Phytochemical Standardization of Oleo Resin of Shorea robusta Gaertn (Dipterocarpaceae) with modern analytical technique

More than 70% of India’s 1.1 billion populations still use non-allopathic systems of medicine like Ayurveda, Unani, Homeopathy and other systems. The global knowledge about Unani and Indian herbals will hopefully be enhanced by information on the evidence-base of these medicinal plants. Resin of Shorea robusta Gaertn known as “Raal” in Unani; Shala in Ayurvedic System belonging to Dipterocarpaceae family plays a foremost role in the Unani system of medicine. It is abundantly available in different parts of Eastern Ghats of Southern Peninsular India and has been widely used in indigenous system for the preparation of different formulations used in the treatment of many skin diseases mainly allergies; diarrhea, dysentery, astringent and as an ingredient in ointments. Due to its therapeutic potentials and vital medicinal properties and also usage of drug in most of the common ailments, lead us to standardize the drug according to WHO guidelines. Phytochemical and physico-chemical studies, macroscopic and microscopic properties of resin were carried out. The main aspects included in the study are organoleptic characters, physico-chemical constants, fluorescence analysis of powdered drug and extracts, TLC profile and Heavy metal analysis, which provide information, which are widely accepted in the quality assessment of herbal drugs and to lay down the standard for the genuine drug. Phytochemical screening, isolation of chemical constituents will help in future to study the pharmacological properties

PEG-400 as an efficient and recyclable reaction medium for the synthesis of 2-aryl-2-methyl-4,5-diphenyl-2,3- dihydro-2<i>H</i>-imidazoles

<p>A productive natural method has been produced for the synthesis of 2-aryl-2-methyl-4,5-diphenyl-2,3-dihydro-2<i>H</i>-imidazoles in great yields under catalyst free-conditions utilizing polyethylene glycol (PEG-400) as a green reaction medium. The highlights of this new method are shorter reaction times, good yields, room temperature, and use of nontoxic, inexpensive, and recyclable PEG-400.</p

Stereoselective synthesis of (S,S)-palythazine from D-mannitol

Exploiting the symmetry element, an asymmetric synthesis of (S,S)-palythazine was accomplished with (R)-glyceraldehyde acetonide as the chiral precursor. The prominent steps involved stereoselective Barbier allylation, ring-closing metathesis, regioselective nucleophilic opening of epoxide, and auto-condensation of aminoketone moiety

Stereoselective total syntheses of leiocarpin A and (-)-galantinic acid starting from D-mannitol

Stereoselective total syntheses of leiocarpin A and (-)-galantinic acid, starting from D-mannitol as a chiral synthon, are described. The key steps involve stereoselective allylations, a Grignard reaction to control the required stereogenic centers, and ring-closing metathesis followed by intramolecular Michael addition

Phosphane-catalyzed Knoevenagel condensation: a facile synthesis of α-cyanoacrylates and α-cyanoacrylonitriles

Triphenylphosphane (TPP) has been utilized as a novel and efficient catalyst for the Knoevenagel condensation of aldehydes with acidic methylene compounds such as ethyl cyanoacetate and malononitrile to afford substituted olefins. The reaction proceeds smoothly under mild and solvent-free conditions and the products are obtained in excellent yields with an E-geometry. This method is applicable for a wide range of aldehydes including aromatic, aliphatic and heterocyclic substrates. Microwave irradiation has been used to achieve enhanced reaction rates and improved yields

Green protocol for the Biginelli three-component reaction: Ag<SUB>3</SUB>PW<SUB>12</SUB>O<SUB>40</SUB> as a novel, water-tolerant heteropolyacid for the synthesis of 3,4-dihydropyrimidinones

Biginelli three-component condensation of an aldehyde, β-keto ester, and urea proceeds smoothly on the surface of the silver salt of heteropolyacid (HPA), i.e. Ag<SUB>3</SUB>PW<SUB>12</SUB>O<SUB>40</SUB>, in water to afford the corresponding 3,4-dihydropyrimidinones in high-to-quantitative yields under mild conditions. The heterogeneous solid acid provides ease of separation of the catalyst and isolation of the products. The recovered catalyst can be recycled in subsequent reactions with consistent activity. Compared to the classical Biginelli reaction conditions, this new method has the advantages of improved yields, reusability of the catalyst, an eco-friendly solvent, ease of isolation of products, and simplicity in the experimental procedure