Batatasin I

Development of an on-line immobilized alpha-glucosidase microreactor coupled to liquid chromatography for screening of alpha-glucosidase inhibitors.[Pubmed:31874312]

J Pharm Biomed Anal. 2020 Feb 20;180:113047.

In order to rapidly screen alpha-glucosidase (alpha-GLU) inhibitors from Chinese herbs extract, an online screening method was developed by using enzymatic microreactors in combination with HPLC. A type of dodecahedral and porous material (ZIF-90) was synthesized at room temperature and employed as supports to construct enzymatic microreactor. The amount of alpha-glucosidase immobilized on ZIF-90 was 58.65mug per mg carrier under the optimized conditions. In the online screening process, the eluent of 30s was selected for detection. For the application of this on-line screening system, three alpha-glucosidase inhibitors with known structure (2,4-dimethoxy-6,7-dihydroxyphenanthrene, Batatasin I, 3,5-dimethoxy-2'-hydroxyaiaryl) were selectively extracted from Dioscorea opposita Thunb. Three compounds screened from honeysuckle leaves were isochlorogenic acid B, 1,5-dicaffeoylquinic acid and isochlorogenic acid C, respectively. Two compounds including (+)-catechin and (-)-epigallocatechin gallate were screened from Xinyang Maojian tea. Three unknown ingredients were also screened out from Radix Rehmanniae Praeparata. The nanomaterials in the microreactor can be conveniently replaced. The screening flow rate and elution time can be easily adjusted and controlled by microinjection pump. Considering the specificity of enzyme binding and convenience of online screening system, this method has great potential for fast real-time fishing of alpha-glucosidase inhibitors from Chinese herbal medicines.

NMR-based metabolomics approach to investigate the distribution characteristics of metabolites in Dioscorea opposita Thunb. cv. Tiegun.[Pubmed:31260979]

Food Chem. 2019 Nov 15;298:125063.

Dioscorea opposita Thunb. cv. Tiegun (DTT), a type of homologous medicinal plant, is commonly used as food in daily life. However, there has always been confusion regarding removal of the peel, as the nutrient metabolite composition of the peel is unclear. Here, a nuclear magnetic resonance (NMR)-based metabolomics approach was used to determine the metabolite distribution in DTT exclude-peel and peel. Thirteen characteristic metabolites with statistical significance were identified and compared using multivariate, univariate and cluster analyses. The results demonstrated that the peel contained the higher levels of alpha-glucose, Batatasin IV, Batatasin I, asparagine, beta-glucose, protodioscin, threonine, protogracillin, dioscin, and beta-sitosteryl acetate, and the samples without the peel had the higher levels of leucine, glutamine and alanine. This study provided scientific data for understanding the distribution characteristics of metabolites in DTT samples, promoting reasonable consumption of DTT.

Rapidly screening of alpha-glucosidase inhibitors from Dioscorea opposita Thunb. peel based on rGO@Fe3O4 nanocomposites microreactor.[Pubmed:30231779]

J Enzyme Inhib Med Chem. 2018 Dec;33(1):1335-1342.

Present study aimed to immobilise the alpha-glucosidase on suitable supports to construct enzymatic microreactors and their subsequent applicability in efficient inhibitor screening from the Chinese Yam (Dioscorea opposita Thunb.) peel. A type of lamellar and porous composites (rGO@Fe3O4) were synthesised with a facile one-step solvothermal method and employed as carriers to construct enzymatic microreactors for screening alpha-glucosidase ligand from the Chinese Yam peel in league with the high performance liquid chromatography and mass spectrometry (HPLC-MS). The immobilisation amount of alpha-glucosidase on rGO@Fe3O4 under the optimised conditions was about 40 mug alpha-glucosidase/mg carriers. Furthermore, the binding capacities of screened inhibitors, 2,4-dimethoxy-6,7-dihydroxyphenanthrene and Batatasin I, were 35.6 and 68.2%, respectively. Hence, considering their high screening efficiency and excellent magnetic separation ability, these as-prepared nanocomposite consisting of rGO and Fe3O4 may be potential supports for the enzyme (such as alpha-glucosidase) immobilisation for rapid alpha-glucosidase inhibitors screening from the diverse nature resources.

Rapid identification of alpha-glucosidase inhibitors from Dioscorea opposita Thunb peel extract by enzyme functionalized Fe3O4 magnetic nanoparticles coupled with HPLC-MS/MS.[Pubmed:28809420]

Food Funct. 2017 Sep 20;8(9):3219-3227.

Dioscorea opposita Thunb, commonly known as "yam" that has a long dietary therapy history for diabetes, is widely consumed as a botanical dietary supplement and widely cultivated in China. In this work, a method for rapid screening of alpha-glucosidase inhibitors from Dioscorea opposita Thunb peel extract was developed using alpha-glucosidase functionalized magnetic nanoparticles (alphaG-MNPs) as a solid phase extraction absorbent in combination with high performance liquid chromatography-mass spectrometry (HPLC-MS). Two alpha-glucosidase inhibitors were selectively extracted and identified as Batatasin I and 2,4-dimethoxy-6,7-dihydroxyphenanthrene. Their alpha-glucosidase inhibitory activities (IC50 = 2.55 mM and 0.40 mM, respectively) were significantly higher than that of acarbose (as control). Taking advantage of the specificity in enzyme binding and the convenience of magnetic separation, this method has great potential for rapid and fast screening of alpha-glucosidase inhibitors from complex natural resources.

Anti-adipogenic constituents from Dioscorea opposita in 3T3-L1 cells.[Pubmed:25273391]

Biol Pharm Bull. 2014;37(10):1683-8.

We previously reported the lipase inhibitory activity of the n-BuOH fraction of Dioscorea opposita (DOB) and its isolates. This study sought to evaluate their anti-adipogenic activity in terms of their effects on the adipogenic transcription factors peroxisome proliferator-activated receptor gamma (PPARgamma) and CCAAT/enhancer binding protein alpha (C/EBPalpha) as well as phosphorylated AMP-activated protein kinase (p-AMPK) and carnitine palmitoyl transferase-1 (CPT-1). DOB apparently attenuated 3T3-L1 adipocyte differentiation (33.6% decrease at 20 microg/mL). In addition, a marked decrease (90.4%) in the expression of PPARgamma was observed in the DOB-treated 3T3-L1 cells. Four isolates from DOB: (4E,6E)-1,7-bis(4-hydroxyphenyl)-4,6-heptadien-3-one (1), (3R,5R)-1,7-bis(4-hydroxy-3-methoxyphenyl)-3,5-heptanediol (2), Batatasin I (3), and (1E,4E,6E)-1,7-bis(4-hydroxyphenyl)-1,4,6-heptatrien-3-one (4), suppressed adipocyte differentiation by inhibiting PPARgamma at 20 microM (85.9%, 68.6%, 76.2%, and 90.2% decrease, respectively) and C/EBPalpha (51.7%, 3.1%, 20.9%, and 59.8% decrease, respectively). Batatasin I was found to increase p-AMPK and CPT-1 at a concentration of 20 microM in 3T3-L1 adipocytes, resulting in inhibiting adipogenesis. Taken together, Batatasin I might be responsible for the anti-adipogenic effect of DOB via inhibition of PPARgamma and C/EBPalpha and activation of p-AMPK and CPT-1.

Batatasin I, a naturally occurring phenanthrene derivative, isolated from tuberous roots of Dioscorea batatas suppresses eicosanoids generation and degranulation in bone marrow derived-mast cells.[Pubmed:21720007]

Biol Pharm Bull. 2011;34(7):1021-5.

To find anti-inflammatory compounds from the tuberous roots of Dioscorea batatas, we isolated 6-hydroxy-2,4,7-trimethoxyphenanthrene (Batatasin I) from the dichloromethane (CH(2)Cl(2)) fraction of this plant. Batatasin I inhibited both the generation of prostaglandin D(2) (PGD(2)), leukotriene C(4) (LTC(4)) and degranulation reaction in mouse bone marrow-derived mast cells (BMMCs). This compound inhibited cyclooxygenase-2 (COX-2) dependent PGD(2) generation in a dose dependent manner, with IC(50) values of 1.78 microM. Western blotting probed with specific anti-COX-2 antibodies showed that the decrease in the quantity of the PGD(2) generation was accompanied by a decrease in the COX-2 protein level. In addition, this compound also inhibited the production of 5-lipoxygenase (5-LOX) dependent LTC(4) in a dose dependent manner (IC(50), 1.56 microM). Batatasin I also inhibited the mast cell degranulation reaction (IC(50), 6.7 microM) in BMMCs. This result indicates that Batatasin I could be developed as an anti-inflammatory agent through further investigation.

Inhibition of photosynthesis and respiration by batatasins.[Pubmed:24414012]

Planta. 1978 Jan;138(2):167-72.

Effects of batatasins I, III and V, phenolic growth inhibitors occuring in dormant bulbils of Dioscorea batatas Decne., on photosynthetic reactions of chloroplasts from spinach (Spinacia oleracea L.) and on respiration of mitochondria from potatoes (Solanum tuberosum L.) were investigated. In chloroplasts, the batatasins effectively inhibited CO2-dependent oxygen evolution and electron flow from water to acceptors such as dichlorophenolindophenol, ferricyanide and methylviologen. Photosystem-I dependent electron transport from ascorbate to oxygen was stimulated. The proton conductivity of thylakoid membranes was increased and phosphorylation was uncoupled from electron transport. Inhibition of electron transport with water as electron donor appeared to precede uncoupling. In mitochondrial, Batatasin I did not much inhibit succinate-dependent O2 uptake in the absence of ADP, but caused strong inhibition in the presence of ADP. Batatasins III and V inhibited oxygen uptake irrespective of the presence or absence of ADP. Inhibition of chloroplast and mitochondrial reactions by batatasins was shown to be reversible.