Ashok K. Prasad

Bio: Ashok K. Prasad is an academic researcher from University of Delhi. The author has contributed to research in topics: Lipase & Aryl. The author has an hindex of 33, co-authored 289 publications receiving 5155 citations. Previous affiliations of Ashok K. Prasad include University of Hawaii & Odense University.

N,N,N′,N′‐Tetraoctyl Diglycolamide (TODGA): A Promising Extractant for Actinide‐Partitioning from High‐Level Waste (HLW)

Abstract: N,N,N′,N′‐Tetraoctyl diglycolamide (TODGA) has been evaluated as an extractant for the partitioning of minor actinides from simulated high level nuclear waste solutions. Acid uptake studies suggested that TODGA is more basic (KH: 4.1) as compared to TRUEX and DIAMEX solvents viz. CMPO (KH: 2.0) and DMDBTDMA (KH: 0.32), respectively. TODGA molecules display a tendency toward aggregation in n‐dodecane at lower acidities. Effect of diluent on the distribution behavior of Am(III) was studied employing diluents of different dielectric constants. N,N‐dialkyl amides with different alkyl groups viz. dibutyl decanamide (DBDA), di(2‐ethylhexyl) acetamide (D2EHAA), di(2‐ethylhexyl) propionamide (D2EHPRA), di(2‐ethylhexyl) isobutyramide (D2EHIBA), dihexyl octanamide (DHOA) and dihexyl decanamide (DHDA) were evaluated as phase modifiers. Distribution behavior of various metal ions viz. Am(III), Pu(IV), U(VI), Eu(III), Fe(III), Sr(II) and Cs(I) was studied from pure nitric acid solution as well as from simulat...

Coumarins as antioxidants.

Abstract: Coumarins, a well-known class of naturally occurring compounds, display a remarkable array of biochemical and pharmacological actions, some of which suggest that certain members of this group of compounds may significantly affect the function of various mammalian cellular systems. The development of coumarins as antioxidant agents has attracted much attention in recent years. Coumarins afford an opportunity for the discovery of new antioxidants with truly novel mechanisms of action. This review updates and expands the 2006 review by the same author. The review considers and incorporates the most recently published literature on coumarins as related to their antioxidant properties. A lot of coumarins have been identified from natural sources, especially green plants. These natural compounds have served as valuable leads for further design and synthesis of more active analogues. Beyond doubt, a deep understanding of the mechanisms of existing synthetic and natural coumarins will build the basis for the rational design.

Chemical Routes for the Transformation of Biomass into Chemicals

Abstract: 3.2.3. Hydroformylation 2467 3.2.4. Dimerization 2468 3.2.5. Oxidative Cleavage and Ozonolysis 2469 3.2.6. Metathesis 2470 4. Terpenes 2472 4.1. Pinene 2472 4.1.1. Isomerization: R-Pinene 2472 4.1.2. Epoxidation of R-Pinene 2475 4.1.3. Isomerization of R-Pinene Oxide 2477 4.1.4. Hydration of R-Pinene: R-Terpineol 2478 4.1.5. Dehydroisomerization 2479 4.2. Limonene 2480 4.2.1. Isomerization 2480 4.2.2. Epoxidation: Limonene Oxide 2480 4.2.3. Isomerization of Limonene Oxide 2481 4.2.4. Dehydroisomerization of Limonene and Terpenes To Produce Cymene 2481

Dialkylbiaryl phosphines in Pd-catalyzed amination: a user's guide

Abstract: Dialkylbiaryl phosphines are a valuable class of ligand for Pd-catalyzed amination reactions and have been applied in a range of contexts. This perspective attempts to aid the reader in the selection of the best choice of reaction conditions and ligand of this class for the most commonly encountered and practically important substrate combinations.

Gut microbiota dysbiosis contributes to the development of hypertension.

Abstract: Recently, the potential role of gut microbiome in metabolic diseases has been revealed, especially in cardiovascular diseases. Hypertension is one of the most prevalent cardiovascular diseases worldwide, yet whether gut microbiota dysbiosis participates in the development of hypertension remains largely unknown. To investigate this issue, we carried out comprehensive metagenomic and metabolomic analyses in a cohort of 41 healthy controls, 56 subjects with pre-hypertension, 99 individuals with primary hypertension, and performed fecal microbiota transplantation from patients to germ-free mice. Compared to the healthy controls, we found dramatically decreased microbial richness and diversity, Prevotella-dominated gut enterotype, distinct metagenomic composition with reduced bacteria associated with healthy status and overgrowth of bacteria such as Prevotella and Klebsiella, and disease-linked microbial function in both pre-hypertensive and hypertensive populations. Unexpectedly, the microbiome characteristic in pre-hypertension group was quite similar to that in hypertension. The metabolism changes of host with pre-hypertension or hypertension were identified to be closely linked to gut microbiome dysbiosis. And a disease classifier based on microbiota and metabolites was constructed to discriminate pre-hypertensive and hypertensive individuals from controls accurately. Furthermore, by fecal transplantation from hypertensive human donors to germ-free mice, elevated blood pressure was observed to be transferrable through microbiota, and the direct influence of gut microbiota on blood pressure of the host was demonstrated. Overall, our results describe a novel causal role of aberrant gut microbiota in contributing to the pathogenesis of hypertension. And the significance of early intervention for pre-hypertension was emphasized.