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Background: The Hedgehog signaling pathway is essential for embryogenesis and for tissue homeostasis in the adult. However, it may induce malignancies in a number of tissues when constitutively activated, and it may also have a role in other forms of normal and maladaptive growth. Cyclopamine, a naturally occurring steroidal alkaloid, specifically inhibits the Hedgehog pathway by binding directly to Smoothened, an important Hedgehog response element. To use cyclopamine as a tool to explore and/or inhibit the Hedgehog pathway in vivo, a substantial quantity is required, and as a practical matter cyclopamine has been effectively unavailable for usage in animals larger than mice., Results: In this paper, we report a rapid and efficient isolation and purification of large quantities of cyclopamine from the roots and rhizomes of Veratrum californicum Dur. (the Corn Lily or Western false hellebore). We also provide unambiguous assignments of the carbon and proton resonances by using the multinuclear spectra and the spin coupling networks., Conclusion: This method could meet a very real need within diverse scientific communities by allowing cyclopamine to become more readily available.

The industrial solvent trichloroethylene (TCE) and its major metabolites have been shown to cause formic aciduria in male rats. We have examined whether chloral hydrate (CH) and trichloroacetic acid (TCA), known metabolites of TCE, produce an increase in formic acid in vitro in cultures of rat hepatocytes or human renal proximal tubule cells (HRPTC). The metabolism and cytotoxicity of CH was also examined to establish that the cells were metabolically active and not compromised by toxicity. Rat hepatocytes and HRPTC were cultured in serum-free medium and then treated with 0.3-3mM CH for 3 days or 0.03-3mM CH for 10 days, respectively and formic acid production, metabolism to trichloroethanol (TCE-OH) and TCA and cytotoxicity determined. No increase in formic acid production in rat hepatocytes or HRPTC exposed to CH was observed over and above that due to chemical degradation, neither was formic acid production observed in rat hepatocytes exposed to TCA. HRPTC metabolized CH to TCE-OH and TCA with a 12-fold greater capacity to form TCE-OH versus TCA. Rat hepatocytes exhibited a 1.6-fold and three-fold greater capacity than HRPTC to form TCE-OH and TCA, respectively. CH and TCA were not cytotoxic to rat hepatocytes at concentrations up to 3mM/day for 3 days. With HRPTC, one sample showed no cytotoxicity to CH at concentrations up to 3mM/day for 10 days, while in another cytotoxicity was seen at 1mM/day for 3 days. In summary, increased formic acid production was not observed in rat hepatocytes or HRPTC exposed to TCE metabolites, suggesting that the in vivo response cannot be modelled in vitro. CH was toxic to HRPTC at millimolar concentrations/day over 10 days, while glutathione derived metabolites of TCE were toxic at micromolar concentrations/day over 10 days [Lock, E.A., Reed, C.J., 2006. Trichloroethylene: mechanisms of renal toxicity and renal cancer and relevance to risk assessment. Toxicol. Sci. 19, 313-331] supporting the view that glutathione derived metabolites are likely to be responsible for nephrotoxicity.

Ethanol elevates methylphenidate (1) plasma concentrations and yields the metabolite ethylphenidate (2). The therapeutic implications are under investigation. The IC(50) for dopamine reuptake inhibition by (+)-2 was 27 nM compared to 367 nM for cocaine and 1730 nM for (-)-2. Binding selectivity for dopamine versus norepinephrine transporters was greater for (+)-2 than for cocaine. Intraperitoneal (+)-2 was approximately half as active as (+)-1 in stimulating mouse motor activity at 5 mg/kg, but (+)-2 was as active as (+)-1 at 10 mg/kg.

The dietary polyphenol resveratrol has been shown to have chemopreventive activity against cardiovascular disease and a variety of cancers in model systems, but it is not clear whether the drug reaches the proposed sites of action in vivo after oral ingestion, especially in humans. In this study, we examined the absorption, bioavailability, and metabolism of 14C-resveratrol after oral and i.v. doses in six human volunteers. The absorption of a dietary relevant 25-mg oral dose was at least 70%, with peak plasma levels of resveratrol and metabolites of 491 +/- 90 ng/ml (about 2 microM) and a plasma half-life of 9.2 +/- 0.6 h. However, only trace amounts of unchanged resveratrol (<5 ng/ml) could be detected in plasma. Most of the oral dose was recovered in urine, and liquid chromatography/mass spectrometry analysis identified three metabolic pathways, i.e., sulfate and glucuronic acid conjugation of the phenolic groups and, interestingly, hydrogenation of the aliphatic double bond, the latter likely produced by the intestinal microflora. Extremely rapid sulfate conjugation by the intestine/liver appears to be the rate-limiting step in resveratrol's bioavailability. Although the systemic bioavailability of resveratrol is very low, accumulation of resveratrol in epithelial cells along the aerodigestive tract and potentially active resveratrol metabolites may still produce cancer-preventive and other effects.

Lawsone (2-hydroxy-1,4-naphthoquinone) is the active ingredient of henna (Lawsonia alba), the crushed leaves of which are used as a cosmetic dye. Application of henna can induce a severe hemolytic anemia, and lawsone is thought to be the causative agent. Administration of lawsone to rats has been shown to induce a hemolytic response that is associated with oxidative damage to erythrocytes. However, direct exposure of isolated erythrocytes to lawsone did not provoke oxidative damage, suggesting that lawsone must undergo extra-erythrocytic bioactivation in vivo. In the present study, the survival of rat 51Cr-labeled erythrocytes in vivo after in vitro exposure to lawsone and its hydroquinone form, 1,2,4-trihydroxynaphthalene (THN) has been examined. Neither lawsone nor THN were directly hemolytic or methemoglobinemic, even at high concentrations (>3 mM). Lawsone had no effect on erythrocytic GSH levels, whereas THN (3 mM) induced a modest depletion (approximately 30%). Cyclic voltammetry revealed that the lack of hemotoxicity of lawsone was associated with a poor capacity to undergo redox cycling. In contrast, ortho-substituted 1,4-naphthoquinones without a 2-hydroxy group, such as 2-methyl- and 2-methoxy-1,4-naphthoquinone, were redox active, were able to deplete GSH, and were direct-acting hemolytic agents. An oxidant stress-associated hemolytic response to lawsone could be provoked, however, if it was incubated with GSH-depleted erythrocytes. The data suggest that lawsone is a weak direct-acting hemolytic agent that does not require extra-erythrocytic metabolism to cause hemotoxicity. Thus, the hemolytic response to henna may be restricted to individuals with compromised antioxidant defenses.

Primaquine is an important antimalarial agent because of its activity against exoerythrocytic forms of Plasmodium spp. Methemoglobinemia and hemolytic anemia, however, are dose-limiting side effects of primaquine therapy. These hemotoxic effects are believed to be mediated by metabolites, although the identity of the toxic specie(s) and the mechanism underlying hemotoxicity have remained unclear. Previous studies showed that an N-hydroxylated metabolite of primaquine, 6-methoxy-8-hydroxylaminoquinoline, was capable of mediating primaquine-induced hemotoxicity. The present studies were undertaken to investigate the hemolytic potential of 5-hydroxyprimaquine (5-HPQ), a phenolic metabolite that has been detected in experimental animals. 5-HPQ was synthesized, isolated by flash chromatography, and characterized by NMR spectroscopy and mass spectrometry. In vitro exposure of (51)Cr-labeled erythrocytes to 5-HPQ induced a concentration-dependent decrease in erythrocyte survival (TC(50) of ca. 40 microM) when the exposed cells were returned to the circulation of isologous rats. 5-HPQ also induced methemoglobin formation and depletion of glutathione (GSH) when incubated with suspensions of rat erythrocytes. Furthermore, when red cell GSH was depleted (>95%) by titration with diethyl maleate to mimic GSH instability in human glucose-6-phosphate dehydrogenase deficiency, a 5-fold enhancement of hemolytic activity was observed. These data indicate that 5-HPQ also has the requisite properties to contribute to the hemotoxicity of primaquine. The relative contribution of N-hydroxy versus phenolic metabolites to the overall hemotoxicity of primaquine remains to be assessed.

Integral membrane proteins have not been readily amenable to the general methods developed for mass spectrometric (or internal Edman degradation) analysis of soluble proteins. We present here a sample preparation method and high performance liquid chromatography (HPLC) separation system which permits online HPLC-electrospray ionization mass spectrometry (ESI-MS) and -tandem mass spectrometry (MS/MS) analysis of cyanogen bromide cleavage fragments of integral membrane proteins. This method has been applied to wild type (WT) bacteriorhodopsin (bR), cysteine containing mutants of bR, and the prototypical G-protein coupled receptor, rhodopsin (Rh). In the described method, the protein is reduced and the cysteine residues pyridylethylated prior to separating the protein from the membrane. Following delipidation, the pyridylethylated protein is cleaved with cyanogen bromide. The cleavage fragments are separated by reversed phase HPLC using an isopropanol/acetonitrile/aqueous TFA solvent system and the effluent peptides analyzed online with a Finnigan LCQ Ion Trap Mass Spectrometer. With the exception of single amino acid fragments and the glycosylated fragment of Rh, which is observable by matrix assisted laser desorption ionization (MALDI)-MS, this system permits analysis of the entire protein in a single HPLC run. This methodology will enable pursuit of chemical modification and crosslinking studies designed to probe the three dimensional structures and functional conformational changes in these proteins. The approach should also be generally applicable to analysis of other integral membrane proteins.

Trichloroethylene has been shown to produce tumors in rodents and is a suspect human carcinogen. In addition, a number of case reports raise the possibility that trichloroethylene can induce an autoimmune disorder known as systemic sclerosis. To investigate whether covalent binding of reactive trichloroethylene metabolites may be involved in the mechanisms underlying these toxic responses, we have developed a polyclonal antibody that can recognize trichloroethylene--protein adducts in tissues. The antibody was prepared by immunizing a rabbit with dichloroacetic anhydride-modified keyhole limpet hemocyanin. Enzyme-linked immunosorbent assay data indicated that the serum antibody recognized dichloroacetic anhydride-modified rabbit serum albumin, but not unmodified protein. In addition, N epsilon-dichloroacetyl-L-lysine was the most potent inhibitor of antibody binding to dichloroacetic anhydride-modified rabbit serum albumin, indicating that the antibody recognizes primarily dichloroacetylated lysine residues. Immunoblots revealed the presence of two major trichloroethylene adducts at 50 and 100 kDa in liver microsomal fractions from male B6C3/F1 mice treated with trichloroethylene. The formation of trichloroethylene adducts was both dose and time dependent. Furthermore, the 50-kDa adduct was found to comigrate on a polyacrylamide gel with cytochrome P450 2E1. These data show that reactive metabolites of trichloroethylene are formed in vivo and bind covalently to discrete proteins in mouse liver. The data also suggest that one of the protein targets is cytochrome P450 2E1. Further studies will be necessary to elucidate the relationship between covalent binding of trichloroethylene and trichloroethylene toxicity.

A system for small-scale (ca. 10-50 mumol) manual multiple peptide synthesis assembled from commercially available solid-phase extraction apparatus is described. This system was used to prepare (on a 15 mumol scale) the five monophosphorylated isomers of the peptide ASTTVSKTE, a proteolytic fragment of the C-terminal region of rhodopsin. The peptides were assembled using serine or threonine active esters without hydroxyl protection at the positions of phosphorylation. Phosphate groups were introduced using postassembly phosphitylation/oxidation according to a published procedure [Andrews, D.M., Kitchin, J. & Seale, P.W. (1991) Int. J. Peptide Protein Res. 38, 469-475; Staerkaer, G., Jakobsen, M.H., Olsen, C.E. & Holm, A., Tetrahedron Lett. 32, 5389-5392; Perich, J.W. (1992) Int. J. Peptide Protein Res. 40 134-140]. The reported system provides a relatively inexpensive approach to multiple peptide synthesis, including synthesis of phosphopeptides, for laboratories whose synthesis requirements do not justify investment in an automated multiple peptide synthesis instrument.

Deactivation of the visual cascade is initiated by the phosphorylation of rhodopsin. We report here identification of the two major sites of phosphorylation in bleached bovine rhodopsin using tandem mass spectrometry in conjunction with synthetic phosphopeptide standards. Both bleached and unbleached rod outer segments were cleaved with endoproteinase Asp-N to release the C-terminal fragment, residues 330-348, containing seven potential sites of phosphorylation. High-performance liquid chromatographic separation of soluble cleavage products from both unbleached and bleached rod outer segments gave a peak which was identified by tandem mass spectrometry and comparison to synthetic standards as monophosphorylated (serine 338) DDEASTTVSKTETSQVAPA. Present only in the chromatogram of bleached ROS were two peaks identified as monophosphorylated (serine 343) and diphosphorylated (serines 338 and 343) derivatives of DDEASTTVSKTETSQVAPA. These results identify serines 338 and 343 as the major sites of phosphorylation within the C-terminal region of bleached bovine rhodopsin and constitute the first example of mass spectrometric characterization of phosphorylation sites in a G-protein coupled receptor.

A high-affinity thromboxane (TX)A2/prostaglandin (PG) H2 receptor antagonist, I-SAP [7-[(1R,2S,3S,5R)-6,6-dimethyl-3-(4- iodobenzenesulfonylamino)bicyclo[3.1.1]hept-2-yl]-5(Z)-heptenoic acid] and its radiolabeled analog [125I]SAP (Mais et al., 1991) are characterized in the present study. I-SAP antagonized I-BOP ([1S-(1 alpha, 2 beta(5Z),3 alpha(1E,3R*),4 alpha)]-7-[3-(3-hydroxy-4- (4'-iodophenoxy)-1-butenyl)-7-oxabicyclo-[2.2.1]heptan-2y l]-5'heptenoic acid) and U46619 [15S-hydroxy-11 alpha,9 alpha-(epoxymethano)-prosta-5Z,13E-dienoic acid)], two different TXA2/PGH2 mimetics, induced aggregation of washed human platelets in a similar manner (pA2 of 8.11 +/- 0.09, Kd = 7.8 nM, n = 3; pA2 = 8.01 +/- 0.05, Kd = 9.7 nM, n = 8, respectively). I-SAP also had agonistic activity, producing platelet shape change (EC50 = 9.7 nM +/- 0.6 nM at pH 7.4, n = 3) which was blocked by pretreatment of platelets with SQ29548 ([1S-(1 alpha,2 beta(5Z),3 beta,4 alpha)]-7-[3-[[2- [(phenylamino)carbonyl]hydrazino]methyl]-7-oxabicyclo[2.2.1]hept- 2-yl]-5-heptenoic acid), a TXA2/PGH2 receptor antagonist. Radioligand binding studies were performed with [125I]SAP using washed human platelets. Competition of three agonists and four antagonists for binding with [125I]SAP was determined. The compounds showed the appropriate rank order potencies, including stereoselective competition by a pair of stereoisomeric antagonists. In washed human platelets, the Kd for I-SAP was 468 +/- 49 pM and the maximum binding (Bmax) was 2057 +/- 156 sites/platelet at pH 7.4 (n = 6). The Bmax was significantly increased 49% to 3072 +/- 205 sites/platelet at pH 6.5 (P less than .01 but the Kd was unchanged (490 +/- 18 pM, n = 6).(ABSTRACT TRUNCATED AT 250 WORDS)

Thromboxane A2 (TXA2) and its precursor prostaglandin H2 (PGH2) induce platelet aggregation and vascular contraction through shared cell surface receptors commonly referred to as TXA2 or TXA2/PGH2 receptors. Whether different subclasses of TXA2/PGH2 receptors exist in platelets and vascular smooth muscle cells is controversial. In this study, TXA2 receptors on washed rat and human platelets and cultured rat aortic smooth muscle cells (RASMC) were characterized using radioligand competition binding assays with the 125I-labeled TXA2/PGH2 receptor agonist [1S-(1 alpha,2 beta(5Z),3 alpha(1E,3R*),4 alpha)] -7- [3-(3-hydroxy-4-(4'-iodophenoxy)-1-butenyl) -7- oxabicyclo-[2.2.1]- heptan-2-yl] -5- heptenoic acid (I-BOP) and various agonists and antagonists. Scatchard analyses of equilibrium binding data revealed Kd values of 205 +/- 68 pM (N = 6), 2.2 +/- 0.3 nM (N = 9) and 310 +/- 60 pM (N = 7) and Bmax values of 1.3 +/- 0.45 fmol/10(6) platelets, 2.8 +/- 0.2 fmol/10(6) platelets and 20.9 +/- 2.2 fmol/10(6) cells for rat and human platelets and RASMC, respectively. Concentration-dependent increases in intracellular free Ca2+ concentrations induced by I-BOP were observed in RASMC loaded with the calcium sensitive dye fura-2. The IC50 values for various TXA2/PGH2 analogues in competition binding assays with 125I-BOP were determined. Based on their IC50 values, the rank orders were I-BOP less than L657925 less than ONO11113 less than or equal to SQ29548 less than PTA-TPO less than PTA-NO less than or equal to L657926 less than or equal to I-PTA-OH less than PTA-OH[2] = meta-I-PTA-PO less than or equal to ONO11120[2] = ONO11120[1] less than PTA-OH[1] in rat platelets. I-BOP less than SQ29548 less than PTA-TPO = L657925 less than or equal to ONO11113 less than I-PTA-OH less than PTA-NO less than or equal to meta-I-PTA-PO less than or equal to PTA-OH[2] less than ONO11120[2] less than or equal to ONO11120[1] less than L657926 less than or equal to PTA-OH[1] in human platelets, and I-BOP less than L657925 less than ONO11113 less than or equal to SQ29548 less than ONO11120[2] less than or equal to L657926 less than or equal to PTA-OH[2] less than PTA-TPO less than ONO11120[1] less than I-PTA-OH less than meta-I-PTA-PO less than PTA-NO less than PTA-OH[1] in RASMC.(ABSTRACT TRUNCATED AT 400 WORDS)

The present study utilizes a newly synthesized TXA2/PGH2 mimetic, I-BOP, to characterize the TXA2/PGH2 receptor in suspensions of cultured human vascular smooth muscle cells. [125I]-BOP bound in a saturable and specific manner (Kd = 2.6 +/- 0.6 nM; Bmax = 33,540 +/- 6,200 sites/cell; 69 fmoles/mg protein, n = 12). Competition binding assays were performed with [125I]-BOP and the TXA2/PGH2 receptor antagonists SQ29548, L657925 and L657926 and the receptor agonist U46619. I-BOP induced concentration-dependent increases in intracellular free calcium which were inhibited by SQ29548. The results provide radioligand binding evidence for the presence of a TXA2/PGH2 receptor in human vascular smooth muscle cells.

The disposition of 4'-hydroxypropranolol (HOP) was determined after iv administration to dogs (2 mg/kg; N = 5) and the pharmacokinetic parameters were calculated from plasma measurements. The clearance of HOP, 66 +/- 6 ml/min/kg (mean +/- SE), was considerably higher than that of propranolol previously determined, suggesting extrahepatic as well as hepatic clearance of HOP. The plasma half-life of HOP, 77 +/- 6 min, was shorter than that of propranolol. Although HOP is considerably less lipophilic than propranolol, its volume of distribution, 6.4 +/- 0.8 liter/kg, surprisingly, was larger. Like propranolol, HOP appeared to be cleared entirely by metabolism. Whereas propranolol is metabolized mainly by oxidation, HOP was metabolized to sulfate (HOPS) and glucuronic acid (HOPG) conjugates. The plasma half-lives of these conjugates were 2 to 3 times longer than for HOP, reflecting a slow, continuous formation from HOP. This was established for HOPS by iv administration of synthetic HOPS. Morover, after HOP administration both formation and renal clearance of HOPS were stereoselective in favor of the R-enantiomer. In summary, the main conclusion of this study is that the large volume of distribution as well as high clearance through sulfation and glucuronidation may explain the low plasma HOP levels observed during propranolol therapy.

The diazonium salt of 9,11-dimethylmethano-11,12-methano-16-(4-aminophenoxy)13,14- dihydro-13-aza-15 alpha beta-omega-tetranor TXA2 (PTA-POA) was synthesized and used as a photoaffinity ligand for the putative human platelet TXA2/PGH2 receptor. Incubation of human platelet membranes with the diazonium salt of PTA-POA followed by photolysis at 290 nm(hv) resulted in a 40% decrease in the specific binding of [125I]PTA-OH as measured in the radioligand binding assay. Co-incubation with a TXA2/PGH2 agonist followed by photolysis resulted in no decrease in specific binding. Incubation of the diazonium salt of PTA-POA with solubilized platelet membranes without photolysis followed by Scatchard analysis resulted in no change in the Kd for [125I]PTA-OH (38 nM) and the preparation which was incubated with the diazonium salt (42 nM). However, the Bmax for [125I]PTA-OH binding was reduced from 2.4 pmole/mg protein for control to 1.4 pmole/mg protein. These studies show that the diazonium salt of PTA-POA may be a useful photoaffinity ligand for human platelet TXA2/PGH2 receptors.

Propranolol (Inderal; 1) is extensively metabolized in man. Metabolites of interest pharmacologically include ring-hydroxylated propranolols (1a-g). In order to identify these ring-oxidized products and to study the effect of hydroxyl position on biological activity, we have synthesized all seven isomers. With the exception of 1b and 1g, the desired compounds were prepared by alkylation of the respective methoxy-1-naphthols with epichlorohydrin and reaction of the resulting epoxide with isopropylamine. Cleavage og the methyl group in fused pyridine hydrochloride afforded 1a,c-f. 1g was prepared by the direct alkylation of 1,8-naphthalenediol (17) with epichlorohydrin, followed by reaction with isopropylamine. 1b was synthesized by treating 2-naphthol (9) with chlorine gas and then treating the resulting 1,1-dichloronaphthalen-2(1H)-one (10) with sodium allyl oxide. Acetylation of the hydroxy function and epoxidatrion of the allyl group, followed by relation with isopropylamine, gave 3'-hydroxy-4'-chloropropranolol (15). Dechlorination gave 1b. All of the racemic hydroxylated propranolols produced beta blockade and direct vasodilation in anesthetized dogs. The potency is strongly dependent upon the position of the hydroxyl group, i.e., 1e is 4 times as potent as 1 as a beta receptor antagonist, whereas 1a, 1b, and 1g are all significantly less potent than 1. For direct vasodilation, 1a and 1g are equipotent to 1, while 1b-f are much less potent. The potencies of the compounds were also compared with their 1-octanol/pH 7.4 buffer distribution coefficients; the direct vasodilating potency was found to increase with increasing lipophilicity, while the beta-adrenergic antagonist potency decreased.

The quinazoline couterpart of folic acid (5,8-deazafolic acid) as well as its 10-methyl analogue has been shown to be an effective inhibitor of thymidylate synthetase from several different sources. This paper describes the synthesis of modifications in which the nitrogen atom at position 10 is replaced by sulfur, oxygen, or methylene affording 10-thia-5,8-deazafolic acid, 10-oxa-5,8-deazafolic acid, and 5,8,10-deazafolic acid, respectively. In preliminary testing, each of the target compounds displayed marginal activity against L1210 leukemia in mice.

This study was designed to determine the structures of several unknown, potentially active, monohydroxylated metabolites of (+/-)-propranolol in rats, dogs, and man. The metabolites were isolated from urine by extraction with ethyl acetate at pH 9.6 after enzymatic hydrolysis. They were then separated as their trimethylsilyl and trifluoroacetyl derivatives and detected by flame-ionization GLC or GC/MS. Structure identification of the metabolites was based on a comparison of their GLC retention times and mass spectra with those of the seven synthetic isomeric hydroxypropranolols (HO-P's). Three metabolites not previously described, 2-HO-P, 5-HO-P, and 7-HO-P, as well as the known 4-HO-P, were identified in the rat. 2-HO-P accounted for about 1% of total monohydroxylated propranolol, 5-HO-P for 7 +/- 2% (mean +/- SE), 7-HO-P for 26 +/- 5%, and 4-HO-P for 66 +/- 5%. The separate administration of (+)- and (-)-propranolol demonstrated stereospecific 7-hydroxylation of (+)-propranolol in the rat. The formation of 5-HO-P was selective for the (-)-isomer, whereas 4-hydroxylation was not stereoselective. Also, the recovery of the dose as the monohydroxylated metabolites in urine was considerably higher after (+)-propranolol, 49 +/- 9%, than after (-)-propranolol, 32 +/- 6%. 4-HO-P was the only hydroxylation product in the dog, whereas in man small quantities of 2-HO-P, 5-HO-P, and 7-HO-P were observed in addition to 4-HO-P.

One of the major metabolites of propranolol (Inderal) is the O-glucuronide. In order to further study its disposition, possible metabolism, and contribution to the antihypertensive effect of propranolol, we have synthesized and separated the two diastereomeric propranolol O-beta-D-glucuronides (9a,b). These compounds were prepared by reaction of naphthol with epichlorohydrin and treatment of the resulting (2RS)-1'-(2,3-epoxypropoxy)naphthalene (2) with sodium azide to give (2RS)-1-(1'-naphthoxy)-3-azido-2-propanol (3). Alkylation of 3 with methyl (2,3,4-tri-O-acetyl-1-bromo-1-deoxy-alpha-D-glucopyranosid)uronate (4) gave methyl (2RS)-[1-(1'-naphthoxy)-3-azido-2-propyl-2",3",4"-tri-O-acetyl-beta-D- glucopyranosid]uronate (5a,b). Reductive alkylation, followed by HPLC separation of the diastereomers, gave methyl (2R)- and (2S)-[1-(1'-naphthoxy)-3-(isopropylamino)-2-propyl-2",3",4"-tri-O-acetyl- beta-D-glucopyranosid]uronate (6a,b). Hydrolytic removal of the acetyl and methyl protecting groups gave the free glucuronides, which were then converted to the sodium salts, 9a,b. The stereochemistry of the glycoside linkage was deduced from the 400-MHz 1H NMR spectra. The absolute configuration of the aglycon portion was determined after Glusulase hydrolysis by derivatization with (R)-(+)- or -(-)-alpha-methylbenzyl isocyanate and comparison of the HPLC retention volumes with those of derivatized reference (R)- and (S)-propranolols.

Stable synthetic mimetics of thromboxane (TX) A2 and prostaglandin (PG) H2 have been synthesized and reported to stimulate platelets and vascular smooth muscle. The synthetic agonists induce aggregation of isolated platelets and contraction of vascular tissue. The tritiated agonists [3H]U46619 and [3H]U44069 have been used in radioligand binding studies to characterize platelet and vascular smooth muscle TXA2/PGH2 receptors, but have limited usefulness due to their low specific activities and variable specific binding. In an attempt to overcome these problems, we have synthesized a stable, high affinity, 125I-radiolabeled TXA2/PGH2 receptor agonist, [1S-(1 alpha, 2 beta (5Z), 3 alpha(1E,3S*), 4 alpha)]-7-[3-(3-hydroxy-4-(4'-iodophenoxy)-1-butenyl)-7-oxabicyclo - [2.2.1]heptan-2-yl]-5-heptenoic acid (I-BOP). I-BOP induced shape change, increased intracellular free calcium concentrations and aggregated isolated human platelets (EC50 = 0.21 +/- 0.05 nM, n = 3; 4.1 +/- 1.1 nM, n = 4; 10.8 +/- 3 nM, n = 9, respectively). The kinetically determined Kd was 1.02 +/- 0.33 nM (kobs = 0.19 +/- 0.05 min-1, k-1 = 0.097 +/- 0.02 min-1, k1 = 0.119 +/- 0.03 min-1 M, n = 4). Equilibrium binding studies of [125I]BOP to isolated human platelets indicated one class of high affinity sites, Kd = 2.2 +/- 0.3 nM and a maximum binding of 0.028 +/- 0.002 x 10(-12) mol/10(7) platelets (1699 +/- 162 sites/platelet, n = 9).(ABSTRACT TRUNCATED AT 250 WORDS)

4'-Hydroxypropranolol sulfate was recently identified as a major metabolite of propranolol (Inderal). In order to confirm the structure and to further study disposition and biological activity, we have synthesized 8 with use of 1,4-naphthoquinone as the starting material. Reduction and alkylation with benzyl iodide gave 4-(benzyloxy)naphthol. Sulfation and chlorosulfuric acid in N,N-dimethylaniline gave potassium 1-(benzyloxy)-4-naphthol sulfate. Catalytic hydrogenation, alkylation with [[[(trifluoromethyl)sulfonyl]oxy]methyl]oxirane, and amination in isopropylamine gave 8. Racemic 8 was found to be 100-1000 times less potent than racemic propranolol as a beta-adrenergic receptor blocking agent in the dog.