Article

Diarylheptanoids from Dioscorea villosa (Wild Yam)

UIC/NIH Center for Botanical Dietary Supplements Research, Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago , Chicago, Illinois 60612, United States.
Journal of Natural Products (Impact Factor: 3.95). 12/2012; 75(12). DOI: 10.1021/np300603z
Source: PubMed

ABSTRACT A fractionation methodology aimed at the metabolomic mining of new phytoconstituents for the widely used botanical, wild yam (Dioscorea villosa), makes use of 1D qHNMR and 2D NMR profiles along the preparative fractionation pathway. This quantifiable and structural guidance led to the isolation of 14 diarylheptanoids (1-14), including five new compounds (1-5) with a tetrahydropyrano core skeleton. The structures, including the absolute configurations of both new and previously known diarylheptanoids, were assigned by a combination of HRESIMS, 1D and 2D NMR, (1)H iterative full spin analysis (HiFSA), and Mosher's ester method. The isolation yields were consistent with yields predicted by qHNMR, which confirms the (semi)quantifiable capabilities of NMR-based preparative metabolomic mining. The qHNMR-aided approach enabled the identification of new and potentially significant chemical entities from a small fraction of the plant extract and, thereby, facilitated the characterization of the residual complexity of the D. villosa secondary metabolome. LC-MS profiling of different D. villosa accessions further confirmed that the diarylheptanoids represent genuine secondary metabolites, which can serve as a new class of markers for botanical integrity analysis of D. villosa.

Download full-text

Full-text

Available from: Shao-Nong Chen, Feb 25, 2014
1 Follower
 · 
134 Views
  • Source
    • "Our group recently reported 14 diarylheptanoids [9]. These diarylheptanoids were first isolated and characterized from wild yam based on a new fractionation methodology using 1D qHNMR and 2D NMR profiles along the preparative fractionation pathway [9]. Primary fractionation of the methanolic extract using a MeOH/H 2 O solvent gradient on a preparative C 18 solid phase extraction (SPE) cartridge effectively enriched the diarylheptanoids into three fractions (4–6), which were further purified by VLC, MPLC, and HPLC. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Two groups of lipidated steroid saponins including seven new compounds (2, 3, 5, and 7-10) were isolated from the widely used botanical, wild yam (Dioscorea villosa), employing a fractionation protocol of metabolomic mining. This methodology has very recently led to the isolation of 14 diarylheptanoids from the same plant. Together with these lipidated steroid saponins, they establish additional new markers for Dioscorea villosa. The lipidation of steroids with analogue long-chain fatty acids containing different degrees of unsaturation generates entire series of compounds which are difficult to purify and analyze. The structures of the two series of lipidated steroid saponins (series A and B) were demonstrated by a combination of 1D and 2D NMR as well as GC-MS after chemical modification. Series A was determined to be a mixture of lipidated spirostanol glycosides (1-5), while series B (6-10) proved to be a mixture of five lipidated clionasterol glucosides. The latter group represents the first derivatives of clionasterol to be found in D. villosa. The discovery of this specific structural type of aliphatic esters of steroid saponins expands the characterization of the secondary metabolome of D. villosa. It also may inspire biological studies which take into account the lipophilic character and significantly altered physiochemical characteristics of these otherwise relatively polar phytoconstituents.
    Fitoterapia 08/2013; 91. DOI:10.1016/j.fitote.2013.07.018 · 2.22 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In a continuing search for bioactive constituents from Dioscoreaceae medicinal plants, two new cyclic diarylheptanoids, diosniponol A (1) and B (2), together with 10 known compounds (3-12) were isolated from the rhizomes of Dioscorea nipponica. The structures of these new compounds were determined by spectroscopic analyses, including extensive two-dimensional nuclear magnetic resonance, high-resolution mass spectrometry, and optical rotation. All isolated compounds 1-12 were evaluated for their effects on nitric oxide (NO) production in murine microglia cell line BV-2. Compounds 8 and 11 showed potent inhibitory activities on NO production (IC50 13.36 and 14.36μM, respectively) without cell toxicity in lipopolysaccharide-activated BV-2 cells.
    Bioorganic & medicinal chemistry letters 05/2013; 23(13). DOI:10.1016/j.bmcl.2013.04.073 · 2.33 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Two new diarylheptanoids with a tetrahydropyran ring, kravanhol A (1) and kravanhol B (2), along with one known diarylheptanoid renealtin A (3) were isolated from the fruits of Amomum kravanh. The structures of compounds 1 and 2 were established by analysis of spectroscopic data and their absolute configurations were determined by Mosher's method and CD experiments. Compound 2 showed inhibitory effect on nitric oxide production in lipopolysaccharide-activated RAW264.7 macrophages with an IC50 value of 38.9 ± 1.8 μM.
    Phytochemistry Letters 08/2013; 6(3):403–406. DOI:10.1016/j.phytol.2013.05.004 · 1.54 Impact Factor
Show more