Two new dammarane-type triterpene sapogenins from Chinese red ginseng

Two new dammarane-type saponins from radix and rhizomes of Panax ginseng C. A. Meyer

Two new dammarane-type ginsenosides elucidated as 6-O-[α-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl]-dammar-24-ene-3β, 6α, 12β, 20S-tetraol, named 20(S)-Ginsenoside Re10 (4); 6-O-[α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl]-20-O-[α-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl]-dammar-24-ene-3β, 6α, 12β, 20R-tetraol, named 20(R)-Ginsenoside Re11 (8); along with one steroidal saponin (1) and six known triterpenoid ginsenosides (2, 3, 5, 6, 7 and 9) were isolated from the radix and rhizomes of mountain-cultivated ginseng (Panax ginseng C. A. Meyer, family Araliaceae). Their structures were determined by comprehensive chemical and spectroscopic analysis. In addition, what's even more concerning is that protodioscin was isolated for the first time from Panax ginseng.

Phytochemistry of Red Ginseng, a Steam-Processed Panax ginseng

Asian ginseng, the root of Panax ginseng C.A. Meyer, occupies a prominent position in the list of best-selling natural products in the world. There are two major types of ginseng roots: white ginseng and red ginseng, each with numerous preparations. White ginseng is prepared by air-drying fresh Asian ginseng roots after harvest. Red ginseng is prepared by steaming roots in controlled conditions using fresh or raw Asian ginseng. Red ginseng is commonly used in Asian countries due to its unique chemical profile, different therapeutic efficacy, and increased stability. Compared with the widespread research on white ginseng, the study of red ginseng is relatively limited. In this paper, after a botanical feature description, the structures of different types of constituents in red ginseng are systematically described, including naturally occurring compounds and those resulting from the steam processing. In red ginseng phytochemical studies, the number of published reports on ginsenosides is significantly higher than that for other constituents. Up to now, 57 ginsenosides have been isolated and characterized in red ginseng. The structural transformation pathways during steaming have been summarized. In comparison with white ginseng, red ginseng also contains other constituents, including polyacetylenes, Maillard reaction products, other types of glycosides, lignans, amino acids, fatty acids, and polysaccharides, which have also been presented. Appropriate analytical methods are necessary for differentiating between unprocessed white ginseng and processed red ginseng. Specific marker compounds and chemical profiles have been used to discriminate red ginseng from white ginseng and adulterated commercial products. Additionally, a brief phytochemical profile comparison has been made between white ginseng and black ginseng, and the latter is another type of processed ginseng prepared from white or red ginseng by steaming several times. In conclusion, to ensure the safe and effective use of red ginseng, phytochemical and analytical studies of its constituents are necessary and even crucial.

Rare ginsenosides: A unique perspective of ginseng research

BACKGROUND

Rare ginsenosides (Rg3, Rh2, C-K, etc.) refer to a group of dammarane triterpenoids that exist in low natural abundance, mostly produced by deglycosylation or side chain modification via physicochemical processing or metabolic transformation in gut, and last but not least, exhibited potent biological activity comparing to the primary ginsenosides, which lead to a high concern in both the research and development of ginseng and ginsenoside-related nutraceutical and natural products. Nevertheless, a comprehensive review on these promising compounds is not available yet.

AIM OF REVIEW

In this review, recent advances of Rare ginsenosides (RGs) were summarized dealing with the structurally diverse characteristics, traditional usage, drug discovery situation, clinical application, pharmacological effects and the underlying mechanisms, structure-activity relationship, toxicity, the stereochemistry properties, and production strategies.

KEY SCIENTIFIC CONCEPTS OF REVIEW

A total of 144 RGs with diverse skeletons and bioactivities were isolated from Panax species. RGs acted as natural ligands on some specific receptors, such as bile acid receptors, steroid hormone receptors, and adenosine diphosphate (ADP) receptors. The RGs showed promising bioactivities including immunoregulatory and adaptogen-like effect, anti-aging effect, anti-tumor effect, as well as their effects on cardiovascular and cerebrovascular system, central nervous system, obesity and diabetes, and interaction with gut microbiota. Clinical trials indicated the potential of RGs, while high quality data remains inadequate, and no obvious side effects was found. The stereochemistry properties induced by deglycosylation at C (20) were also addressed including pharmacodynamics behaviors, together with the state-of-art analytical strategies for the identification of saponin stereoisomers. Finally, the batch preparation of targeted RGs by designated strategies including heating or acid/ alkaline-assisted processes, and enzymatic biotransformation and biosynthesis were discussed. Hopefully, the present review can provide more clues for the extensive understanding and future in-depth research and development of RGs, originated from the worldwide well recognized ginseng plants.

Saponins of ginseng products: a review of their transformation in processing

The primary processed product of Panax ginseng C.A. Meyer (P. ginseng) is red ginseng. As technology advances, new products of red ginseng have arisen. Red ginseng products, e.g., traditional red ginseng, sun ginseng, black ginseng, fermented red ginseng, and puffed red ginseng, are commonly used in herbal medicine. Ginsenosides are the major secondary metabolites of P. ginseng. The constituents of P. ginseng are significantly changed during processing, and several pharmacological activities of red ginseng products are dramatically increased compared to white ginseng. In this paper, we aimed to review the ginsenosides and pharmacological activities of various red ginseng products, the transformation law of ginsenosides in processing, and some clinical trials of red ginseng products. This article will help to highlight the diverse pharmacological properties of red ginseng products and aid in the future development of red ginseng industrialization.

Advances and challenges in ginseng research from 2011 to 2020: the phytochemistry, quality control, metabolism, and biosynthesis

Covering: 2011 to the end of 2020Panax species (Araliaceae), particularly P. ginseng, P. quinquefolius, and P. notoginseng, have a long history of medicinal use because of their remarkable tonifying effects, and currently serve as crucial sources for various healthcare products, functional foods, and cosmetics, aside from their vast clinical preparations. The huge market demand on a global scale prompts the continuous prosperity in ginseng research concerning the discovery of new compounds, precise quality control, ADME (absorption/disposition/metabolism/excretion), and biosynthesis pathways. Benefitting from the ongoing rapid development of analytical technologies, e.g. multi-dimensional chromatography (MDC), personalized mass spectrometry (MS) scan strategies, and multi-omics, highly recognized progress has been made in driving ginseng analysis towards "systematicness, integrity, personalization, and intelligentization". Herein, we review the advances in the phytochemistry, quality control, metabolism, and biosynthesis pathway of ginseng over the past decade (2011-2020), with 410 citations. Emphasis is placed on the introduction of new compounds isolated (saponins and polysaccharides), and the emerging novel analytical technologies and analytical strategies that favor ginseng's authentic use and global consumption. Perspectives on the challenges and future trends in ginseng analysis are also presented.

In vivo pharmacokinetics, distribution, and excretion of an anticancer agent isolated from red ginseng, in rat

The compound 20(S),25-epoxydammarane-3β,12β,24α-triol (24-hydroxy-panaxadiol or 24-OH-PD), isolated from the red Panax ginseng CA Meyer possesses anticancer activity. Our aim was to study the pharmacokinetic characteristics of 24-OH-PD, which is essential for pre-clinical research during the development of new drugs. In this study, a simple and sensitive ultra-performance liquid chromatography-mass spectrometry (LC-MS/MS) method was established and used for studying the pharmacokinetics, in vitro protein binding, tissue distribution, and elimination profiles of 24-OH-PD in rats. 24-OH-PD was characterized by linear pharmacokinetics in the dose range of 2.5-10 mg/kg and had relatively longer half-life (4.82-5.45 h) than the other ginsenosides. It had a wide tissue distribution profile in rats and was primarily distributed in the lung. Within 96 h of intravenous administration, 13.84% of 24-OH-PD was excreted out via feces and 0.02% via urine in its unchanged form. In conclusion, a simple LC-MS/MS method with high sensitivity and selectivity was established for the quantification of 24-OH-PD.

Two new dammarane-type triterpenoid saponins from ginseng medicinal fungal substance

Two new triterpenoid saponins, namely ginsenoside Re8 (1) and notoginsenoside ST-8 (2), were isolated from ginseng medicinal fungal substance. Their structures were elucidated by spectroscopic data and chemical analysis.