ABSTRACT
ABSTRACT Thirteen pentacyclic triterpenes, methyl 3-oxours-12-en-23-oate, marsformosanone, taraxerone, β-amyrenone, α-amyrenone, lupenone, 24-methylencycloartan-3-one, moretenol acetate, β-amyrin acetate, germanicol acetate, 24-methylencycloartanyl acetate, β-amyrin, and α-amyrin were identified in a chloroform-methanol propolis extract from Melipona beecheii. Additionally, were identified in this propolis, hexadecanoic acid, methyl ester, octadecanoic acid, methyl ester and 1-triacontanol. The purification of the propolis extract was carried out using different chromatographic techniques, including vacuum liquid chromatography, gravity column chromatography and gel filtration chromatography Sephadex LH-20. The identification of the metabolites was performed using mass spectrometry.
ABSTRACT
Objective: To study the chemical constituents of the whole herbs of Sargassum fusiforme. Methods: The chemical constituents from S. fusiforme were separated and purified by silica gel, MCI, ODS, Sephadex LH-20 gel column chromatographies, and preparative HPLC. Their structures were identified by analysis of NMR, MS, ORD, etc, and comparing physicochemical properties of compounds with references. Results: A total of 19 compounds were obtained from the 50% ethanol-H2O extract of S. fusiforme, and their structures were determined as lupenone (1), bauerenone (2), β-amyrenone (3), α-amyrenone (4), loliolide (5), isololiolide (6), (3S,5R,6S,7E)-5,6-epoxy-3-hydroxy-7-megastigmen-9-one (7), (R)-dehydrovomifoliol (8), 24-ethylcholesta-4,24 (28)-dien-3-one (9), fucosterol (10), 29-hydroperoxystigmasta-5,24 (28)-dien-3β-ol (11), 24-hydroperoxy-24-vinylcholesterol (12), saringosterol (13), (24R)-5,28-stigmastadiene-3β,24-diol-7-one (14), dihydroquercetin (15), aurantiamide acetate (16), dibutyl phthalate (17), glycerol monopalmitate (18), and methyl hexadecanoate (19). Conclusion: The compounds isolated from S. fusiforme were mainly identified as triterpenoids, sesquiterpenoids, highly oxidized sterols, alkaloids and so on. Compounds 1-4, 7-8 and 14-19 are isolated from S. fusiforme for the first time.
ABSTRACT
Objective To discover lead lupane triterpenoid's potential isolated from Pueraria lobata roots against β-site amyloid precursor protein cleaving enzyme 1 (BACE1), which serve as a rate limiting step in amyloid beta (Aβ) production altering the course of Alzheimer's disease. In addition, enzyme kinetics study and molecular docking were conducted to establish the inhibition type and structure activity relationship. Methods A systematic study of 70% ethanolic P. lobata root extract was employed to identify its BACE1 inhibitory potential. Further, BACE1 inhibitory potential of two lupane terpenoids, yielded from ethanolic extract, was assessed. In order to determine their inhibition mode, Lineweaver–Burk plots and Michaelis–Menten model for BACE1 was performed. AutoDock 4.2 program in addition determined the molecular interaction of BACE1 with isolated terpenoids. Results Considering the inhibitory potential of 70% ethanolic extract of P. lobata against BACE1 (IC
ABSTRACT
Objective: To isolate and identify the chemical constituents of petroleum ether soluble part of 60% aq. ethanol extracts from the whole herb of Mulgedium tataricum. Methods: Separation and purification were performed on silica gel column chromatography and recrystallization, PTLC, PHPLC, and related techniques. Their chemical structures were elucidated through spectroscopic analyses (NMR). Results: Nine compounds were isolated and identified as taraxasterol (1), pseudotaraxasterol (2), lupeol (3), olean-18-en-3β-ol (4), β-sitosterol (5), olean-18-en-3-one (6), 3β-hydroxy-taraxaster-20(30)-ene-28-oic acid (7), stigmasterol (8), and lupenone (9), respectively. Conclusion: Compounds 3, 4, 6, 7, and 9 are separated from this plant for the first time.
ABSTRACT
OBJECTIVE@#To discover lead lupane triterpenoid's potential isolated from Pueraria lobata roots against β-site amyloid precursor protein cleaving enzyme 1 (BACE1), which serve as a rate limiting step in amyloid beta (Aβ) production altering the course of Alzheimer's disease. In addition, enzyme kinetics study and molecular docking were conducted to establish the inhibition type and structure activity relationship.@*METHODS@#A systematic study of 70% ethanolic P. lobata root extract was employed to identify its BACE1 inhibitory potential. Further, BACE1 inhibitory potential of two lupane terpenoids, yielded from ethanolic extract, was assessed. In order to determine their inhibition mode, Lineweaver-Burk plots and Michaelis-Menten model for BACE1 was performed. AutoDock 4.2 program in addition determined the molecular interaction of BACE1 with isolated terpenoids.@*RESULTS@#Considering the inhibitory potential of 70% ethanolic extract of P. lobata against BACE1 (IC = 80.35 μg/mL), lupeol and lupenone were subsequently isolated and exhibited notable or moderate BACE1 inhibitory activity with IC values of 5.12 and 62.98 μmol/L, respectively, as compared to the positive control quercetin (IC = 21.28 μmol/L). The enzyme kinetics study enabled us to identify both compounds as competitive inhibitors, where lupeol displayed a very potent inhibition against BACE1 with low inhibition constant (K) value of 1.43 μmol/L, signifying greater binding affinity. In order to understand the binding mechanism and structure-activity relationship of two triterpene-based BACE1 inhibitors, we employed computer aided docking studies which evidently revealed that hydroxyl group of lupeol formed two hydrogen bonds with the ASP32 (catalytic aspartic residue) and SER35 residues of BACE1 with the binding energy of (-8.2 kcal/mol), while the ketone group of lupenone did not form any hydrogen bonds with BACE1 giving evidence for less binding affinity. These results in turn have predicted the dependence of the inhibitory activity in the presence of hydroxyl group which has provided a new basis for BACE1 blockade.@*CONCLUSIONS@#Our results have successfully explored the molecular mechanism of lupane triterpenoids via BACE1 inhibition, suggesting that lupeol in particular could be utilized as a useful therapeutic and preventive agent to mitigate Alzheimer's disease.
ABSTRACT
Abstract A phytochemical investigation of methanol and n-hexane extracts of tuber/roots of Corynaea crassa Hook. f., Balanophoraceae, led to the isolation and characterization of β-sitosterol, lupenone, β-amyrone, lupeol, and β-amyrine. Unusual complex 1:1 mixtures of lupenone/β-amyrone and lupeol/β-amyrine obtained from the extracts were identified by NMR and HR-MS experiments. The structure of the 1:1 lupenone/β-amyrone mixture was confirmed by X-ray analysis. These triterpene ketone derivatives, only distinguished either by 5- or 6-membered E ring, co-crystallize in one common unit cell in the solid state.
ABSTRACT
Objective: To investigate the chemical constituents from the pods of Glycine max. Methods: The chemical constituents were isolated by repeated silica gel chromatography, Sephadex LH-20 gel column chromatography, medium pressure column chromatography, and semi-preparative liquid chromatography. Their structures were elucidated by chemical properties and spectroscopic analyses. Results: Fourteen compounds were identified to be 4,4'-diphenylmethane-bis (ethyl) carbamates (1), 2,6-dimethoxy-1,4-benzoquinone (2), (+)-medioresinol (3), taraxerone (4), lupenone (5), 7,3',4'-trihydroxyflavone (6), coumestrol (7), indole-3-carboxylic acid (8), apigenin (9), phaseol (10), 7,4'-dihydroxyflavone (11), stigmasterol (12), β-sitosterol (13), and β-daucosterol (14). Conclusion: Compounds 1-5 are obtained from the pods of G. max for the first time, and compound 6 is obtained from this plant for the first time.
ABSTRACT
BACKGROUND: Adenophora triphylla var. japonica is empirically used for controlling airway inflammatory diseases in folk medicine. We evaluated the gene expression and production of mucin from airway epithelial cells in response to lupenone, lupeol and taraxerol derived from Adenophora triphylla var. japonica. METHODS: Confluent NCI-H292 cells were pretreated with lupenone, lupeol or taraxerol for 30 minutes and then stimulated with tumor necrosis factor alpha (TNF-alpha) for 24 hours. The MUC5AC mucin gene expression and production were measured by reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. Additionally, we examined whether lupenone, lupeol or taraxerol affects MUC5AC mucin production induced by epidermal growth factor (EGF) and phorbol 12-myristate 13-acetate (PMA), the other 2 stimulators of airway mucin production. RESULTS: Lupenone, lupeol, and taraxerol inhibited the gene expression and production of MUC5AC mucin induced by TNF-alpha from NCI-H292 cells, respectively. The 3 compounds inhibited the EGF or PMA-induced production of MUC5AC mucin in NCI-H292 cells. CONCLUSION: These results indicated that lupenone, lupeol and taraxerol derived from Adenophora triphylla var. japonica regulates the production and gene expression of mucin, by directly acting on airway epithelial cells. In addition, the results partly explain the mechanism of of Adenophora triphylla var. japonica as a traditional remedy for diverse inflammatory pulmonary diseases.
Subject(s)
Campanulaceae , Enzyme-Linked Immunosorbent Assay , Epidermal Growth Factor , Epithelial Cells , Gene Expression , Lung Diseases , Medicine, Traditional , Methods , Mucins , Tumor Necrosis Factor-alphaABSTRACT
Many phenolic compounds such as xanthones, quinones and coumarins have been isolated from Kielmeyera species; however the presence of flavonoids have been showed in other genera in the Calophylleae tribe as Caraipa, Mesua and Calophyllum. Six known glycosidic flavonoids: quercetin 3-β-O-galactopyranoside (1), quercetin 3-β-O-glucopyranoside (2), quercetin 3-O-α-rhamnoside (3), luteolin 6-C-β-glucopyranoside (4), isovitexin (5), kaempferol 3-O-α-rhamnoside (6) and one triterpene, lupenone (7) were isolated, for the first time, from organic crude extract of Kielmeyera variabilis Mart. & Zucc., Calophyllaceae, leaves. The crude organic extract from K. variabilis leaves exhibited 95% of leishmanidal activity at 20 µg/mL on amastigote-like form of Leishmania (Leishmania) amazonensis in vitro model and only compound 3 showed 40-45% of growth inhibition at concentration ranging from 0.78 to 20 µg/mL. In addition, quercetin 3-O-α-rhamnoside (quercitrin) was found to be the major metabolite. Our results and previous reports suggest that synergistic effects of flavonoid glycosides are the cause of significant leishmanidal activity of the crude organic extract from K. variabilis leaves.