Comparison of the cytotoxicities of Fusarium metabolites and Alternaria metabolite AAL-toxin to cultured mammalian cell lines

The structure of pyramidatine [1], a new bisamide alkaloid from leaves of Aglaia pyramidata, was determined through extensive nmr studies, including homonuclear COSY, NOESY, APT, HETCOR, and selective INEPT techniques. Revision of the 13C-nmr assignment of piriferine [2], an alkaloid previously isolated from A. pirifera, was achieved by examination of several 2D nmr spectra (homonuclear COSY, NOESY, and HETCOR) and confirmed by selective INEPT nmr experiments. Evaluation of the cytotoxic potential of the two alkaloids, along with two other bisamides from Aglaia odorata, odorine [3] and 5'-epi-odorine [4], was carried out in eleven human cancer cell lines. None of these bisamides showed significant cytotoxicity. Nevertheless, piriferine [2], odorine [3], and 5'-epi-odorine [4] were found to inhibit the growth of the vinblastine-resistant KB cells by enhancing the anticancer activity of vinblastine.     

The delta-opioid receptor regulates activity of ryanodine receptors in the human neuroblastoma cell line SK-N-BE

Recent studies have demonstrated that opioid agonists affect the cytosolic Ca2+ concentration ([Ca2+]i) either by regulating plasma membrane Ca(2+)-channel activity or by mobilizing intracellular Ca2+ stores. The present report documents the [Ca2+]i increase induced by opioid agonists in a human neuroblastoma cell line, SK-N-BE, expressing delta-opioid receptors. In the presence, as well as in the absence, of extracellular Ca2+, opioid agonists enhanced significantly [Ca2+]i, whereas carbachol, known to mobilize specifically inositol 1,4,5-trisphosphate-sensitive intracellular Ca2+ stores, acted only in the presence of extracellular Ca2+. The opioid-induced increase in [Ca2+]i was not affected by treatments modifying the trimeric Gl, Go, and Gs protein transduction mechanisms or the activity of adenylyl cyclase. The Ca(2+)-ATPase pump-inhibiting sesquiterpene lactone, thapsigargin, did not modify the opioid-induced [Ca2+]i response, whereas it abolished the effects of carbachol. The Ryana speciosa alkaloid, ryanodine, at concentrations known to block endoplasmic reticulum ryanodine receptors, decreased significantly the response to opioids without affecting the effects of carbachol. Thus, our results suggest that, in SK-N-BE cells, delta-opioid receptors mobilize Ca2+ from intracellular ryanodine-sensitive stores and the mechanism involved is independent of Gl/Go Gs proteins and protein kinase A activation.     

Isokotanins A-C: new bicoumarins from the sclerotia of Aspergillus alliaceus

Three new bicoumarin metabolites, isokotanins A [1], B [2], and C [3], were isolated from the sclerotia of Aspergillus alliaceus. Isokotanin A is a regioisomer of the known bicoumarin kotanin [4]. The structures and spectral assignments for 1-3 were determined on the basis of selective INEPT, HMQC, and NOESY nmr data, as well as by chemical interconversions. Isokotanins B and C show activity against the corn earworm Helicoverpa zea and the dried fruit bettle Carpophilus hemipterus. The known compounds kotanin [4], desmethylkotanin [5], nominine, and paspaline were also isolated from extracts of A. alliaceus sclerotia.     

Four new dimeric peptide alkaloids, anchinopeptolides B-D, and cycloanchinopeptolide C, congeners of anchinopeptolide A, from the Mediterranean marine sponge Anchinoe tenacior

Following the characterization of anchinopeptolide A[1], three new congeneric dimeric peptide alkaloids, named anchinopeptolides B [2], C[3], and D[4], have been isolated from the Mediterranean sponge Anchinoe tenacior. A fourth compound, cycloanchinopeptolide C[5], which is related to anchinopeptolide C[3] by a head-to-head intramolecular [2+2] cyclo-addition reaction, has also been isolated. The structures of these peptide alkaloids have been elucidated on the basis of spectral evidence. Anchinopeptolides bind to the somatostatin, human B2 bradykinin, and neuropeptide Y receptors.     

Sesquiterpenes from the leaves of Tithonia diversifolia

Two new compounds, a germacrane sesquiterpene, 1-acetyltagitinin A (1), and a guaianane sesquiterpene, 8beta-isobutyryloxycumambranolide (2), were isolated from leaves of Tithonia diversifolia, together with two known compounds, methyl 3alpha-acetoxy-4alpha-hydroxy-11(13)-eudesmen-12-oa te and tagitinin A. The structures of compounds 1 and 2 were elucidated on the basis of spectral and chemical evidence.     

Bioactive metabolites from Sicilian marine fennel, Crithmum maritimum

Bioactivity-guided fractionation of the lipid extract of Crithmum maritimum using the brine shrimp lethality assay led to the isolation of three bioactive compounds. Two of these are known C17 polyacetylenic metabolites, falcarinol [1] and falcarindiol [2], previously isolated from several species of the Umbelliferae and Araliaceae. The third active principle was identified as O-geranylvanillin [3], an aromatic ether described in the literature as a synthetic compound but unknown as a natural product. Cytotoxic activity of the pure compounds was significant for 1 and 2, much less intense for 3.     

New azacyclopropene derivatives from Dysidea fragilis collected in Pohnpei

The sponge Dysidea fragilis from Pohnpei contained four azacyclopropene derivatives, (4E)-S-dysidazirine [2], which is the optical enantiomer of the known compound dysidazirine [1], (4Z)-dysidazirine [3], (4E)-S-antazirine [4], and (4Z)-antazirine [5]. The structures of the new compounds were elucidated by interpretation of spectral data.     

4-Diazinyl- and 4-pyridinylimidazoles: potent angiotensin II antagonists. A study of their activity and computational characterization

A series of N-[biphenylyl(tetrazolyl)methyl]-2-butylimidazoles containing variously substituted diazine or pyridine moieties either as their free bases or N-oxide derivatives attached to the 4-position of the imidazole ring was synthesized and tested for interaction with the AT1 receptors of rat adrenal cortex membranes (receptor binding assay). Some compounds were then chosen for further evaluation in vivo in the A II-induced pressor response in conscious normotensive rats. The most potent in the AT1 binding assay were found to be compounds in which the diazine or pyridine ring nitrogen is adjacent to the point of attachment between the two heteroaromatic rings such as 2-butyl-4-(3,6-dimethylpyrazin-2-yl)-1-[[2'-(1H-tetrazol-5-y l)-biphenyl-4- yl]methyl]-1H-imidazole (3b) or 2-butyl-4-[5-(methoxycarbonyl)pyrid-2-yl]-1-[[2'-(1H-tetrazol++ +-5- yl)biphenyl-4-yl]methyl]-1H-imidazole (6c). The binding affinities and oral activities of the pyridine N-oxide imidazoles in which a stabilizing group ortho to the pyridine ring nitrogen is present were markedly improved as in 2-butyl-4-[(3-methoxycarbonyl)-6-methyl-N-oxopyridin-2-yl]-1-[[2'- (1H- tetrazol-5-yl)biphenyl-4-yl]methyl]-1H-imidazole 31b. Molecular modeling studies were carried out to determine the molecular electrostatic potential values of related model systems and to correlate their receptor interaction energies with the observed activities of our compounds.     

Studies on the acetogenins of Formosan annonaceous plants. II. Cytotoxic acetogenins from Annona reticulata

Using cytotoxicity as a guide to fractionation, one novel acetogenin, annoreticuin-9-one [3], and four known cytotoxic acetogenins, squamone [4], solamin [5], annomonicin [6] and rolliniastatin 2 [7], were isolated from active extracts of the leaves of the Formosan plant Annona reticulata. Their structures were elucidated on the basis of uv, ir, 1H- and 13C-nmr, and ms data of the natural compounds and their derivatives.     

Makaluvamines H-M and damirone C from the pohnpeian sponge Zyzzya fuliginosa

Seven new pyrroloiminoquinone alkaloids, makaluvamines H-M [19-24] and damirone C[25], together with the known compounds, makaluvamines C[13], D[14], and G[17], were isolated from the sponge Zyzzya fuliginosa collected at Nahpali Island, Pohnpei, Micronesia. The structures of the new compounds were elucidated by interpretation of spectral data. The chemotaxonomic relationships involving the makaluvamines and related pyrroloiminoquinone alkaloids are discussed.     

Studies towards the synthesis of the hypermodified nucleoside of rat liver phenylalanine transfer ribonucleic acid: improved synthesis of the base beta-hydroxywybutine

An improved synthesis of the key intermediates (3 and 8) for the synthesis of beta-hydroxywybutines [[R-(R*,S*)]- and [S-(R*,R*)]-4], the most probable structures for the minor base from rat liver tRNA(Phe), has been achieved by the Wittig reaction between 1-benzyl-7-formylwye (1) and the phosphorane derived from (R)-2-[(methoxycarbonyl)amino]-3-(triphenylphosphonio)propanoate (10), followed by methylation, OsO4 oxidation, and cyclocondensation with COCl2 in the presence of pyridine. The racemic forms of beta-hydroxywybutines [(R*,S*)- and (R*,R*)-4], which were required for the determination of the optical purity of [R-(R*,S*)]- and [S-(R*,R*)]-4 by means of chiral HPLC, were conveniently prepared through pyrolysis of the cyclic carbonate 3 followed by NaBH4 reduction and catalytic hydrogenolysis. The samples of [R-(R*,S*)]- and [S-(R*,R*)]-4 were thus shown to be optically pure.     

Human growth hormone-releasing hormone hGHRH(1-29)-NH2: systematic structure-activity relationship studies

Two complete and two partial structure-activity relationship scans of the active fragment of human growth hormone-releasing hormone, [Nle27]-hGHRH(1-29)-NH2, have identified potent agonists in vitro. Single-point replacement of each amino acid by alanine led to the identification of [Ala8]-, [Ala9]-, [Ala15]- (Felix et al. Peptides 1986 1986, 481), [Ala22]-, and [Ala28, Nle27]-hGHRH(1-29)-NH2 as being 2-6 times more potent than hGHRH(1-40)-OH (standard) in vitro. Nearly complete loss of potency was seen for [Ala1], [Ala3], [Ala5], [Ala6], [Ala10], [Ala11], [Ala13], [Ala14], and [Ala23], whereas [Ala16], [Ala18], [Ala24], [Ala25], [Ala26], and [Ala29] yielded equipotent analogues and [Ala7], [Ala12], [Ala17], [Ala20], [Ala21], and [Ala27] gave weak agonists with potencies 15-40% that of the standard. The multiple-alanine-substituted peptides [MeTyr1,Ala15,22,Nle27]-hGHRH(1-29)-NH2 (29) and [MeTyr1,Ala8,9,15,22,28,Nle 27]-hGHRH(1-29)-NH2 (30) released growth hormone 26 and 11 times, respectively, more effectively than the standard in vitro. Individual substitution of the nine most potent peptides identified from the Ala series with the helix promoter alpha-aminoisobutyric acid (Aib) produced similar results, except for [Aib8] (doubling vs [Ala8]), [Aib9] (having vs [Ala9]), and [Aib15] (10-fold decrease vs [Ala15]). A series of cyclic analogues was synthesized having the general formula cyclo(25-29)[MeTyr1,-Ala15,Xaa25,Nle27,Yaa29+ ++]-GHRH(1-29)-NH2, where Xaa and Yaa represent the bridgehead residues of a side-chain cystine or [i-(i + 4)] lactam ring. The ring size, bridgehead amino acid chirality, and side-chain amide bond location were varied in this partial series in an attempt to maximize potency. Application of lactam constraints in the C-terminus of GHRH(1-29)-NH2 identified cyclo(25-29)[MeTyr1,Ala15,DAsp25,Nle27,Orn29+ ++]-hGHRH(1-29)-NH2 (46) as containing the optimum bridging element (19-membered ring) in this region of the molecule. This analogue (46) was 17 times more potent than the standard. Equally effective was an [i-(i + 3)] constraint yielding the 18-membered ring cyclo(25-28)[MeTyr1,Ala15,Glu25,Nle,27Lys28]- hGHRH-(1-29)-NH2 (51) which was 14 times more potent than the standard. A complete [i-(i + 3)] scan of cyclo(i,i + 3)[MeTyr1,Ala15,Glui,Lys(i + 3),Nle27]-hGHRH(1-29)-NH2 was then produced in order to test the effects of a Glu-to-Lys lactam bridge at all points in the peptide. Of the 26 analogues in the series, 11 had diminished potencies of less than 10% that of the agonist standard, 4 were weak agonists (15-40% relative potency), and 4 analogues were equipotent to the standard. The 7 most potent analogues ranged in potency from 3 to 14 times greater than that of the standard and contained the [i-(i + 3)] cycles between residues 4-7, 5-8, 9-12, 16-19, 21-24, 22-25, and 25-28. The combined results from these systematic studies allowed for an analysis of structural features in the native peptide that are important for receptor activation. Reinforcement of the characteristics of amphiphilicity, helicity, and peptide dipolar effects, using recognized medicinal chemistry approaches including introduction of conformational constraints, has resulted in several potent GHRH analogues.     

Molecular characterization of berberine bridge enzyme genes from opium poppy

In Papaver somniferum (opium poppy) and related species, (S)-reticuline serves as a branch-point intermediate in the biosynthesis of numerous isoquinoline alkaloids. The berberine bridge enzyme (BBE) ([S]-reticuline:oxygen oxidoreductase [methylene bridge forming], EC 1.5.3.9) catalyzes the stereospecific conversion of the N-methyl moiety of (S)-reticuline into the berberine bridge carbon of (S)-scoulerine and represents the first committed step in the pathway leading to the antimicrobial alkaloid sanguinarine. Three unique genomic clones (bbe1, bbe2, and bbe3) similar to a BBE cDNA from Eschscholtzia californica (California poppy) were isolated from opium poppy. Two clones (bbe2 and bbe3) contained frame-shift mutations of which bbe2 was identified as a putative, nonexpressed pseudogene by RNA blot hybridization using a gene-specific probe and by the lack of transient expression of a chimeric gene fusion between the bbe2 5' flanking region and a beta-glucuronidase reporter gene. Similarly, bbe1 was shown to be expressed in opium poppy plants and cultured cells. Genomic DNA blot-hybridization data were consistent with a limited number of bbe homologs. RNA blot hybridization showed that bbe genes are expressed in roots and stems of mature plants and in seedlings within 3 d after germination. Rapid and transient BBE mRNA accumulation also occurred after treatment with a fungal elicitor or with methyl jasmonate. However, sanguinarine was found only in roots, seedlings, and fungal elicitor-treated cell cultures.     

"The experience of "forgetting" childhood abuse: A national survey of psychologists": Correction.

Reports 2 errors in the Results section of the original article by S. Feldman-Summers and K. S. Pope (Journal of Consulting and Clinical Psychology, 1994[June], Vol 62[3], 636–639). The 1st sentence of paragraph 2 in the subsection Reported Abuse should read, "Sexual abuse was reported by 22.7% of the women and by 16.5% of the men, for a total of 20% of the sample.' A correction is also provided for the final sentence of paragraph 3 in the subsection Forgotten Abuse. (The following abstract of this article originally appeared in record 1994-39093-001.) A national sample of psychologists were asked whether they had been abused as children and, if so, whether they had ever forgotten some or all of the abuse. Almost a quarter of the sample (23.9%) reported childhood abuse, and of those, approximately 40% reported a period of forgetting some or all of the abuse. The major findings were that (1) both sexual and nonsexual abuse were subject to periods of forgetting; (2) the most frequently reported factor related to recall was being in therapy; (3) approximately one half of those who reported forgetting also reported corroboration of the abuse; and (4) reported forgetting was not related to gender or age of the respondent but was related to severity of abuse. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Role of MgADP in the development of diastolic dysfunction in the intact beating rat heart

Sarcomere relaxation depends on dissociation of actin and myosin, which is regulated by a number of factors, including intracellular [MgATP] as well as MgATP hydrolysis products [MgADP] and inorganic phosphate [Pi], pHi, and cytosolic calcium concentration ([Ca2+]c). To distinguish the contribution of MgADP from the other regulators in the development of diastolic dysfunction, we used a strategy to increase free [MgADP] without changing [MgATP], [Pi], or pHi. This was achieved by applying a low dose of iodoacetamide to selectively inhibit the creatine kinase activity in isolated perfused rat hearts. [MgATP], [MgADP], [Pi], and [H+] were determined using 31P NMR spectroscopy. The [Ca2+]c and the glycolytic rate were also measured. We observed an approximately threefold increase in left ventricular end diastolic pressure (LVEDP) and 38% increase in the time constant of pressure decay (P < 0.05) in these hearts, indicating a significant impairment of diastolic function. The increase in LVEDP was closely related to the increase in free [MgADP]. Rate of glycolysis was not changed, and [Ca2+]c increased by 16%, which cannot explain the severity of diastolic dysfunction. Thus, our data indicate that MgADP contributes significantly to diastolic dysfunction, possibly by slowing the rate of cross-bridge cycling.     

Naamidine A is an antagonist of the epidermal growth factor receptor and an in vivo active antitumor agent

The known 2-aminoimidazole alkaloid naamidine A (1) was isolated from a Fijian Leucetta sp. sponge as an inhibitor of the epidermal growth factor (EGF) receptor. The compound exhibited potent ability to inhibit the EGF signaling pathway and is more specific for the EGF-mediated mitogenic response than for the insulin-mediated mitogenic response. Evaluation in an A431 xenograft tumor model in athymic mice indicated that naamidine A exhibited at least 85% growth inhibition at the maximal tolerated dose of 25 mg/kg. Preliminary mechanism of action studies indicate that the alkaloid fails to inhibit the binding of EGF to the receptor and has no effect on the catalytic activity of purified c-src tyrosine kinase.     

Exhaled nitric oxide (NO) is reduced shortly after bronchoconstriction to direct and indirect stimuli in asthma

Exhaled NO is increased in patients with asthma and may reflect disease severity. We examined whether the level of exhaled NO is related to the degree of airway obstruction induced by direct and indirect stimuli in asthma. Therefore, we measured exhaled NO levels before and during recovery from histamine and hypertonic saline (HS) challenge (Protocol 1) or histamine, adenosine 5'-monophosphate (AMP), and isotonic saline (IS) challenge (Protocol 2) in 11 and in nine patients with mild to moderate asthma, respectively. The challenges were randomized with a 2-d interval. Exhaled NO and FEV1 were measured before and at 4, 10, 20, and 30 min after each challenge. NO was measured during a slow VC maneuver with a constant expiratory flow of (0.05 x FVC)/s against a resistance of 1 to 2 cm H2O. Baseline exhaled NO levels were not significantly different between study days in Protocol 1 (mean +/- SD: 4.8 +/- 1.8 ppb [histamine] versus 5.4 +/- 2.1 ppb [HS], p = 0.4) or in Protocol 2 (7.9 +/- 4.7 ppb [histamine], 8.3 +/- 5.2 ppb [AMP], and 7.2 +/- 3.7 ppb [IS], p = 0.7). A significant reduction in exhaled NO was observed directly after HS (mean +/- SEM: 39.2 +/- 3.9 %fall) and AMP challenge (32.3 +/- 7.3 %fall) (MANOVA, p < 0.001), respectively, whereas exhaled NO levels tended to decrease after histamine challenge. Isotonic saline challenge did not induce changes in exhaled NO (p = 0.7). There was a positive correlation between %fall in FEV1 and the %fall in exhaled NO after histamine, HS, and AMP challenge as indicated by the mean slope of the within-subject regression lines (p <= 0.04). We conclude that acute bronchoconstriction, as induced by direct and indirect stimuli, is associated with a reduction in exhaled NO levels in asthmatic subjects. This suggests that airway caliber should be taken into account when monitoring exhaled NO in asthma.     

Effects of various isoquinoline alkaloids on in vitro 3H-dopamine uptake by rat striatal synaptosomes

Various alkaloids having an isoquinoline skeleton from different species of the Annonaceae, Fumariacae, and Aristolochiacae (aporphine, cularine, benzylisoquinoline, and bisbenzylisoquinoline derivatives) were tested for their ability to inhibit in vitro 3H-dopamine uptake by rat striatal dopamine D1 3H-SCH 23390 AND D2 3H-raclopride binding sites. Except for some aporphine derivatives (anonaine [1], norstephalagine [2], isopiline [3]) and some bisbenzylisoquinoline alkaloids (dimethylgrisabine [27], antioquine [28], obaberine [29], isotetrandrine [30]) that displayed affinities of the same order as the reference compounds (nomifensine [38], amineptine [39], dexamphetamine [40]), the other tested products had low, or no, affinity on the 3H-dopamine uptake since, in comparison, its affinity at dopamine D1 3H-SCH 23390 and D2 3H-raclopride binding sites was low. These data suggest that it could be possible to synthesize anonaine-like products displaying intense dopamine-uptake inhibitory properties, which could lead to a potential antidepressant activity.     

Helminths of six species of Anolis lizards (Polychrotidae) from Hispaniola, West Indies

The gastrointestinal tracts of gekkonid lizards from Guam (Gehyra mutilata [n = 4], Gehyra oceanica [n = 11], Hemidactylus frenatus [n = 43], and Lepidodactylus lugubris [n = 38]) and Rota (Gehyra oceanica [n = 2], Hemidactylus frenatus [n = 13], and Lepidodactylus lugubris [N = 20] were examined for helminths. Found were 2 species of cestodes, Cylindrotaenia allisonae, Oochoristica javaensis, 1 species of trematode, Allopharynx macallisteri, and 5 species of nematodes, Pharyngodon lepidodactylus, Spauligodon gehyrae, Spauligodon hemidactylus, Skrjabinelazia machidai, Oswaldocruzia sp. New host records included Gehyra mutilata for Spauligodon hemidactylus, Gehyra oceanica for Oochoristica javaensis, Hemidactylus frenatus for Skrjabinelazia machidai, and Lepidodactylus lugubris for Cylindrotaenia allisonae and Oswaldocruzia sp. These helminths are known only from Pacific Islands and the Australian biogeographic realm.