Author: Dirgha Joshi, Nisha Adhikari

सार

Throughout a long time, green chemistry (GC) reviled how a basic scientific methodology and advanced practice can enhance the safe output to the human life and the environment without compromising the desired outcomes. For this, the advancement in scientific processes were made in the field of designing safer reagents and solvents, advancement in catalysis and possible development of the renewable feedstock. From the past lesson, currently the future chemists are being taught and trained to a wider concept of green chemistry to the practice and increased awareness towards human as well as environmental impact. A need for GC practice is highly demanding and the adherence to the 12 principles of GC concept is growing rapidly. A need for great change in policy, rules and regulations which will force industry, research institute, academia, and other is still highly demanding. Moreover the better is encouragements, awareness and make an individual person responsible to adapt to a GC concept in a real practical way. Green action always acts louder than the green words.

Author: Dirgha Joshi, Nisha Adhikari

Phase-transfer catalyst (PTC) has been popular for more than four decades in synthetic chemistry. The PT catalysis uses the PTC in a catalytic amount and it allows to react the reactants of two different phases via facilitating transfer of reactants from interface, which are not miscible and itself regenerated again and the cycle is repeated. The use of PTC is wide from liquid-liquid, solid-liquid to liquid-gas system. Due to its diversified application, PTC is also combined with other rate enhancing techniques like microwave, electro-organic synthesis, sono-chemistry, photochemistry and many more are exploring. The PTC application in the field of manufacturing of the fine chemicals and organic intermediates are unlimited.

Author: Dirgha Joshi, Nisha Adhikari

Abstact

Black pepper, the ‘King of spices’ (Piper nigrum L.), is a widely used spice, known for its pungent odour. From time immemorial, plant sources were used in traditional systems of medicine and day-to-day common use, such as in meal preparation and cosmetic purposes. This is due to their vast pharmacological potential with minimum side effects. Among the various species of the Piperaceae family, black pepper is one of the most popular due to its principle pharmacological component, piperine. Which is an alkaloid that has diverse pharmacological activities like antioxidant, anti-obesity, antitumor, antipyretic, anticonvulsant, anti-thyroid, antifungal, antibacterial, insecticidal, hepatoprotective, anti-asthmatic, larvicidal, antihypertensive, anti-inflammatory, antidiabetic, antidiarrheal, bio-availability enhancer, immunomodulator, antiepileptic, antifertility, GI stimulant, lipid metabolism accelerator, anticancer, CNS stimulant, diuretic, aphrodisiac, blood purifier and antiplatelet activities, etc. Due to some religious value of black pepper, its being popular from ancient time to modern generation. This review is aimed to provide a literature review on recent advancement of chemistry, pharmacognosy, pharmacological activities, new piperine based formulations and other general use of Piper nigrum.​

Author: Dirgha Joshi, Nisha Adhikari

सार

A proper selection of acid and base plays pivotal role in organic synthesis. The rate of reaction, desired product, yield, handling easiness, stability, solubility, and many more factors depends on acids and bases what we are using. Both the acid and base can be categorized in two classes; organic (eg. Acid-Acetic acid, Formic acid, Ascorbic acid etc., Base-DMAP, DBU, Triethylamine, n-Butyllithium etc.) and inorganic (Acid-Boric acid, Sulfuric acid, Hydrochloric acid, Phosphoric acid etc., Base-Sodium hydroxide, Ammonium hydroxide, Calcium carbonate, Sodium amide etc.). Furthermore, the Lewis acid (eg. Aluminium bromide, Boron trifluoride, Tin (IV) chloride etc.), and Phosphazene base (eg. P 1-t-Bu, P 2-t-Bu, P 4-t-Bu, P 1-t-Oct, P 2-F, BTPP, BEMP etc.) are also more popular classes. Based on the molecular structure we may need weak, mild, strong or strongest acid and base. This concise review provides updated information about acids and bases commonly used in organic synthesis.