21 research outputs found

    1,2-: Cis -Selective glucosylation enabled by halogenated benzyl protecting groups

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    This journal is © The Royal Society of Chemistry. We report on our initial results from a systematic effort to implement electron-withdrawing protecting groups and Lewis basic solvents/additives as an approach to 1,2-cis(α)-selective O-glucosylation. 1,2-cis-Selective O-glucosylations are reported with thioglucosides and glucosyl trichloroacetimidates and a range of acceptors. A correlation between electron-withdrawing effects and 1,2-cis selectivity has been established. This phenomenon may prove to be broadly applicable in the area of chemical O-glycosylation

    Artificial light at night alters diurnal and nocturnal behavior and physiology in green anole lizards

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    Artificial light at night (ALAN) disrupts biological rhythms across widely diverse organisms. To determine how energy is allocated by animals in different light environments, we investigated the impacts of ALAN on behavior and physiology of diurnal green anole lizards (Anolis carolinensis). Two groups of 24 adult lizards (half males, half females) were maintained in a controlled lab setting for six weeks. One group was exposed to a simulated natural summer light-dark cycle; the other was exposed to ALAN that simulated urban, nocturnal light exposure. After an acclimation period, we conducted four behavioral trials. One trial examined behavioral time allocation over two 24 h periods, and three others were conducted during mid-day and mid-night: open field tests, to examine exploratory behavior; foraging trials, to examine prey consumption; and social interaction trials, to examine same-sex interactions. We then measured each lizard\u27s snout-vent length and mass of its body, abdominal fat pads, liver, and, for males, testes. Lizards exposed to ALAN were more likely to be awake at night, using nocturnal light to explore, forage, and display to conspecifics. However, during the day, ALAN lizards were less likely to be awake, slower to move, and females displayed less frequently. ALAN lizards had heavier fat pads and testes, but ALAN did not impact body mass, liver mass, or snout-vent length. In sum, ALAN appears to cause a broad shift towards increased nocturnal activity and may alter metabolic and reproductive processes. Future work should examine the fitness consequences of these behavioral and physiological changes

    β-Amyrin Synthase1 Controls the Accumulation of the Major Saponins Present in Pea (Pisum sativum).

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    The use of pulses as ingredients for the production of food products rich in plant proteins is increasing. However, protein fractions prepared from pea or other pulses contain significant amounts of saponins, glycosylated triterpenes that can impart an undesirable bitter taste when used as an ingredient in foodstuffs. In this article, we describe the identification and characterization of a gene involved in saponin biosynthesis during pea seed development, by screening mutants obtained from two Pisum sativum TILLING (Targeting Induced Local Lesions IN Genomes) populations in two different genetic backgrounds. The mutations studied are located in a gene designated PsBAS1 (β-amyrin synthase1), which is highly expressed in maturing pea seeds and which encodes a protein previously shown to correspond to an active β-amyrin synthase. The first allele is a nonsense mutation, while the second mutation is located in a splice site and gives rise to a mis-spliced transcript encoding a truncated, nonfunctional protein. The homozygous mutant seeds accumulated virtually no saponin without affecting the seed nutritional or physiological quality. Interestingly, BAS1 appears to control saponin accumulation in all other tissues of the plant examined. These lines represent a first step in the development of pea varieties lacking bitterness off-flavors in their seeds. Our work also shows that TILLING populations in different genetic backgrounds represent valuable genetic resources for both crop improvement and functional genomics

    Effects of vernalization and plant regulators on growth and flowering of Lilium longiflorum Thunb

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    Lily bulbs were held at 22°C or vernalized at 4° or 8°C for two weeks and then soaked for 12 hours in 1,000 ppm gibberellic acid (GA) or 1,000 ppm indolylacetic acid (IAA) before being planted in the field. Treatment of lily bulbs with 4°C for two weeks delayed shoot emergence. This delay by vernalization was removed when bulbs were soaked for 12 hours in 1,000 ppm GA or IAA. Vernalization and plant regulators had no consistent effects on the plant height or on the plant quality. Bulbs vernalization at 4° or 8°C for two weeks reduced the number of stems produced. There were no differences in the dates of anthesis between the treatments. Flower quality was improved by bulb vernalization at 8°C for two weeks or by immersion for 12 hours in 1,000 ppm IAA.Bulbos de lírio foram mantidos a 22°C ou vernalizados a 4º ou 8°C por duas semanas, sendo então imersos por 12 horas em soluções de ácido giberélico (GA) 1000 ppm ou ácido indolilacético (IAA) 1000 ppm, antes de serem plantados em condições de campo. Tratamento dos bulbos a 4°C, durante duas semanas, atrasou a emergência das brotações. Este atraso devido a vernalização foi removido quando os bulbos foram imersos por 12 horas em soluções de GA ou IAA 1000 ppm. Vernalização e fitoreguladores não afetaram a altura nem a qualidade das plantas de lírio. A vernalização dos bulbos a 4º ou 8°C, durante duas semanas, reduziu o número de hastes produzidas. Nao se verificaram diferenças entre os tratamentos em relação ao período de tempo para a ocorrência da antese floral. A qualidade da inflorescência foi melhorada pela vernalização do bulbo a 8°C durante duas semanas ou por imersão durante 12 horas em solução de IAA 1000 ppm

    A MEN1 syndrome with a paraganglioma.

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    International audienceGermline mutations of the MEN1 gene cause multiple endocrine neoplasia type 1 (MEN1), an autosomal dominant disorder characterized by tumors of the parathyroids, the pancreas, and the anterior pituitary. Paraganglioma (PGL) is a rare endocrine tumor, which can be sporadic or genetically determined. To date, PGL has never been reported as a feature of MEN1.We report here a patient presenting three features of MEN1 syndrome (hyperparathyroidism, pancreatic neuroendocrine tumor, and adrenocortical adenoma) associated with PGL. Genetic analysis of MEN1 gene revealed a new missense mutation in exon 5 (AGGAAG), causing the substitution of arginine by lysine at codon 275. Screening for other genetic disorders (SDHx, TMEM127, MAX, CDKN1B) causing PGL was negative. Immunohistochemical analyses showed normal levels of succinate dehydrogenase (SDH)A and SDHB in the PGL. The proband's sister, bearing the mutation, had primary hyperparathyroidism. It was the first typical MEN1 syndrome reported with an extra-adrenal PGL
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