The generally useful estimate of solvent systems method facilitates off‐line two‐dimensional countercurrent chromatography for isolating compositions from Siraitia grosvenorii roots

Abstract

Solvent system selection is a crucial and the most time‐consuming step for successful countercurrent chromatography separation. A thin‐layer chromatography‐based generally useful estimate of solvent systems method has been developed to simplify the solvent system selection. We herein utilized the method to select a solvent system for off‐line two‐dimensional countercurrent chromatography to separate chemical compositions from a complex fraction of the Siraitia grosvenorii root extract. The first‐dimensional countercurrent separation using chloroform/methanol/water (10:5.5:4.5, v/v/v) yielded four compounds with high purity and three mixture fractions (Fr I, III, and VII). The second‐dimensional countercurrent separation conducted on Fr I, III, and VII using the hexane/ethyl acetate/methanol/water (4:6:6:4, 3:7:3:7, v/v/v) and chloroform/methanol/water (10:9:6, v/v/v) solvent systems, respectively, produced another four compounds. Four triterpenoids and four lignans were finally isolated, including two novel compounds. Hence, the generally useful estimate of solvent systems method is a feasible and efficient approach for selecting an applicable solvent system for separating complex samples. In addition, the off‐line two‐dimensional countercurrent chromatography method can improve both the peak resolution and the capacity of countercurrent chromatography.

Identification and Isolation of α-Glucosidase Inhibitors from Siraitia grosvenorii Roots Using Bio-Affinity Ultrafiltration and Comprehensive Chromatography

“…The peaks 1–3, 13, and 15–17 were distributed over a broad range in the HPLC chromatogram, but they all showed low and medium polarity, as observed by TLC analysis; therefore, they were distributed in the organic phase when partitioned by the aqueous phase. Previous studies show that HSCCC is highly effective in separating such compounds [ 17 , 19 ]. Hence, HSCCC was employed to separate peaks 1–3, 13, and 15–17.…”

“…The other 10 known compounds were identified to be (-)-lariciresinol ( 1 ) [ 31 ], 3,4′-dimethoxy-4,9,9′-trihydroxy-benzofuranolignan-7′-ene ( 2 ) [ 32 ], 23,24-dihydrocucurbitacin F ( 3 ) [ 33 ], siraitic glycoside II F ( 5 ) [ 17 ], siraitic acid II B ( 12 ) [ 16 ], 23,24-dihydrocucurbitacin F-25-acetate ( 13 ) [ 34 ], siraitic acid II C ( 14 ) [ 16 ], cucurbitacin B ( 15 ) [ 35 ], 23,24-dihydrocucurbitacin B ( 16 ) [ 36 ], and dihydroisocucurbitacin B-25-acetate ( 17 ) [ 37 ], respectively, based on their 1 H and 13 C NMR spectroscopic data ( Supporting Information ), as well as the comparison of these data with those reported previously.…”

“…S. grosvenorii root extracts (SGR) were prepared as described previously [ 17 ]. Briefly, air-dried and powdered roots of S. grosvenorii (10 kg) were immersed in 70% ( v / v ) ethanol, extracted three times every two weeks at 25 °C (2 × 50 L), and concentrated under reduced pressure.…”

“…Sci. 2023, 24, x FOR PEER REVIEW 5 of 18 compounds [17,19]. Hence, HSCCC was employed to separate peaks 1-3, 13, and 15-17.…”

“…Although several S. grosvenorii roots are available, they have only been used as organic materials and fertilizers in plantations. A few phytochemical investigations have revealed that the ethanolic extract of the roots mainly consists of cucurbitane-type compounds, including cucurbitacin B, cucurbitacin Q1, siraitic acids A–H, siraitic acid II B, siraitic acid II C, and siraitic glycoside II F [ 16 , 17 , 18 , 19 , 20 ]. Our preliminary study revealed that S. grosvenorii root extract inhibits α-glucosidase, but the active constituents that inhibit α-glucosidase have not been determined yet.…”