Polygonatum sibiricum

Polygonatum sibiricum (Huang Jing) rhizome contains a complex nutritional and bioactive profile. Polysaccharides are the dominant bioactive fraction, typically comprising 6–15% of dried rhizome weight (mainly homogeneous heteropolysaccharides composed of glucose, galactose, mannose, and galacturonic acid residues; molecular weights ranging ~10–500 kDa). Steroidal saponins (e.g., diosgenin-type glycosides, sibiricoside A–D) are present at approximately 0.2–1.5% of dry weight and are considered key pharmacological constituents. Lectins (Polygonatum sibiricum lectin, PSL) are found in notable concentrations in fresh rhizome (~0.1–0.5% dry weight). Flavonoids include kaempferol, quercetin, and vitexin glycosides (estimated total flavonoid content ~0.3–1.0% dry weight). Alkaloids are present in trace amounts. Amino acids: the rhizome contains all essential amino acids; total free amino acid content is approximately 3–6% of dry weight, with relatively high proportions of aspartic acid, glutamic acid, and leucine. Lipids: total fat content is low (~1–3%), with linoleic acid and palmitic acid as predominant fatty acids. Dietary fiber: crude fiber constitutes roughly 8–15% of dried rhizome. Carbohydrates: total carbohydrate content (including polysaccharides and oligosaccharides such as fructo-oligosaccharides) is approximately 50–65% of dry weight; notable presence of reducing sugars (~5–10%). Minerals: potassium (~8–12 mg/g dry weight), calcium (~2–5 mg/g), magnesium (~1.5–3 mg/g), iron (~0.05–0.15 mg/g), zinc (~0.02–0.06 mg/g), manganese (~0.01–0.04 mg/g), and selenium (trace, ~0.01–0.05 µg/g). Vitamins: modest amounts of vitamin C (~10–30 mg/100 g fresh weight), B-complex vitamins (B1, B2 in trace quantities), and small amounts of vitamin E (~0.5–2 mg/100 g dry weight). Other bioactive compounds: anthraquinones (trace), phenolic acids (including ferulic acid, chlorogenic acid at ~0.1–0.5% dry weight), and volatile oils (trace). Bioavailability notes: Polysaccharides have limited direct intestinal absorption due to high molecular weight but exert significant prebiotic effects via gut microbiota fermentation into short-chain fatty acids; processing (steam-curing/jiuzhi) substantially increases Maillard reaction products (e.g., 5-HMF) and enhances polysaccharide bioactivity. Steroidal saponins undergo hydrolysis by gut flora to aglycones (e.g., diosgenin) which improves absorption. Flavonoid glycosides have moderate oral bioavailability (~5–20%) improved by co-administration with lipids. Traditional wine-processing (jiuzheng) of the herb is documented to enhance overall bioavailability of lipophilic constituents.