recovery of phytochemicals from Stevia rebaudiana Bertoni leaves: A review.
2018
Stevia rebaudiana Bertoni has gained increased industrial and scientific interests in the last 20 years, representing a suitable nutritional alternative to sucrose and artificial sweeteners. Moreover, this plant contains polyphenols, chlorophylls, and carotenoids that may be extracted for production of nutraceuticals and functional foods. Because of nutritional and technological advantages over sucrose, innovative approaches for the extraction of highly valued compounds from Stevia leaves have been developed and optimized. In contrast to conventional alternatives, innovative extraction methods allow higher yields in a shorter time, less usage of organic solvents, and reduced energy consumpt…
Localized versus systemic effect of arbuscular mycorrhizal fungi on defence responses to Phytophthora infection in tomato plants
2002
Development of biological control for plant diseases is accepted as a durable and environmentally friendly alternative for agrochemicals. Arbuscular mycorrhizal fungi (AMF), which form symbiotic associations with root systems of most agricultural, horticultural and hardwood crop species, have been suggested as widespread potential bioprotective agents. In the present study the ability of two AMF (Glomus mosseae and Glomus intraradices) to induce local or systemic resistance to Phytophthora parasitica in tomato roots have been compared using a split root experimental system. Glomus mosseae was effective in reducing disease symptoms produced by P. parasitica infection, and evidence points to …
Triterpenoid saponins from the cultivar “Green Elf” of Pittosporum tenuifolium
2021
Four oleanane-type glycosides were isolated from a horticultural cultivar “Green Elf” of the endemic Pittosporum tenuifolium (Pittosporaceae) from New Zealand: three acylated barringtogenol C glycosides from the leaves, with two previously undescribed 3-O-β-d-glucopyranosyl-(1→2)-[α-l-arabinopyranosyl-(1→3)]-β-d-glucuronopyranosyl-21-O-angeloyl-28-O-acetylbarringtogenol C, 3-O-β-d-galactopyranosyl-(1→2)-[α-l-arabinopyranosyl-(1→3)]-β-d-glucuronopyranosyl-21-O-angeloyl-28-O-acetylbarringtogenol C, and the known 3-O-β-d-glucopyranosyl-(1→2)-[α-l-arabinopyranosyl-(1→3)]-β-d-glucuronopyranosyl-21-O-angeloyl-28-O-acetylbarringtogenol C (Eryngioside L). From the roots, the known 3-O-β-d-glucopyra…
Lauroside B, a Megastigmane Glycoside from Laurus Nobilis (Bay Laurel) Leaves, Induces Apoptosis in Human Melanoma Cell Lines by Inhibiting NF-κB Act…
2010
Malignant melanoma is a highly aggressive tumor that frequently resists chemotherapy, so the search for new agents for its treatment is of great importance. In the present study, the antiproliferative propensity against human melanoma cell lines of lauroside B (1), a megastigmane glycoside isolated from Laurus nobilis (bay laurel) leaves, was investigated. This compound suppressed the proliferation of three human melanoma cell lines, namely, A375, WM115, and SK-Mel-28. The 1-induced inhibition of human melanoma cell proliferation was due to the induction of apoptosis, as demonstrated by FACS analysis with annexin V/PI staining and confirmed by activation of caspase-3 and by the cleavage of …
Preparation and Characterization of Aminoglycoside-Loaded Chitosan/Tripolyphosphate/Alginate Microspheres against E. coli
2021
Although aminoglycosides are one of the common classes of antibiotics that have been widely used for treating infections caused by pathogenic bacteria, the evolution of bacterial resistance mechanisms and their inherent toxicity have diminished their applicability. Biocompatible carrier systems can help sustain and control the delivery of antibacterial compounds while reducing the chances of antibacterial resistance or accumulation in unwanted tissues. In this study, novel chitosan gel beads were synthesized by a double ionic co-crosslinking mechanism. Tripolyphosphate and alginate, a polysaccharide obtained from marine brown algae, were employed as ionic cross-linkers to prepare the chitos…