[Show abstract][Hide abstract] ABSTRACT: Four new dammarane-type saponins, operculinosides A-D (1-4), were isolated from the aerial parts of Operculina turpethum, of which 1 and 2 are the first two dammarane-type triterpenoids having an oxymethyl group at C-24. Their structures were determined by spectroscopic analysis and acid hydrolysis. The absolute configuration of operculinoside A (1) was confirmed by X-ray crystallography. Compounds 1 and 3 showed significant protective activities against d-galactosamine-induced toxicity in L-02 human hepatic cells.
[Show abstract][Hide abstract] ABSTRACT: 3-Hydroxy-3-methylglutaryl coenzyme A reductase (class II HMGR) could serve as a potential target to discover drugs fighting against the invasive diseases originated from Streptococcus pneumoniae, one of the major causes of bacterial disease in human. However, no strongly effective inhibitors of class II HMGR have been found so far. In the present study, for the first time, four annonaceous acetogenins (ACGs) were explored for the inhibition on S. pneumoniae HMGR. The results showed that the ACGs had higher inhibitory activities against S. pneumoniae HMGR with K(i) values in the range of 6.45-20.49 μM than the statin drug lovastatin (K(i)=116.25 μM), a classical inhibitor of class I HMGR. Then, three-dimensional modeling and docking simulations analyzed the possible binding mode of ACGs to S. pneumoniae HMGR and suggested a kind of novel structural and binding mode for designing promising inhibitor candidates of the targeted enzyme S. pneumoniae II HMGR.
[Show abstract][Hide abstract] ABSTRACT: 3,12-Dihydroxy-cis-3,4-methylenedodecanoic acid 3-O-β-d-glucopyranoside, trivially named litchioside C (1), the first cyclopropyl-containing fatty acid glycoside, was isolated along with three previously uncharacterized galactosylacylglycerols from the seeds of Litchi chinensis. Its structure was established on the basis of spectroscopic analysis including HRESIMS and 2D NMR spectra. Its antioxidant and antibacterial activities were evaluated and its biogenetic pathway was discussed.
[Show abstract][Hide abstract] ABSTRACT: The first stilbene possessing a γ-aminobutyric acid lactam function, artocarpene (1), and a new flavanone, 2-hydroxynaringenin 4'-O-β-d-glucopyranoside (2), were isolated from the stems of Artocarpus nitidus subsp. lingnanensis along with four known compounds, 2-hydroxynaringenin (3), oxyresveratrol (4), 3,4',5-trihydroxy-3'-prenylstilbene (5) and norartocarpetin (6). Their structures were elucidated on the basis of spectroscopic data. Compounds 1 exhibited weak antioxidant activity and 2 displayed weak cytotoxicity against human lung cancer A549 cell line.
[Show abstract][Hide abstract] ABSTRACT: Two new monoterpenoid indole alkaloid derivatives, turpiniside (1) and 11-methoxyjavaniside (2), along with the known alkaloids, vincosamide (3), (3 R)-pumiloside (4), and paratunamide C (5), were isolated from the leaves of Turpinia arguta (Lindl.) Seem. Their structures were determined on the basis of spectroscopic data. Compounds 1 and 3-5 were found to effect relaxation of the supercoiled pBR322 plasmid DNA in the presence of Cu²+.
[Show abstract][Hide abstract] ABSTRACT: Seven flavonoid glycosides, including one new (1) and five previously uncharacterized (3-7), were obtained from the seeds of lychee ( Litchi chinensis Sonn. cv. Heiye) by means of repetitive column chromatography and high-performance liquid chromatography (HPLC) preparation. They were identified as litchioside D (1), (-)-pinocembrin 7-O-neohesperidoside (2), (-)-pinocembrin 7-O-rutinoside (3), taxifolin 4'-O-β-d-glucopyranoside (4), kaempferol 7-O-neohesperidoside (5), tamarixetin 3-O-rutinoside (6), and phlorizin (7) on the basis of spectroscopic analysis and comparison of their data to the values reported in the literatures. Among them, compounds 1, 4, and 5 showed in vitro antitumor activity against A549, LAC, Hep-G2, and HeLa cell lines in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay.
Journal of Agricultural and Food Chemistry 02/2011; 59(4):1205-9. DOI:10.1021/jf104387y · 3.11 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A new isocoumarin, 7-hydroxyl-4-methyl isocoumarine (1), together with three known monoterpenes, (3R, 4R, 6S)-3, 6-dihydroxy-1-menthene (2), (+)-(1R, 3S, 4R, 6S)-6-hydroxymenthol (3) and 4-isopropyl-1-methylcyclohex-2-ene-1, 6-diol (4), was isolated from the methanol extract of Brickellia rosmarinifolia. The structures were determined by spectroscopic means. Compounds 1, 2, 3 and 4 showed antifungal activities against Colletotrichum musae and Peronophythora litchii in vitro.
[Show abstract][Hide abstract] ABSTRACT: Two new sesquiterpene glucosides, litchiosides A (1) and B (2), were obtained along with pumilaside A (3) and funingensin A (4) from lychee (Litchi chinensis Sonn.) seed. Their structures were elucidated on the basis of spectroscopic and chemical evidence. The in vitro antitumour activity of compounds 1–4 against A549, LAC, Hela, and Hep-G2 cell lines was determined using the MTT colourimetric assay. Pumilaside A (3) exhibited significant activity against all the tested cell lines with IC50 values of 0.012–6.29 μM, and funingensin A (4) showed moderate activity against Hep-G2 cells (IC50 = 39.27 μM), while litchiosides A (1) and B (2) were found to be inactive.
[Show abstract][Hide abstract] ABSTRACT: Two new A-type trimeric proanthocyanidins with two doubly bonded interflavanoid linkages, litchitannin A1 [epicatechin-(2β→O→7,4β→6)-epicatechin-(2β→O→7,4β→8)-catechin] (1) and litchitannin A2 [epicatechin-(2β→O→7,4β→6)-epicatechin-(2β→O→7,4β→6)-epicatechin] (2), were isolated from lychee (Litchi chinensis Sonn. cv. Heiye) seeds together with aesculitannin A (3), epicatechin-(2β→O→7,4β→8)-epiafzelechin-(4α→8)-epicatechin (4), proanthocyanidin A1 (5), proanthocyanidin A2 (6), proanthocyanidin A6 (7), epicatechin-(7,8-bc)-4β-(4-hydroxyphenyl)-dihydro-2(3H)-pyranone (8), and epicatechin (9). Their structures were elucidated on the basis of spectroscopic and chemical evidence. It is the first time that compounds 1-4, 7, and 8 have been reported in this species. Compounds 1-9 showed more potent antioxidant activity than L-ascorbic acid with ferric reducing antioxidant power (FRAP) values of 3.71-24.18 mmol/g and IC50 values of 5.25-20.07 μM toward DPPH radicals. Moreover, litchitannin A2 (2) was found to exhibit in vitro antiviral activity against coxsackie virus B3 (CVB3) and compounds 3 and 6 displayed antiherpes simplex virus 1 (HSV-1) activity.
Journal of Agricultural and Food Chemistry 10/2010; 58(22):11667-72. DOI:10.1021/jf1033202 · 3.11 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Sarcandracoumarin (1), the first coumarin having a 1-phenylethyl substituent at the C-3 position, was isolated along with eleven known phenolic compounds from the water extract of Sarcandra glabra. Its structure was elucidated on the basis of spectroscopic data. Compound 1 exhibited moderate or weak cytotoxicity against several tumor cell lines.
[Show abstract][Hide abstract] ABSTRACT: Six new beta-resorcylic acid lactones (1-6), named paecilomycins A-F, and five known compounds, aigilomycin B (7), zeaenol (8), aigialomycin D (9), aigialomycin F (10), and aigialospirol, were isolated from the mycelial solid culture of Paecilomyces sp. SC0924. Their structures were elucidated by extensive NMR analysis, single-crystal X-ray study, and chemical correlations. Compounds 5 and 10 exhibited antiplasmodial activity against Plasmodium falciparum line 3D7 with IC(50) values of 20.0 and 10.9 nM, respectively, and compounds 5-7 showed moderate activity against the P. falciparum line Dd2.
[Show abstract][Hide abstract] ABSTRACT: Further chemical investigation of the whole plants of Gentiana loureirii led to the isolation and characterization of three new compounds, cyclic 4-O-beta-D-glucopyranosylcaffeic acid dimer (1), a new alpha-tetralone, 4-hydroxy-6-methyl-alpha-tetralone 4-O-beta-D-glucopyranoside (2), and 3beta,30-dihydroxy-12-ursen-28-oic acid 28-O-beta-D-glucopyranosyl ester (3), along with five known compounds. To the best of our knowledge, compound 1 is the first cyclic phenolic acid glycoside dimer.
Chemical & pharmaceutical bulletin 04/2010; 58(4):565-7. · 1.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The experiments were performed to extract and purify substrates for polyphenol oxidase (PPO) from pericarp tissue of postharvest litchi fruit. Two purified PPO substrates were identified as (−)-epicatechin and procyanidin A2. The antioxidant properties of two PPO substrates were further evaluated in the present study. Variation in the content of the major substrate (−)-epicatechin of litchi fruit during storage at 25°C was analysed using the HPLC-UV method. The results showed that (−)-epicatechin exhibited stronger antioxidant capability than procyanidin A2, in terms of reducing power and scavenging activities of DPPH radical, hydroxyl radical and superoxide radical. Furthermore, (−)-epicatechin content in pericarp tissue tended to decrease with increasing skin browning index of litchi fruit during storage at 25°C. Thus, these two compounds can be used as potential antioxidants in litchi waste and the fresh pericarp tissue of litchi fruit exhibited a better utilisation value.
[Show abstract][Hide abstract] ABSTRACT: Phytoecdysteroid glucosides, brainesterosides A-E, were isolated from the rhizomes of Brainea insignis along with three known phytoecdysteroids, ponasteroside A, ponasterone A, and 20-hydroxyecdysone. Their structures were elucidated by spectroscopic and chemical means. A possible biogenetic pathway is postulated for these compounds. The chemosystematic significance of ponasterone A is discussed.
[Show abstract][Hide abstract] ABSTRACT: Two new metabolites, 4R*-hydroxy-3,5R*-dimethoxycyclohex-2-enone (1) and 2-hydroxy-N-(2-hydroxyphenyl)propionamide (2), were isolated from solid cultures of the phytopathogen Peronophythora litchii, along with 4-hydroxybenzyl alcohol (3) and methyl D-indole-3-lactate (4). Their structures were elucidated on the basis of spectroscopic and spectrometric data. These metabolites were not toxic to brine shrimps (LC50 > 500 microg/mL).
[Show abstract][Hide abstract] ABSTRACT: Fruits of wampee [Clausena lansium (Lour.) Skeels] contain a significant amount of coumarins with many health benefits. The activity-guided separation of an ethyl acetate-soluble fraction on a polyamide column followed by silica gel column and high performance liquid chromatography (HPLC) preparation afforded a pure compound, which was identified to be 8-hydroxypsoralen based on the 1H, 13C NMR (nuclear magnetic resonance), and ESI-MS (electrospray ionisation mass spectrometric) analysis. This isolate exhibited good scavenging activities against DPPH radical and superoxide anion as well as significant reducing power. It also showed potent proliferation inhibitory activity against human hepatocellular liver carcinoma cell line (HepG2), human lung adenocarcinoma epithelial cell line (A549) and human cervical carcinoma cell line (HELA). This is the first report on the antioxidant and cytotoxic properties of C. lansium fruit extract. The food and pharmaceutical industry could be benefited by the usage of this extract containing this constituent.
[Show abstract][Hide abstract] ABSTRACT: High pressure as a new extraction technique was carried out to extract corilagin from longan fruit pericarp. The effects of different solvents, solvent concentration and solid to liquid ratio on corilagin contents were individually determined. The optimum conditions of high pressure extraction (HPE) for corilagin content were carried out also at various pressures (200–500MPa), time (2.5–30min) and temperatures (30–90°C). The content of corilagin obtained by HPE (9.65mg/g dry matter) was higher than the ultrasonic (7.91mg/g dry matter) or conventional (2.35mg/g dry matter) extraction. Thus, application of HPE obtained higher corilagin content and required less extraction time compared to other extraction methods. The pharmaceutical and food industry can be benefited by the usage of high pressure extraction technology.
[Show abstract][Hide abstract] ABSTRACT: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.