Microwave assisted Wolff rearrangement: A facile method for the synthesis of Fmoc-β-amino acids

The Wolff rearrangement of α-diazoketones, derived from Fmoc-α-amino acids, under no base conditions on exposure to microwave irradiation for 40 to 60 sec to Fmoc-β-amino acids with retention of configuration in good yield (91-95%) is described

N-Silylation of amines and amino acid esters under neutral conditions employing TMS-Cl in the presence of zinc dust

An expedient synthetic approach to N-silylamines has been developed. The protocol, using TMS-Cl/zinc dust instead of BSA, is useful for the conversion of amines or amino acid esters to the corresponding silyl derivatives, followed by acylation with an acyl chloride or Fmoc-amino acid chloride to give the corresponding amide or peptide. This procedure, affording products in good to excellent yields, is also efficient for the coupling of sterically hindered amino acids like α,α-dialkylamino acids and NMe-amino acids. Further, the use of an equimolar quantity of organic base, such as Et 3N/pyridine, is circumvented. © 2005 Published by Elsevier Ltd

Direct synthesis of Fmoc protected amino acid hydroxamates from acid chlorides mediated by magnesium oxide

The synthesis of Fmoc protected amino acid hydroxamates using Fmoc-amino acid chlorides and magnesium oxide is described. The method is simple and efficient, results in complete conversion, and gives good yields and satisfactory purity. © 2003 Elsevier Science Ltd. All rights reserved

On the occurrence of Acanthaster planci (the crown-of-thorns) at Minicoy Atoll.

The predation of coral-polyps by the multi-armed star fish Acanthaster planci is identified during the last two decades as a major biological factor that causes large scale death to reef corals at several parts of the Indo-Pacific. During a recent visit by a team of scientists from Central Marine Fisheries Research Institute,the presence of this star fish in the lagoon of Minicoy Atoll was noticed in November, 1979.Many control measures of star fishes have been practised elsewhere in the Pacific. However, hand-picking of the adults with the aid of pointed spears and killing them with formalin or ammonia solution is the most eifective.Careful search among the corals is required, since the crown-of-thorns hide under the crevices during day time

ROLE OF PATHYAPATHYAS IN THE ADMINISTRATION OF RASOUSHADHAS

Ayurveda is a medical system which has well developed systems of diagnosis and treatment. It is the only medical system in world, which has apparatus to deal with complete human being, which comprises of mind, body and soul. The treatment is highly personalized according to the patients physical nature, age, immunity, mind power, habit etc. A customized diet, life style, exercise, mental support, breathing and meditation techniques also form the part of the treatment. There is a section in Ayurveda called Rasasastra which describes the use of metals, minerals, and poisons with their actions to combat chronic and complicated diseases. As we all know most of the Rasa drugs are toxic. These pass through extensive processing before they are declared fit for internal use. These preparations are sustaining themselves since centuries in clinical use. A thing that does not adversely affect the body and mind is known as Pathya (wholesome) the diet and regimens opposite to these qualities are said to be Apathya (unwholesome). Many Pathyapathya ahara viharas are mentioned in the Rasa classics. The rationale behind the selection of Aharas and Viharas as Pathya (wholesome) or Apathya (unwholesome) mainly depends on the properties of drugs which are used as Pathya as well as that of drug which is used as medicine. The implied meaning is rules and regulations about diet and movements etc. to be advised by the Physician along with treatment. The medicines are ineffective unless these are followed. In the case of Pathya most probable drug interaction will be synergism and of Apathya dravyas will be antagonism. However, their improper processing, misuse, improper mode of administration may cause adverse effects in the human body. Even though the drugs are in assimilable forms, there should be suitable vehicles for their absorption. Here comes the importance of Pathyapathya while using these metallic forms. Suitable Pathya is necessary while using these Rasa drugs for proper absorption of drug, to reduce its adverse effects, to increase its bio-availability etc

Phytochemical Screening, GC-MS Analysis and Antibacterial Evaluation of Ethanolic Leaves Extract of Avicennia marina

Medicinal plants were used to treat diseases traditionally since ancient times. The present work aims to investigate the bioactive constituents through GC MS analysis of ethanolic leaf extracts of A.marina. Phytochemical screening confirmed the presence of Alkaloids, Flavonoids, Phenols, Reducing sugars, Saponins, Tannin, Glycoside, Triterpenoids and Carbohydrate in A.marina. The characterization of the compounds by Gas Chromatography – Mass Spectrometry (GC-MS) technique has reported the presence of thirty compounds in A.marina leaves. These compounds possess different pharmacological properties like anti-microbial, antioxidant, anti-inflammatory and hepatoprotective properties. Keywords: Avicennia marina, GC-MS, Bioactive compounds, Antibacterial activity

Fmoc-amino acid azides in peptide synthesis

Fmoc-amino acid azides can be prepared from the corresponding acid chlorides and sodium azide. All the compounds made have been obtained as solids in good yield and purity. They are found to be shelf stable at room temperature for longer periods. Their storage at room temperature does not lead to the formation of isocyanates. Employing them as coupling agents, the synthesis of a few dipeptides is described

Thermophysical and thermodynamic properties of binary liquid systems of [BMIM][MeSO4] ionic liquid with carboxylic acids

1136-1147Thermophysical properties, namely, density (ρ) and speed of sound (u) of binary mixtures of 1-butyl-3-methylimidazolium methyl sulphate [BMIM][MeSO4] ionic liquid (IL), with acetic acid or propionic acid have been measured in the mole fraction range from 0.1 to 1.0 at temperature ranging from 293.15 to 313.15 K at a 5 K interval, under atmospheric pressure of 101 kPa. From these measured values, the derived thermodynamic parameters, such as, isentropic compressibility (κs), deviation in isentropic compressibility (Δκs), excess molar volume (V) and intermolecular free length (Lf) have been calculated. It is observed that V and Δκs decrease with increasing the temperature. Furthermore, these values are negative in the whole range of binary compositions. The measured data and variations in derived thermodynamic values suggest that significant interactions occur when the IL forms a binary mixture with carboxylic acids. These derived thermodynamic parameters (V, Lf and Δκs) are correlated byusing the Redlich-Kister polynomial equation to generate binary factors and standard errors