Late Cretaceous origin of the rice tribe provides evidence for early diversification in Poaceae.

Rice and its relatives are a focal point in agricultural and evolutionary science, but a paucity of fossils has obscured their deep-time history. Previously described cuticles with silica bodies (phytoliths) from the Late Cretaceous period (67-65 Ma) of India indicate that, by the latest Cretaceous, the grass family (Poaceae) consisted of members of the modern subclades PACMAD (Panicoideae-Aristidoideae-Chloridoideae-Micrairoideae-Arundinoideae-Danthonioideae) and BEP (Bambusoideae-Ehrhartoideae-Pooideae), including a taxon with proposed affinities to Ehrhartoideae. Here we describe additional fossils and show that, based on phylogenetic analyses that combine molecular genetic data and epidermal and phytolith features across Poaceae, these can be assigned to the rice tribe, Oryzeae, of grass subfamily Ehrhartoideae. The new Oryzeae fossils suggest substantial diversification within Ehrhartoideae by the Late Cretaceous, pushing back the time of origin of Poaceae as a whole. These results, therefore, necessitate a re-evaluation of current models for grass evolution and palaeobiogeography.

Palynoflora from Deccan volcano-sedimentary sequence (Cretaceous-Palaeogene transition) of central India: implications for spatio-temporal correlation.

The sedimentary beds associated with Deccan Continental Flood Basalt (DCFB) sequences exposed in the volcanic subprovinces of Jabalpur-Mandla-Chhindwara (JMC) regions of Madhya Pradesh and Nand-Dongargaon (N-D) basin and the adjoining areas to the west in Yeotmal-Nanded in Maharashtra were studied for their palynofloral analysis. The sediments were characterized palynologically and changes in the palynoflora are observed at different stratigraphic levels in a number of sections including several new intertrappean localities recorded in recent years. For the purpose of effective correlation of different subprovinces, palynofloras of some of the previously studied intertrappeans are also reviewed. Our studies suggest that before the start of the Deccan volcanic activity, the palynoflora found in the Lameta sediments, was dominated by gymnosperms-angiosperm association. The plant canopy consisted mainly of gymnosperms (Conifers and Podocarpaceae) whereas, the understory members were mostly of palms and herbs (Poaceae and Asteraceae). The eruption of Deccan volcanic flows severely affected the existing floral association and proved fatal for the well established plant community. The immediately overlying sediments associated with the earliest volcanic flows are dominated by pteridophytes and angiosperm taxa (Azolla cretacea, Aquilapollenites bengalensis, Ariadnaesporites sp., Gabonisporis vigourouxii and Triporoletes reticulatus). Higher up in the stratigraphic sequence, similar forms continued with simultaneous appearance of new taxa including Scabrastephanocolpites spp. At still higher stratigraphic levels, abundance of fungi especially the mycorrhizal fungi, concurrent with sharp decline in pollen/spore recovery was observed. In the culminating phase (i.e. Palaeocene) of Deccan volcanic history a new palynofloral assemblage of typical Palaeocene taxa (Dandotiaspora dilata, D. pseudoauriculata, D. plicata, Spinizonocolpites echinatus, Matanomadhiasulcites sp., and Lakiapollis ovatus) was encountered.

Protective effect of Tinospora cordifolia, Phyllanthus emblica and their combination against antitubercular drugs induced hepatic damage: an experimental study.

This study investigated the hepatoprotective effect of two Indian medicinal plants Tinospora cordifolia (Tc), Phyllanthus emblica (Pe), and their combination, in a rat model of isoniazid, rifampicin and pyrazinamide induced hepatic damage. Hepatic damage was assessed using a composite score assigned to histopathological findings of degeneration, necrosis and fibrosis. The antituberculosis treatment (ATT), when given for 90 days, induced significant degeneration and necrosis (score: 7.5; p < 0.01 vs vehicle) associated with morphological changes. However, no change was found in the serum bilirubin and liver enzymes. Co-administration of silymarin (positive control, 50 mg/kg) with ATT protected against necrosis (score: 1.5; p < 0.001 vs ATT). Tc (100 mg/kg) showed a reduction in liver damage (score: 6.5), which was not statistically significant. On the other hand, Pe (300 mg/kg) prevented the necrotic changes to a significant extent (grade 1.0; p < 0.05; score [corrected] 5.5). Combination of Tc and Pe in their therapeutic doses (1:3) significantly prevented the necrosis (score: 3.5; p < 0.001 vs ATT). Similar effects were seen even when the doses were halved and were comparable to the silymarin group. Thus, this study proves the synergistic protective effects exerted by the combination of Tc and Pe when co-administered with ATT.

A randomised double-blind study comparing sodium feredetate with ferrous fumarate in anaemia in pregnancy.

Iron deficiency anaemia is a major health problem in India especially in women of reproductive age group. The World Health Organisation recommends that the haemoglobin concentration should not fall below 11.0 g/dl at any time during pregnancy. The aim of study was to compare the efficacy and safety of two doses of sodium feredetate with ferrous fumarate in improving haemoglobin profile in pregnant anaemic women. Pregnant women with gestation period between 12 and 26 weeks having serum haemoglobin < 10 g/dl, serum ferritin levels less than 12 microg/l were included in the study. Patients were divided into 3 groups and drugs administered accordingly. A total of 48 patients were available for analysis which included 37 patients who had completed all the visits up to 75 days follow-up and 11 patients who were treatment failures. In group A combination of sodium feredetate (containing 33 mg of elemental iron) along with vitamin B12 (15 microg) and folic acid (1.5 mg) was administered twice a day. In group B combination of sodium feredetate (containing 66 mg of elemental iron) along with vitamin B12 (15 microg) and folic acid (1.5 mg) was administered twice a day. In group C combination of ferrous fumarate (containing 100 mg of elemental iron) along with vitamin B12 (15 microg) and folic acid (1.5 mg) was administered twice a day. Patients were evaluated for Hb, RBC count, MCV, MCH and MCHC at day 0, 30, 45, 60 and 75. Serum ferritin, serum iron, TIBC and transferrin saturation were assessed at recruitment and end study. Mean rise of haemoglobin at the completion of study, over that of basal values was 1.79 g/dl (0.71 to 2.87, 95% CI, p < 0.05) in group A, 1.84 g/dl (0.82 to 2.86, 95% CI, p < 0.05) in group B and 1.63 g/dl (0.38 to 2.88, 95% CI, p < 0.05) in group C. Safety assessment was done by doing liver and kidney function test at the time of recruitment and end study. Low doses of sodium feredetate (33 mg and 66 mg of elemental iron given twice daily) produce comparable results as higher dose of ferrous fumarate (100 mg elemental iron given twice daily). As there were no adverse effects reported with sodium feredetate, it can be concluded from this study that this new formulation appears to be effective in improving haemoglobin profile in pregnant anaemic women and is tolerated well.

Chlorination of aromatic compounds in micellar media: regioselectivity.

Chlorination of phenol and ortho-chlorophenol was studied in micellar media in order to observe the effect on regioselectivity. Hydrogen peroxide/hydrochloric acid-aqueous system, which is environmentally a safer route was employed for chlorination. Selectivity ratio was found to be dependent on the nature and concentration of the surfactant. Ortho/para selectivity ratio up to 12 was realized for the chlorination of phenol. 2,6-/2,4-dichlorophenol ratio up to 1.01 was realized for the chlorination of ortho-chlorophenol.

5'-bromoacetamido-5'-deoxyadenosine. A novel reagent for labeling adenine nucleotide sites in proteins.

We have synthesized and characterized 5'-bromoacetamido-5'-deoxyadenosine (5'-BADA), a new reagent for labeling adenine nucleotide binding sites in enzymatic and regulatory proteins. 5'-BADA possessed exceptionally high solubility and stability in aqueous buffers between pH 5.0 and 8.6 at 25 degrees C. A Dixon plot of data from enzyme kinetic measurements showed that 5'-BADA is a competitive inhibitor of NADH oxidation by 3 alpha,20 beta-hydroxysteroid dehydrogenase with a Ki value of 11.8 mM. This compares with a Ki value of 10 mM for adenosine under similar experimental conditions. Incubating 5'-BADA with a 3 alpha,20 beta-hydroxysteroid dehydrogenase at pH 7.0 and 25 degrees C caused simultaneous loss of both 3 alpha and 20 beta activity. The enzyme inactivation reaction proceeded by a first order kinetic process. The rates of enzyme inactivation as a function of 5'-BADA concentration obeyed saturation kinetics. 2-Bromoacetamide, at ten times the maximum concentration of 5'-BADA, had no measurable effect on enzyme activity during 25 h of incubation. NADH and AMP protected 3 alpha,20 beta-hydroxysteroid dehydrogenase against inactivation by 5'-BADA. The results suggest that 5'-BADA inactivates the enzyme by irreversibly binding to the adenine domain of the NADH cofactor binding region at the catalytic site of 3 alpha,20 beta-hydroxysteroid dehydrogenase. Irreversible binding follows from an alkylation reaction between the bromoacetamido side chain of 5'-BADA and an amino acid at or near the enzyme catalytic site. 5'-BADA is presented as a new reagent for selectively labeling amino acid residues at the adenine nucleotide binding sites of enzymatic and regulatory proteins.

Nicotinamide adenine dinucleotide binding and promotion of enzyme activity: model based on affinity labeling of 3 alpha, 20 beta-hydroxysteroid dehydrogenase with a nucleoside.

5'-[p-(Fluorosulfonyl)benzoyl]adenosine (FSA) was used to affinity-label the NADH binding region of 3 alpha, 20 beta-hydroxysteroid dehydrogenase (3 alpha, 20 beta-HSD) to further test our hypothesis [Sweet, F., & Samant, B. R. (1980) Biochemistry 19, 978-986] that 3 alpha and 20 beta activities occur at the same active site. Incubation of 3 alpha, 20 beta-HSD (0.45 microM) with FSA (125 microM) at pH 7.0 and 0 degrees C caused simultaneous loss of 3 alpha and 20 beta activities by a first-order kinetic process, with t1/2 = 300 min for both activities. Dinucleotides and adenosine mononucleotides which acted as competitive inhibitors protected 3 alpha, 20 beta-HSD against inactivation by FSA in a concentration-dependent manner, in the order reduced nicotinamide dinucleotide phosphate greater than oxidized nicotinamide dinucleotide phosphate greater than adenosine diphosphate-ribose greater than adenosine diphosphate greater than adenosine monophosphate (AMP) greater than adenosine. Oxidized and reduced nicotinamide mononucleotides (NMH and NMNH) and steroid substrates did not protect 3 alpha, 20 beta-HSD against affinity labeling by FSA. Although NMN was not a competitive inhibitor of 3 alpha, 20 beta-HSD, NMN with AMP and also AMP with NMNH produced positive cooperativity for competitive inhibition of 3 alpha, 20 beta-HSD. The results from FSA affinity labeling of the cofactor region confirm that both 3 alpha and 20 beta activities share the same active site of 3 alpha, 20 beta-HSD and suggest a model of cofactor binding and promotion of enzyme activity. The adenosine 5'-phosphate component anchors the NAD or NADH to an adenosine domain in the cofactor binding region. The nicotinamide nucleotide component then carries out the hydrogen-transfer reaction at a neighboring domain near the steroid binding region.

Affinity labeling of 3 alpha, 20 beta-hydroxysteroid dehydrogenase with a nucleoside analog.

Incubation of 3 alpha, 20 beta-hydroxysteroid dehydrogenase (3 alpha, 20 beta-HSD; E.C.1.1.1.53) with the nucleoside 5'-p-fluorosulfonylbenzoyladenosine (FSA) caused a time-dependent and irreversible loss in enzyme activity. Both 3 alpha- and 20 beta-hydroxysteroid oxidoreductase activities decreased at equal rates by a first order kinetic process (in 0.05M phosphate buffer at pH 6.0 and 25 degrees C, t1/2 = 170 min). Incubation of 3 alpha, 20 beta-HSD was quenched by addition of 2-mercaptoethanol which instantaneously reacts with the fluorosulfonyl group of FSA. The cofactor NADH protected 3 alpha, 20 beta-HSD against inactivation by FSA, in a concentration-dependent manner. However, progesterone did not protect 3 alpha, 20 beta-HSD against inactivation by FSA. Evidently, FSA causes inactivation of the enzyme by irreversibly binding to the NADH-binding region at the active site of 3 alpha, 20 beta-HSD. Both 3 alpha- and 20 beta-hydroxysteroid oxidoreductase activities disappeared at equal rates under a variety of enzyme-inactivating conditions. These results suggest that both 3 alpha- and 20 beta-activities occur at the same active site of 3 alpha, 20 beta-HSD.

Synthesis of medroxyprogesterone bromoacetate for affinity labeling.

Medroxyprogesterone bromoacetate (17alpha-hydroxy-6alpha-methyl-4-pregnene-3,20-dione 17-bromoacetate) was synthesized by reaction of 17alpha-hydroxy-6alpha-methyl-4-pregnene-3,20-dione with bromoacetic acid--trifluoroacetic anhydride followed by treatment of the intermediate with dilute ethanolic HBr. The product forms conjugates with L-cysteine, L-histidine, and L-methionine and inactivates 20beta-hydroxy steroid dehydrogenase (E.C. 1.1.1.53.) from Streptomyces hydrogenans in a time-dependent and irreversible manner. The title compound possesses a long-acting progestational effect in day 9 pregnant bilaterally ovariectomized rats. The affinity labeling analogue of the oral contraceptive medroxyprogesterone acetate is proposed for use in reproductive biological experiments.