Impact of alkyl esters of caffeic and ferulic acids on tumor cell proliferation, cyclooxygenase enzyme, and lipid peroxidation

The antioxidant ferulic and caffeic acid phenolics are ubiquitous in plants and abundant in fruits and vegetables. We have synthesized a series of ferulic and caffeic acid esters and tested for tumor cell proliferation, cyclooxygenase enzymes (COX-1 and -2) and lipid peroxidation inhibitory activities in vitro. In the tumor cell proliferation assay, some of these esters showed excellent growth inhibition of colon cancer cells. Among the phenolics esters assayed, compounds 10 (C12-caffeate), 11 (C16-caffeate), 21 (C8-ferulate), and 23 (C12-ferulate) showed strong growth inhibition with IC50 values of 16.55, 13.46, 18.67, and 7.57 microg/mL in a breast cancer cell line; 9.65, 7.45, 17.05, and 4.35 microg/ mL in a lung cancer cell line; 5.78, 3.5, 4.29, and 2.46 microg/mL in a colon cancer cell line; 12.04, 12.21, 14.63, and 8.09 microg/ mL in a central nervous system cancer cell line; and 8.62, 7.76, 11.0, and 5.37 in a gastric cancer cell line. In COX enzyme inhibitory assays, ferulic and caffeic acid esters significantly inhibited both COX-1 and COX-2 enzymes. Caffeates 5-10 (C4-C12), inhibited COX-1 enzyme between 50% and 90% and COX-2 enzyme by about 70%, whereas ferulates 15-21 (C3-C8) inhibited COX-1 and COX-2 enzymes by 85-95% 25 microg/mL. Long-chain caffeates 11-14 (C16-C22) and short-chain ferulates 15-20 (C3-C5) were the most active in lipid peroxidation inhibition and showed 60-70% activity at 5 microg/mL concentration.     

Insulin secretion and cyclooxygenase enzyme inhibition by cabernet sauvignon grape skin compounds

Bioassay-guided isolation and purification of hexane and ethyl acetate extracts of Cabernet Sauvignon grape skin yielded nine compounds (1-9), which were identified as beta-sitosterol-6'-linolenoyl-3-O-beta-D-glucopyranoside (1), beta-sitosterol (2), beta-sitosterol-3-O-beta-D-glucoside (3), oleanolic acid (4), oleanolic aldehyde (5), resveratrol (6), (+)-epsilon-viniferin (7), (-)-catechin (8), and 1-triacontanol (9). The structures of these compounds were established by spectroscopic methods. The compounds were assayed for insulin production using an INS-1 cell assay. In a dose-response study, compound 4 stimulated insulin production of INS-1 cells by 20.23, 87.97, 1.13, and 6.38 ng of insulin/mg of protein at 6.25, 12.5, 25, and 50 microg/mL, respectively. This trend was similar to the dose-dependent insulin production of INS-1 cells by glucose. Compound 5 also showed a dose-dependent insulin production in this assay. The isolated compounds were also assayed for cyclooxygenase-1 and -2 (COX) enzyme inhibitory activities. At 100 microg/mL, compounds 2, 3, and 4 inhibited the COX-2 enzyme by 11, 12, and 10%, respectively, but did not show activities on the COX-1 enzyme. Compounds 6, 7, and 8 at 100 microg/mL inhibited the COX-1 enzyme by 98, 99, and 98%, respectively, and the COX-2 enzyme by 0, 47, and 72%, respectively. This is the first report of beta-sitosterol-6'-linolenoyl-3-O-beta-D-glucopyranoside (1) from grape skin and insulin secretion activities of compounds 4 and 5.     

Tumor cell proliferation and cyclooxygenase enzyme inhibitory compounds in Amaranthus tricolor

Amaranthus tricolor is consumed as a vegetable in Asia. Bioassay-directed isolation of leaves and stems of A. tricolor yielded three galactosyl diacylglycerols (1-3) with potent cyclooxygenase and human tumor cell growth inhibitory activities. The purified compounds were characterized by spectroscopic methods. In addition, the fatty acid moieties in diacyl galactosyl glyerols were characterized by GC-MS analyses. The galactosyl diacylglycerols 1-3 inhibited the cyclooxygenase-1 (COX-1) enzyme by 78, 63, and 93% and the cyclooxygenase-2 (COX-2) enzyme by 87, 74, and 95%, respectively. These compounds were tested for antiproliferative activity using human AGS (gastric), CNS (central nervous system; SF-268), HCT-116 (colon), NCI-H460 (lung), and MCF-7 (breast) cancer cell lines. Compound 1 inhibited the growth of AGS, SF-268, HCT-116, NCI-H460, and MCF-7 tumor cell lines with IC50 values of 49.1, 71.8, 42.8, 62.5, and 39.2 mug/mL, respectively. For AGS, HCT-116, and MCF-7 tumor cell lines, the IC50 values of compounds 2 and 3 were 74.3, 71.3, and 58.7 microg/mL and 83.4, 73.1, and 85.4, respectively. This is the first report of the COX enzyme inhibitory activity for galactosyl glycerols and antiproliferative activities against human colon, breast, lung, stomach, and CNS tumor cell lines.     

Cyclooxygenase inhibitory and antioxidant compounds from the mycelia of the edible mushroom Grifola frondosa

The bioassay-guided isolation and purification of the hexane extract of the cultured mycelia of Grifola frondosa led to the characterization of a fatty acid fraction and three compounds, ergosterol (1), ergostra-4,6,8(14),22-tetraen-3-one (2), and 1-oleoyl-2-linoleoyl-3-palmitoylglycerol (3). The composition of fatty acid fraction was confirmed as palmitic, oleic, and linoleic acids by GC-MS and by comparison with the retention values of authentic samples. The structures of compounds 1-3 were established by spectroscopic methods. The fatty acid fraction and compounds 1-3 showed cyclooxygenase (COX) enzyme inhibitory and antioxidant activities. The inhibition of COX-1 enzyme by the fatty acid fraction and compounds 1-3 at 250 microg/mL were 98, 37, 55, and 67%, respectively. Similarly, COX-2 enzyme activity was reduced by fatty acid fraction and compounds 1-3 at 250 microg/mL by 99, 37, 70, and 4%, respectively. The inhibitions of liposome peroxidation by the fatty acid fraction and compounds 1 and 2 at 100 microg/mL were 79, 48, and 42%, respectively. This is the first report of compounds 2 and 3 from the cultured mycelia of G. frondosa. The COX inhibitory activities of compounds 1-3 are reported here for the first time.     

Bioactive compounds and 1,3-Di[(cis)-9-octadecenoyl]-2-[(cis,cis)-9, 12-octadecadienoyl]glycerol from Apium graveolens L. seeds

Bioassay-directed isolation and purification of the hexane extract of Apium graveolens L. seeds led to the characterization of three compounds: beta-selinene (1), 3-n-butyl-4,5-dihydrophthalide (2) and 5-allyl-2-methoxyphenol (3). The structures of these compounds were established by using (1)H and (13)C NMR spectral methods. Compounds, 1-3 demonstrated 100% mortality on fourth-instar Aedes aegyptii larvae at 50, 25, and 200 microg mL(-)(1), respectively, in 24 h. Also, 2 inhibited the growth of Candida albicans and Candida kruseii at 100 microg mL(-)(1). It inhibited both topoisomerase-I and -II enzyme activities at 100 microg mL(-)(1). Compound 2 displayed 100% mortality at 12.5 and 50 microg mL(-)(1), respectively, when tested on nematodes, Panagrellus redivivus and Caenorhabditis elegans. The triglyceride, 1,3-di[(cis)-9-octadecenoyl]-2-[(cis,cis)-9, 12-octadecadienoyl]glycerol (4) and 3 were isolated for the first time from A. graveolens seeds, although 4 was not biologically active.     

Isolation and identification of strawberry phenolics with antioxidant and human cancer cell antiproliferative properties

Studies suggest that consumption of berry fruits, including strawberries ( Fragaria x ananassa Duch.), may have beneficial effects against oxidative stress mediated diseases such as cancer. Berries contain multiple phenolic compounds, which are thought to contribute to their biological properties. Comprehensive profiling of phenolics from strawberries was previously reported using high-performance liquid chromatography with mass spectrometry (HPLC-MS) detection. The current study reports the isolation and structural characterization of 10 phenolic compounds from strawberry extracts using a combination of Amberlite XAD16-resin and C18 columns, HPLC-UV, and nuclear magnetic resonance (NMR) spectroscopy methods. The phenolics were cyanidin-3-glucoside ( 1), pelargonidin (2), pelargonidin-3-glucoside (3), pelargonidin-3-rutinoside (4), kaempferol (5), quercetin (6), kaempferol-3-(6'-coumaroyl)glucoside) (7), 3,4,5-trihydroxyphenyl-acrylic acid (8), glucose ester of ( E)- p-coumaric acid (9), and ellagic acid . Strawberry crude extracts and purified compounds 1- 10 were evaluated for antioxidant and human cancer cell antiproliferative activities by the Trolox equivalent antioxidant capacity (TEAC) and luminescent ATP cell viability assays, respectively. Among the pure compounds, the anthocyanins 1 (7156 microM Trolox/mg), 2 (4922 microM Trolox/mg), and 4 (5514 microM Trolox/mg) were the most potent antioxidants. Crude extracts (250 microg/mL) and pure compounds (100 microg/mL) inhibited the growth of human oral (CAL-27, KB), colon (HT29, HCT-116), and prostate (LNCaP, DU145) cancer cells with different sensitivities observed between cell lines. This study adds to the growing body of data supporting the bioactivities of berry fruit phenolics and their potential impact on human health.     

Comparison of isothiocyanate yield from wasabi rhizome tissues grown in soil or water

The isothiocyanate (ITC) yield of wasabi, the Japanese horseradish (Wasabi japonica), was measured on its release from glucosinolates in the rhizomes of plants grown in two traditional ways. Mature plants of 18 months old were harvested from two different commercial farms located in the South Island of New Zealand. At one farm, the plants were grown in raised soil beds, while the plants at the other farm were grown in gravel irrigated by river water. Following harvest, the rhizomes from each growth medium were divided into five size groups based on the weight and length of the rhizomes. The different sized rhizomes were also subdivided into proximal, medial, and distal portions of the rhizomes and each portion was further subdivided into epidermis plus cortex, and vascular plus pith. The individual and total ITC contents of each portion (proximal, medial, and distal) of the rhizomes were measured using dichloromethane extraction followed by the GC-FPD. The total ITC content of the rhizomes grown in soil increased (13 times) linearly from 6 to 114 g of rhizome weight, while the mean ITC content of the water-grown wasabi increased (10 times) nonlinearly for similar sized rhizomes. Water-grown rhizomes in the weight range from 18 to 45 g gave significantly (P = 0.030) higher total ITC (1-2 times) than similarly sized soil-grown rhizomes. Analysis of the tissues showed that the total and the individual ITCs were found in significantly higher levels (73 and 64%, respectively) in the skin and cortex tissue compared to the vascular and pith tissues. Analysis of the ITC content of the different locations of the wasabi rhizome showed that the distal portion of the rhizome contained significantly higher levels of both total and individual ITCs compared to the medial and proximal portions of the rhizome.     

Novel compounds from Piper methysticum Forst (Kava Kava) roots and their effect on cyclooxygenase enzyme

Milled Piper methysticum roots were extracted sequentially with hot water and methanol. Cyclooxygenase (COX) enzyme inhibitory assay directed purification of the methanol extract yielded bornyl esters of 3,4-methylenedioxy cinnamic acid (1) and cinnamic acid (2), pinostrobin (3), flavokawain B (4), and 5,7-dimethoxyflavanone (5). The structures of compounds 1-5 were accomplished by spectral experiments. The aqueous extract contained previously reported kava lactones, as confirmed by TLC analysis. Compounds 3 and 5 were isolated for the first time from kava kava roots. Compound 4 showed the highest COX-I inhibitory activity at 100 microg/mL. All the compounds tested gave good COX-I and moderate COX-II enzyme inhibitory activities at 100 microg/mL. This is the first report of COX-I and -II inhibitory activities for compounds 1-5.     

Glycoalkaloids and metabolites inhibit the growth of human colon (HT29) and liver (HepG2) cancer cells

As part of an effort to improve plant-derived foods such as potatoes, eggplants, and tomatoes, the antiproliferative activities against human colon (HT29) and liver (HepG2) cancer cells of a series of structurally related individual compounds were examined using a microculture tetrazolium (MTT) assay. The objective was to assess the roles of the carbohydrate side chain and aglycon part of Solanum glycosides in influencing inhibitory activities of these compounds. Evaluations were carried out with four concentrations each (0.1, 1, 10, and 100 microg/mL) of the the potato trisaccharide glycoalkaloids alpha-chaconine and alpha-solanine; the disaccharides beta(1)-chaconine, beta(2)-chaconine, and beta(2)-solanine; the monosaccharide gamma-chaconine and their common aglycon solanidine; the tetrasaccharide potato glycoalkaloid dehydrocommersonine; the potato aglycon demissidine; the tetrasaccharide tomato glycoalkaloid alpha-tomatine, the trisaccharide beta(1)-tomatine, the disaccharide gamma-tomatine, the monosaccharide delta-tomatine, and their common aglycon tomatidine; the eggplant glycoalkaloids solamargine and solasonine and their common aglycon solasodine; and the nonsteroidal alkaloid jervine. All compounds were active in the assay, with the glycoalkaloids being the most active and the hydrolysis products less so. The effectiveness against the liver cells was greater than against the colon cells. Potencies of alpha-tomatine and alpha-chaconine at a concentration of 1 microg/mL against the liver carcinoma cells were higher than those observed with the anticancer drugs doxorubicin and camptothecin. Because alpha-chaconine, alpha-solanine, and alpha-tomatine also inhibited normal human liver HeLa (Chang) cells, safety considerations should guide the use of these compounds as preventative or therapeutic treatments against carcinomas.     

In vitro anti-inflammatory and anti-proliferative activity of sulfolipids from the red alga Porphyridium cruentum

A sulfoglycolipidic fraction (SF) isolated from the red microalga Porphyridium cruentum was analyzed for fatty acid composition and assayed for ability to inhibit, in vitro, the generation of superoxide anion in primed leucocytes and the proliferation of a panel of human cancer cell-lines. Results demonstrated that SF contained large amounts of palmitic acid (26.1%), arachidonic acid (C20: 4 omega-6, 36.8%), and eicopentaenoic (C20:5 omega-3, 16.6%) acids, and noticeable amounts of 16:1n-9 fatty acid (10.5%). It strongly inhibited both the production of superoxide anion generated by peritoneal leukocytes primed with phorbol myristate acetate (IC(50): 29.5 microg/mL), and the growth of human colon adenocarcinoma DLD-1 and to a lesser extent of human breast adenocarcinoma MCF-7, human prostate adenocarcinoma PC-3, and human malignant melanoma M4 Beu cell-lines, and therefore might have a chemopreventive or chemotherapeutic potential, or both. It was found markedly more cytotoxic than sulfoquinovosyldiacylglycerols from plant used as a standard (STD), due to a stronger ability to inhibit DNA alpha-polymerase (IC(50): 378 microg/mL, vs 1784 microg/mL for STD). After a 48-h continuous treatment, IC(50) values for growth inhibition were in the range of 20-46 microg/mL instead of 94 to >250 microg/mL for STD, and those for inhibition of metabolic activity were in the range of 34-87 microg/mL instead of >250 microg/mL for STD. The higher anti-proliferative effect was observed on colon adenocarcinoma DLD-1 cells, and the weaker effect was observed on breast adenocarcinoma MCF-7.     

Antioxidant and antiproliferative activities of loach ( Misgurnus anguillicaudatus ) peptides prepared by papain digestion

Loach protein hydrolysates (LPH) prepared by papain digestion were fractionated into four fractions, LPH-I (MW > 10 kDa), LPH-II (MW = 5-10 kDa), LPH-III (MW = 3-5 kDa), LPH-IV (MW < 3 kDa), and the in vitro antioxidant and antiproliferative (anticancer) activities of all fractions were determined. LPH-IV showed the lowest IC(50) value (16.9 ± 0.21 mg/mL) for hydroxyl radical scavenging activity and the highest oxygen radical scavenging capacity (ORAC) value (reaching 215 ± 5.9 mM Trolox/100 g loach peptide when the concentration was 60 μg/mL). Compared with other fractions, LPH-IV also exhibited stronger antiproliferative activity for human liver (HepG2), breast (MCF-7), and colon (Caco-2) cancer cell lines in a dose-dependent manner. When the protein concentration was 40 mg/mL, the HepG2 and MCF-7 cell proliferation of LPH-IV reached 7 and 4%, respectively, with no significant difference from those of LPH (8 and 7%, p > 0.05), with significantly less growth than those of LPH-I, LPH-II, and LPH-III, respectively (p < 0.05). The Caco-2 colon cell proliferation of LPH-IV was 12.8- and 8.7-fold smaller than those of LPH-I and LPH-II, respectively (p < 0.05). All of the fractions had a greater ability to inhibit Caco-2 colon cancer cell proliferation than to inhibit HepG2 liver cancer and MCF-7 breast cancer cell proliferation. The ORAC values of most of the fractions correlated (R(2) > 0.86, p < 0.01) with the antiproliferative activity of the three cancer cell lines, suggesting that higher antioxidant activity leads to better antiproliferative activity. However, further mechanistic and human clinical studies of the anticancer activity of loach protein hydrolysate fractions are needed.     

Synthesis and herbicidal activity of N,N-diethyl-3-(arylselenonyl)-1H-1,2,4-triazole-1-carboxamide

Based on the carbamoyl triazole herbicide Cafenstrole, 12 novel selenium-containing compounds were designed and synthesized. All of the compounds were characterized and confirmed by IR, 1H NMR, and high-resolution mass spectroscopy. The bioassay tests showed that some of the compounds (C2, C4, C(7-8), and C12) exhibited good inhibitory activity against cucumber (Cucumis sativus L.) and semen euphorbiae (Leptochloa chinensis N.). Especially, compound C6 inhibited the growth of cucumber and semen euphorbiae by >90% at a concentration of 1.875 microg/mL, and the inhibition of the compound on the rice (Oryza sativa L.) was only 8.3% at a concentration of 7.5 microg/mL, which indicated a higher selectivity between weed and rice than that shown by Cafenstrole.     

Lipoperoxidation and cyclooxygenases 1 and 2 inhibitory compounds from Iryanthera juruensis

Plants from Iryanthera genus have been traditionally used as food supplements by South American Indians. The MeOH extract of leaves of Iryanthera juruensis, one of the plants endemic to the Amazon region and consumed in Brazil, and the hexane extract from its seeds inhibited lipid peroxidation (LPO) and cyclooxygenase (COX-1 and -2)) enzymes in in vitro assays. Further analyses of these extracts yielded 5-deoxyflavones (1-5) from the leaf extract and sargachromenol (6), sargaquinoic acid (7), a novel juruenolic acid (8), omega-arylalkanoic acids (9a-c), and the lignan guaiacin (10) from the seed extract. Compounds 3-5 inhibited LPO by 86%, 77%, and 88% at 10 ppm, respectively, and compounds 6 and 9a-c showed inhibition at 76% and 78% at 100 ppm, respectively. However, compounds 7 and 8 were inactive and lignan 10 exhibited LPO inhibitory activity by 99% at 100 ppm compared to commercial antioxidants butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and vitamin E. The flavones 1-5 also inhibited COX-1 and -2 enzymes by 50-65% at 100 ppm. Compound 6 showed high but nonselective inhibition of COX-1 and COX-2 enzymes, when compared to aspirin and Celebrex, a nonsteroidal anti-inflammatory drug (NSAID). Compounds 7 and 10 inhibited COX-1 by 60% and 65% and COX-2 by 37% and 18%, respectively, whereas compounds 8 and 9a-c showed little or no activity against these enzymes.     

Larvicidal and adulticidal activity of alkylphthalide derivatives from rhizome of Cnidium officinale against Drosophila melanogaster

The insecticidal activity of the chloroform extract of Cnidium officinale rhizomes and its constituents was investigated against larvae and adults of Drosophila melanogaster and compared with that of rotenone. Bioassay-guided isolation of the chloroform extract of C. officinale resulted in the isolation and characterization of four alkylphthalides, cnidilide (1), (Z)-ligustilide (2), (3S)-butylphthalide (3), and neocnidilide (4). The structures of these compounds were established by spectroscopic analysis. The isolated compounds 2, 3, and 4 exhibited LC50 values of 2.54, 4.99, and 9.90 micromol/mL of diet concentration against larvae of D. melanogaster, respectively. Against both sexes (males/females, 1:1) of adults (5-7 days old), compound 3 showed the most potent activity of the compounds isolated with the LD50 value of 5.93 microg/adult, comparable to that of rotenone (LD50 = 3.68 microg/adult). Structure-activity relationships of phthalides isolated suggest that the presence of conjugation with the carbonyl group in the lactone ring appeared to play an important role in the larvicidal activity. Acetylcholinesterase (prepared from the adult heads of D. melanogaster) inhibitory activity was also investigated in vitro to determine the insecticide mode of action for the acute adulticidal activity.     

Mosquitocidal, nematicidal, and antifungal compounds from Apium graveolens L. seeds

The methanolic extract of Apium graveolens seeds was investigated for bioactive compounds and resulted in the isolation and characterization of mosquitocidal, nematicidal, and antifungal compounds sedanolide (1), senkyunolide-N (2), and senkyunolide-J (3). Their structures were determined by 1H and 13C NMR spectral methods. Compounds 1-3 gave 100% mortality at 25, 100, and 100 microg mL(-1), respectively, on the nematode, Panagrellus redivivus. Compound 1 showed 100% mortality at 50 microg mL(-1) on nematode, Caenorhabditis elegans, and fourth-instar mosquito larvae, Aedes aegyptii. Also, it inhibited the growth of Candida albicans and Candida parapsilasis at 100 microg mL(-1). Compounds 2 and 3 were isolated for the first time from A. graveolens. This is the first report of the mosquitocidal, nematicidal, and antifungal activities of compounds 1-3.     

Isolation and structural elucidation of some glycosides from the rhizomes of smaller galanga (Alpinia officinarum Hance)

Glycosidically bound compounds were isolated from the methanol extract of fresh rhizomes of smaller galanga (Alpinia officinarum Hance). Nine glycosides (1-9) were finally obtained by reversed-phase HPLC and their structures were elucidated by MS and NMR analyses. They were the three known glycosides, (1R,3S,4S)-trans-3-hydroxy-1,8-cineole beta-D-glucopyranoside (1), benzyl beta-D-glucopyranoside (3), and 1-O-beta-D-glucopyranosyl-4-allylbenzene (chavicol beta-D-glucopyranoside, 4); and the six novel glycosides, 3-methyl-but-2-en-1-yl beta-D-glucopyranoside (2), 1-hydroxy-2-O-beta-D-glucopyranosyl-4-allylbenzene (5), 1-O-beta-D-glucopyranosyl-2-hydroxy-4-allylbenzene (demethyleugenol beta-D-glucopyranoside, 6), 1-O-(6-O-alpha-L-rhamnopyranosyl-beta-D-glucopyranosyl)-2-hydroxy-4-allylbenzene (demethyleugenol beta-rutinoside, 7), 1-O-(6-O-alpha-L-rhamnopyranosyl-beta-D-glucopyranosyl)-4-allylbenzene (chavicol beta-rutinoside, 8), and 1,2-di-O-beta-D-glucopyranosyl-4-allylbenzene (9). Compounds 2-9 were detected for the first time as constituents of galanga rhizomes.     

HIV-1 integrase and neuraminidase inhibitors from Alpinia zerumbet

AIDS and influenza are viral pandemics and remain one of the leading causes of human deaths worldwide. The increasing resistance of these diseases to synthetic drugs demands the search for novel compounds from plant-based sources. In this regard, the leaves and rhizomes of Alpinia zerumbet, a traditionally important economic plant in Okinawa, were investigated for activity against HIV-1 integrase (IN) and neuraminidase (NA). The aqueous extracts of leaves and rhizomes had IN inhibitory activity with IC(50) values of 30 and 188 μg/mL, whereas against NA they showed 50% inhibition at concentrations of 43 and 57 μg/mL, respectively. 5,6-Dehydrokawain (DK), dihydro-5,6-dehydrokawain (DDK), and 8(17),12-labdadiene-15,16-dial (labdadiene) were isolated from the rhizomes and were tested for enzyme inhibitions. DK and DDK strongly inhibited IN with IC(50) of 4.4 and 3.6 μg/mL, respectively. Against NA, DK, DDK, and labdadiene exhibited mixed type of inhibition with respective IC(50) values of 25.5, 24.6, and 36.6 μM and K(i) values ranging from 0.3 to 2.8 μM. It was found that DDK is a slow and time-dependent reversible inhibitor of NA, probably with a methoxy group as its functionally active site. These results suggest that alpinia could be used as a source of bioactive compounds against IN and NA and that DK and DDK may have possibilities in the design of drugs against these viral diseases.     

Novel biological properties of Oenothera paradoxa defatted seed extracts: effects on metallopeptidase activity

In this study, for the first time, we used the in vitro metallopeptidase model for the identification of a potential novel activity of defatted evening primrose seed extracts. Prepared extracts of different polarity (aqueous, 60% ethanolic, isopropanolic, and 30% isopropanolic) at concentrations of 1.5-100 microg/mL exhibited a significant and dose dependent inhibition of three tested enzymes. The 50% inhibition of enzymes activity showed that aminopeptidase N (APN) was the enzyme affected to the greatest extent with IC50 at the level of 2.8 microg/mL and 2.9 microg/mL for aqueous and 30% isopropanolic extracts, respectively. The activity of neutral endopeptidase (NEP) was quite strongly inhibited by the extracts as well. The HPLC-DAD analysis and bioguided fractionation led to the identification of four active compounds: (-)-epicatechin gallate, proanthocyanidin B3, oenothein B, and penta-O-galloyl-beta-D-glucose (PGG). Oenothein B has been shown previously to inhibit metallopeptidases. The three other compounds are known to inhibit angiotensin-converting enzyme (ACE), but they have not been previously reported to inhibit the NEP and APN activity. PGG and procyanidins with different degrees of polymerization, as the dominating compounds in O. paradoxa seeds, seemed to play a role in the crude extract activity.     

Anti-inflammatory activities of new succinic and maleic derivatives from the fruiting body of Antrodia camphorata

Six new compounds, trans-3-isobutyl-4-[4-(3-methyl-2-butenyloxy)phenyl]pyrrolidine-2,5-dione (1), trans-1-hydroxy-3-(4-hydroxyphenyl)-4-isobutylpyrrolidine-2,5-dione (2), cis-3-(4-hydroxyphenyl)-4-isobutyldihydrofuran-2,5-dione (3), 3-(4-hydroxyphenyl)-4-isobutyl-1H-pyrrole-2,5-dione (4), 3-(4-hydroxyphenyl)-4-isobutylfuran-2,5-dione (5), and dimethyl 2-(4-hydroxyphenyl)-3-isobutylmaleate (6), together with one known compound, 3-isobutyl-4-[4-(3-methyl-2-butenyloxy)phenyl]furan-2,5-dione (7), were isolated from the fruiting bodies of Antrodia camphorata. The structures of the compounds were elucidated by analysis of their spectroscopic data. To investigate the immunomodulatory potential of the compounds, RAW264.7 macrophage cells were treated with the compounds. Compound 1 significantly increased spontaneous TNF-alpha secretion from unstimulated RAW264.7 cells but suppressed IL-6 production [50% inhibition concentration value (IC50) = 10 microg/mL] in LPS-stimulated cells. Compounds 3, 4, and 6 also suppressed IL-6 production with IC50 values of 17, 18, and 25 microg/mL, respectively, suggesting that these four compounds may have an anti-inflammatory effect on macrophage-mediated responses. Of the six compounds, compound 1 was the most effective, exerting both immunostimulatory and anti-inflammatory effects.     

Antioxidant activity and characterization of volatile constituents of Taheebo (Tabebuia impetiginosa Martius ex DC)

Volatiles were isolated from the dried inner bark of Tabebuia impetiginosa using steam distillation under reduced pressure followed by continuous liquid-liquid extraction. The extract was analyzed by gas chromatography and gas chromatography-mass spectrometry. The major volatile constituents of T. impetiginosa were 4-methoxybenzaldehyde (52.84 microg/g), 4-methoxyphenol (38.91 microg/g), 5-allyl-1,2,3-trimethoxybenzene (elemicin; 34.15 microg/g), 1-methoxy-4-(1E)-1-propenylbenzene (trans-anethole; 33.75 microg/g), and 4-methoxybenzyl alcohol (30.29 microg/g). The antioxidant activity of the volatiles was evaluated using two different assays. The extract exhibited a potent inhibitory effect on the formation of conjugated diene hydroperoxides (from methyl linoleate) at a concentration of 1000 microg/mL. The extract also inhibited the oxidation of hexanal for 40 days at a level of 5 microg/mL. The antioxidative activity of T. impetiginosa volatiles was comparable with that of the well-known antioxidants, alpha-tocopherol, and butylated hydroxytoluene.