Rehmannia glutinosa (RG), officially recognized as a medicinal and edible substance in China since 2024, exhibits significant potential for pharmaceutical and functional food applications. Its processed forms—Fresh Rehmanniae Radix (FRR, Xiandihuang), Dried Rehmanniae Radix (DRR, Shengdihuang), and Rehmanniae Radix Preparata (RRP, Shudihuang)—display distinct oligosaccharide (RGO) and polysaccharide (RGP) profiles that directly influence their bioactivities. While FRR/DRR are rich in stachyose-type RGOs with hypoglycemic and hepatoprotective effects, RRP is rich in polysaccharides with immunomodulatory, anti-aging, and anti-inflammatory properties. Despite their therapeutic promise, systematic comparisons of these saccharides across processing methods remain scarce. This review comprehensively analyzes extraction techniques, structural features, bioactivities, and structure-activity relationships of RGOs/RGPs, highlighting their mechanisms in metabolic regulation, gut microbiota modulation, and multi-organ protection, while bridging traditional applications with modern scientific validation. Notably, RGPs demonstrate enhanced bioavailability and therapeutic efficacy when formulated into liposomes or nano-adjuvants. This study systematically examines processing-induced structural transformations, bioactivities and safety profiles to establish theoretical foundations for advancing RGOs/RGPs development and proposes novel research directions. The findings provide critical guidance for developing RG-based functional ingredients targeting diabetes management, immune modulation, and preventive healthcare, with expected applications in pharmaceuticals, health foods, and nutritional supplements.

Polysaccharides are the important biologically active components found in the peel of Dioscorea opposita Thunb. (DTTP). The influences of 4 extraction methods, namely hot water extraction (W), acidic extraction (HA), hot-compressed water extraction (HCW) and enzyme-assisted extraction (EAE), on the yields, physicochemical properties, hypoglycemic and antioxidant activities of polysaccharides from DTTP were studied and compared. Among these DTTP polysaccharides, DTTP-HA was outstanding in several respects. DTTP-HA was the most water soluble; it had the highest total carbohydrate content (85.08%), the highest uronic acid (13.20%) and the highest thermal stability. DTTP-HA and DTTP-W possessed a triple-helix structure. These 4 kinds of polysaccharides have the same types of monosaccharides, but in different molar percentages. Extraction method had a significant impact on the microstructures of the extracted polysaccharides. DTT-HA exhibited irregular structure with many holes. Among the 4 extracted methods, the DTTP-HA and DTTP-W initially exhibited higher hypoglycemic and antioxidant activities. The better bioactivities of DTTP-HA may be related to the above factors. The findings indicated that acid extraction is an effective method to extract polysaccharides with high biological activities from DTTP.

Two interesting cyathane-type diterpenoids, scabronines G and H, isolated from the fruiting bodies of the basidiomycete, Sarcodon scabrosus (L.: Fr.) Karst, were tested against the bacteria, Staphylococcus aureus, Bacillus thuringiensis, Escherichia coli, Bacillus megaterium and Bacillus subtilis. Both scabronine G and H showed promising activity in vitro against the five bacteria tested at 1 mg/ml and 100 μg/ml. The degree of antibacterial activity of both scabronine G and H was almost the same as streptomycin. Scabronines G and H were also tested against the pathogenic fungi, Gibberella zeae (Schwein.) Petch, Sclerotinia sclerotiorum (Lib.) de Bary, Fusarium moniliforme Sheldon, Fusarium oxysporum Schltdl., Fusarium oxysporum f. sp. vasinfectum, and Fusarium oxysporum f. sp. capsicum. Both scabronines G and H showed promising activity in vitro against G. zeae, S. sclerotiorum, F. moniliforme, F. oxysporum at 1 mg/ml and showed weak activity in vitro against F. oxysporum f. sp. vasinfectum and F. oxysporum f. sp. capsicum at the same concentration.

This review surveys the chemical and biological literature dealing with the isolation, structural elucidation and bioactivity of hericenones and erinacines from the fruiting body and mycelium of Hericium erinaceus, concentrating on work that has appeared in the literature up to December 2009.