Saponins are a diverse group of compounds widely distributed in the plant kingdom, which are characterized by their structure containing a triterpene or steroid aglycone and one or more sugar chains. Consumer demand for natural products coupled with their physicochemical (surfactant) properties and mounting evidence on their biological activity (such as anticancer and anticholesterol activity) has led to the emergence of saponins as commercially significant compounds with expanding applications in food, cosmetics, and pharmaceutical sectors. The realization of their full commercial potential requires development of new processes/processing strategies to address the processing challenges posed by their complex nature. This review provides an update on the sources, properties, and applications of saponins with special focus on their extraction and purification. Also reviewed is the recent literature on the effect of processing on saponin structure/properties and the extraction and purification of sapogenins.

Saponins: Properties, Applications and Processing

Ginsenosides are a special group of triterpenoid saponins that can be classified into two groups by the skeleton of their aglycones, namely dammarane‐ and oleanane‐type. Ginsenosides are found nearly exclusively in Panax species (ginseng) and up to now more than 150 naturally occurring ginsenosides have been isolated from roots, leaves/stems, fruits, and/or flower heads of ginseng. Ginsenosides have been the target of a lot of research as they are believed to be the main active principles behind the claims of ginsengs efficacy. The potential health effects of ginsenosides that are discussed in this chapter include anticarcinogenic, immunomodulatory, anti‐inflammatory, antiallergic, antiatherosclerotic, antihypertensive, and antidiabetic effects as well as antistress activity and effects on the central nervous system. Ginsensoides can be metabolized in the stomach (acid hydrolysis) and in the gastrointestinal tract (bacterial hydrolysis) or transformed to other ginsenosides by drying and steaming of ginseng to more bioavailable and bioactive ginsenosides. The metabolization and transformation of intact ginsenosides, which seems to play an important role for their potential health effects, are discussed. Qualitative and quantitative analytical techniques for the analysis of ginsenosides are important in relation to quality control of ginseng products and plant material and for the determination of the effects of processing of plant material as well as for the determination of the metabolism and bioavailability of ginsenosides. Analytical techniques for the analysis of ginsenosides that are described in this chapter are thin‐layer chromatography (TLC), high‐performance liquid chromatography (HPLC) combined with various detectors, gas chromatography (GC), colorimetry, enzyme immunoassays (EIA), capillary electrophoresis (CE), nuclear magnetic resonance (NMR) spectroscopy, and spectrophotometric methods.

Ginsenosides: Chemistry, biosynthesis, analysis and potential health effects

Influence of heat treatment on the antioxidant activities and polyphenolic compounds of Shiitake (Lentinus edodes) mushroom

The therapeutic potential of ginseng has been studied extensively, and ginsenosides, the active components of ginseng, are shown to be involved in modulating multiple physiological activities. This article will review the structure, systemic transformation and bioavailability of ginsenosides before illustration on how these molecules exert their functions via interactions with steroidal receptors. The multiple biological actions make ginsenosides as important resources for developing new modalities. Yet, low bioavailability of ginsenoside is one of the major hurdles needs to be overcome to advance its use in clinical settings.

https://link.springer.com/content/pdf/10.1186%2F1749-8546-5-20.pdf

Pharmacology of ginsenosides: a literature review.

Antioxidant and anti-tumor promoting activities of the methanol extract of heat-processed ginseng.

The present study was performed to evaluate the effect of steaming ginseng at a temperature over 100 degrees C on its chemical constituents and biological activities. Raw ginseng was steamed at 100, 110, and 120 degrees C for 2 h using an autoclave. The ginseng steamed at 120 degrees C was more potent in its ability to induce endothelium-dependent relaxation. Steaming the raw ginseng at 120 degrees C also remarkably increased the radical-scavenging activity. Ginsenosides F(4), Rg(3), and Rg(5), which were not present in raw ginseng, were produced after steaming. Ginsenosides Rg(3) and Rg(5) were the most abundant ginsenosides in the ginseng steamed at 120 degrees C, accounting for 39% and 19% of all ginsenosides, respectively.

Steaming of Ginseng at High Temperature Enhances Biological Activity

Liquid chromatographic determination of less polar ginsenosides in processed ginseng.

Three new dammarane glycosides were isolated from the processed ginseng (SG; Sun Ginseng). Their structure were determined to be 3β,12β-dihydroxydammar-20(21),24-diene-3-O-β-D-glucopyranosyl(1 → 2)-β-D-glucopyranoside; 3β,12β-dihydroxydammar-20(21),24-diene-3-O-β-D- glucopyranoside and 3β,6α,12β-trihydroxydammar-20(21),24-diene-6-O-β-D-glucopyr-anoside based on spectroscopic evidences. The compounds were named as ginsenoside Rk1 Rk2, and Rk3 respectively.

Three new dammarane glycosides from heat processed ginseng.

A genuine dammarane glycoside, named ginsenoside Rg5, has been isolated by repeated column chromatography and preparative HPLC from the MeOH extract of Korean red ginseng (Panax ginseng C.A. Meyer). The chemical structure of ginsenoside Rg5 was determined as 3-O-[β-D-glucopyranosyl (1→2)-β-D-glucopyranosyl] dammar-20(22),24-diene-3β,12β-diol by spectral and chemical methods. The stereostructure of a double bond at C-20(22) of ginsenoside Rg5 was characterized as (E) from the chemical shift of C-21 in the13C-NMR and a NOESY experiment in the1H-NMR.

Jong Moon Kim

Papers

Steaming of Ginseng at High Temperature Enhances Biological Activity

Liquid chromatographic determination of less polar ginsenosides in processed ginseng.

Three new dammarane glycosides from heat processed ginseng.

Ginsenoside Rg5, a genuine dammarane glycoside from Korean red ginseng

A New Processed Ginseng with Fortified Activity