Sheng Di Huang (Rehmannia glutinosa, raw)

Sheng Di Huang (raw Rehmannia glutinosa root) contains a complex array of bioactive compounds with limited conventional macronutrient characterization, as it is used medicinally rather than as a dietary staple. Carbohydrates are the dominant macronutrient, comprising approximately 60-70% of dry weight, primarily in the form of oligosaccharides (notably rehmannose, stachyose, and verbascose) and polysaccharides (RPS-b, RG-I type pectic polysaccharides) which contribute to immunomodulatory activity. Moisture content in fresh root is approximately 85-90%. Protein content is modest at approximately 5-8% dry weight, including free amino acids such as arginine, glutamic acid, and alanine. Fat content is minimal at less than 1% dry weight. Key bioactive iridoid glycosides include catalpol (0.3-1.0% dry weight, the primary active marker compound), aucubin, and rehmannioside A, B, C, and D. Phenylethanoid glycosides include acteoside (verbascoside) and echinacoside at trace to 0.1% concentrations. Sugars include d-glucose, d-galactose, and d-fructose. Trace minerals present include potassium (approximately 1,200-1,500 mg/100g dry weight), calcium (approximately 300-400 mg/100g dry weight), magnesium (approximately 80-120 mg/100g dry weight), iron (approximately 15-25 mg/100g dry weight), zinc, manganese, and phosphorus. Vitamin content is limited but includes small amounts of B vitamins and vitamin C in fresh root, largely degraded upon drying. Mannitol is present at approximately 0.5-1.5% dry weight, contributing to its slightly sweet taste. Sterol compounds including beta-sitosterol and stigmasterol are present at trace levels. Bioavailability note: Catalpol and iridoid glycosides demonstrate moderate oral bioavailability with intestinal microbiota playing a significant role in their metabolism and activation; processing method (raw vs. prepared/Shu Di Huang) significantly alters the glycoside and sugar profiles.