Cytotoxic terpenoids from Juglans sinensis leaves and twigs

Bioassay-guided fractionation of an 80% MeOH extract of Juglan sinensis leaves and twigs has resulted in the isolation of three new triterpenes (1-3) and two new sesquiterpenes (4-5) along with two known sesquiterpenes (6-7). The new compounds were determined to be 3β, 11α, 19α, 24, 30-pentahydroxy-20β, 28-epoxy-28β-methoxy-ursane (1), 1α, 3β-dihydroxy-olean-18-ene (2), 2α, 3α, 23-trihydroxy-urs-12-en-28-oic acid 28-O-β-d-glucopyranoside (3), (4S, 5S, 7R, 8R, 14R)-8, 11-dihydroxy-2, 4-cyclo-eudesmane (4), 15-hydroxy-α-eudesmol-11-O-β-d-glucopyranoside (5), by spectroscopic analysis. The cytotoxicity of compounds (1-7) against four cancer cell lines such as B16F10, Hep-2, MCF-7 and U87-MG was evaluated. Compounds 1, 2, 6 and 7 showed potent cytotoxicity against all of four cancer cell lines, respectively.     

钮子瓜化学成分研究

从民间药物钮子瓜全草95%乙醇提取物中首次分离得到14个化合物,应用波谱方法及与已知品对照的手段鉴定它们为(2S,3S,4R,10E)2[(2R)2-羟基二十四烷酰氨基]10十八烷-1,3,4-三醇(1)、(2S,3S,4R)2-二十四烷酰胺基十八烷-1,3,4-三醇(2)、胡萝卜苷(3)、swertish(4)、苯甲酸(5)、水杨酸(6)、loliolide(7)、胸腺嘧啶(8)、尿嘧啶(9)、(23Z)-9,19-环阿尔廷-23-烯-3β,25-二醇(10)、(20S,22E,24R)5α,8α-表二氧麦角甾6,22二烯3β醇(11)、十六烷酸1甘油酯(12)、大豆脑苷Ⅰ(13)、(22E,24S)24甲基5α胆甾7,22二烯3β,5α,6β三醇(14)。     

Interleukin-11 binds specific EF-hand proteins via their conserved structural motifs

Interleukin-11 (IL-11) is a hematopoietic cytokine engaged in numerous biological processes and validated as a target for treatment of various cancers. IL-11 contains intrinsically disordered regions that might recognize multiple targets. Recently we found that aside from IL-11RA and gp130 receptors, IL-11 interacts with calcium sensor protein S100P. Strict calcium dependence of this interaction suggests a possibility of IL-11 interaction with other calcium sensor proteins. Here we probed specificity of IL-11 to calcium-binding proteins of various types: calcium sensors of the EF-hand family (calmodulin, S100B and neuronal calcium sensors: recoverin, NCS-1, GCAP-1, GCAP-2), calcium buffers of the EF-hand family (S100G, oncomodulin), and a non-EF-hand calcium buffer (α-lactalbumin). A specific subset of the calcium sensor proteins (calmodulin, S100B, NCS-1, GCAP-1/2) exhibits metal-dependent binding of IL-11 with dissociation constants of 1–19 μM. These proteins share several amino acid residues belonging to conservative structural motifs of the EF-hand proteins, ‘black’ and ‘gray’ clusters. Replacements of the respective S100P residues by alanine drastically decrease its affinity to IL-11, suggesting their involvement into the association process. Secondary structure and accessibility of the hinge region of the EF-hand proteins studied are predicted to control specificity and selectivity of their binding to IL-11. The IL-11 interaction with the EF-hand proteins is expected to occur under numerous pathological conditions, accompanied by disintegration of plasma membrane and efflux of cellular components into the extracellular milieu.     

Evaluation of two progestogen-based estrous synchronization protocols in yearling heifers of Bos indicus × Bos taurus breeding

Yearling Bos indicus × Bos taurus heifers (n = 410) from three locations, were synchronized with either the Select Synch/CIDR+timed-AI (SSC+TAI) or 7-11+timed-AI (7-11+TAI) treatments. On Day 0 of the experiment, within each location, heifers were equally distributed to treatments by reproductive tract score (RTS; Scale 1-5: 1 = immature, 5 = estrous cycling) and body condition score. The 7-11+TAI treatment consisted of melengestrol acetate (0.5 mg/head/d) from Days 0 to 7, with PGF_2α (25 mg im) on Day 7, GnRH (100 μg im) on Day 11, and PGF_2α (25 mg im) on Day 18. The SSC+TAI heifers received the same carrier supplement (without MGA) from Days 0 to 7, and on Day 11 they were given 100 μg GnRH and an intravaginal CIDR (containing 1.38 g progesterone). The CIDR were removed on Day 18, concurrent with 25 mg PGF_2α im For both treatments, estrus was visually detected for 1 h twice daily (0700 and 1600 h) for 72 h after PGF_2α, with AI done 6 to 12 h after a detected estrus. Non-responders were timed-AI and received GnRH (100 μg im) 72 to 76 h post PGF_2α. The 7-11+TAI heifers had a greater (P < 0.05) estrous response (55.2 vs 41.9%), conception rate (47.0 vs 31.3%), and synchronized pregnancy rate (33.5 vs 24.8%) compared to SSC+TAI heifers, respectively. Heifers exhibiting estrus at 60 h (61.7%) had a greater (P < 0.05) conception rate compared to heifers that exhibited estrus at ≤ 36 (35.3%), 48 (31.6%), and 72 h (36.2%), which were similar (P > 0.05) to each other. As RTS increased from ≤ 2 to ≥ 3, estrous response, conception rate, synchronized pregnancy rate, and 30 d pregnancy rate all increased (P < 0.05), irrespective of synchronization treatment. In conclusion, the 7-11+TAI treatment yielded greater synchronized pregnancy rates compared to SSC+TAI treatment in yearling Bos indicus × Bos taurus heifers.     

肋果茶中的萜类化学成分研究

从肋果茶(Sladenia celastrifolia)95％乙醇提取物的乙酸乙酯部位中分离得到15个萜类化合物,经波谱学方法分别鉴定为sladeniafolin A(1),grasshopper ketone (2),(3S,5R,6S,7E,9R) -7-megastigmene-3,6,9-triol (3),hedytriol (4),(3S,5R,6R,7E,9R) -3,5,6,9-tetrahydroxy-7-megastigmene(5),1′S*,4′R*-8-(4′-hydroxy-2′,6′,6′-trimethylcyclohex-2-enyl)-6-methyloct-3E,5E,7E-trien -2-one (6),2α,3α,19α,23-tetrahydroxyurs-12-en-28-oic acid (7),2α,3β,19α,23-tetrahydroxyurs-12-en-28-oic acid(8),pomolic acid(9),3-O-acetyl pomolic acid(10),ursaldehyde (11),camarolide (12),3β-hydroxyurs-11-en-13β(28) -olide (13),3β-hydroxy -11α,12α-epoxy-urs-13β,28-olide (14)和28-0-β-D-glucopyranosyl euscaphic acid (15).以上化合物均首次从该植物中分离得到,其中1为新的C9裂环烯醚萜.     

Structural studies of urinary oliogosaccharides from patients with mannosidosis

Eight neutral oligosaccharide fractions were obtained from the pooled urine of two patients with mannosidosis by Bio-Gel P2 and Bio-Gel P4 column chromatography. The structures of seventeen oligosaccharides were determined by monosaccharide composition analysis, methylation studies, acetolysis, Smith degradation, and ¹³C NMR analysis. Three of the proposed structures, Manα1-3Manβ1-4GlcNAc, Manα1-2Manα1-3Manβ1-4GlcNAc, and Manα1-2Manα1-2Manα1-3Manβ1-4GlcNAc are identical to those first published by Norden et al. (N. E. Norden, A. Lundblad, S. Svennson, P. A. Ockerman, and S. Autio, 1973. J. Biol. Chem.248, 6210–6215; N. E. Norden, A. Lundblad, S. Svennson, and S. Autio, 1974. Biochemistry13, 871–874). Thirteen of them, Manα1-3Manα1-6(Manα1-3)-Manβ1-4GlcNAc, Manα1-3Manα1-6(Manα1-2Manα1-3)Manβ1-4GlcNAc, and 11 isomers of (Manα1-2)_0–4[Manα1-6(Manα1-3)Manα1-6(Manα1-3)Manβ1-4GlcNAc], are the same as those first published by Yamashita et al. (K. Yamashita, Y. Tachibana, K. Mihara, S. Okada, H. Yabuuchi, and A. Kobata, 1980, J. Biol. Chem.255, 5126–5133); a tetrasac-charide, Manα1-6(Manα1-3)Manβ1-4GlcNAc, is newly reported and several other structural possibilities are proposed.     

攀援孔药花化学成分研究

从攀援孔药花全草95%乙醇提取物中首次分离得到19个化合物,通过波谱数据或与已知物对照,它们分别鉴定为:(2S,3S,4R)-2-[(2R)-2-羟基-二十一酰胺基]-二十一烷-1,3,4-三醇(1)、(2S,3S,4R)-2-二十四酰胺基-十八烷-1,3,4-三醇(2)、胡萝卜甙(3)、β-谷甾醇(4)、(20S,22E,24R)-5α,8α-表二氧-麦角甾-6,22-二烯-3β-醇(5)、6β-羟基-豆甾-4-烯-3-酮(6)、十六烷酸-1-甘油酯(7)、桦木酸(8)、大黄素(9)、二十二烷酸-1-甘油酯(10)、对羟基苯甲醛(11)、十七烷酸-1-甘油酯(12)、金色酰胺醇乙酸酯(13)、十九烷酸-1-甘油酯(14)、棕榈酸(15)(、E)-p-香豆酸(16)、(22E,24S)-24-甲基-5α-胆甾-7,22-二烯-3β,5α,6β-三醇(17)、2-去氧-β-蜕皮激素(18)和auranamide(19)。     

Inhibition of the monkey corpus luteum with 15-methyl prostaglandins

The corpus luteum inhibiting properties of eighteen 15-methyl prostaglandin analogs were determined in the rhesus monkey during concomitant stimulation of the corpus luteum with chorionic gonadotropin. The methyl ester of (15S)-15-methyl PGF_2^α (15M-PGF_2^α, 12.5 mg/monkey) lowered serum progesterone to 12% of pretreatment values within 24 hours, however progesterone returned to normal limits within 48 hours. Elongation of the top side-chain by two carbons (2a,2b-dihomo-15M-PGF_2^α methyl ester, 13 mg/monkey), substitution of a hydroxymethyl group at carbon 1 (2-decarboxy-2-hydroxymethyl-15M-PGF_2^α, 12 mg/monkey), or the formation of the carbon 1 amide (15M-PGF_2^α amide, 12.5 mg/monkey) improved the inhibitory activity of 15M-PGF_2^α; serum progesterone for these 3 analogs was depressed to 15–30% of pretreatment levels within 24 hours, and did not return to control values. Luteal function was not inhibited (12 or more mg/monkey) when the 15-methyl group was placed in the R configuration, the top side chain was shortened by two carbons, an amino group was substituted for carbon 1, the 5-oxa modification was added, or the 1,9-lactone was formed. Some other modifications of 15M-PGF_2^α were also inactive, although not all were tested at equivalent doses: 2,2-difluoro; 4,5-cis-didehydro; 9,11-dideoxy-9α,11α-dichloro; 11-deoxy; 17-phenyl; 1,15-lactone; and the p-benzamidophenyl ester of 2a,2b-dihomo-15M-PGF_2^α. (15S)-15-Methyl PGE₂ methyl ester (1 mg/monkey) depressed serum progesterone concentrations to 42% of pretreatment values within 24 hours; 2a,2b-dihomo-11-deoxy-(15S)-15-methyl PGE₂ methyl ester was inactive (5 mg/monkey). A corpus luteum inhibiting action of certain 15-methyl prostaglandins can be demonstrated in the rhesus monkey.     

Methods for quantitative analysis of PGF2 , PGE2, 9 , 11 -dihydroxy-15-keto-prost-5-enoic acid and 9 , 11 , 15-trihydroxy-prost-5-enoic acid from body fluids using deuterated carriers and gas chromatography--mass spectrometry

The preparation of (3,3,4,4-D₄)-PGE₂, (3,3,4,4-D₄)-PGF_2α, (3,3,4,4-D₄)-9α,11α-dihydroxy-15-ketoprost-5-enoic acid and (3,3,4,4-D₄)-9α,11α,15-trihydroxyprost-5-enoic acid is described. These compounds have been used for quantitative determination of corresponding nondeuterated prostaglandins by gas-liquid chromatography-mass spectrometry. The method is based on addition of a known amount of carrier to the sample and after purification and derivatization the ratio between the protium and deuterium form is measured in the mass spectrometer. Ions originating in deuterated and nondeuterated molecules are focused one at a time on the electron multiplier using an accelerating voltage alternator.With this technique 400 pg of PGF_2α can be determined with a precision of ±3.7% (SD). The recoveries from plasma samples, containing 1–2.5 ng/ml of any of the compounds, is about 100±10%.     

Precursor-to-product ratios reflect biochemical phenotype in congenital adrenal hyperplasia

Precursor-to-product ratios in steroid hormone metabolism may accurately reflect enzymatic activity and production of metabolites relative to their disappearance. The purpose of this study was to explore the use of direct precursor-to-product steroid ratios to discriminate between infants with congenital adrenal hyperplasia (CAH) due to 21-α-hydroxylase deficiency and infants with no disorder, thus characterizing the biochemical phenotype in CAH. Deidentified dried blood spot samples from confirmed CAH cases identified by newborn screen (CAH-positive, N = 8) and from cases with no disorder (CAH-negative, N = 10) were obtained from the California State Newborn Screening Program. Samples (~6.25 mm circular spots) underwent methanol and water extraction (9:1 ratio). Deuterated steroids served as isotope internal standards. 17-α-hydroxyprogesterone (17-OHP), 11-deoxycortisol (S), androstenedione (A4) and cortisol (F) concentrations were determined by liquid chromatography–tandem mass spectrometry (LC–MS/MS), and the 17-OHP/S, 17-OHP/A4, and S/F ratios were calculated. The mean 17-OHP and A4 concentrations in samples from CAH cases were significantly increased when compared to cases with no disorder (p = 0.003 for both). 17-OHP/S and 17-OHP/A4 ratios were also significantly elevated in CAH cases (p = 0.007 and p < 0.001, respectively). In contrast, S and F concentrations and the S/F ratio were similar between the two groups. In CAH, the elevated 17-OHP/S ratio is a biomarker of diminished 21-α-hydroxylase activity, and the elevated 17-OHP/A4 ratio is a biomarker of adrenal androgen excess via increased 17,20-lyase activity. The similar S/F ratio indicates that the rate of production via 11-β-hydroxylase and disappearance of F is maintained in CAH.     

The S100-b Protein: Tyrosine Residues Do Not Exhibit an Abnormal Fluorescence Spectrum

The β subunit of the bovine brain S100-b protein (ββ) lacks tryptophyl residue but contains one tyrosine. Our experiments show that this protein is characterized by a typical tyrosine fluorescence spectrum, with a maximum at 303 nm. Identical fluroescence properties were found for the rat brain S100-b protein. Comparison with the fluorescence spectrum of the bovine brain S100-a’ protein (α'β), which contains a tryptophan residue in the α’ subunit, enables us to demonstrate that the recent report describing an abnormal fluorescence spectrum for the bovine brain S100-b protein may result from a contamination of the S100-b by the S100-α’ protein.     

Liposomal membranes XI. A suggestion to structural characteristics of acido-thermophilic bacterial membranes

To understand the role of ω-cyclohexyl fatty acid residue of lipids in acido-thermophilic bacterial membranes, three unusual phosphatidylcholines, 1,2-di-11-cyclohexylundecanoyl-l-α-phosphatidylcholine (11_CYPC), 1,2-di-13-cyclohexyltridecanoyl-l-α-phosphatidylcholine (13_CYPC), and 1–13-cyclohexyltridecanoyl-2–11-cyclohexylundecanoyl-l-α-phosphatidylcholine (1–13_CY-2–11_CYPC) were prepared and the steady-state fluorescence anisotropy of 1,6-diphenylhexatriene (DPH) in the hydrophobic domain of these liposomal bilayers was determined. Compared with the case of dipalmitoyl (DPPC) or dimyristoyl phosphatidylcholine (DMPC), introducing the ω-cyclohexyl moiety onto lecithins makes the bilayers fluid below the phase transition temperature, while immobilizes them above the phase transition temperatures. The properties of the unusual phosphatidylcholine liposomes suggested by the steady-state fluorescence anisotropy investigation were in good agreement with those obtained from the thermotropic and permeability investigations. Results obtained are discussed from the view point of the role and function of lipid membranes of acido-thermophilic bacteria which contain unusual fatty acids.     

Volatile‐Oils Composition,and Bioactivity of the Essential Oils of Plectranthus barbatus,P. neochilus,and P. ornatus Grown in Portugal

Volatile‐oils chemical composition and bioactivity of the essentail oils from Plectranthus barbatus, P. neochilus, and P. ornatus (Lamiaceae) were assessed. Aerial parts from these three related Plectranthus species were collected from cultivated plants grown in Portugal, during vegetative and flowering phases. Volatiles, isolated by distillation? extraction, were analyzed by GC and GC/MS. Monoterpene hydrocarbons (12–74%) and sesquiterpene hydrocarbons (4–45%) constituted the main fractions in all volatiles. α‐Pinene ( 3 ; 12–67%), oct‐1‐en‐3‐ol ( 6 ; traces–28%), β‐pinene ( 7 ; 0.1–22%), and β‐caryophyllene ( 50 ; 7–12%) dominated P. barbatus volatiles. P. neochilus major volatile components were α‐terpenyl acetate ( 41 ; traces–48%), α‐thujone ( 2 ; 2–28%), β‐caryophyllene ( 50 ; 2–28%), β‐pinene ( 7 ; 1–25%), and α‐pinene ( 3 ; 1–19%). Oct‐1‐en‐3‐ol ( 6 ; 13–31%), β‐pinene ( 7 ; 11–24%), α‐pinene ( 3 ; 11–19%), and β‐caryophyllene ( 50 ; traces–11%) were the main constituents from P. ornatus volatiles. These chemical compositions were rather different from those previously found for specimens harvested in Africa and Brazil. Moreover, the volatiles from the flowers are herewith reported for the first time. Essential oils, isolated by hydrodistillation from leaves and stems, showed a yellowish color and unpleasant odor, with yields ranging from 0.08% to 0.84% (v/dry weight). Antioxidant and antimicrobial activities of the essential oils were evaluated by DPPH^. and TBARS assays, and agar disc‐diffusion method, respectively. Results showed low or moderate antioxidant capacity and significant antimicrobial activity against Gram‐positive bacteria.     

苋科植物的丛枝菌根

有些种子植物如莎草科、十字花科、灯心草科、藜科、石竹科等20余科,以往曾被认为不能或不易形成丛枝菌根(郭秀珍等,1989;刘润进等,2000).随着对菌根的深入研究,曾被认为是不易与菌根菌组合的湿地生植物、寄生性植物、或一年生植物都被发现是可以形成内生菌根的(Trappe等,1992).此外,Allen等(1989)研究证实,Salsola kali,Atriplex roseum等生长于沙漠、海滨的藜科植物,进行接种处理后,也能形成丛枝菌根.我们在西双版纳调查热带雨林植物的丛枝菌根状况时,偶然发现刺苋(Amaranthus spinosus Linn.)的根系受到了丛枝菌根真菌的侵染,因此,对苋科植物作了扩大采样调查.本文主要报道从热带采集的5属6种苋科植物的根受丛枝菌根真菌感染形成丛枝菌根(arbuscular mycorrhiza,AM)和这些植物根际士壤中的丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)的状况.     

尼泊尔水东哥的化学成分研究

从尼泊尔水东哥树皮的95%乙醇提取物中首次分离到12个化合物,应用波谱方法或与已知品对照的手段鉴定为auranamide(1)、aurantiamide benzoate(2)、齐墩果酸(3)、β-谷甾醇(4)、β-胡萝卜甙(5)、乌苏酸(6)、2α,3α-二羟基-12-烯-28-乌苏酸(7)、2α,3β,24-三羟基-12-烯-28-乌苏酸(8)、(2S,3S,4R,10E)-2-[(2′R)-2′-hydroxytetracosanoylamino]-10-octadecene-1,3,4-triol(9)、2α,3α,24-三羟基-12-烯-28-齐墩果酸(10)、2α,3β-二羟基-12-烯-28-乌苏酸(11)和2α,3α,24-三羟基-12-烯-28-乌苏酸(12)。     

Energetics and protomer communication in the dynamical structure of S100A13 in free and protein-bound states

S100A13 is S100 family of EF-hand-containing calcium-binding protein involved in the secretion of some growth factors and pro-inflammatory cytokines lacking signal peptides. The involvement of S100A13 in cancer progression and inflammatory diseases has been reported. In this study, structures generated during atomistic molecular dynamics simulation were studied. Dynamical network analysis data revealed that native inter-protomer communication network driven principally by vdW interaction (~550 kj/mol) is altered (Receptor for advanced glycation end products (RAGE) C2- and Fibroblast growth factor (FGF)-1-bound S100A13) or completely abolished (interleukin-1 (IL1)-α- and C2A-p40Syt1-bound S100A13) in protein-bound S100A13 homodimer. Bulk water density (weighted atomic density) around exposed S100A13 homodimer surface explored tends to follow the dynamical network lead as S100A13 homodimer appeared densely solvated in C2A-p40Syt1- and IL1)-α-bound states but not in RAGE C2- and FGF-1-bound biosystems. Furthermore, projection of radius of gyration and root mean square deviation (from native structure) variables of the generated structures along the 3D-free energy surface showed anti-parallel β-sheet proximal to Ca²⁺-binding loops-I/II in most metastable complexes retrieved from energy minima state with strong indications for β-sheet network formation during protein binding. Interaction between S100A13 homodimer and ligand–proteins may be dictated by the strength of vdW and electrostatic interaction with possible involvement of bulk water desolvation in some complexes. All these results strongly suggest that disruption of multiprotein receptor complex can be achieved by designing specific compounds targeting a specific aspect of S100A13/protein interaction; such drugs may have clinical usefulness in blocking angiogenesis, reversing cell proliferation and attenuating inflammatory processes.     

Microbiological hydroxylation of androst-1,4-dien-3,17-dione by Neurospora crassa

Nine hydroxy-derived androstadiene compounds were isolated from the fermentation broth of Neurospora crassa when incubated in the presence of androst-1,4-dien-3,17-dione (ADD; I) for 7 days. Hydroxylations at 6β, 7β, 11α, 14α- positions and 17-carbonyl reduction of the substrate were the characteristics observed in this biotransformation. Their structures were determined by spectroscopic methods as 17β-hydroxyandrost-1,4-dien-3-one (II), 14α-hydroxyandrost-1,4-dien-3,17-dione (III), 6β-hydroxyandrost-1,4-dien-3,17-dione (IV), 11α-hydroxyandrost-1,4-dien-3,17-dione (V), 6β,17β-dihydroxyandrost-1,4-dien-3-one (VI), 7β-hydroxyandrost-1,4-dien-3,17-dione (VII), 14α,17β-dihydroxyandrost-1,4-dien-3-one (VIII), 6β,14α-dihydroxyandrost-1,4-dien-3,17-dione (IX), and 11α,17β-dihydroxyandrost-1,4-dien-3-one (X). A new steroid substance, 6β,14α-dihydroxyandrost-1,4-dien-3,17-dione (IX), was also characterized during this study. The best fermentation condition was found to be 7-day incubation at 25°C and pH values of 5.0–6.0 in the presence of 0.05 g 100 mL^?1 of the substrate. At a concentration above 0.075 g 100 mL^?1, the biotransformation was completely inhibited.     

Insulin-Stimulated Glycogen Synthesis in Cultured Hepatoma Cells: Differential Effects of Inhibitors of Insulin Signaling Molecules

Abstract

In rat HTC hepatoma cells overexpressing human insulin receptors, insulin stimulated glycogen synthesis by 55–70%. To study postreceptor signaling events leading to insulin-stimulated glycogen synthesis in these cells, we have employed pathway-specific chemical inhibitors such as LY294002, rapamycin and PD98059 to inhibit phosphatidylinositol-3-kinase (PI3K), p70 ribosomal S6 kinase and mitogen-activated protein kinase (MAPK) kinase/MAPK, respectively. LY294002 (50 μM) completely abolished insulin-stimulated glycogen synthesis whereas rapamycin (2–20 nM) partially inhibited it. Neither LY294002 nor rapamycin significantly affected the basal glycogen synthesis. However, PD98059 (100 μM) significantly inhibited the basal glycogen synthesis without affecting insulin-stimulated glycogen synthesis. In these cells, insulin at 100 nM decreased glycogen synthase kinase 3α (GSK3α) activity by 30–35%. LY294002, but neither rapamycin nor PD98059, abolished insulin-induced inactivation of GSK3α. These data suggest that insulin-stimulated glycogen synthesis in rat HTC hepatoma cells is mediated mainly by PI3K-dependent mechanism. In these cells, inactivation of GSK3α, downstream of PI3K, may play a role in insulin-stimulated glycogen synthesis.     

Reduced high affinity 5 -dihydrotestosterone receptor capacity in the ventral prostate of the aging rat

Cytoplasmic extracts of ventral prostates obtained from young (50–90 day old) rats 24 hours post orchidectomy contained high affinity binding activity for 5α-dihydrotestosterone which migrated with a sedimentation coefficient of 10–11S on linear sucrose gradients. By contrast, when cytoplasmic extracts were prepared from ventral prostates of aging rats (10–14 months old), 80 percent of the animals evidenced a complete absence of 10–11S binding activity. A single extract prepared from the ventral prostates of the remaining aging animals in the 10–14 month age category had a level of 10–11S binding activity that was about 20 to 25 percent of the value routinely obtained for identical preparations from young animals. Cytoplasmic extracts prepared from the ventral prostate of animals older than 14 months were always found to be devoid of 10–11S binding activity.     

A high-yield route to synthesize the P-glycoprotein radioligand [11C]N-desmethyl-loperamide and its parent radioligand [11C]loperamide

N-Desmethyl-loperamide and loperamide were synthesized from α,α-diphenyl-γ-butyrolactone and 4-(4-chlorophenyl)-4-hydroxypiperidine in five and four steps with 8% and 16% overall yield, respectively. The amide precursor was synthesized from 4-bromo-2,2-diphenylbutyronitrile and 4-(4-chlorophenyl)-4-hydroxypiperidine in 2 steps with 21–57% overall yield. [¹¹C]N-Desmethyl-loperamide and [¹¹C]loperamide were prepared from their corresponding amide precursor and N-desmethyl-loperamide with [¹¹C]CH₃OTf through N-[¹¹C]methylation and isolated by HPLC combined with solid-phase extraction (SPE) in 20–30% and 10–15% radiochemical yields, respectively, based on [¹¹C]CO₂ and decay corrected to end of bombardment (EOB), with 370–740 GBq/μmol specific activity at EOB.