GC-MS analysis of the methanolic extracts of Smilax china and Salix alba and their antioxidant activity

Abstract

Smilax china L. (family Smilacaceae) and Salix alba L. (family Salicaceae) are plants that have been traditionally used to treat various ailments in Indian and Chinese medicine. A quantitative estimation of the methanolic extracts of these plants was performed by GC-MS analysis to obtain insight into its phytoconstituents responsible for therapeutic action. The antioxidant potential of the methanol extracts of Smilax china (MESC) and Salix alba (MESA) were assessed with DPPH by using a UV spectrophotometer at a wavelength of 517 nm. The prevailing compounds found in MESC were lactam sugars including 2,5-dimethyl-2,4-dihydroxy-3(2H)-furanon (1.40%), 1,5-anhydro-6-deoxyhexo-2,3-diulose (4.33%), and alpha-methyl-1-sorboside (1.80%); the two alkaloids found were 1,4-methane-4,4a,5,6,7,8,9,9a-octahydro-10,10-dimethyl cyclohepta[d] pyridazine (0.87%) and 1,3,7-trimethyl-2,6-dioxopurine(0.54%); terpenes included deltacadinene (0.39%), terpineol, (+)-cedrol (22.13%), 3-thujanol (0.77%), and 9,10-dehydro-cycloisolongifolene (0.34%); fatty acids included cis-vaccenic acid (4.98%) and telfairic acid (1.10%); esters included 1,2,3-propanetriol diacetate (7.56%), 7-hexadecenoic acid, methyl ester (1.77%), eicosanoic acid, and methyl ester (0.95%); and glycerol included 1,2,3-propanetriol (28.75%). The interesting compounds found in MESA were reducing sugars like D-allose (4.40%) and pyrogallol (10.48%), alkaloids like caffeine (63.49%), and esters like methyl octadecanoate (0.53%). Both fractions revealed considerable antioxidant activity. The reported existing phenolic compounds and terpenes are responsible for the antioxidant activity of the plant extracts.

Keywords: DPPH assay; GC-MS; Salix alba; Smilax china; total antioxidant potential.

Figure 1

GC-MS chromatogram of the methanolic extract of Smilax china

Figure 2

Chemical compound hits on GC-MS chromatogram of methanolic extract of Smilax china .

Figure 3

GC-MS chromatogram of methanolic extract of Salix alba

Figure 4

Chemical compound hits on GC-MS chromatogram of methanolic extract of Salix alba .

Figure 5

Dose-dependent scavenging of DPPH radicals by the methanolic extracts of Smilax china (MESC) and Salix alba (MESA) compared with standard drug α-tocopherol. Each value represents mean ±SD (n = 4). IC₅₀ values of MESC, MESA, and α-tocopherol were 82 ±1.14, 57 ±1.75, and 42 ±1.18 μg/mL.