Infectious diseases caused by bacteria has become a global health issue, especially antibacterial drug resistance. The most serious concern with antibacterial resistance is that some bacteria became resistant to almost all antibacterial drugs, which makes them less effective. Archidendron jiringa is one of the most potent medicinal plants to be developed as a new source of antibacterial components. In current study, based on the antibacterial assay-guided approach, the separation of bioactive fractions of A. jiringa stem roots was carried out through several stages including isolation, fractionation, and characterization. The stages of isolation of secondary metabolites were conducted by gradually extraction followed by fractionation using chromatographic methods. The antibacterial potential of extracts was evaluated by the disc diffusion and microdilution methods employing the resazurin assay against one Gram-negative resistant bacteria, Escherichia coli, and one Gram-positive bacteria, Bacillus subtilis. Among three extracts obtained, ethyl acetate and methanol extracts demonstrated to be the most significant antibacterial effects, while no antibacterial activity was shown on the n-hexane extract. The fractionation of ethyl acetate extract led to the isolation of the most bioactive fractions (E2815 and E2816) with the MIC's values ranging of 12.5-25 µg/mL for both resistant bacteria. Due to the low amount, only the fraction E2816 was subjected to analysis by 1 H-NMR spectroscopy. The results exhibited that the bioactive fraction was obtained as a mixture of at least three major constituents. However, the purification of the bioactive fraction is required, to further clarify the antibacterial compound that can be utilized as a new promising antibacterial agent. The bioassay-guided separation approach and the dye resazurin as an indicator of the growth of bacteria are applied for the first time for the phytopharmacological investigation from this plant. The present study represented the most effective method for subsequent finding and isolation of potential novel antibacterial constituents from A. jiringa stem roots, in particular against the multi-drug resistant strains.

The aim of this study was to identify and characterize groups of antioxidant active naturally from methanol extract of the stem of Anredera cordifolia through antioxidant assay-guided separation. The methanol extract (ME) displayed the highest antioxidant activity, compared to ethyl acetate extract (EE) and hexane extract (HE) using cyclic voltammetry method. Ascorbic acid was used as a positive control in this research. The repeated fractionation of active ME by MPLC and HPLC analyses yielded a constituent with strong antioxidant property. The active constituent (RNV-1) was predicted as a flavonoid type based on the UV spectrum data. The antioxidant activity results exhibited that RNV-1 had a coefficient of antioxidant activity (K) sligtly higher than K of ascorbic acid with the values of 0.055 and 0.052 respectively. It was found that RNV-1 demonstrated an excellent antioxidant activity in comparison with the standard antioxidant activity through antioxidant assays-guided separation. The results obtained suggested that the stem of A. cordifolia can be used potentially as a source of natural antioxidants by contributing beneficial health effects.