Chemical Constituents & Their Bioactivities Of Two Schisandra Sp. & Two Hydnellums Sp., And Depolymerization Of Cranberry Procyanidins

Mother nature provides us with a huge treasure of bioactive natural products, of which plants and fungi have long been the most important sources due to their abundance and biodiversity. Thus, it is the most effective way to explore active compounds from these two resources. Aimed to seek bioactive leading compounds, the study of chemical components and bioassay of two schisandra plants and two hydnellum fungi were carried out using various purification techniques. The structures were elucidated based on spectral data [MS, 1D-NMR, 2D-NMR (HMQC, 1H-1H COSY, HMBC, and NOESY). Furthermore, based on the notion of cancer prevention by antioxidants, the depolymerization of cranberry procyanindins into oligomeric antioxidants was studied by HPLC-MSn.1. The family Schisandraceae (Illiciales), which is one of the most important medicinal plant resources of China, consists of two genera, Schisandra and Kadsura. There are 60 species around the world while 30 species distribute in China. Phytochemical investigation on S. grandiflora (Wall.) Hook. F. et Thoms. resulted in 28 compounds, among which 23 were structurally identified. There are 11 ursane triterpenes, 5 oleanane triterpenes, 2 lupane tripterpenes and 4 other types of compounds, of which 3 were new compounds. All compounds were isolated from this plant for the first time; Thirty-two compounds were isolated from the stems of S. sphenanthera Rehd. et Wils., of which one identified as a new compound and 23 as known compounds, including 10 lignans, 6 sesquiterpenes, 4 flavonoids, 2 steroids, and 2 monoglycerides. Five of them were reported from this plant for the first time.Brine shrimp assay and anti-plant pathogenic test discovered that 2α,3α-dihydroxyurs-12-en-28-oic acid, corosolic acid, acetylursolic acid, lupeol, schisanbicolorin A, gomisin J, schisantherin A, and the new lignan schisantherin A1 showed marked cytotoxic activity towards brine shrimp larvae, with LC50 of 17.0, 25.8, 25.2, 28.0, 20.2, 52.2, 73.5, and 97.5μg/mL, respectively. Asiatic acid and 2α,3α,19α-trihydroxyurs-12-en-28-oic acid, each with three hydroxyl groups, both had minimum inhibitory concentrations (MIC) of 100, 50, 25 and 25μg/mL against four plant pathogenic bacteria, respectively.2. Chemical investigations on the fruit body of Hydnellum sp. No.1 led to the isolation of eleven compounds, of which one new compound, together with eight known ones, were identified; Another seven known compounds were identified from Hydnellum sp. No.2. The identified compounds from the two species belong to sphingolipid, steroid and phenolic three groups, and 4 comounds were reported for the first time from this genus.3. Purified cranberry procyanidins (CP) using chromatographic methods were depolymerized using (+)-catechin, (-)-epicatechin, or epigallocatechin gallate (EGCG) in 0.1 or 1 M methanolic HCl using different CP-to-flavanol mass ratios. The reaction products were identified as B-type and A-type dimer, trimers and tetramers using HPLC-ESI-MSn. The yield of the oligomers increased when higher amount of flavan-3-ols were used for depolymerization. The yield of B-type oligomers was higher than that of A-type ones. Compared to (+)-catechin, (-)-epicatechin, the use of EGCG as chain breaker led to fewer procyanidin oligomers with new structures.