The present study describes the synthesis of piceatannol (2) and its analogs (3–8) using Wittig‐Horner reaction, Colvin rearrangement, and Sonogashira reaction as key steps and also evaluation of their inhibitory potency on the production of inflammatory mediator nitric oxide (NO) in lipopolysaccharide (LPS)‐induced RAW‐264.7 macrophages. Three compounds 7 (90.1%), 8 (60.8%), and 6 (55.2%) were found to potently inhibit NO production induced by LPS without affecting the viability of RAW‐264.7 cells. In addition, their Arginase I and II inhibition activity was also evaluated. In this study, three compounds, i.e., compounds 2–4 were showed good inhibition activity to both arginase I and II. Of the synthesized compounds, compound 2 exhibited maximum inhibitory activity of 28% (arginase I) and 26% (arginase II) at 10 μM concentration followed by compounds 3 and 4 of 20 and 22% to arginase I, 22 and 23% to arginase II, respectively.

Simple and efficient first syntheses of phoyunbenes A‐D and thunalbene have been developed using Horner–Wadsworth–Emmons reaction as a key step. Later, their anti‐inflammatory effects were investigated in lipopolysaccharide‐induced RAW‐264.7 macrophages. The results revealed that phoyunbenes A‐D and thunalbene showed weak inhibitory activities without cytotoxicity on the production of nitric oxide (NO) which is an important inflammatory mediator.

Reactive oxygen species (ROS) referring free radicals with oxygen molecules are produced in the body as byproducts during the normal metabolic process which generates energy by the oxidation of carbohydrates, fats, and proteins. Free radicals such as superoxide anion radicals (O 2 •¯), hydroxyl radicals (•OH) and non-free radical species such as hydrogen peroxide (H 2 O 2 ) and singlet oxygen ( 1 O 2 ) are considered as ROS.1 These ROS not only oxidize membrane lipids but damage nucleic acids, proteins and carbohydrates leading to mutations.2 If ROS are not scavenged by antioxidants, they could be involved in ageing and various diseases related to oxidative stress.