Cytokinin antagonists: Synthesis and physiological effects of 7-Substituted 3-Methylpyrazolo[4,3-d]Pyrimidines

A series of sixteen pyrazolo[4,3-d]pyrimidine derivatives has been synthesized and tested for cytokinin antagonist activity in the tobacco bioassay     

Synthetic C-nucleosides: 3-(alpha- and beta-D-arabinofuranosyl)pyrazolo(4,3-d)pyrimidine-5,7-diones

2,3,5-Tri-O-benzyl-D-arabinofuranosyl bromide (4) was converted into 2,5-anhydro-3,4,6-tri-O-benzyl-D-glucononitrile (5), mixed with 20% of the D-manno epimer 6. The mixture was reduced to the amine 7, which via the N-nitrosoacetamide 10 afforded the 1-deoxy-l-diazo sugar 11. Dipolar addition to dimethyl acetylene-dicarboxylate afforded the C-nucleoside derivative, dimethyl 3-(2,3,5-tri-O-benzyl-α-β-D-arabinofuranosyl)pyrazole-4,5-dicarboxylate (20). Selective ammonolysis afforded the 4-ester-5-carboxamide 21, which was separated chromatographically into the α-(minor) and β-(major) anomers. Hydrazinolysis and Curtius reaction of the pair of 4-acid hydrazides (α-22 and β-22) afforded the anomeric 3-glycosyl-1H-pyrazolo-[4,3-d]pyrimidine-5,7-diones (α-24 and β-24). Hydrogenolytic debenzylation yielded the β-D)-arabino epimer (1) of oxoformycin B, and the α-D-arabino form 2. These anomeric C-nucleosides were distinguished by circular dichroism spectra that showed the same relationship as α- and β-D-arabino anomers of normal purine nucleosides.     

Aminopyrimidines and Derivatives. 151. Synthesis of 3-Glycosyl-vic-Triazolo-(4,5-d) Pyrimidines2

Abstract

A series of 3-glycosyl-vic-triazolo-(4,5-d) pyrimidines 2 and their O-acetyl derivatives 3 were prepared. Desulphurization of some of them has led to the 9-glycosyl-8-azahypoxantines 4.     

细胞外钙调素对烟草悬浮培养细胞蛋白质磷酸化作用的影响

用液体闪烁计数法研究了细胞外钙调素对烟草悬浮培养细胞质蛋白质磷酸化的作用。结果表明烟草细胞细胞质蛋白质磷酸化活性在细胞培养过程中逐渐增加,达到最高峰后又开始下降。在细胞质蛋白质磷酸化强度高峰时,加入抗CaM血清后,细胞质蛋白质磷酸化活性受到了部分抑制。加抗CaM血清后再补加CaM能够部分解除抗CaM血清对细胞质部分与细胞核部分蛋白质磷酸化的抑制作用。外加纯化钙调素可以引起烟草悬浮培养细胞细胞质蛋白质磷酸化的活性增强,并且这种增强作用具有时间（高峰为70min）与剂量（最适为CaM10-7mmol/L）依赖性。CaM引起的细胞质蛋白质磷酸化变化与红光所引起的细胞质蛋白质磷酸化变化在时间进程上是不相同的。     

缺磷胁迫对甘蔗悬浮细胞磷素吸收特性和相关酶活性的影响

在初始磷浓度为1.25 mmol.L-1的MS培养基中,甘蔗悬浮细胞在继代后的1 d之内几乎将磷完全吸收.此后,细胞在数天内仍能继续生长.缺磷细胞对磷的吸收动力学参数Imax增加,Km减少.在培养过程中,缺磷细胞的无机磷含量变化不大,但随着培养时间的延长,细胞酸性磷酸酶活性逐渐升高,且在培养的第8天,活性增加4倍.甘蔗悬浮细胞中不仅有植酸酶的存在,且在培养的第8天,缺磷细胞植酸酶活性比不缺磷的增高2.5倍.     

Short-acting 5-(trifluoromethyl)pyrido[4,3-d]pyrimidin-4(3H)-one derivatives as orally-active calcium-sensing receptor antagonists

Synthesis and structure–activity relationship (SAR) studies on 5-trifluoromethylpyrido[4,3-d]pyrimidin-4(3H)-ones, a novel class of calcium receptor antagonists is described with particular emphasis on optimization of the pharmacokinetic/pharmacodynamic parameters required for a short duration of action compound. Orally-active compounds were identified which displayed the desired animal pharmacology (rapid and transient stimulation of parathyroid hormone) essential for bone anabolic effects.     

Effects of bPTH fragments (1-34), (3-34) and (7-34) on uterine contraction

Synthetic bovine parathyroid hormone containing the NH2 terminal 34 amino acids [bPTH-(1-34)] was recently demonstrated to inhibit oxytocin stimulated uterine contraction in vitro. The parathyroid hormone analogues [Nle8, Nle18, Tyr34]bPTH-(3-34)amide [NTA-(3-34)] and [Tyr34]bPTH-(7-34)amide [NTA-(7-34)] have been reported to act as inhibitors of antagonists of parathyroid hormone (PTH) in numerous assays. In the present study the effects of these PTH analogues on uterine contraction and the ability of these analogues to act as antagonists to the uterine inhibitory action of bPTH-(1-34) in vitro were investigated. The NTA-(3-34) fragment had no effect on oxytocin stimulated uterine contractions. However, the NTA-(3-34) fragment was able to alter the ability of bPTH (1-34) to reduce oxytocin stimulated uterine contraction in a dose-related manner. Bovine PTH(1-34) (0.3 microgram/ml) reduced the contractile response obtained with oxytocin (0.5 mU/ml) by 20%. A dose of 15 micrograms/ml) of NTA-(3-34) abolished this inhibitory action of bPTH-(1-34) on oxytocin stimulated uterine contraction. In contrast the NTA-(7-34) caused a change in itself, stimulated contraction of resting uterine horns in a dose-related manner; 3.0 micrograms/ml of NTA-(7-34) caused a change in gram tension of + 1.5 grams. Bovine PTH-(1-34) was able to reduce the uterine contraction stimulated by NTA-(7-34) and 0.3 microgram/ml of bPTH-(1-34) reduced the contractile response obtained with 3.0 micrograms/ml of NTA-(7-34) by as much as 70%.(ABSTRACT TRUNCATED AT 250 WORDS)     

人ApoE转基因小鼠与TGE_（7－2） TGE_（7－3）转基因鼠系的建立

用含小鼠金属硫蛋白（ＭＴ－１）基因启动子与突变的人ＡｐｏＥ７基因的６．０ＫｂＤＮＡ片段作为目的基因制备转基因小鼠,利用显微注射法将目的基因导入４４１枚受精卵,移植于２０只假孕鼠,其中１５只受孕,共产仔鼠８０只,经ａ－３２Ｐ斑点杂交与Ｓｏｕｔｈｅｒｎ杂交法鉴定出两只整合有人ＡｐｏＥ基因的转基因雌鼠,其拷贝数分别为２和５。将两只首建鼠（雌性Ｆｏ代）与正常雄鼠交配,建立Ｆ１代转基因鼠系ＴＧＥ７－２和ＴＧＥ７－３,为进一步从整体上研究ＡｐｏＥ在脂质代谢中的作用以及ＡｐｏＥ与动脉粥样硬化和Ａｌｚｈｅｉｍｅｒ’ｓ病的关系创造条件。     

甘草甜素对树突状细胞表型及生物学功能的影响

培养小鼠髓系DC2．4细胞,加入LPS（阳性对照组）或甘草甜素,用扫描电镜观察DC的超微结构、流式细胞仪检测DC表面分子MHCII、CD86及CD40的表达、4-氨基安替比林（4-AAP）比色检测DC内酸性磷酸酶活性、ELISA方法检测DC培养上清中IL—12的浓度,体外刺激淋巴细胞增殖实验检测DC对同种异体T淋巴细胞的刺激能力。结果表明,与对照组相比,甘草甜素刺激后,DC表面树突状突起增多,表面分子MHCⅡ、CD86及CD40表达增加,酸性磷酸酶活性下降,培养上清中IL-12浓度升高,刺激同种异体T淋巴细胞的能力也明显增强。结果表明,甘草甜素能够促进小鼠髓系DC2.4表型及功能的成熟。     

Effects of Several Tunicamycin-like Antibiotics on Glycoprotein Biosynthesis in Mung Beans and Suspension-cultured Soybean Cells

The antibiotics Streptovirudin and 24010 were tested to determine their effects on the formation of lipid-linked saccharide intermediates associated with glycoprotein biosynthesis in mung bean (Vigna radiata) and suspension-cultured soybean cells (Glycine max cv. Mandarin). In vitro both compounds strongly inhibited the transfer of N-acetyl[³H]glucosamine from UDP-N-[³H]acetylglucosamine to N-acetylglucosaminyl-pyrophosphoryl-polyisoprenol and lipid-linked oligosaccharides, although they had no apparent effect on the incorporation of [¹⁴C]mannose from GDP-[¹⁴C]mannose into mannosyl-phosphoryl-dolichol with a small inhibition into lipid-linked oligosaccharides. In vivo, Streptovirudin and tunicamycin dramatically inhibited the incorporation of N-[¹⁴C]acetylglucosamine and [³H]mannose into Pronase-released material (glycoproteins), whereas there was no effect on [³H]leucine incorporation into Pronase-released material (protein). Because the action of Streptovirudin and antibiotic 24010 in plants and other systems is similar to that for tunicamycin, these antibiotics are believed to be closely related. The use of tunicamycin is discussed with respect to its importance in studying glycoprotein biosynthesis and function in animal and plant systems.     

Isorhamnetin3-(2,6-dirhamnosylgalactoside)-7-rhamnoside and 3-(6-rhamnosylgalactoside)-7-rhamnoside from Rhazya stricta

Robinin and two novel glycosides: isorhamnetin 3-(6-rhamnosylgalactoside)-7-rhamnoside and 3-(2,6-dirhamnosylgalactoside)-7-rhamnoside were isolated from a leaf extract of Rhazya stricta. Naringinase catalysed hydrolysis of both glycosides removed the rhamnose from the 7-hydroxyl. The product isorhamnetin 3-(2,6-dirhamnosylgalactoside) was shown by ¹H NMR to be identical with a glycoside previously isolated from Primula veris.     

Synthesis of AZT analogues: 7-(3-azido-2hydroxypropyl)-, 7-(3-amino-2-hydroxypropyl)-, 7-(3-triazolyl-2-hydroxypropyl)theophyllines

Nucleophilic displacement of the tosyloxy group in 7-(2-hydroxy-3-p-toluenesulfonyloxypropyl)theophylline (1) with azide anion afforded 7-(3-azido-2-hydroxypropyl)theophylline (2). Reduction of the 3-azido group in 2 with Ph₃P/Py/NH₄OH afforded the 3-amino derivative 4, alternatively obtained by regioselective amination of 7-(2,3-epoxypropyl)theophylline (3). Selective acetylation of 4 gave the N-acetyl derivative 5. 1,3-Dipolar cycloaddition of the azide group in 2 with N¹-propargyl thymine (6) afforded the regioisomeric triazole 7.     

Synthesis of AZT analogues: 7-(3-azido-2-hydroxypropyl)-, 7-(3-amino-2-hydroxypropyl)-,7-(3-triazolyl-2-hydroxypropyl)theophylline

Nucleophilic displacement of the tosyloxy group in 7-(2-hydroxy-3-p-toluenesulfonyloxypropyl)theophylline (1) with azide anion afforded 7-(3-azido-2-hydroxypropyl)theophylline (2). Reduction of the 3-azido group in 2 with Ph3P/Py/NH4OH afforded the 3-amino derivative 4, alternatively obtained by regioselective amination of 7-(2,3-epoxypropyl)theophylline (3). Selective acetylation of 4 gave the N-acetyl derivative 5. 1,3-Dipolar cycloaddition of the azide group in 2 with N1-propargyl thymine (6) afforded the regioisomeric triazole 7.     

InCl3-catalysed synthesis of 2-aryl quinazolin-4(3H)-ones and 5-aryl pyrazolo[4,3-d]pyrimidin-7(6H)-ones and their evaluation as potential anticancer agents

A convenient and practical methodology for the synthesis of 2-aryl quinazolin-4(3H)-ones by the condensation of o-aminobenzamides with aromatic aldehydes under mild conditions using catalytic InCl(3) with good yields and high selectivities. This method has been extended for the synthesis of 5-aryl pyrazolo[4,3-d]pyrimidin-7(6H)-ones which have potential applications in medicinal chemistry. Many of these compounds were evaluated for their anti-proliferative properties in vitro against four cancer cell lines and several compounds were found to be active. Further in vitro studies indicated that inhibition of sirtuins could be the possible mechanism of action of these molecules.     

Synthesis and Biological Evaluation of 3-Chloro-4-(D-Ribofuranosyl)-Pyridine and 3-(D-Ribofuranosyl)-2- Pyridone

Abstract

Condensation of 2-fluoro-3-lithio pyridine and 3-chloro-4-lithio pyridine with 2,4:3,5-di-O-benzylidene-alde-hydo-D-ribose gives the corresponding D-allo- and D-altro-addition products. These were converted into the corresponding mesylates and cyclized to the ribofuranosyl nucleosides with an overall yield of 60–70 %. Both nucleosides did not show any inhibitory effect on L-₁₂₁₀-cells.     

5-(3-Bromophenyl)-7-(6-morpholin-4-ylpyridin-3-yl)pyrido[2,3-d]pyrimidin-4-ylamine: structure-activity relationships of 7-substituted heteroaryl analogs as non-nucleoside adenosine kinase inhibitors

4-Amino-5,7-disubstituted pyridopyrimidines are potent, non-nucleoside inhibitors of adenosine kinase (AK). We recently identified a potent, orally efficacious analog, 4 containing a 7-pyridylmorpholine substituted ring system as the key structural element of this template. In this report, we disclose the pharmacologic effects of five- and six-membered heterocyclic ring replacements for the pyridine ring in 4. These replacements were found to have interesting effects on in vivo efficacy and genotoxicity as well as in vitro potency. We discovered that the nitrogen in the heterocyclic ring at C(7) is important for the modulation of mutagenic side effects (Ames assay).