A chiral template-driven synthesis of a 3'-deoxy-3'-18F-fluorothymidine precursor.

An asymmetric synthesis of a 3'-deoxy-3'-18F-fluorothymidine (18F-FLT) precursor has been developed wherein the deoxysugar moiety was synthesized using a novel Ga-mediated allylation of (R)-2,3-cyclohexylideneglyceraldehyde as the key step. The synthesis deviates significantly from the previous syntheses of the 18F-FLT precursors wherein the expensive starting material, thymidine was used.

syn-Selective crotylation of aldehydes using bismuth-crotyl bromide-(1-butyl-3-methylimidazolium bromide) combination: some synthetic applications.

The Bi-[bmim][Br] combination has been found to offer high syn-selectivity in the crotylation of aldehydes with crotyl bromide using practically stoichiometric amounts of the reagents. The room temperature ionic liquid (RTIL), [bmim][Br], activated Bi metal in the presence of oxygen to produce crotylbismuthdibromide, which reacted with the aldehydes at room temperature. The major anti-syn diastereomeric product obtained from the crotylation of (R)-cyclohexylideneglyceraldehyde was utilized for the synthesis of dictyostatin and cryptophycin segments, and (+)-cis-aerangis lactone, using standard synthetic protocols.

Utility of a questionnaire tool (QUARAS) for localizing and lateralizing seizures in the epilepsy monitoring unit (EMU).

OBJECTIVES: An accurate description of the seizure semiology improves the recognition of the ictal onset zone and helps in hypothesizing the possible epileptogenic zone (EZ). Semiology based on a reliable description of seizures may be as good as investigative modalities, as has been shown by numerous studies. The main objective of this study was to apply a questionnaire-tool for auras and semiology (QUARAS) in refractory epilepsy cohort and compare its yield to that of standard history-taking. METHODS: A drug refractory epilepsy cohort of 139 subjects was selected, based on inclusion and exclusion criteria. All subjects underwent routine history-taking, and a structured interview with QUARAS (in Hindi language) about 3-6 months later when they were admitted for pre-surgical work-up (Video-EEG, MRI, SPECT and PET), by an epilepsy nurse. Seizures were localised and lateralised at the each step separately, in a blinded manner; concordance with the final hypothesis was checked, after the epilepsy-surgery case-conference, and statistical significance of the difference calculated. RESULTS: Auras were reported in significantly more number of patients after administration of QUARAS (p<0.001); there was also higher concordance between the final hypothesis and the localization and lateralization based on QUARAS than an unstructured history (p<0.001). CONCLUSION: Administering a structured questionnaire in the native language of patients by trained personnel leads to better localisation and lateralisation and may help arrive at a hypothesis about the EZ.

Can home video facilitate diagnosis of epilepsy type in a developing country?

OBJECTIVES: The study aimed to evaluate the feasibility and yield of semiological features from home videos and compare them to those inferred from history provided by the caregiver of a person with epilepsy (PWE). A comparison of the accuracy of classification of epilepsy based on home videos and medical history was also done. METHODS: We enrolled PWEs who were awaiting admission for video electroencephalography (VEEG) to the epilepsy monitoring unit (EMU) in this prospective observational study. In phase I of the study, we encouraged caregivers to make home videos which were analyzed. A structured questionnaire dealing with 29 different semiological features was completed based on the information gathered from home videos. In phase II of the study, the questionnaire was administered to the patient's caregivers. In phase III the patients underwent VEEG recording, and the semiology from VEEG was analyzed to complete the same questionnaire. We also classified epilepsy type using home videos and medical history and compared it to that using VEEG finding. The information gathered from VEEG was considered the gold standard. Accuracy was calculated for the different semiological signs comparing medical history to VEEG findings. RESULTS: A total of 340 PWE fulfilled the inclusion and exclusion criteria, and their caregivers completed the questionnaire. Home videos were collected from 312 patients and 624 seizures were analyzed. The mean number of signs of semiology recorded after analysis of home videos was 3.3±2.2, and from the medical history was 2.1±1.1 (P<0.01). A total of 572 seizures in 282 patients admitted in the EMU were evaluated on VEEG. Bilateral generalized clonic movements of limbs, motor movement around mouth, fear, visual phenomenon, hemisensory phenomenon, and post-ictal unilateral weakness had the highest accuracy. The overall agreement of semiological signs inferred from medical history versus VEEG was 0.75 and between home video recordings versus VEEG was 0.92. A larger number of patients were correctly categorized into the focal epilepsy group when home videos were used to classify compared to when medical history was used. CONCLUSIONS: Home videos are more reliable in picking up semiological signs and classifying epilepsy type than history provided by caregivers of PWEs. Home videos are a complementary tool in a developing country like India.

Evaluation of Ictal Consciousness in Temporal and Extra Temporal Epilepsy: Observations from a Tertiary Care Hospital in India.

BACKGROUND AND PURPOSE: Differences in consciousness during seizures depend on the location of the seizure onset. METHODS: The present study evaluates ictal consciousness using the ictal consciousness inventory (ICI) in drug refractory mesial temporal (MTLE), neocortical temporal (NTLE) and extra temporal epilepsy (ETLE). This was a cross sectional cohort study with 45 patients with mesial temporal epilepsy, 47 with extra temporal and 11 patients with neocortical temporal epilepsy. The ICI a 20 item questionnaire was used to calculate the scores for level (L, question 1-10) and content (C, question 11-20) of consciousness. RESULTS: The patients in mesial temporal group had higher ICI-L scores, p = 0.0129 as compared to the extra temporal group, but no difference was observed in the content of consciousness. The ICI-L and C scores were not different in the mesial temporal and the neocortical temporal group (p = 0.53 and 0.65) respectively. CONCLUSIONS: Patients with mesial temporal epilepsy had a higher level of consciousness than the extra temporal group but there was no difference in the content. Also there was no difference in the level and content of consciousness between mesial and the neocortical temporal group.

A chemoenzymatic synthesis of hept-6-ene-2,5-diol stereomers: application to asymmetric synthesis of decarestrictine L, pyrenophorol, and stagonolide E.

The stereomers of hept-6-ene-2,5-diol derivatives were conceived as useful chiral intermediates and were synthesized starting from sulcatol using two lipase-catalyzed acylation reactions as the key steps. The versatility of the intermediates was demonstrated by converting them to the titled tetrahydropyran, macrolide, and macrodiolide compounds using standard synthetic protocols.

Optimization of chelators to enhance uranium uptake from tailings for phytoremediation.

A greenhouse experiment was set up to investigate the ability of citric acid (CA), oxalic acid (OA), nitrilotriacetic acid (NTA) and EDTA for phytoremediation of uranium tailings by Indian mustard [Brassica juncea (L.) Czern. et Coss]. Uranium tailings were collected from Umra mining region and mixed with 75% of garden soil which yielded a 25:75 mixture. Prepared pots were divided into four sets and treated with following different concentrations - 0.1, 0.5, 2.5 and 12.5 mmol kg(-1) soil additions for each of the four chelators. Control pots which were not treated with chelators. Experiments were conducted in completely randomized block design with triplicates. The optimum concentrations of these chelators were found on the basis of biomass production, tolerance and accumulation potential. The data collected were expressed statistically. EDTA produced maximum growth depression whereas, minimum occurred in the case of NTA. Maximum U uptake (3.5-fold) in the roots occurred at 2.5 mmol of CA, while NTA proved to be the weakest for the same purpose. Severe toxicity in the form of reduced growth and plant death was recorded at 12.5 mmol of each chelator. Minimum growth inhibition produced by chelators occurred in NTA which was followed by OA, moderate in CA and maximum was traced in EDTA applications. Chelator strengthened U uptake in the present study follows the order: CA>EDTA>OA>NTA.

[bmim][Br] as a solvent and activator for the Ga-mediated Barbier allylation: direct formation of an N-heterocyclic carbene from Ga metal.

The room-temperature ionic liquid (RTIL) [bmim][Br] has been found to be an excellent green and inexpensive medium for the Ga-mediated allylation of aromatic and aliphatic aldehydes and ketones. The RTIL activated the metal via formation of a Ga-N-heterocyclic carbene complex that assisted in the completion of the reaction at ambient temperature with only 0.5 equiv of Ga and 1.2 equiv of allyl bromide with respect to the carbonyl substrates. The present protocol required a much shorter time than those reported in the literature using other metals and solvents and proceeded with good yields and excellent selectivity.

Expression of SbGSTU (tau class glutathione S-transferase) gene isolated from Salicornia brachiata in tobacco for salt tolerance.

Tau class glutathione transferases (GSTU) genes are plant specific, induced by different abiotic stress, and important for protecting plants against oxidative damage. GST gene was isolated using 5' RACE from an extreme halophyte Salicornia brachiata, cloned, sequenced and its protein structure was predicted. Transcript profiling of SbGST gene expression was studied under different abiotic stress conditions and plant growth regulator treatments, viz. salt, cold, drought, ABA and salicylic acid, with time period point and concentration point. The expression of SbGST gene was up-regulated in all stress conditions, except SA treatment. Seed germination percentage, GST enzyme assay, fresh weight and other growth parameters (root length, shoot length and leaf area) were studied and results indicate that over-expression of SbGST gene in transgenic tobacco leads to enhanced seed germination and growth under salt stress. Transgenic lines were evaluated for their performance under salt stress and tobacco plants over-expressing SbGST showed higher seed germination and survival compared to wild type. These results confirm that expression of SbGST gene is up-regulated by different stresses and over-expression of tau class SbGST gene in transgenic tobacco plays a vital role in abiotic stress tolerance. SbGST gene expressed conspicuously under salt stress leading to enhance seed germination and better growth. Furthermore, GST is a potential candidate gene to be used in genetic engineering for enhancing abiotic stress tolerance.

Metal-dependent reaction tuning with cyclopentylmetal reagents: application to the asymmetric synthesis of (+)-alpha-conhydrine and (S)-2-cyclopentyl-2-phenylglycolic acid.

The reaction profile of the cyclopentyl organometallic reagents with the aliphatic ketones can be tuned to reduction or addition by changing the metal atom. Cyclopentylmagnesium bromide (CPMB) reduces aromatic and aliphatic aldehydes and ketones to the corresponding alcohols without any C-C bond formation and shows good diastereoselectivity in the reduction of the substituted cyclic and polycyclic ketones as well as chiral alpha-oxygenated aliphatic ketones. However, in the presence of 10 mol % of ZnCl(2), the cyclopentylmagnesium halides follow a normal Grignard addition to the ketones to give tertiary alcohols with complete diastereoselectivity. The reductive as well as the addition protocols were used for the asymmetric synthesis of two medicinally important compounds, (+)-alpha-conhydrine and (S)-2-cyclopentyl-2-phenylglycolic acid.

Vertical ionisation potentials of a number of crown ethers from charge transfer bands of their EDA complexes.

Vertical ionisation potentials (I(v)D) of a number of crown ethers, viz. dibenzo-30-crown-10 (Crown 1), benzo-15-crown-5 (Crown 2), dibenzo-24-crown-8 (Crown 3), dicyclohexano-24-crown-8 (Crown 4) and 4'-nitrobenzo-15-crown-5 (Crown 5) are being reported for the first time from a study of EDA interaction of these crown ethers with a number of electron acceptors like C60, C70, o-chloranil, p-chloranil, 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) and pyromellitic diimide (PMD). The study has been carried out in CCl4 medium by electronic absorption spectroscopy. Charge transfer (CT) absorption bands in the 360-900 nm range have been found in each case (excepting the 60 fullerene-Crown 4 system). The vertical ionisation potentials (I(v)D) of all the crown ethers thus determined show a good correlation with those calculated by the semiempirical AM1 method. Of the six acceptors under study the vertical electron affinity of PMD was not found in the literature. This has also been determined from an analysis of the present h(nu)(CT) data.