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Weak Interactions in Carbon-Hetero Atom Bond Forming Reactions
Anima Bose and Prasenjit Mal

Prayogic Rasayan 2021, 5, 43-48

DOI: https://www.doi.org/10.53023/p.rasayan-20210930


Controlling various reactions by multiple weak interactions or soft forces has become an widespread topic under supramolecular catalysis. This review has made a literature collection that explores cooperative weak or noncovalent interactions. These are charge transfer complexation, H-bonding, S-H...pi, acid-base, cation-pi, etc., towards C-hetero bond formation reactions. This review article will discuss the specific reactivity of chemical systems controlled by weak interactions.

Synthesis of Tunable Fluorescent Carbon Dots: A Mini Review
Varsha UshaVipinachandran, Sathish Rajendran, Indhumathi Ashokan, Kabir Hussain Badagoppam Haroon and Susanta Kumar Bhunia

Prayogic Rasayan 2021, 5, 49-56

DOI: https://www.doi.org/10.53023/p.rasayan-20210715


Tunable fluorescent carbon dots synthesis via different methods have been demonstrated.

Chemical Safety Concern Led to Small-scale Chemistry and Green Chemistry
Supawan Tantayanon

Prayogic Rasayan 2021, 5, 57-59

DOI: https://www.doi.org/10.53023/p.rasayan-20210917


In designing the Small-Lab Kit, the chemical safety, the cost and the lab performancewere all taken into account. It comprises of enough glasswares and necessary equipmentthat all the basic organic experiments as well as a wide range of organic reactions can be carried out as usual, but downsized to 1 mL upto 25 mL.Overall, the small-lab kit is a portable organic lab and can be used at any place even though there is no formal laboratory available.

FeCl3-Catalyzed Highly Efficient Nazarov Type Cyclization of Arylvinyl Carbinols: Total Syntheses of Naturally Occurring Taiwaniaquinoids
Badrinath N. Kakde, Amarchand Parida, Vipin R. Gavit, Rhituparna Nandi, Sourav Kundu, and Alakesh Bisai*

Prayogic Rasayan 2021, 5, 60-69

DOI: https://www.doi.org/10.53023/p.rasayan-20211115


FeCl3-catalyzed cyclization of arylvinylcarbinols for the synthesis of [6,5,6]-carbotricyclic core sharing an all-carbon quaternary center has been described in this full article. A careful mechanistic details suggest that the reaction follows a stepwise mechanism via the intermediacy of arylallyl carbocationic species. The carbocation subsequently reacts with an adjacent aromatic ring to form [6,5,6]-carbotricyclic scaffold of abeo-abietane diterpenoids. The methodology works under mild conditions to afford a variety of carbotricyclic core ingood to excellent yields (up to 99% yield). Our strategy has been applied to a concise synthesis of a number of structurally intriguing naturally occurring taiwaniaquinoids, ±-taiwaniaquinol F (1a), ±-taiwaniaquinol B (1b), ±-dichronanone(1c), ±-taiwaniaquinone H (1d) and unnatural ±-5-epi-taiwaniaquinoneG (epi-1e).

In vitro evaluation of UV-filtering and anti-tyrosinase potential in selected medicinal plants in Sri Lanka for the development of herbal cosmetics
Mayuri Napagoda,* Maduwanthi Kumari,, Udari Samaranayake

Prayogic Rasayan 2021, 5, 70-75

DOI: https://www.doi.org/10.53023/p.rasayan-20211102


TThis study was conducted to evaluate the in vitro Ultra-Violet(UV) filtering and anti-tyrosinase potential in several medicinal plants. The methanolic extract of Tagetes erecta has displayed a sun protection factor (SPF) of 40 and was found to be photostable. Furthermore, an extreamly potent tyrosinase inhibition (IC50 = 48.27 µg/mL) as well as antioxidant activity (EC50 = 14.82 µg/mL) were observed for the same extract revealing the high potential for the development of herbal cosmetics.