A synthetic route towards the synthesis of TAN1251B was developed utilizing an alkylidene carbene insertion reaction as a key step to construct the quartenary centre. The α-hydroxylation of the 5,6-spirocyclic enone with iodosobenzene was successful to give a mixture of diastereomer compounds 20 and 21 in 1:1.2 ratios.
This study investigates the characteristics of an antioxidant cream made from the methanol extract of Piper sarmentosum leaves, which is locally known as the wild betel or pokok kadok in Malay. The secondary metabolites of the leaves were subjected to phytochemical tests to detect the presence of natural compounds. Antioxidant activity was described by its total phenolic content (TPC) and total flavonoid content (TFC), which was assessed by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay. A phase diagram was constructed to find a possible region to formulate an antioxidant cream. In phytochemical screening, the methanolic extract showed positive presence of alkaloids, flavonoids, steroids, terpenoids and tannins. In quantitative analysis of antioxidative components, besides having significantly higher TFC content compared with quercetin (P