Effects of Aspen Phenolic Glycosides on Gypsy Moth (Lepidoptera: Lymantriidae) Susceptibility to \u3ci\u3eBacillus Thuringiensis\u3c/i\u3e

Performance of the gypsy moth, Lymantria dispar, on quaking aspen, Populus tremuloides, is strongly affected by foliar concentrations of phenolic glycosides. Because the microbial insecticide Bacillus thuringiensis is widely used against gypsy moths and has a mode of action similar to that of phenolic glycosIdes, we investigated the combined effects of the two toxins on gypsy moth larvae. The experimental design was a 2 x 2 factorial: two levels (0, +) of phenolicglycosides for each of two levels (0, +) of B. thuringiensis. The toxins were incorporated into artificial diets and bioassayed against first and fourth instars. Bacillus thuringiensis and phenolic glycosides ne~atively and addi· tively affected larval survival, growth and development tImes. Both agents slightly reduced consumption rates. In addition, B. thuringiensis reduced diet digestibility whereas phenolic glycosides decreased the efficiency with which food was converted to biomass. These results suggest that the efficacy of B. thuringiensis applications in aspen forests is likely to be affected by the allelo· chemical composition of foliage

Organosolv pretreatment of Sitka spruce wood: conversion of hemicelluloses to ethyl glycosides

A range of organosolv pretreatments, using ethanol:water mixtures with dilute sulphuric acid, were applied to Sitka spruce sawdust with the aim of generating useful co-products as well as improving saccharification yield. The most efficient of the pretreatment conditions, resulting in subsequent saccharification yields of up to 86%, converted a large part of the hemicellulose sugars to their ethyl glycosides as identified by GC/MS. These conditions also reduced conversion of pentoses to furfural, the ethyl glycosides being more stable to dehydration than the parent pentoses. Through comparison with the behaviour of model compounds under the same reaction conditions it was shown that the anomeric composition of the products was consistent with a predominant transglycosylation reaction mechanism, rather than hydrolysis followed by glycosylation. The ethyl glycosides have potential as intermediates in the sustainable production of high-value chemicals

Flavonoid glycosides from Persea caerulea. Unraveling their interactions with SDS-micelles through matrix-assisted DOSY, PGSE, mass spectrometry, and NOESY

Two flavonoid glycosides derived from rhamnopyranoside (1) and arabinofuranoside (2) have been isolated from leaves of Persea caerulea for the first time. The structures of 1 and 2 have been established by 1H NMR, 13C NMR, and IR spectroscopy, together with LC–ESI–TOF and LC–ESI–IT MS spectrometry. From the MS and MS/MS data, the molecular weights of the intact molecules as well as those of quercetin and kaempferol together with their sugar moieties were deduced. The NMR data provided information on the identity of the compounds, as well as the α and β configurations and the position of the glycosides on quercetin and kaempferol. We have also explored the application of sodium dodecyl sulfate (SDS) normal micelles in binary aqueous solution, at a range of concentrations, to the diffusion resolution of these two glycosides, by the application of matrix‐assisted diffusion ordered spectroscopy (DOSY) and pulse field gradient spin echo (PGSE) methodologies, showing that SDS micelles offer a significant resolution which can, in part, be rationalized in terms of differing degrees of hydrophobicity, amphiphilicity, and steric effects. In addition, intra‐residue and inter‐residue proton–proton distances using nuclear Overhauser effect build‐up curves were used to elucidate the conformational preferences of these two flavonoid glycosides when interacting with the micelles. By the combination of both diffusion and nuclear Overhauser spectroscopy techniques, the average location site of kaempferol and quercetin glycosides has been postulated, with the former exhibiting a clear insertion into the interior of the SDS‐micelle, whereas the latter is placed closer to the surface.Junta de Andalucía P12-FQM-266

Bright spots in the darkness of cancer: A review of starfishes-derived compounds and their anti-tumor action

The fight against cancer represents a great challenge for researchers and, for this reason, the search for new promising drugs to improve cancer treatments has become inevitable. Oceans, due to their wide diversity of marine species and environmental conditions have proven to be precious sources of potential natural drugs with active properties. As an example, in this context several studies performed on sponges, tunicates, mollusks, and soft corals have brought evidence of the interesting biological activities of the molecules derived from these species. Also, echinoderms constitute an important phylum, whose members produce a huge number of compounds with diverse biological activities. In particular, this review is the first attempt to summarize the knowledge about starfishes and their secondary metabolites that exhibited a significant anticancer effect against different human tumor cell lines. For each species of starfish, the extracted molecules, their effects, and mechanisms of action are described

Preliminary qualitative screening for cancer chemopreventive agents in Telfairia occidentalis Hook.f., Gnetum africanum Welw., Gongronema latifolium Benth. and Ocimum gratissimum L. from Nigeria

The leaves of four plant foods commonly consumed in Nigeria namely Gnetum africanum (Igbo name: Ukazi), Gongronema latifolium (Igbo name: Utazi), Telfairia occidentalis (Igbo name: Ugu), Ocimum gratissimum (Igbo name: Nchoanwu), were each screened for the presence of known potential chemopreventive agents using paper chromatography, thin layer chromatography and various chemical tests. All four vegetables showed the presence of phenolic compounds, flavonoids, phytosterols, tannins, saponins, chlorophyll and glycosides. Only Telfairia occidentalis and Gnetum africanum showed traces of alkaloids

Predicting the substrate specificity of a glycosyltransferase implicated in the production of phenolic volatiles in tomato fruit

The volatile compounds that constitute the fruit aroma of ripe tomato (Solanum lycopersicum) are often sequestered in glycosylated form. A homology-based screen was used to identify the gene SlUGT5, which is a member of UDP-glycosyltransferase 72 family and shows specificity towards a range of substrates, including flavonoid, flavanols, hydroquinone, xenobiotics and chlorinated pollutants. SlUGT5 was shown to be expressed primarily in ripening fruit and flowers, and mapped to chromosome I in a region containing a QTL that affected the content of guaiacol and eugenol in tomato crosses. Recombinant SlUGT5 protein demonstrated significant activity towards guaiacol and eugenol, as well as benzyl alcohol and methyl salicylate; however, the highest in vitro activity and affinity was shown for hydroquinone and salicyl alcohol. NMR analysis identified isosalicin as the only product of salicyl alcohol glycosylation. Protein modelling and substrate docking analysis were used to assess the basis for the substrate specificity of SlUGT5. The analysis correctly predicted the interactions with SlUGT5 substrates, and also indicated that increased hydrogen bonding, due to the presence of a second hydrophilic group in methyl salicylate, guaiacol and hydroquinone, appeared to more favourably anchor these acceptors within the glycosylation site, leading to increased stability, higher activities and higher substrate affinities

Toxic Phenolic Glycosides From \u3ci\u3ePopulus:\u3c/i\u3e Physiological Adaptations of the Western North American Tiger Swallowtail Butterfly, \u3ci\u3ePapilio Rutulus\u3c/i\u3e (Lepidoptera: Papilionidae)

The phenolic glycosides tremulacin and salicortin found in quaking aspen, Populus tremuloides, and other members of the Salicaceae, are known to be toxic to larvae of the Eastern tiger swallowtail butterfly, Papilio glaucus, but not to the Canadian tiger swallowtail, P. canadensis. Larvae of the western tiger swallowtail, P. rutulus, were not killed nor were their growth rates suppressed when fed a mixture of tremulacin and salicortin on black cherry leaves. When the Salicaceae adapted P. rutulus penultimate instar larvae were fed a combination of the two phenolic glycosides and the esterase inhibitor (DEF S,S,S-tributylphosphorotrithioate), growth was reduced more than 50OJo compared to controls, and half of the larvae died before completing the instaL Our results indicate that esterase detoxification mechanisms are involved in the western tiger swallowtail, P. rutulus, as is also known to be the case for the northern tiger swallowtail, P. canadensis. It is not known whether the same esterase isozyme is involved in both species. From an evolutionary perspective such information could help resolve whether the Salicaceae-adapted swallowtails species are a monophyletic group (perhaps due to isolation in the Beringial Pleistocene glacial refuge of Alaska)

Phytochemical Screening and in vivo antioxidant activity of Ethanolic extract of caesalpinia bondus (L.) Roxb

Phytochemical screening, antioxidant activity in vivo and lipid peroxidation of 75 % ethanolic extract of young twigs and leaves of Caesalpinia bonduc were carried out by chemical test, and assessment of catalase and peroxidase activities and lipid peroxidation in Wistar rats after oral administration of different concentrations of the plant extract for ten days. Phytochemical screening of the extract revealed the presence of all major classes of phytochemicals: tannins, flavonoids, saponin, steroids, terpenoids, cardiac glycosides, glycosides, except phlobatannins. There were significant (p<0.05) graded increase in catalase and peroxidase activities and decrease in TBARS concentrations in the extract tested rats in comparison with normal control, Vitamin C and amodiaquine tested rats. The various pharmacological activities of C. bonduc may be due to its antioxidant activity