Goadsporin, a chemical substance which promotes secondary metabolism and Morphogenesis in streptomycetes. II. Structure determination

The structure of goadsporin was determined by using spectroscopic techniques. NMR analysis revealed that goadsporin consists of 19 amino acids, two of which are dehydroalanines (Deala), and six of which are cyclized to oxazoles (Oxz) and thiazoles (Thz) by dehydrative cyclization and dehydrogenation from serine, threonine and cysteine. NMR analysis established seven partial structures, and their sequence was determined by CID-MS/MS. Negative mode FAB-MS/MS gave product ions arising from charge-remote fragmentation that allowed determination of the sequence of the amino acid components as AcNH-Ala-MeOxz-Val-Deala-MeOxz-Ile-Leu-Thz-Ser-Gly-Gly-MeOxz-Leu-Deala-Oxz-Ala-Gly-Thz-Val-OH. The chiral amino acids were determined by the advanced Marfey's method to have L-configurations.

Structure elucidation of ostreocin D, a palytoxin analog isolated from the dinoflagellate Ostreopsis siamensis

The structure of ostreocin D, a palytoxin analog isolated from the marine dinoflagellate Ostreopsis siamensis, was found to be 42-hydroxy-3,26-didemethyl-19,44-dideoxypalytoxin by detailed 2D NMR analyses of intact ostreocin D and its ozonolysis products. Partial stereochemical assignments were done. This result indicates that the dinoflagellate O. siamensis is one of the biogenetic origins of palytoxin.

Supraclinoid carotid dissection in a pediatric patient

The authors present the case of a 13-year-old boy with a left temporal lobe infarction that developed during a 400-m run. Magnetic resonance (MR) angiography showed segmental narrowing of the left supraclinoid internal carotid artery (ICA) and a duplicated left middle cerebral artery (MCA). MR angiographic source images revealed a crescent-shaped left carotid lumen, indicative of a supraclinoid carotid dissection.

Conformational study of a highly specific CXCR4 inhibitor, T140, disclosing the close proximity of its intrinsic pharmacophores associated with strong anti-HIV activity

We report the solution structure of T140, a truncated polyphemusin peptide analogue that efficiently inhibits infection of target cells by T-cell line-tropic strains of HIV-1 through its specific binding to a chemokine receptor, CXCR4. Nuclear magnetic resonance analysis and molecular dynamic calculations revealed that T140 has a rigidly structured conformation constituted by an antiparallel beta-sheet and a type II' beta-turn. A protuberance is formed on one side of the beta-sheet by the side-chain functional groups of the three amino acid residues (L-3-(2-naphthyl)alanine, Tyr5 and Arg14), each of which is indispensable for strong anti-HIV activity. These findings provide a rationale to dissect the structural basis for the ability of this compound to block the interaction between CXCR4 and envelope glycoproteins from T-tropic strains of HIV-1.

Cyclic malyl anthocyanins in Dianthus caryophyllus

3,5-Di-O-(beta-glucopyranosyl) pelargonidin 6''-O-4,6'''-O-1-cyclic malate and a previously reported cyanidin equivalent, 3,5-di-O-(beta-glucopyranosyl) cyanidin 6''-O-4,6'''-O-1-cyclic malate were identified from petals of deep pink and red-purple flower cultivars of Dianthus caryophyllus, respectively.

New malyngamides from the Hawaiian cyanobacterium Lyngbya majuscula

Isomalyngamides A and B (1, 2) were isolated and characterized from a collection of the cyanobacterium Lyngbya majuscula from Hawaiian waters. These compounds represent a new type of malyngamide, similar to malyngamides Q and R, in which the conformation of the chloromethylene group is opposite from the majority of previously reported malyngamides. The geometry of the chloromethylene moiety was elucidated from the long-range coupling constants ((3)J(C)(-)(H)) obtained from editing-HETLOC and phase-sensitive HMBC experiments. Isomalyngamides A and B (1, 2) showed lethal toxicity to crayfish.

Synthesis, biological evaluation, and conformational analysis of A-ring diastereomers of 2-methyl-1,25-dihydroxyvitamin D(3) and their 20-epimers: unique activity profiles depending on the stereochemistry of the A-ring and at C-20

All eight possible A-ring diastereomers of 2-methyl-1, 25-dihydroxyvitamin D(3) (2) and 2-methyl-20-epi-1, 25-dihydroxyvitamin D(3) (3) were convergently synthesized. The A-ring enyne synthons 19 were synthesized starting with methyl (S)-(+)- or (R)-(-)-3-hydroxy-2-methylpropionate (8). This was converted to the alcohol 14 as a 1:1 epimeric mixture in several steps. After having been separated by column chromatography, each isomer led to the requisite A-ring enyne synthons 19 again as 1:1 mixtures at C-1. Coupling of the resulting A-ring enynes 20a-h with the CD-ring portions 5a,b in the presence of a Pd catalyst afforded the 2-methyl analogues 2a-h and 3a-h in good yield. In this way, all possible A-ring diastereomers were synthesized. The synthesized analogues were biologically evaluated both in vitro and in vivo. The potency was highly dependent on the stereochemistry of each isomer. In particular, the alpha alpha beta-isomer 2g exhibited 4-fold higher potency than 1 alpha,25-dihydroxyvitamin D(3) (1) both in bovine thymus VDR binding and in elevation of rat serum calcium concentration and was twice as potent as the parent compound in HL-60 cell differentiation. Furthermore, its 20-epimer, that is, 20-epi-alpha alpha beta 3g, exhibited exceptionally high activities: 12-fold higher in VDR binding affinity, 7-fold higher in calcium mobilization, and 590-fold higher in HL-60 cell differentiation, as compared to 1 alpha,25-dihydroxyvitamin D(3) (1). Accordingly, the double modification of 2-methyl substitution and 20-epimerization resulted in unique activity profiles. Conformational analysis of the A-ring by (1)H NMR and an X-ray crystallographic analysis of the alpha alpha beta-isomer 2g are also described.

The antiplatelet activity of tetramethylpyrazine is mediated through activation of NO synthase

Tetramethylpyrazine (TMPZ) is an active ingredient of a Chinese herbal medicine (Ligusticum wallichii Franchat). In this study, TMPZ (50-200 microM) significantly increased production of nitrate and cyclic GMP in human platelets within a 15-min incubation period. TMPZ concentration-dependently inhibited intracellular Ca2+ mobilization in human platelets stimulated by collagen (5 microg/ml). Furthermore, TMPZ concentration (50 and 200 microM)- and time (15 and 30 min)-dependently triggered endothelial-type constitutive nitric oxide synthase (ecNOS) protein expression in human platelets. These results indicated that TMPZ at micromolar concentrations stimulated nitric oxide production in human platelets via a novel mechanism that activated ecNOS protein expression.

Vasoactive intestinal peptide and pituitary adenylyl cyclase-activating polypeptide inhibit tumor necrosis factor-alpha production in injured spinal cord and in activated microglia via a cAMP-dependent pathway

Tumor necrosis factor-alpha (TNF-alpha) production accompanies CNS insults of all kinds. Because the neuropeptide vasoactive intestinal peptide (VIP) and the structurally related peptide pituitary adenylyl cyclase-activating polypeptide (PACAP) have potent anti-inflammatory effects in the periphery, we investigated whether these effects extend to the CNS. TNF-alpha mRNA was induced within 2 hr after rat spinal cord transection, and its upregulation was suppressed by a synthetic VIP receptor agonist. Cultured rat microglia were used to examine the mechanisms underlying this inhibition because microglia are the likely source of TNF-alpha in injured CNS. In culture, increases in TNF-alpha mRNA resulting from lipopolysaccharide (LPS) stimulation were reduced significantly by 10(-7) m VIP and completely eliminated by PACAP at the same concentration. TNF-alpha protein levels were reduced 90% by VIP or PACAP at 10(-7) m. An antagonist of VPAC(1) receptors blocked the action of VIP and PACAP, and a PAC(1) antagonist blocked the action of PACAP. A direct demonstration of VIP binding on microglia and the existence of mRNAs for VPAC(1) and PAC(1) (but not VPAC(2)) receptors argue for a receptor-mediated effect. The action of VIP is cAMP-mediated because (1) activation of cAMP by forskolin mimics the action; (2) PKA inhibition by H89 reverses the neuropeptide-induced inhibition; and (3) the lipophilic neuropeptide mimic, stearyl-norleucine(17) VIP (SNV), which does not use a cAMP-mediated pathway, fails to duplicate the inhibition. We conclude that VIP and PACAP inhibit the production of TNF-alpha from activated microglia by a cAMP-dependent pathway.

Arisostatins A and B, new members of tetrocarcin class of antibiotics from Micromonospora sp. TP-A0316. II. Structure determination

Structures of arisostatins A and B were determined by spectroscopic analyses. Arisostatins were found to be new analogs of tetrocarcin A and possess an iso-butanoyldigitoxose unit instead of the acetyldigitoxose one. NMR analyses of arisostatins and tetrocarcin A led to the revision of the anomeric configurations in the tetrasaccharide moiety of tetrocarcin A.

Acoustic inspection of bond strength of steel-reinforced mortar after exposure to elevated temperatures

In order to evaluate the bond strength between the reinforcement and concrete after fire damage, a combination of acoustic through-transmission and pull-out tests were used. Previous studies have shown a 25% decrease in the ultrasonic pulse velocity at 90% of the maximum load at room temperature. The specimens were kept in the oven at an elevated temperature for 1, 2, or 3 h. They were then removed and cooled to room temperature. Inspection was conducted using a high-power ultrasonic pulse velocity system while a pull-out load was applied. The correlation between preheated temperature, acoustic wave velocity, and the applied load was analyzed. Initial results show that bond strength and pulse velocity decreased substantially as the temperature or the heating time increased.

An active-site mutation causes enhanced reactivity and altered regiospecificity of transglucosylation catalyzed by the Bacillus sp. SAM1606 α-glucosidase

Bacillus sp. SAM1606 alpha-glucosidase catalyzes the transglucosylation of sucrose to produce three regioisomers of the glucosylsucroses, with theanderose (6-O(G)-glucosylsucrose) as the most abundant transfer product. To find the active-site amino acid residues which can affect the reactivity and regiospecificity of the glucosyl transfer, 16 mutants with amino acid substitutions near the active site were allowed to react with 1.75 M sucrose at 60 degrees C, pH 6.0, and the course of transglucosylation as well as the product specificity were analyzed. The sites of the amino acid substitutions were selected by comparing the conserved amino acid sequences located near the active site of the SAM1606 enzyme with those of the Bacillus oligo-1,6-glucosidases (O16G), which have very high amino acid sequence similarities near the active site but have a distinct substrate specificity. The results showed that, among the mutated SAM1606 enzymes examined, only the mutants with substitution of Gly273 with Pro showed an altered reactivity and specificity of transglucosylation; these mutants exhibited a significantly enhanced initial velocity of glucosyl transfer, yielding isomelezitose (6-O(F)-glucosylsucrose) instead of theanderose as the major transfer product. These results indicate that the substitution of Gly273 with Pro critically governs the enhanced reactivity and altered specificity of the transglucosylation. The notion that the amino acid residue at this position is the determinant of the glucosyl-transfer specificity was further confirmed by observation that the Bacillus cereus O16G, which has a proline at the corresponding position, produced isomelezitose as the major transfer product during transglucosylation with sucrose.

A new depsipeptide from the sacoglossan mollusk Elysia ornata and the green alga Bryopsis species

A new cyclic depsipeptide, kahalalide O (1), was isolated from the sacoglossan Elysia ornata and its algal diet Bryopsis sp. The structure was elucidated primarily by NMR and MS spectral methods, and the stereochemistry of the amino acid residues was determined by chiral HPLC and Marfey analyses. Unlike the related metabolite kahalalide F, which is in development as a potential anticancer agent, kahalalide O (1) was inactive in arresting the growth of P-388, A549, HT29, and MEL28 cancer cell lines in vitro.

Kahalalide K: A new cyclic depsipeptide from the hawaiian green alga bryopsis species

Kahalalide K (1), a new cyclic depsipeptide, was isolated from the Hawaiian green alga Bryopsis sp. Kahalalide K was determined to possess a new array of three L- and three D-amino acids, including a 3-hydroxy-9-methyldecanoic acid that had been previously reported in kahalalides E, H, and J.

Long-distance charge transport in duplex DNA: the phonon-assisted polaron-like hopping mechanism

An anthraquinone-linked duplex DNA oligomer containing 60 base pairs was synthesized by PCR. The strand complementary to the quinone-containing strand has four isolated GG steps, which serve as traps for a migrating radical cation. Irradiation of the quinone leads to electron transfer from the DNA to the quinone forming the anthraquinone radical anion and a base radical cation. The radical cation migrates through the DNA, causing reaction at GG steps revealed as strand breaks. The efficiency of strand cleavage falls off exponentially with distance from the quinone (slope = -0.02 A(-1)). This finding necessitates reinterpretation of mechanisms proposed for radical cation migration in DNA. We propose that radical cations form self-trapped polarons that migrate by thermally activated hopping.

Reduction in lipopolysaccharide-induced thrombocytopenia by triflavin in a rat model of septicemia

BACKGROUND

Thrombocytopenia frequently occurs early in the course of Gram-negative bacterial infections. Triflavin, an Arg-Gly-Asp-containing disintegrin, has been suggested to interfere with the interaction of fibrinogen with the glycoprotein IIb/IIIa complex. The present study was undertaken to determine whether triflavin could prevent thrombocytopenia in lipopolysaccharide (LPS)-treated rats.

METHODS AND RESULTS

In this study, 51Cr-labeled platelets were used to assess blood and tissue platelet accumulation after LPS challenge. The administration of LPS (4 mg/kg IV bolus) for 4 hours induced a reduction in radiolabeled platelets in blood and an obvious accumulation of platelets in liver. Triflavin (500 microg/kg) but not GRGDS (20 mg/kg) significantly prevented the alteration of radiolabeled platelet distribution in blood and liver when induced by LPS. Furthermore, triflavin but not GRGDS markedly suppressed the elevation in plasma thromboxane B2 concentration within the 4-hour period of LPS administration. In LPS-treated rats, the 5-hydroxytryptamine level was lower in the blood and higher in the liver compared with levels in normal saline-treated rats. Pretreatment with triflavin (500 microg/kg) significantly reversed the 5-hydroxytryptamine concentration in blood and liver of LPS-treated rats. In histological examinations and platelet adhesion assay, triflavin markedly inhibited the adhesion of platelets to subendothelial matrixes in vivo and in vitro.

CONCLUSIONS

The results indicate that triflavin effectively prevents thrombocytopenia, possibly through the following 2 mechanisms: (1) Triflavin markedly inhibits platelet aggregation, resulting in decreased thromboxane A2 formation. (2) It inhibits the adhesion of platelets to subendothelial matrixes, thereby leading to a reversal in the distribution of platelets in blood and liver in LPS-treated rats.

Identification of the major antioxidative metabolites in biological fluids of the rat with ingested (+)-catechin and (-)-epicatechin

(+)-Catechin and (-)-epicatechin are known to be biologically effective antioxidants present in the human diet, particularly in wine and tea. We studied the metabolism of these compounds to elucidate the truly active structures in biological fluids by their oral administration to rats. Without any treatment with beta-glucuronidase and sulfatase, a pair of metabolites were detected at much higher concentrations in the plasma, bile, and urine than the originally ingested compounds. Each major metabolite found in the plasma at the highest concentration was excreted in both the bile and urine, and was purified from urine. Their chemical structures were established to be (+)-catechin 5-O-beta-glucuronide and (-)-epicatechin 5-O-beta-glucuronide by MS and NMR analyses. These glucuronide conjugates exhibited high antioxidative activities as superoxide anion radical scavengers like their parent compounds. It is concluded that (+)-catechin 5-O-beta-glucuronide and (-)-epicatechin 5-O-beta-glucuronide are the biologically active in vivo structures of the ingested polyphenolic antioxidants.

Vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide inhibit tumor necrosis factor alpha transcriptional activation by regulating nuclear factor-kB and cAMP response element-binding protein/c-Jun

Tumor necrosis factor alpha (TNFalpha), an early cytokine produced by activated macrophages, plays an essential role in normal and pathological inflammatory reactions. The excessive production of TNFalpha is prevented by the so-called "macrophage-deactivating factors." This study examines the role of two structurally related neuropeptides, the vasoactive intestinal peptide (VIP) and the pituitary adenylate cyclase-activating peptide (PACAP), as inhibitors of TNFalpha. Both VIP and PACAP inhibit TNFalpha production from lipopolysaccharide-stimulated RAW 246.7 cells in a dose- and time-dependent manner. Although the activated cells express mRNA for all three VIP/PACAP receptors, agonist and antagonist studies indicate that the major receptor involved is VIP1R. VIP/PACAP inhibit TNFalpha gene expression by affecting both NF-kB binding and the composition of the cAMP responsive element binding complex (CREB/c-Jun). Two transduction pathways, a cAMP-dependent and a cAMP-independent pathway, are involved in the inhibition of TNFalpha gene expression and appear to differentially regulate the transcriptional factors involved. Because TNFalpha plays a central role in various inflammatory diseases such as endotoxic shock, multiple sclerosis, cerebral malaria, and various autoimmune conditions, the down-regulatory effect of VIP/PACAP may have a significant therapeutic potential.

Enzymatic reaction with unnatural substrates: DNA photolyase (Escherichia coli) recognizes and reverses thymine [2+2] dimers in the DNA strand of a DNA/PNA hybrid duplex

Peptide nucleic acids (PNA) are mimics with normal bases connected to a pseudopeptide chain that obey Watson-Crick rules to form stable duplexes with itself and natural nucleic acids. This has focused attention on PNA as therapeutic or diagnostic reagents. Duplexes formed with PNA mirror some but not all properties of DNA. One fascinating aspect of PNA biochemistry is their reaction with enzymes. Here we show an enzyme reaction that operates effectively on a PNA/DNA hybrid duplex. A DNA oligonucleotide containing a cis, syn-thymine [2+2] dimer forms a stable duplex with PNA. The hybrid duplex is recognized by photolyase, and irradiation of the complex leads to the repair of the thymine dimer. This finding provides insight into the enzyme mechanism and provides a means for the selective repair of thymine photodimers.

The antiplatelet activity of rutaecarpine, an alkaloid isolated from Evodia rutaecarpa, is mediated through inhibition of phospholipase C

In this study, the mechanism involved in the antiplatelet activity of rutaecarpine in human platelet suspensions was investigated. In platelet suspensions (4.5 x 10(8)/ml), rutaecarpine (100 and 200 microM) did not influence the binding of FITC-triflavin to platelet glycoprotein IIb/IIIa complex. Additionally, rutaecarpine (200 microM) did not significantly change the fluorescence of platelet membrane labeled with diphenylhexatriene (DPH). On the other hand, rutaecarpine (50 and 100 microM) dose-dependently inhibited the increase in intracellular free Ca2+ of Fura 2-AM loaded platelets stimulated by collagen. Moreover, rutaecarpine (100 and 200 microM) did not significantly affect the thromboxane synthetase activity of aspirin-treated platelet microsomes. Furthermore, retaecarpine (100 and 200 microM) significantly inhibited [3H]arachidonic acid released in collagen-activated platelets but not in unactivated-platelets. Nitric oxide (NO) production in human platelets was measured by a chemiluminesence detection method in this study. Rutaecarpine (100 and 200 microM) did not significantly affect nitrate production in collagen (10 microg/ml)-induced human platelet aggregation. On the other hand, various concentrations of rutaecarpine (50, 100, and 200 microM) dose-dependently inhibited [3H]inositol monophosphate formation stimulated by collagen (10 microg/ml) in [3H]myoinositol-loaded platelets at different incubation times (1, 2, 3, and 5 minutes). It is concluded that the antiplatelet activity of rutaecarpine may possibly be due to the inhibition of phospholipase C activity, leading to reduce phosphoinositide breakdown, followed by the inhibition of thromboxane A2 formation, and then inhibition of [Ca2+]i mobilization of platelet aggregation stimulated by agonists.

Mechanisms involved in the antiplatelet activity of Escherichia coli lipopolysaccharide in human platelets

In this study, Escherichia coli lipopolysaccharide (LPS) dose-dependently (100-300 microg/ml) and time-dependently (10-60 min) inhibited platelet aggregation in human platelets stimulated by agonists. LPS also dose-dependently inhibited the phosphoinositide breakdown and the intracellular Ca+2 mobilization in human platelets stimulated by collagen. LPS (300 microg/ml) also significantly inhibited the thromboxane A2 formation stimulated by collagen in human platelets. Moreover, LPS (100-300 microg/ml) dose-dependently decreased the fluorescence of platelet membranes tagged with diphenylhexatrience. In addition, LPS (200 and 300 microg/ml) significantly increased the formation of cyclic GMP but not cyclic AMP in platelets. LPS (200 microg/ml) also significantly increased the production of nitrate within a 30 min incubation period. Rapid phosphorylation of a platelet protein of Mr 47,000, a marker of protein kinase C activation, was triggered by phorbol-12-13-dibutyrate (PDBu, 50 nM). This phosphorylation was markedly inhibited by LPS (200 microg/ml) within a 30 min incubation period. These results indicate that the antiplatelet activity of LPS may be involved in two important pathways. (1) LPS may induce conformational changes in the platelet membrane, leading to change in the activity of phospholipase C. (2) LPS also activated the formation of nitric oxide (NO)/cyclic GMP in human platelets, resulting in inhibition of platelet aggregation. Therefore, LPS-mediated alteration of platelet function may contribute to bleeding diathesis in septicaemic and endotoxaemic patients.

Malyngamides M and N from the Hawaiian Red Alga Gracilaria coronopifolia

Two new malyngamides, M and N (1, 2), were isolated along with malyngamide I acetate (3) from the Hawaiian red alga Gracilaria coronopifolia. Our results suggest that malyngamide N (2) is a revised structure of deacetoxystylocheilamide (5). The absolute configuration of malyngamide I acetate was deduced to be 3 using the reversed octant rule.

Mechanisms involved in the antiplatelet activity of tetramethylpyrazine in human platelets

Tetramethylpyrazine is the active ingredient of a Chinese herbal medicine. In this study, tetramethylpyrazine was tested for its antiplatelet activities in human platelet suspensions. In human platelets, tetramethylpyrazine (0.5-1.5 mM) dose-dependently inhibited both platelet aggregation and ATP-release reaction induced by a variety of agonists (i.e., ADP, collagen, and U46619). Tetramethylpyrazine (0.5 mM) did not significantly change the fluorescence of platelet membranes labeled with diphenylhexatriene, even at the high concentration (1.5 mM). Furthermore, tetramethylpyrazine (0.5-1.5 mM) dose-dependently inhibited [3H]inositol monophosphate formation stimulated by collagen (5 microg/ml) in [3H]myoinositol loaded platelets. Tetramethylpyrazine (0.5-1.5 mM) also dose-dependently inhibited the intracellular free Ca2+ rise of Fura 2-AM loaded platelets stimulated by collagen (5 microg/ml). Moreover, tetramethylpyrazine (0.5-1.5 mM) inhibited thromboxane B2 formation stimulated by collagen. At a higher concentration (1.0 mM), tetramethylpyrazine has also been shown to influence the binding of FITC-triflavin to platelet glycoprotein IIb/IIIa complex. Triflavin, a specific glycoprotein IIb/IIIa complex antagonist purified from Trimeresurus flavoviridis venom. It is concluded that the antiplatelet activity of tetramethylpyrazine may possibly involve two pathways: 1) at a lower concentration (0.5 mM), tetramethylpyrazine is shown to inhibit phosphoinositide breakdown and thromboxane A2 formation; and 2) at a higher concentration (1.0 mM), it leads to the inhibition of platelet aggregation through binding to the glycoprotein IIb/IIIa complex.

Inhibition of angiogenesis in vitro and in vivo: comparison of the relative activities of triflavin, an Arg-Gly-Asp-containing peptide and anti-alpha(v)beta3 integrin monoclonal antibody

Disintegrin which contains the amino acid sequence Arg-Gly-Asp (RGD), has been implicated as a recognition site in interactions between extracellular matrix (ECM) and cell membrane receptors. Triflavin, a 7.5 kDa cysteine-rich polypeptide purified from Trimeresurus flavoviridis snake venom, belongs to a family of disintegrins. Integrin alpha(v)beta3 has recently been identified as a marker of angiogenic blood vessels and therefore anti-alpha(v)beta3 mAb may significantly inhibit angiogenesis. Therefore, this study was designed to compare the relative activity of triflavin and anti-alpha(v)beta3 mAb in human umbilical vein endothelial cell (HUVEC) adhesion and migration in vitro, and on angiogenesis induced by TNF(alpha) in chicken chorioallantoic membrane (CAM). In this study, it was shown that triflavin (0.1 to 0.4 microM) dose-dependently inhibited the adhesion of HUVECs to ECMs (i.e., vitronectin, fibronectin, laminin and collagen type IV). At a concentration of 10 microM, anti-alpha(v)beta3 mAb almost completely inhibited the adhesion of cells to vitronectin, had a moderate inhibitory effect on fibronectin and laminin, but only a slight inhibitory effect on collagen type IV. On the other hand, vitronectin and fibronectin promote a significantly greater extent of cell adhesion and migration than laminin or collagen type IV over a wide range of concentrations (5 to 15 microg/ml). In cell migration studies, triflavin (0.4 microM) inhibited more markedly vitronectin- and fibronectin-mediated migration than that mediated by laminin- and collagen type IV. Comparison of the relative effectiveness of triflavin with anti-alpha(v)beta3 mAb, showed that triflavin was at least twenty to thirty times more potent than anti-alpha(v)beta3 mAb at inhibiting cell adhesion and migration. Furthermore, we used TNF(alpha) as an inducer of angiogenesis in the CAM assay. Close examination of the effects of triflavin and anti-alpha(v)beta3 mAb on TNF(alpha)-induced angiogenesis revealed the presence of discontinuous and disrupted blood vessels. However, anti-alpha(v)beta3 mAb showed a significant effect only at a higher concentration (10 microM). These results suggest that the inhibition of angiogenesis may have been due to interference with the adhesion and migration of endothelial cells to ECMs. The results also indicate that triflavin has a more powerful inhibitory effect than anti-alpha(v)beta3 mAb on angiogenesis, suggesting that triflavin could theoretically be used as a reasonable therapeutic adjuvant for therapy or prevention of angiogenesis-induced diseases.