C-phycocyanin, a very potent and novel platelet aggregation inhibitor from Spirulina platensis

The aim of this study was to systematically examine the inhibitory mechanisms of C-phycocyanin (C-PC), one of the major phycobiliproteins of Spirulina platensis (a blue-green alga), in platelet activation. In this study, C-PC concentration-dependently (0.5-10 nM) inhibited platelet aggregation stimulated by agonists. C-PC (4 and 8 nM) inhibited intracellular Ca2+ mobilization and thromboxane A2 formation but not phosphoinositide breakdown stimulated by collagen (1 microg/mL) in human platelets. In addition, C-PC (4 and 8 nM) markedly increased levels of cyclic GMP and cyclic GMP-induced vasodilator-stimulated phosphoprotein (VASP) Ser(157) phosphorylation. Rapid phosphorylation of a platelet protein of Mw 47,000 (P47), a marker of protein kinase C activation, was triggered by phorbol-12,13-dibutyrate (150 nM). This phosphorylation was markedly inhibited by C-PC (4 and 8 nM). In addition, C-PC (4 and 8 nM) markedly reduced the electron spin resonance (ESR) signal intensity of hydroxyl radicals in collagen (1 microg/mL)-activated platelets. The present study reports on a novel and very potent (in nanomolar concentrations) antiplatelet agent, C-PC, which is involved in the following inhibitory pathways: (1) C-phycocyanin increases cyclic GMP/VASP Ser157 phosphorylation and subsequently inhibits protein kinase C activity, resulting in inhibition of both P47 phosphorylation and intracellular Ca2+ mobilization, and (2) C-PC may inhibit free radicals (such as hydroxyl radicals) released from activated platelets, which ultimately inhibits platelet aggregation. These results strongly indicate that C-PC appears to represent a novel and potential antiplatelet agent for treatment of arterial thromboembolism.     

Isolation and identification of antiplatelet aggregatory principles from the leaves of Piper lolot

The methanolic extract of Piper lolot, having shown potent inhibitory activity on platelet aggregation induced by arachidonic acid (AA) and platelet activating factor (PAF), was subjected to activity-guided isolation to yield twelve new amide alkaloids, piperlotine A-L (1-12), along with twenty-nine known compounds. Their structures were elucidated on the basis of spectroscopic analysis. The isolated compounds were tested for their inhibitory activity on the rabbit platelet aggregation. The compounds piperlotine A (1), piperlotine C (3), piperlotine D (4), piperlotine E (5), 3-phenyl-1-(2,4,6-trihydroxyphenyl)propan-1-one (21), 3-(4-methoxyphenyl)-1-(2,4,6-trihydroxyphenyl)propan-1-one (22), 1-trans-cinnamoylpyrrolidine (24), sarmentine (26), pellitorine (27), methyl 3-phenylpropionate (32), and (10S)-10-hydroxypheophorbide a methyl ester (40) showed potent antiplatelet aggregation activity.     

alpha-Naphthoflavone, a potent antiplatelet flavonoid, is mediated through inhibition of phospholipase C activity and stimulation of cyclic GMP formation

The aim of this study was to systematically examine the inhibitory mechanisms of the flavonoid alpha-naphthoflavone (alpha-NF) in platelet activation. In this study, alpha-NF concentration dependently (5-20 microM) inhibited platelet aggregation stimulated by agonists. alpha-NF (5 and 10 microM) inhibited intracellular Ca(2+) mobilization, phosphoinositide breakdown, and thromboxane A(2) formation stimulated by collagen (1 microg/mL) in human platelets. In addition, alpha-NF (5 and 10 microM) markedly increased levels of cyclic GMP and cyclic GMP-induced vasodilator-stimulated phosphoprotein (VASP) Ser(157) phosphorylation. Rapid phosphorylation of a platelet protein of Mr 47,000 (P47), a marker of protein kinase C activation, was triggered by phorbol-12,13-dibutyrate (60 nM). This phosphorylation was markedly inhibited by alpha-NF (5 and 10 microM). However, alpha-NF (5 and 10 microM) did not reduce the electron spin resonance (ESR) signal intensity of hydroxyl radicals in collagen (1 microg/mL)-activated platelets. These results indicate that the antiplatelet activity of alpha-NF may be involved in the following pathways. (1) alpha-NF may inhibit the activation of phospholipase C, followed by inhibition of phosphoinositide breakdown, protein kinase C activation, and thromboxane A(2) formation, thereby leading to inhibition of intracellular Ca(2+) mobilization. (2) alpha-NF also activated the formation of cyclic GMP, resulting in inhibition of platelet aggregation. These results strongly indicate that alpha-NF appears to represent a novel and potent antiplatelet agent for treatment of arterial thromboembolism.     

Inhibitory effect of α-lipoic acid on platelet aggregation is mediated by PPARs

Peroxisome proliferator-activated receptors (PPARs) isoforms (α, β/δ, and γ are present in human platelets, and activation of PPARs inhibits platelet aggregation. α-Lipoic acid (ALA), occurring naturally in human food, has been reported to exhibit an antiplatelet activity. However, the mechanisms underlying ALA-mediated inhibition of platelet aggregation remain unknown. The aim of this study was to investigate whether the antiplatelet activity of ALA is mediated by PPARs. ALA itself significantly induced PPARα/γ activation in platelets and increased intracellular amounts of PPARα/γ by blocking PPARα/γ secretion from arachidonic acid (AA)-activated platelets. Moreover, ALA significantly inhibited AA-induced platelet aggregation, Ca(2+) mobilization, and cyclooxygenase-1 (COX-1) activity, but increased cyclic AMP production in rabbit washed platelets. Importantly, ALA also enhanced interaction of PPARα/γ with protein kinase Cα (PKCα) and COX-1 accompanied by an inhibition of PKCα activity in resting and AA-activated platelets. However, the above effects of ALA on platelets were markedly reversed by simultaneous addition of selective PPARα antagonist (GW6471) or PPARγ antagonist (GW9662). Taken together, the present study provides a novel mechanism by which ALA inhibition of platelet aggregation is mediated by PPARα/γ-dependent processes, which involve interaction with PKCα and COX-1, increase of cyclic AMP formation, and inhibition of intracellular Ca(2+) mobilization.     

Mechanisms involved in the antiplatelet activity of rutin, a glycoside of the flavonol quercetin, in human platelets

The aim of this study was to systematically examine the inhibitory mechanisms of rutin, a well-known flavonoid in platelet aggregation. In this study, rutin concentration-dependently (250 and 290 microM) inhibited platelet aggregation in human platelets stimulated by agonists (i.e., collagen). Rutin (250 and 290 microM) did not significantly interfere with the binding of FITC-triflavin to the glycoprotein IIb/IIIa complex in human platelets. Rutin (250 and 290 microM) markedly inhibited intracellular Ca(2+) mobilization and thromboxane A(2) formation in human platelets stimulated by collagen. Rapid phosphorylation of a platelet protein of M(r) 47000 (P47), a marker of protein kinase C activation, was triggered by collagen (1 microg/mL). This phosphorylation was markedly inhibited by rutin (250 and 290 microM). On the other hand, rutin (250 and 290 microM) did not significantly increase the formations of cyclic AMP and nitric oxide/cyclic GMP in platelets. In conclusion, these results indicate that the antiplatelet activity of rutin may involve the following pathways: rutin inhibited the activation of phospholipase C, followed by inhibition of protein kinase C activity and thromboxane A(2) formation, thereby leading to inhibition of the phosphorylation of P47 and intracellular Ca(2+) mobilization, finally resulting in inhibition of platelet aggregation.     

Characterization of the key aroma compounds in soy sauce using approaches of molecular sensory science

Application of aroma extract dilution analysis (AEDA) to the volatiles isolated from a commercial Japanese soy sauce revealed 30 odor-active compounds in the flavor dilution (FD) factor range of 8-4096, among which 2-phenylethanol showed the highest FD factor of 4096, followed by 3-(methylsulfanyl)propanal (methional), the tautomers 4-hydroxy-5-ethyl-2-methyl- and 4-hydroxy-2-ethyl-5-methyl-3(2H)-furanone (4-HEMF), 4-hydroxy-2,5-dimethyl-3(2H)-furanone (4-HDF), and 3-hydroxy-4,5-dimethyl-2(5H)-furanone (sotolone), all showing FD factors of 1024. Thirteen odorants were quantified by stable isotope dilution assays, and their odor activity values (OAVs) were calculated as ratio of their concentrations and odor thresholds in water. Among them, 3-methylbutanal (malty), sotolone (seasoning-like), 4-HEMF (caramel-like), 2-methylbutanal (malty), methional (cooked potato), ethanol (alcoholic), and ethyl 2-methylpropanoate (fruity) showed the highest OAVs (>200). An aqueous model aroma mixture containing 13 odorants, which had been identified with the highest OAVs, in concentrations that occur in the soy sauce showed a good similarity with the overall aroma of the soy sauce itself. Heat treatment of the soy sauce resulted in a clear change of the overall aroma. Quantitation of selected odorants revealed a significant decrease in sotolone and, in particular, increases in 2-acetyl-1-pyrroline, 4-HDMF, and 4-HEMF induced by heating.     

Antioxidative and antiplatelet effects of aqueous inflorescence Piper betle extract

Piper betle, belonging to the Piperaceae family, is a tropical plant, and its leaf and inflorescence are popularly consumed by betel quid (BQ) chewers in Taiwan and many other South and Southeast Asian countries. However, little is known about the biochemical properties of inflorescence Piper betle (IPB) toward reactive oxygen species (ROS) and platelet functions. In the present work, aqueous IPB extract was shown to be a scavenger of H(2)O(2), superoxide radical, and hydroxyl radical with a 50% inhibitory concentration (IC(50)) of about 80, 28, and 73 microg/mL, respectively. IPB extract also prevented the hydroxyl radical induced PUC18 plasmid DNA breaks at concentrations higher than 40 microg/mL. Since ROS are crucial for platelet aggregation, we further found that IPB extract also inhibited the arachidonic acid (AA) induced and collagen-induced platelet aggregation, with an IC(50) of 207 and 335 microg/mL, respectively. IPB extract also inhibited the AA-, collagen- (>100 microg/mL of IPB), and thrombin (>250 microg/mL of IPB)-induced thromboxane B(2) (TXB(2)) production by more than 90%. However, IPB extract showed little effect on thrombin-induced aggregation. These results indicated that aqueous components of IPB are potential ROS scavengers and may prevent the platelet aggregation possibly via scavenging ROS or inhibition of TXB(2) production.     

Exploration of the antiplatelet activity profile of betulinic acid on human platelets

Betulinic acid, a natural pentacyclic triterpene acid, presents a diverse mode of biological actions including antiretroviral, antibacterial, antimalarial, and anti-inflammatory activities. The potency of betulinic acid as an inhibitor of human platelet activation was evaluated, and its antiplatelet profile against in vitro platelet aggregation, induced by several platelet agonists (adenosine diphosphate, thrombin receptor activator peptide-14, and arachidonic acid), was explored. Flow cytometric analysis was performed to examine the effect of betulinic acid on P-selectin membrane expression and PAC-1 binding to activated platelets. Betulinic acid potently inhibits platelet aggregation and also reduced PAC-1 binding and the membrane expression of P-selectin. Principal component analysis was used to screen, on the chemical property space, for potential common pharmacophores of betulinic acid with approved antithrombotic drugs. A common pharmacophore was defined between the NMR-derived structure of betulinic acid and prostacyclin agonists (PGI2), and the importance of its carboxylate group in its antiplatelet activity was determined. The present results indicate that betulinic acid has potential use as an antithrombotic compound and suggest that the mechanism underlying the antiplatelet effects of betulinic acid is similar to that of the PGI2 receptor agonists, a hypothesis that deserves further investigation.     

Transcriptome profiling of heat-resistant strain Bacillus licheniformis CGMCC3962 producing Maotai flavor

Although Maotai flavor liquor is exclusive due to its soy sauce flavor, knowledge of its key compound and production mechanism is still scarce until now. To gain insight into the production mechanism of soy sauce flavor, a soy sauce flavor producing strain with high efficiency and heat-resistant capability was obtained, and the metabolic mechanism of the strain was investigated with the technique of microarray profiling. Because high temperature was a key factor for soy sauce flavor production, the global gene expression of this heat-resistant strain fermented at 55 °C was analyzed. Except for the responsive increase of heat shock proteins, which maintained cell survival during heat stress, biosynthesis of cysteine was also up-regulated. In addition, some metabolites were significantly increased when cysteine was added to the fermentation medium, such as 2,3-butanediol, 3-hydroxy-2-butanone, and tetramethylpyrazine, which were important flavor compounds in soy sauce flavor liquor and might be related with soy sauce flavor. The results indicated that cysteine might play an important role in the formation of soy sauce flavor compound, and it might act as an indirect precursor or stimulator of soy sauce flavor formation. This was the first use of the microarray profiling tool to investigate the fermentative strains for Chinese traditional liquor, which would allow a deeper insight into the mechanism of the formation of soy sauce flavor compound.     

大豆酱油电渗析脱盐工艺参数对其脱盐率及品质的影响

为了降低大豆酱油的含盐量,该文利用电渗析技术对大豆酱油进行脱盐处理,通过单因素试验探讨了电压、流速、pH值对电渗析脱盐效果的影响,确定了较佳电渗析工艺。结果表明在电压为9 V,流速为2.4 cm/s,pH值为4.2,电渗析50 min时脱盐效果较好,氨基酸态氮损失较小,氨基酸态氮损失19.4%,脱盐率达到81.6%。利用氨基酸自动分析仪和气相色谱-质谱联用仪（gas chromatography-mass spectrometry）分析了电渗析前后游离氨基酸及挥发性风味物质的变化规律,结果表明电渗析过程中氨基酸及风味物质均有损失。几种苦味氨基酸如组氨酸、精氨酸、赖氨酸损失较大,分别损失了23.79%、26.39%和28.5%;电渗析过程中,酱油风味物质中醇类、酚类损失较大,尤其是4-乙基愈创木酚损失最多,但因其气味阈值较低,因此对酱油风味影响较小。研究结果为减盐酱油系列产品的生产提供了参考和依据。     

Apigenin inhibits platelet adhesion and thrombus formation and synergizes with aspirin in the suppression of the arachidonic acid pathway

Previous studies using washed platelets demonstrated that certain flavonoids inhibit platelet function through several mechanisms including blockade of TxA(2) receptors (TPs). We aimed to analyze the binding capacity of flavonoids to TPs in platelet rich plasma (PRP), investigated their effect in flowing blood, and evaluated the ability of apigenin to improve the efficacy of aspirin in the inhibition of platelet aggregation. The binding of flavonoids to TPs in PRP was explored using binding assays and the TP antagonist [ (3)H]SQ29548. Effects of flavonoids on platelet adhesion were assessed using arterial subendothelium with annular plate perfusion chambers, and global evaluation of apigenin on high-shear-dependent platelet function was determined by the PFA-100. To evaluate the ability of apigenin to potentiate the effect of aspirin, arachidonic acid-induced platelet aggregation was measured prior to and after consumption of subaggregatory doses of aspirin in the presence or absence of apigenin. Binding assays revealed that apigenin was an efficient competitor of [ (3)H]SQ29548 binding to PRP ( K i = 155.3 +/- 65.4 microM), and perfusion studies showed that apigenin, genistein, and catechin significantly diminished thrombus formation when compared to control (26.2 +/- 3.8, 33.1 +/- 5.2, and 26.2 +/- 5.2 vs 76.6 +/- 2.6%, respectively; p < 0.05). Apigenin, similarly to the TP antagonist SQ29548, significantly prolonged collagen epinephrine-induced PFA-100 closure time in comparison to the control and, when added to platelets that had been exposed in vivo to aspirin, potentiated its inhibitory effect on platelet aggregation. The inhibitory effect of some flavonoids in the presence of plasma, particularly apigenin, might in part rely on TxA(2) receptor antagonism. There is a clear increase in the ex vivo antiplatelet effect of aspirin in the presence of apigenin, which encourages the idea of the combined use of aspirin and certain flavonoids in patients in which aspirin fails to properly suppress the TxA(2) pathway.     

Effects of hydroxytyrosol and hydroxytyrosol acetate administration to rats on platelet function compared to acetylsalicylic acid

Virgin olive oil (VOO) contains the polyphenols hydroxytyrosol (HT) and hydroxytyrosol acetate (HT-AC). This study investigated the antiplatelet effect of HT and HT-AC in healthy rats and compared their effects to acetylsalicylic acid (ASA). All compounds were administered orally for 7 days. HT and HT-AC inhibited platelet aggregation in whole blood, with a 50% inhibitory dose (ID50) of 48.25 mg/kg per day for HT, 16.05 mg/kg per day for HT-AC, and 2.42 mg/kg per day for ASA. Platelet synthesis of thromboxane B2 was inhibited by up to 30% by HT and 37% by HT-AC; the ID50 of this effect for ASA was 1.09 mg/kg per day. Vascular prostacyclin production was inhibited by up to 27.5% by HT and 32% by HT-AC; the ID50 of this effect for ASA was 6.75 mg/kg per day. Vascular nitric oxide production was increased by up to 34.2% by HT, 66% by HT-AC, and 64% by ASA. We conclude that HT and HT-AC administered orally inhibited platelet aggregation in rats and that a decrease in thromboxane synthesis along with an increase in nitric oxide production contributed to this effect.     

Biological activity of acetylated phenolic compounds

In recent years an effort has been made to isolate and identify biologically active compounds that are included in the Mediterranean diet. The existence of naturally occurring acetylated phenolics, as well as studies with synthetic ones, provide evidence that acetyl groups could be correlated with their biological activity. Platelet activating factor (PAF) is implicated in atherosclerosis, whereas its inhibitors seem to play a protective role against cardiovascular disease. The aim of this study was to examine the biological activity of resveratrol and tyrosol and their acetylated derivatives as inhibitors of PAF-induced washed rabbit platelet aggregation. Acetylation of resveratrol and tyrosol was performed, and separation was achieved by HPLC. Acetylated derivatives were identified by negative mass spectrometry. The data showed that tyrosol and its monoacetylated derivatives act as PAF inhibitors, whereas diacetylated derivatives induce platelet aggregation. Resveratrol and its mono- and triacetylated derivatives exert similar inhibitory activity, whereas the diacetylated ones are more potent inhibitors. In conclusion, acetylated phenolics exert the same or even higher antithrombotic activity compared to the biological activity of the initial one.     

Low molecular weight compounds responsible for savory taste of Indonesian soy sauce

Indonesian soy sauce is made using only soybeans as the nitrogenous source. Moromi obtained from fermentation of yellow soybeans using Aspergillus sojae as the starter was investigated. The fraction with molecular weights of less than 500 Da obtained by stepwise ultrafiltration was then fractionated by several chromatographic procedures, including gel filtration chromatography and RP-HPLC. Several chemical analyses, CE profiles, and taste profiles were performed to obtain the most intense umami fraction. The main components eliciting or enhancing the umami taste present in the fraction were purified and identified by protein sequencing, ESI-MS, and (1)H NMR at 400 MHz. Besides free l-glutamic acid and aspartic acid, free aromatic amino acids such as l-phenylalanine and l-tyrosine may also play an important role in impressing savory or umami taste of Indonesian soy sauce at their subthreshold concentrations and in the presence of salt and free acidic amino acids. This is reported as a new phenomenon of the so-called bitter amino acids.     

Effect of cooking on garlic (Allium sativum L.) antiplatelet activity and thiosulfinates content

The raw form of garlic and some of its preparations are widely recognized as antiplatelet agents that may contribute to the prevention of cardiovascular disease. Herein, we examined the in-vitro antiaggregatory activity (IVAA) of human blood platelets induced by extracts of garlic samples that were previously heated (in the form of crushed versus uncrushed cloves) using different cooking methods and intensities. The concentrations of allicin and pyruvate, two predictors of antiplatelet strength, were also monitored. Oven-heating at 200 degrees C or immersing in boiling water for 3 min or less did not affect the ability of garlic to inhibit platelet aggregation (as compared to raw garlic), whereas heating for 6 min completely suppressed IVAA in uncrushed, but not in previously crushed, samples. The latter samples had reduced, yet significant, antiplatelet activity. Prolonged incubation (more than 10 min) at these temperatures completely suppressed IVAA. Microwaved garlic had no effect on platelet aggregation. However, increasing the concentration of garlic juice in the aggregation reaction had a positive IVAA dose response in crushed, but not in uncrushed, microwaved samples. The addition of raw garlic juice to microwaved uncrushed garlic restored a full complement of antiplatelet activity that was completely lost without the garlic addition. Garlic-induced IVAA was always associated with allicin and pyruvate levels. Our results suggest that (1) allicin and thiosulfinates are responsible for the IVAA response, (2) crushing garlic before moderate cooking can reduce the loss of activity, and (3) the partial loss of antithrombotic effect in crushed-cooked garlic may be compensated by increasing the amount consumed.     

Separation of biologically active lipids from red wine

A number of lines of evidence suggest that red wine exerts a protective effect against coronary heart disease, but the nature of the protective compounds is unclear and the mechanism is incompletely understood. In this study, total lipids of a Greek red wine were separated into neutral and polar lipids. Polar lipids were further separated into glyco- and phospholipids, which were fractionated by HPLC. Each lipid fraction was tested in vitro for its ability to inhibit platelet-activating factor (PAF) and thrombin-induced washed rabbit platelet aggregation and/or to cause platelet aggregation. A significant number of glyco- and phospholipids that exerted the above biological activities were detected. Structural data of an active phosphoglycolipid are also provided. trans-Resveratrol demonstrated also a dose-dependent inhibition of PAF-induced platelet aggregation along with the already reported inhibitory activity against thrombin and adenosine-5'-diphosphate. Because it has already been reported that PAF is involved in atheromatosis generation, the existence of PAF inhibitors in red wine may contribute to the protective role of red wine against atherosclerosis.     

Identification of 4-methylspinaceamine, a pictet-spengler condensation reaction product of histamine with acetaldehyde, in fermented foods and its metabolite in human urine

Previous study demonstrated that 4-methylspinaceamine (4-methyl-4,5,6,7-tetrahydro-1H-imidazo[4,5-c]pyridine), a Pictet-Spengler condensation reaction product of histamine with acetaldehyde, is present in human urine. The current study sought to determine whether 4-methylspinaceamine is present in fermented foods; its presence might be expected since both histamine and acetaldehyde are often present in these foods. Soy sauce, fish sauce, cheese, and shao hsing wine (Chinese wine) were found to contain 4-methylspinaceamine. The concentration of 4-methylspinaceamine excreted in human urine was greatly elevated after ingestion of a meal containing soy sauce as a dietary source of 4-methylspinaceamine, demonstrating that the level of 4-methylspinaceamine in human urine was affected by dietary foods. In addition, a metabolite of 4-methylspinaceamine in human urine was investigated. An enhanced peak in the HPLC chromatogram of human urine samples after ingestion of 4-methylspinaceamine-containing foods was observed. A peak at the same retention time was also observed from a human urine sample after administration of 4-methylspinaceamine, suggesting that the peak was due to a metabolite. By comparison with the newly synthesized authentic compound, the metabolite was identified as 1,4-dimethylspinaceamine.     

Differential inhibition of human platelet aggregation by selected Allium thiosulfinates

Thiosulfinates (TSs) have been implicated as a principle source of the antiplatelet property of raw onion and garlic juice. The in vitro responses of human platelets to dosages of four TSs were measured using whole blood aggregometry and compared by regression analysis. Of the compounds evaluated, methyl methane-TS (MMTS), propyl propane-TS (PPTS), and 2-propenyl 2-propene-TS (allicin) are present in freshly cut Allium vegetables, whereas ethyl ethane-TS (EETS) has not been detected. All TSs were synthesized using a model reaction system. PPTS and allicin had the strongest antiplatelet activity at 0.4 mM, inhibiting aggregation by 90 and 89%, respectively. At the same concentration, EETS and MMTS were significantly weaker, inhibiting 74 and 26%, respectively. Combinations of TSs were not additive in their inhibition of aggregation, indicating that the antiplatelet potential of Allium extracts cannot be easily predicted by quantifying organosulfur components. EETS, PPTS, and allicin were significantly more potent platelet inhibitors than aspirin at nearly equivalent concentrations.     

Reaction of tryptophan with carbohydrates: identification and quantitative determination of novel beta-carboline alkaloids in food

The formation of various carbohydrate-derived beta-carbolines was observed when model reactions of tryptophan with glucose were studied by means of HPLC with diode array detection, as well as by means of HPLC-MS. Isolation of these compounds and subsequent characterization by tandem mass spectrometry and NMR spectroscopy led to the identification of diastereomeric 1-(1,3,4,5-tetrahydroxypent-1-yl)-9H-pyrido[3,4-b]indoles (1a/b), 1-(1,4,5-trihydroxypent-1-yl)-9H-pyrido[3,4-b]indoles (2a/b), and E/Z isomers of 1-(1,5-dihydroxypent-3-en-1-yl)-9H-pyrido[3,4-b]indole (3a/b). HPLC-MS was used to prove the presence of these novel beta-carboline alkaloids in various food samples. In addition, quantitative determination of beta-carbolines 1a, 1b, and 2a/b in numerous products was achieved by means of HPLC with fluorometric detection. Concentrations ranged from 12 to 1922 microg/L for 1a and 1b and from 3 to 644 microg/L for 2a/b. The highest concentrations of all carbohydrate-derived beta-carbolines under study were found in ketchup, soy sauce, and fish sauce.     

Biological activity of total lipids from red and white wine/must.

Wine is an essential component of the Mediterranean diet, and it is thought to exert a protective effect against coronary heart disease. Although many efforts have been made to determine the protective compounds in wines, their exact nature and how they are involved in the protection mechanisms are still unclear. In this study, total lipids, total polar lipids, and total neutral lipids of five wines and three musts were tested in vitro for their ability to induce washed rabbit platelet aggregation and/or to inhibit platelet activating factor (PAF) induced aggregation. The results showed that the biological activity of wine/must total lipids can be attributed mainly to total polar lipids. In the red wine Cabernet Sauvignon, we fractionated total neutral lipids, total polar lipids, and pigments by HPLC. Each fraction was tested in vitro for its biological activity. Structural data of the most active fractions, based on biological, chemical, and spectral methods, are also presented.