Extraction efficiency, phytochemical profiles and antioxidative properties of different parts of Saptarangi (Salacia chinensis L.) - An important underutilized plant

Abstract

The study aimed to evaluate extraction efficiency, detection and quantification of phytochemicals, minerals and antioxidative capacity of different parts of Salacia chinensis L. Continuous shaking extraction, steam bath assisted extraction, ultrasonic extraction and microwave assisted extraction with varied time intervals were employed for extraction of phenolics, flavonoids, and antioxidants. Preliminary screening revealed the presence of wide array of metabolites along with carbohydrates and starch. Steam bath assisted extraction for 10 min exposure was found most suitable for extraction phenolics (46.02 ± 2.30 mg of gallic acid equivalent per gram of dry weight and 48.57 ± 2.42 mg of tannic acid equivalent per gram of dry weight) and flavonoids (35.26 ± 1.61 mg of quercetin equivalent per gram of dry weight and 51.60 ± 2.58 mg of ellagic acid equivalent per gram of dry weight). In support, reverse phase-high performance liquid chromatography- diode array detector confirmed the presence of seven pharmaceutically important phenolic acids. Antioxidant capacity was measured by 1, 1- diphenyl-1-picryl hydrazyl (DPPH), ferric reducing antioxidant power (FRAP), 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) scavenging (ABTS) and N, N-dimethyl-p-phenylenediamine (DMPD) assays and represented as trolox equivalent antioxidant capacity (TEAC) and ascorbic acid equivalent antioxidant capacity (AEAC). Antioxidant capacity ranged from 121.02 ± 6.05 to 1567.28 ± 78.36 µM trolox equivalent antioxidant capacity and 56.62 ± 2.83 to 972.48 ± 48.62 µM ascorbic acid equivalent antioxidant capacity. Roots showed higher yields of illustrated biochemical parameters, however fresh fruit pulp was found a chief source of minerals. Gas chromatography-mass spectroscopic analysis revealed the presence of a vast array of phytoconstituents associated with different plant parts. The present study revealed the amounts of minerals and diverse phytoconstituents in various parts of S. chinensis and confirmed its medicinal and nutritional implications.

Keywords: ABTS, 2, 2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid); AC, Antioxidant capacity; AEAC, ascorbic acid equivalent antioxidant capacity; Antioxidative capacity; CSE, continuous shaking extraction; DAD, diode array detector; DMPD, N, N-dimethyl-p-phenylenediamine; DPPH, 1, 1- diphenyl-1-picryl hydrazyl; DW, Dry weight; EAE, ellagic acid equivalent; Extraction optimization; FRAP, 2, 4, 6-tris (2-pyridyl)-s-triazine; Flavonoids; GAE, gallic acid equivalent; GC-MS; GC-MS, gas chromatography-mass spectroscopy; LOD, limit of detection; LOQ, limit of quantification; MAE, microwave assisted extraction; Minerals; NIST, national institute of standards; Phenolic acids; Phytoconstituents; QE, quercetin equivalent; RP-HPLC, reversed phase-high performance liquid chromatography; RP-HPLC-DAD; SBAE, steam bath assisted extraction; Salacia chinensis; TAE, tannic acid equivalent; TEAC, trolox equivalent antioxidant capacity; TFC, total flavonoid content; TIC, total ion chromatogram; TPC, total phenolic content; UE, ultrasonic extraction.

Graphical abstract

Fig. 1

RP-HPLC-DAD profiles of phenolic acids and related compounds from various parts of S. chinensis. A: Standards (100 ppm), B: Root, C: Stem, D: Leaf, E: Fruit pulp and F: Seed.

Fig. 2

Antioxidant capacities of various parts of S. chinensis. A: DPPH, B: FRAP, C: ABTS, D: DMPD assay.

Fig. 3

GC-MS total ion chromatograms (TIC) of various parts of S. chinensis. A: Root, B: Stem, C: Fruit pulp, D: Seed.

Fig. 4

PCA plots for data obtained from A: Total polyphenols (TPC and TFC); B: Antioxidant activities (DPPH, FRAP, DMPD and ABTS); C: HPLC analysis.