LSD and phenithylamine hallucinogens: New structural analogy and implications for receptor geometry

The hallucinogen analog $\text{trans}$-2-(2,5-dimethoxy-4-methylphenyl)-cyclopropylamine (DMCPA) was resolved into its two optical isomers. Examination of selected behavioral profiles in mice and cats clearly showed that the levorotatory isomer of DMCPA possesses stereoselective activity when compared with the dextro isomer. The results parallel those obtained using the isomers of the known hallucinogen, DOM (STP) in the same animal models. Comparison of the optical rotatory dispersion (ORD) curves for the N-(5-bromosalicylidene) derivatives of DMCPA and $\text{trans}$-2-phenylcyclopropylamine (tranylcypromine) of known absolute configuration established the configuration of DMCPA to be (-)-1R,2S. This stereoselective activity and proof of absolute configuration lend strong support to a new model of the hallucinogen receptor. The proposed model suggests possible structural similarities between LSD and phenethylamine hallucinogens.     

Identification of the para-isomer of tyramine in rat brain

By means of thin layer chromatography and mass spectrometry of dansylated tissue extracts tyramine has been identified in different regions of the rat CNS. The isomer present is the $\text{para}$-tyramine; no $\text{ortho}$- or $\text{meta}$-tyramine could be found.     

Inhibition of porphobilinogen synthase by heme and an enol-ether amino acid

The enol-ether amino acid, L-2-amino-4-methoxy-$\text{trans}$-butenoic acid (AMTB) is an inhibitor of porphobilinogen synthase (PBG synthase) when added prior to the addition of the substrate δ-aminolevulinic acid. The inhibition of PBG synthase by several stereoisomers and analogues of AMTB was investigated to determine those structural features of AMTB which may be necessary for inhibition. The D-$\text{trans}$ isomer was also an inhibitor after preincubation, whereas the L-$\text{cis}$ isomer inhibited with or without preincubation. The amino acid analogues, DL-vinylglycine, DL-2-aminobutanoic acid, the reduced form of L-2-amino-4-methoxy-$\text{trans}$-3-butenoic acid, L-2-amino-4-(2-aminoethoxy)-$\text{trans}$-3-butenoic acid and its reduced congener did not inhibit PBG synthase even with preincubation. This structure activity relationship indicates that the $\text{trans}$ double bond and methoxy moiety of L-2-amino-4-methoxy-$\text{trans}$-3-butenoic acid are probably required for inhibition.Heme, when preincubated with PBG synthase, was an inactivator of the enzyme. However, when both L-2-amino-4-methoxy-$\text{trans}$-3-butenoic acid and heme were simulatneously preincubated with PBG synthase, inactivation of the enzyme was greater than with either compound separately. The possibility of multiple catalytic sites was suggested by the use of multiple inhibition kinetics in the presence of heme and L-2-amino-4-methoxy-$\text{trans}$-3-butenoic acid.     

Chloramphenicol damages bacterial DNA.

L(+)-$\text{threo}$-chloramphenicol induces reversion of His^?$\text{Salmonella typhimurium}$ strains TA100 and TA1535 in the conventional Ames' assay without microsomal activation. Any mutagenicity of D(?)-$\text{threo}$-chloramphenicol was masked by toxicity. Similarly, a sensitive fluctuation test showed mutagenesis with L(+)-$\text{threo}$-chloramphenicol at concentrations of 0.5 μM and above but the D(?) isomer proved to be toxic even at these low levels. The L(+) isomer caused single strand breaks in the DNA of $\text{Escherichia coli}\text{B}\text{r}$ and $\text{Salmonella typhimurium}$ strains TA1535, TA100 and TA1976. The D(?) isomer caused breaks in $\text{Escherichia coli}\text{B}\text{r}$ and $\text{Salmonella typhimurium}$ TA1976 although it was less effective and it did not produce DNA breaks in TA1535 or TA100.     

Role of protein binding and pharmacokinetics in the lack of correlation between in vitro inhibition of PG-synthetase and in vivo antiinflammatory activity of a homologous series of nonsteroidal antiinflammatory compounds.

The antiinflammatory activity of a homologous series of α-alkyl substituted [4-(1-oxo-2-iso-indolinyl)-phenyl]-acetic acid has been assayed by some $\text{in}$$\text{vitro}$ and $\text{in}$$\text{vivo}$ tests.These compounds were shown to be particularly active in inhibiting prostaglandin biosynthesis from bovine seminal vesicles, and their potency was seen to increase as the size of the substituents in the side chain increased.The antiinflammatory activity $\text{in}$$\text{vivo}$ is not correlated with $\text{in}$$\text{vitro}$ inhibition of PG-synthetase. Discussion of the data takes into account the plasma protein binding and pharmacokinetics of these compounds.     

Leukotriene A: stereochemistry and enzymatic conversion to leukotriene B

Leukotriene A was assigned the structure 5(S)-$\text{trans}$-5,6-oxido-7,9-$\text{trans}\text{-11,14-}\text{cis}$-eicosatetraenoic acid by the enzymatic conversion of a synthetic product of known stereochemistry into the naturally occurring isomer of 5(S),12(R)-dihydroxy-6,8,10,14-eicosatetraenoic acid in human polymorphonuclear leukocytes.     

Pharmacologic identification of muscarinic receptors in the pylorus of the cat by binding of [3H]-quinuclidinyl benzilate

Muscarinic receptors in the smooth muscle of the cat pylorus (pyloric sphincter) were identified by binding of the ligand (±) [³H]-quinuclidinyl benzilate ([³H]-QNB). Receptor related binding of [³H]-QNB reached steady-state in thirty minutes at 37°C, was saturable, showed pharmacologic specificity and was stereoselective. An apparent equilibrium dissociation constant, K_D, of 1.9 ± 0.3 nM and maximum receptor concentration of 122 ± 13 femtomoles per mg of protein (means ± S.E.M.) were determined from Scatchard plots of [³H]-QNB binding. Hill coefficients of 0.99 and 1.01 indicated the absence of cooperative interactions. The muscarinic antagonists atropine and propantheline inhibited binding with IC₅₀ values in the nanomolar range, whereas bethanechol was over four orders of magnitude less potent. Noncholinergic agents had little or no effect on [³H]-QNB binding. The $\text{levo}$ isomer of QNB was about seventy times more effective at inhibiting binding than its $\text{dextro}$ isomer while $\text{dextro}$ benzetimide was greater than two thousand fold more active than $\text{levo}$ benzetimide. The isomers of another anticholinergic compound, tropicamide, also competed for [³H]-QNB binding sites in a stereoselective manner, the $\text{levo}$ isomer being eighty-five times more potent than the $\text{dextro}$ isomer.     

Stereochemical course of the biosynthesis of 1-aminocyclopropane-1-carboxylic acid. I. Role of the asymmetric sulfonium pole and the α-amino acid center

The substrate stereospecificity of 1-aminocyclopropane-1-carboxylic acid synthase, a pyridoxal phosphate-containing enzyme, from the pericarp tissue of $\text{Lycopersicon esculentum}$ (tomatoes) was studied using the various stereoisomers of $\text{S}$-adenosylmethionine (AdoMet) at both the sulfonium pole and the amino acid center. The data indicate that only the naturally occurring isomer (?)Ado-L-Met acts as substrate (Km = 20±5 μM). Both (±)Ado-D-Met and (+)Ado-L-Met were inactive as substrates. The (+)Ado-L-Met (Ki = 15±5 μM) was found to be a potent inhibitor of ACC synthase whereas (±)Ado-D-Met (Ki = 70±20 μM) was less active as an inhibitor. This active isomer has the ($\text{S}$) configuration at both the sulfur and the α-carbon of the amino acid portion of AdoMet.     

Adult ovaries of Locusta migratoria contain the sequence of biosynthetic intermediates for ecdysone

Ovaries of adult $\text{Locusta migratoria}$ have recently been shown to produce impressive amounts of ecdysone together with low polarity ecdysteroids, some of which cross-react with ecdysone in our RIA. A gas chromatographic-mass spectrometric analysis of extracts from ovaries of $\text{Locusta}$ has shown the presence of following compounds (less polar than ecdysone): 2-deoxy-ecdysone, 2,22-bis-deoxy-ecdysone, 2, 22, 2 5-tri-deoxy-ecdysone, 2, 14, 22, 2 5-tetra-deoxy-ecdysone. No other related ecdysteroids were present in our extracts. Cholesterol is used by $\text{Locusta}$ ovaries as a precursor for ecdysone biosynthesis, as our previous studies with labelled products have shown, and we propose that the compounds detected in the present work represent biosynthetic intermediates between cholesterol and ecdysone in $\text{Locusta}$ ovaries.     

Structure activity relationship of lidocaine type local anesthetics.

The structure activity relationship of nine compounds were studied and compared to lidocaine. The extent of local anesthetic activity was ascertained by the tail pinch method in mice, and by the isolated frog sciatic nerve method. The effective and lethal dose in 50% of the animals was also determined. Three of the nine compounds appeared to possess significant local anesthetic activity in the $\text{in vivo}$ studies and thus were selected for further investigation $\text{in vitro}$. The $\text{in vivo}$ studies also indicated that two of the three were more toxic than lidocaine. The $\text{in vitro}$ results demonstrated that methyl substitution at positions 2,3 and 5 on the benzene ring produced a compound of slightly more anesthetic potency in an acid medium. At pH 7.8 all three compounds approached the potency of lidocaine. These data indicate that methyl substitution at other than the ortho position of the benzene ring generally results in compounds of lesser local anesthetic activity while tending to increase the toxicity.     

Studies in antifertility agents — Part XLI: Secosteroids — X: Syntheses of various stereoisomers of (±) 2,6β-diethyl-7α-ethynyl-3-(p-hydroxyphenyl)-trans-bicyclo[4.3.0]nonan-7β-ol

The syntheses of (±) 2α,6β-diethyl-7α-ethynyl-3α-($\text{p}$-hydroxyphenyl)-$\text{trans}$-bicyclo[4.3.0]nonan-7β-ol ($\text{8}$), (±)2β,6β-diethyl-7α-ethynyl-3β-($\text{p}$-methoxyphenyl)-$\text{trans}$-bicyclo[4.3.0]nonan-7β-ol ($\text{12}$) and (±) 2α,6β-diethyl-7α-ethynyl-3β-($\text{p}$-hydroxyphenyl)-$\text{trans}$-bicyclo[4.3.0]nonan-7β-ol ($\text{18}$) and their derivatives, which are essentially B-seco-steroids having $\text{cis-anti-trans}\text{,}\text{cis-syn-trans}$ and $\text{trans-anti-trans}$ geometries have been carried out. A study of their antiimplantation activities (AI) and receptor binding affinities (RBA) show that $\text{trans-anti-trans}$ compounds are biologically most potent, followed by the corresponding $\text{cis-anti-trans}$ and $\text{cis-syn-trans}$ compounds. The most potent compound $\text{18}$ is active at 1 mg/kg in rats. Introduction of 7α-ethynyl group increases their AI activity; however, no significant effect on their RBA is observed.     

Novel nucleotides from E.coli isolated and partially characterized

Two new nucleotides have been found in the formic acid extracts of $\text{Escherichia}\text{coli}$, $\text{Clostridium}\text{botulinum}$, $\text{Bacillus}\text{subtilis}$ and $\text{Rhodospirillum}\text{rubrum}$ isolated during log phase growth. In $\text{E.}\text{coli}$ the compounds are present at all times during cell growth but increase in amount during interruption of aeration and transition to stationary phase. They migrate close to ppGpp during one dimensional chromatography on PEI cellulose but are clearly separated from ppGpp by paper chromatography. The compounds are unstable on PEI cellulose and purification was effected by chromatography on A25 Sephadex ion exchange columns. Preliminary characterization indicates that the predominant compound is a dinucleoside polyphosphate and that both compounds contain a modified adenosine nucleoside.     

Isolation and preliminary characterization of 1-O-Octadec-cis-11-enyl glycerol from Paramecium phospholipids

1-O-Octadec-$\text{cis}$-11-enyl glycerol, paramecyl alcohol, was isolated from $\text{Paramecium}\text{tetraurelia}$ and $\text{P.}\text{caudatum}$ phospholipids. This isomer of 1-O-octadec-9-enyl glycerol, selachyl alcohol, had not been previously reported as a component of naturally-occurring phospholipids. The preliminary characterization of the structure of this compound was determined by 1) gas chromatography of the parent compound as well as the products following hydrogenation, ozonolysis and oxidation, 2) mass spectrometry of the parent compound and an oxidation product, 3) infrared spectroscopy, and 4) proton magnetic resonance.     

Differentiation by cholinergic stimulation of positive inotropic actions mediated via alpha- and beta-adrenoceptors in the rabbit heart.

In the isolated rabbit papillary muscle, experiments were carried out in order to elucidate whether or not cholinergic stimulation produces a differential antagonistic action on the positive inotropic effects mediated $\text{via}$ β- and α-adrenoceptor stimulation. Carbachol (0.1–30 μM) alone scarcely affected the basal tension developed. The postive inotropic effects of phenylephrine (30 μM) in the presence of phentolamine and of isoprenaline, which were mediated $\text{via}$ β-adrenoceptors, were markedly inhibited by carbachol. Carbachol (3 μM) shifted the dose-response curve for isoprenaline in a parallel manner, and that for phenylephrine with phentolamine to the right and downwards. Carbachol administered during induction of the positive inotropic effects $\text{via}$ α-adrenoceptors by phenylephrine (30 μM) with pindolol or by methoxamine failed to inhibit these effects and increased further the tension developed. The dose-response curve for phenylephrine determined in the presence of pindolol was not affected by carbachol. The present results indicate that the cholinergic antagonism of the adrenergic action on the contractility of the mammalian ventricular myocardium is exerted specifically to the β-adrenoceptor-mediated action, but not to the α-adrenoceptor-mediated one.     

Cell surface antigens on erythroid cells: A comparison of normal and anemic (WW) mice

Cell surface antigens of normal and anemic ($\text{W}\text{W}$) mouse erythroid cells have been examined in cytotoxicity assays with two rat antisera. When tested on fetal liver cells, a rat anti-erythroblast serum recognized antigen(s) present on erythroid cells early in development, while rat anti-adult red blood cell serum recognized antigen(s) present on mature erythroid cells. Each of these sera had different activity on normal (+/+ or $\text{W}\text{+}$) as compared to anemic ($\text{W}\text{W}$) erythroid cells.     

Synthesis and relative stereochemistry of the four mercapturic acids derived from styrene oxide and N-acetylcysteine

The chemical reaction between (±)-styrene oxide and N-acetylcysteine produces both positional isomers ($\text{1}$ and $\text{2}$) as a mixture of diastereoisomers with a preference for the benzylic thioether isomer $\text{1}$ (2 : 1). Synthesis of the mercapturic acid conjugates from either (+)- or (?)-styrene oxide produces only two of the four possible stereoisomers. The single diastereoisomers of $\text{1}$ and $\text{2}$ were separated by high pressure liquid chromatography (HPLC) and identified by ¹H- and ¹³C-nuclear magnetic resonance (NMR). The relative stereochemistry at the benzylic carbon center of the mercapturic acid conjugates was assigned on the basis of the established chemical correlation between optically pure styrene oxide and its precursor mandelic acid, and considerations on the mechanism of ring opening of epoxides by sulfur nucleophiles. The stereochemical definition of the isomers $\text{3}$–$\text{6}$ should prove useful in investigations of the biotransformation of the glutathione (GSH) conjugates of styrene oxide.     

Action of insulin analogues on cultured human fibroblasts reflects biological potency.

The biological sensitivity of cultured human skin-derived fibroblasts was examined in terms of the ability of insulin and insulin analogues to stimulate the uptake of alpha-aminoisobutyrate in these cells. The relative biological activity measured: insulin=desalanine insulin > proinsulin > desoctapeptide insulin parallels exactly the relative activity of these compounds on fat and muscle preparations both $\text{in}$$\text{vitro}$ and $\text{in}$$\text{vivo}$. Inactive insulin analogues do not stimulate alpha-aminoisobutyrate uptake. It is concluded that the chemical specificity of human fibroblast insulin receptors is retained in culture and that the biological responsiveness (alpha-aminoisobutyrate uptake) of such cells to insulin should prove useful for comparative studies of receptors obtained from different individuals.     

Inhibition of biogenic amines uptake by imipramine,desipramine, 2 OH-imipramine and 2 OH-desipramine in rat brain

The tricyclic antidepressant imipramine and its metabolites desipramine, 2-hydroxyimipramine and 2-hydroxydesipramine are all pharmacologically active in the central nervous system as determined by $\text{in vitro}$ inhibition of biogenic amine uptake by rat brain synaptosomes and their $\text{in vivo}$ effect on spontaneous and forced motor activity. Since $\text{in vivo}$ hydroxylation of both imipramine and desipramine produced compounds of similar pharmacological activity as the parent compounds, these results suggest that clinical studies relating plasma levels of tricyclic antidepressants to efficacy should also take into consideration the levels of hydroxylated metabolites.     

Enzymatic resolution and cholinergic properties of (±)3-quinuclidinol derivatives

Resolution of (±)3-quinuclidinol into its enantiomers was obtained, at relatively high yield, based on the stereoselective enzymatic hydrolysis of R-(?)-3-quinuclidinyl butyrate by horse serum butyrylcholinesterase. The S-(+) isomer of 3-quinuclidinol was obtained from the racemate of 3-quinuclidinyl butyrate by a complete digestion of the (?) ester; the R-(?) isomer of 3-quinuclidinol was prepared by a partial hydrolysis of the racemate. The enantiomers obtained by this method were of high optical purity ([α]_D²⁵ = (+)46°). The cholinergic interactions of the benzilate esters of the 3-quinuclidinol enantiomers were characterized in mice $\text{in vivo}$ and in isolated guinea pig ileum. The R to S potency ratio is around 10–15 for the muscarinic antagonist 3-quinuclidinyl benzilate (QNB) in the $\text{in vivo}$ experiments compared to the reported ratio of 100 in competition experiments $\text{in vitro}$.     

Interactions between polynucleotides and platinum (II) complexes

Reaction of either $\text{cis}$ or $\text{trans}$ Pt(NH₃)₂Cl₂ with poly(A) in dilute aqueous solution leads to quantitative precipitation of the polymer at Pt/nucleotide ratios above 0.5. It is proposed that at ratios less than this, intramolecular binding of one Pt to two bases is favored; at higher ratios, intermolecular cross-linking becomes important and precipitation results. The absence of isomer selectivity in precipitation implies that the biological specificity of the $\text{cis}$ form results from a process other than cross-linking of polynucleotide strands. Other observations suggest that the coordinated ammonia of nucleotide-platinum(II) ammine complexes may be unusually labile.