bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemoselective and Regiospecific Synthesis of Iminospiro‐γ‐lactones from Maleic Anhydride or Citraconic Anhydride and Alkyl Isocyanides with Dialkyl Acetylenedicarboxylates
Authors: Bayat Mohammad , Imanieh Hossien , Abbasi Hossien 
Published: April 2010

AbstractIsocyanides, dialkyl acetylenedicarboxylates (=dialkyl but‐2‐ynedioates), and anhydrides such as maleic anhydride (=furan‐2,3‐dione) or citraconic anhydride (=3‐methylfuran‐2,3‐dione) react in one pot to afford novel iminospiro‐γ‐lactones in fairly good yields at room temperature (Schemes 1 and 3).
A Novel and Efficient One‐Pot Synthesis of 2‐Aminopyrimidinones and Their Self‐Assembly
Authors: Bararjanian Morteza , Balalaie Saeed , Rominger Frank , Barouti Sanaz 
Published: April 2010

AbstractA three‐component reaction of benzaldehyde derivatives, methyl cyanoacetate, and guanidinium carbonate affords 2‐amino‐4‐aryl‐1,6‐dihydro‐6‐oxopyrimidine‐5‐carbonitriles and the four‐component reaction of benzaldehyde derivatives, methyl cyanoacetate, and guanidinium hydrochloride in the presence of piperidine leads to piperidinium salts of pyrimidinones. X‐ray crystallography data confirm self‐assembly and H‐bonding in these compounds.
Diketopiperazine Alkaloids from Penicillium spp. HS‐3, an Endophytic Fungus in Huperzia serrata
Authors: Shan Wei‐Guang , Ying You‐Min , Yu Hai‐Ning , Liu Wen‐Hong , Zhan Zha‐Jun 
Published: April 2010

AbstractCultivation of the fungus Penicillium spp. HS‐3, an endophytic fungus from the stems of Huperzia serrata, led to the isolation of a new diketopiperazine alkaloid, named as tryhistatin (1), together with three known ones, 2–4, all of which share a similar backbone. The structure of 1 was established by detailed interpretation of the 1D‐ and 2D‐NMR spectra, and HR‐ESI‐MS data. Furthermore, 1D‐ and 2D‐NMR experiments were employed to elucidate the structure of 2 which was deduced previously only on the basis of the LC/MS method. In this article, we confirmed the correctness of the previously reported structure and made a complete assignment of the NMR signals of 2 for the first time.
Three New C19‐Diterpenoid Alkaloids from Aconitum hemsleyanum var. circinatum
Authors: Gao Feng , Liu Xiao‐Yu , Wang Feng‐Peng 
Published: April 2010

AbstractFurther phytochemical investigation of the roots of Aconitum hemsleyanum var. circinatum resulted in the isolation of three new aconitine‐type C19‐diterpenoid alkaloids, hemsleyanines E–G (1–3, resp.). The structures of these new alkaloids were elucidated on the basis of spectral data including 2D‐NMR.
Regioselective Synthesis of 4‐(Arylsulfanyl)‐2‐hydroxyhomophthalates by [4+2] Cycloaddition of 3‐(Arylsulfanyl)‐1‐(trimethylsilyloxy)buta‐1,3‐dienes with Dimethyl Penta‐2,3‐dienedioate
Authors: Imran Muhammad , Iqbal Inam , Fischer Christine , Langer Peter 
Published: April 2010

AbstractThe [4+2] cycloaddition of 3‐(arylsulfanyl)‐1‐(trimethylsilyloxy)buta‐1,3‐dienes with dimethyl penta‐2,3‐dienedioate provides a convenient and regioselective approach to a variety of 4‐(arylsulfanyl)‐2‐hydroxyhomophthalates.
New Diterpenoid Alkaloids from Aconitum liangshanicum
Authors: Zhang Zhong‐Tang , Liu Xiao‐Yu , Chen Dong‐Lin , Wang Feng‐Peng 
Published: April 2010

AbstractOne new C19‐diterpenoid alkaloid, named liangshantine (1), and three new C20‐diterpenoid alkaloids, liangshansines A–C (2–4, resp.), as well as eight known compounds, were isolated from the roots of Aconitum liangshanicum. The structures of these new alkaloids were elucidated by spectroscopic methods.
Synthesis of 1‐Methyl‐6,10‐diphenylheptalene Derivatives
Authors: Jin Xudong , Linden Anthony , Hansen Hans‐Jürgen 
Published: April 2010

AbstractThe reduction of heptalene diester 1 with diisobutylaluminium hydride (DIBAH) in THF gave a mixture of heptalene‐1,2‐dimethanol 2a and its double‐bond‐shift (DBS) isomer 2b (Scheme 3). Both products can be isolated by column chromatography on silica gel. The subsequent chlorination of 2a or 2b with PCl5 in CH2Cl2 led to a mixture of 1,2‐bis(chloromethyl)heptalene 3a and its DBS isomer 3b. After a prolonged chromatographic separation, both products 3a and 3b were obtained in pure form. They crystallized smoothly from hexane/Et2O 7 : 1 at low temperature, and their structures were determined by X‐ray crystal‐structure analysis (Figs. 1 and 2). The nucleophilic exchange of the Cl substituents of 3a or 3b by diphenylphosphino groups was easily achieved with excess of (diphenylphospino)lithium (=lithium diphenylphosphanide) in THF at 0° (Scheme 4). However, the purification of 4a/4b was very difficult since these bis‐phosphines decomposed on column chromatography on silica gel and were converted mostly by oxidation by air to bis(phosphine oxides) 5a and 5b. Both 5a and 5b were also obtained in pure form by reaction of 3a or 3b with (diphenylphosphinyl)lithium (=lithium oxidodiphenylphospanide) in THF, followed by column chromatography on silica gel with Et2O. Carboxaldehydes 7a and 7b were synthesized by a disproportionation reaction of the dimethanol mixture 2a/2b with catalytic amounts of TsOH. The subsequent decarbonylation of both carboxaldehydes with tris(triphenylphosphine)rhodium(1+) chloride yielded heptalene 8 in a quantitative yield. The reaction of a thermal‐equilibrium mixture 3a/3b with the borane adduct of (diphenylphosphino)lithium in THF at 0° gave 6a and 6b in yields of 5 and 15%, respectively (Scheme 4). However, heating 6a or 6b in the presence of 1,4‐diazabicyclo[2.2.2]octane (DABCO) in toluene, generated both bis‐phosphine 4a and its DBS isomer 4b which could not be separated. The attempt at a conversion of 3a or 3b into bis‐phosphines 4a or 4b by treatment with t‐BuLi and Ph2PCl also failed completely. Thus, we returned to investigate the antipodes of the dimethanols 2a, 2b, and of 8 that can be separated on an HPLC Chiralcel‐OD column. The CD spectra of optically pure (M)‐ and (P)‐configurated heptalenes 2a, 2b, and 8 were measured (Figs. 4, 5, and 9).
Oligonucleotide Analogues with Integrated Bases and Backbones. Part 23
Authors: Bogliotti Nicolas , Bernet Bruno , Vasella Andrea 
Published: April 2010

AbstractThe sulfone 2, and the sulfoxides (S)‐3 and (R)‐3 were obtained by oxidation of the thiomethylene‐linked A*[s]U dinucleoside 1. Conformational analysis and association studies of 2, (S)‐3, and (R)‐3 reveal a strong influence of the configuration on the conformation of the linking unit and on the self‐association of the dinucleosides.
Oligonucleotide Analogues with Integrated Bases and Backbones. Part 24
Authors: Chiesa Katja , Shvoryna Alyena , Bernet Bruno , Vasella Andrea 
Published: April 2010

AbstractInspection of Maruzen models and force‐field calculations suggest that oligonucleotide analogues integrating backbone and bases (ONIBs) with an aminomethylene linker form similar cyclic duplexes as the analogous oxymethylene linked dinucleosides. The self‐complementary adenosine‐ and uridine‐derived aminomethylene‐linked A*[n]U dinucleosides 15–17 were prepared by an aza‐Wittig reaction of the aldehyde 10 with an iminophosphorane derived from azide 6. The sequence‐isomeric U*[n]A dinucleosides 18–20 were similarly prepared from aldehyde 3 and azide 12. The N‐ethylamine 5, the acetamides 7 and 14, and the amine 13 were prepared as references for the conformational analysis of the dinucleosides. In contradistinction to the results of calculations, the N‐ethylamine 5 exists as intramolecularly H‐bonded hydroxyimino tautomer. The association in CDCl3 of these dinucleosides was studied by 1H‐NMR and CD spectroscopy. The A*[n]U dinucleosides 16 and 17 associate more strongly than the sequence isomers 19 and 20; the cyclic duplexes of 16 form preferentially Watson–Crick‐type base pairs, while 17, 19, and 20 show both Watson–Crick‐ and Hoogsteen‐type base pairing. The cyclic duplexes of the aminomethylene‐linked dinucleosides prefer a gg‐orientation of the linker. No evidence was found for an intramolecular H‐bond of the aminomethylene group. The CD spectra of 16 and 17 show a strong, those of 19 a weak, and those of 20 almost no temperature dependence.
Stereochemical Models for Discussing Additions to α,β‐Unsaturated Aldehydes Organocatalyzed by Diarylprolinol or Imidazolidinone Derivatives – Is There an ‘(E)/(Z)‐Dilemma’?
Authors: Seebach Dieter , Gilmour Ryan , Grošelj Uroš , Deniau Gildas , Sparr Christof , Ebert Marc‐Olivier , Beck Albert K. , McCusker Lynne B. , Šišak Dubravka , Uchimaru Tadafumi 
Published: April 2010

AbstractThe structures of iminium salts formed from diarylprolinol or imidazolidinone derivatives and α,β‐unsaturated aldehydes have been studied by X‐ray powder diffraction (Fig. 1), single‐crystal X‐ray analyses (Table 1), NMR spectroscopy (Tables 2 and 3, Figs. 2–7), and DFT calculations (Helv. Chim. Acta 2009, 92, 1, 1225, 2010, 93, 1; Angew. Chem., Int. Ed. 2009, 48, 3065). Almost all iminium salts of this type exist in solution as diastereoisomeric mixtures with (E)‐ and (Z)‐configured +NC bond geometries. In this study, (E)/(Z) ratios ranging from 88 : 12 up to 98 : 2 (Tables 2 and 3) and (E)/(Z) interconversions (Figs. 2–7) were observed. Furthermore, the relative rates, at which the (E)‐ and (Z)‐isomers are formed from ammonium salts and α,β‐unsaturated aldehydes, were found to differ from the (E)/(Z) equilibrium ratio in at least two cases (Figs. 4 and 5, a, and Fig. 6, a); more (Z)‐isomer is formed kinetically than corresponding to its equilibrium fraction. Given that the enantiomeric product ratios observed in reactions mediated by organocatalysts of this type are often ≥99 : 1, the (E)‐iminium‐ion intermediates are proposed to react with nucleophiles faster than the (Z)‐isomers (Scheme 5 and Fig. 8). Possible reasons for the higher reactivity of (E)‐iminium ions (Figs. 8 and 9) and for the kinetic preference of (Z)‐iminium‐ion formation are discussed (Scheme 4). The results of related density functional theory (DFT) calculations are also reported (Figs. 10–13 and Table 4).
Combined action of the dinuclear platinum compound BBR3610 with the PI3‐K inhibitor PX‐866 in glioblastoma
Authors: Gwak Ho‐Shin , Shingu Takashi , Chumbalkar Vaibhav , Hwang Yeo‐Hyeon , DeJournett Robert , Latha Khatri , Koul Dimpy , Alfred Yung W. K. , Powis Garth , Farrell Nicholas P. , Bögler Oliver 
Published: April 2010

AbstractPolynuclear platinum compounds are more effective at killing glioblastoma cells than cisplatin, work by a different mechanism, and typically do not induce high levels of apoptosis at early time points after exposure. Here, we tested the hypothesis that combining BBR3610, the most potent polynuclear platinum, with a phosphoinositide‐3‐kinase (PI3K) inhibitor would promote apoptosis and enhance the impact on glioblastoma cells. The PI3K pathway is commonly activated in glioblastoma and promotes tumor cell survival, suggesting that its inhibition would make cells more sensitive to cytotoxic agents. We chose PX‐866 as a PI3K inhibitor as it is a clinically promising agent being evaluated for brain tumor therapy. Combining BBR3610 and PX‐866 resulted in synergistic killing of cultured glioma cells and an extension of survival in an orthotopic xenograft animal model. Both agents alone induced autophagy, and this appeared to be saturated, because when they were combined no additional autophagy was observed. However, the combination of PX‐866 and BBR3610 did induce statistically significant increases in the level of apoptosis, associated with a reduction in pAkt and pBad, as well as inhibition of transwell migration. We conclude that combining polynuclear platinums with PI3K inhibitors has translational potential and alters the cellular response to include early apoptosis.
Personal history of breast cancer as a significant risk factor for endometrial serous carcinoma in women aged 55 years old or younger
Authors: Liang Sharon X. , Pearl Micheal , Liang Shu , Xiang Li , Jia Lin , Yang Binlie , Fadare Oluwole , Schwartz Peter E. , Chambers Setsuko K. , Kong Beihua , Zheng Wenxin 
Published: April 2010

AbstractA comparative study between endometrial serous carcinoma (ESC) and endometrial endometrioid carcinoma (EEC) was performed to determine whether a personal history of breast cancer is a risk factor for ESC in women aged ≤55 yr. Study subjects consisted of 348 women who were diagnosed with ESC and 830 comparison subjects who had EEC. Variables studied included age at diagnosis, a history of breast cancer, tamoxifen therapy, hormonal replacement therapy and smoking history. Overall, 19.4% of women with ESC had a history of breast cancer, which was significantly higher than that of 3% in comparison subjects. Among the study subjects, the incidence of a prior breast cancer was significantly higher in patients who were 55 yr of age or younger (41.5%) than those who were older than 55 yr (16%). The statistical significance of both of the aforementioned comparisons was independent of tamoxifen usage on multivariate analyses. The mean time interval between prior breast cancer and endometrial cancer was 92.5 mo (range 7–240 mo) in the study group and 79 mo (range 7–192 mo) in the comparison group. For the whole cohort and individual subgroups (ESC, EEC, ≤55 yr and >55 yr), a personal history of breast cancer did not adversely affect the patient outcomes, which was largely dependent on standard clinicopathologic parameters such as International Federation of Gynecology and Obstetrics stage, as has previously been demonstrated. These findings suggest that a personal history of breast cancer may be a significant risk factor for the development of ESC in women aged ≤55 yr. Further studies are needed to clarify the relationship between these two cancers in this age group and whether this increased risk is reflective of a genetic predisposition.
Ethnicity in trauma and psychiatric disorders: findings from the collaborative longitudinal study of personality disorders
Authors: Pérez Benítez Carlos I. , Yen Shirley , Shea M. Tracie , Edelen Maria O. , Markowitz John C. , McGlashan Thomas H. , Ansell Emily B. , Grilo Carlos M. , Skodol Andrew E. , Gunderson John G. , Morey Leslie C. 
Published: April 2010

AbstractThe study's aims are to explore ethnic differences in rates of adverse childhood experiences and lifetime traumatic events and in rates of psychiatric disorders for patients exposed to similar traumas. Rates of these events and rates of major depressive disorder, posttraumatic stress, substance use, and borderline personality disorders were compared among 506 non‐Hispanic Whites (N‐HW), 108 Latina(o)s, and 94 African Americans (AA) participating in the Collaborative Longitudinal Personality Disorder Study. We found that Whites reported higher rates of neglect than African Americans and Latina(o)s, higher rates of verbal/emotional abuse than African Americans, and higher rates of accidents and injuries/feared serious injury than Latina(o)s. African Americans had higher rates of seeing someone injured/killed than Whites. No significant interaction was observed between adverse events and ethnicity for mental disorders. © 2010 Wiley Periodicals, Inc. J Clin Psychol: 66:1–16, 2010.
Many new down‐ and up‐regulatory signaling pathways, from known cancer progression suppressors to matrix metalloproteinases, differ widely in cells of various cancers
Authors: DeLassus Gregory S. , Cho Hyojin , Hoang Stanley , Eliceiri George L. 
Published: April 2010

AbstractPreviously we detected new signaling pathways, some downregulatory and others upregulatory, from seven known suppressors of cancer progression to the expression of eight cancer‐promoting matrix metalloproteinases (MMPs) in breast cancer cells. The goals of the present study were to test whether the preceding observations occur only in breast cancer cells and, if not, whether the same downregulatory and upregulatory signaling pathways are active in cells of other human cancers, focusing on activator protein‐2α, E‐cadherin, fibulin1D, interleukin 4, p16INK4α, p53, PTEN, and RKIP, and on MMP1, MMP2, MMP7, MMP13, MMP14, MMP16, MMP19, and MMP25. To this end, in the present study we tested the effects of raising the cellular levels of wild‐type copies of these known suppressors of cancer progression on the expression of these MMPs. This study yielded several unexpected results. We have detected 53 new signaling pathways in cells of prostate, brain, lung, ovarian and breast human cancers, with an abundance of signaling pathways as high as ∼40% of the cancer progression regulator/MMP pairs tested in cells of prostate and breast cancers. Cells of various cancers differed widely and sequence‐specifically in the identity of their signaling pathways, so that almost 90% of the pathways were different in cells from one cancer to another. In each of 18 out of 51 signaling pathways, a known suppressor of cancer progression stimulated, rather than inhibited, the expression of a cancer‐promoting MMP. Ten signaling pathways were upregulatory in cells of some cancers and downregulatory in cells of other cancers. J. Cell. Physiol. 224: 549–558, 2010. © 2010 Wiley‐Liss, Inc.
Novel 2‐hydrazino‐pyrimidin‐4(3H)‐one derivatives as potential dihydrofolate reductase inhibitors
Authors: Degani Mariam S. , Bag Seema , Bairwa Ranjeet , Tawari Nilesh R. , Queener Sherry F. 
Published: April 2010

Abstract
magnified imageNovel substituted 2‐hydrazino‐pyrimidin‐4(3H)‐one derivatives were synthesized and examined for their antifolate activity against DHFR from Pneumocystis carinii (pc), Toxoplasma gondii (tg), Mycobacterium avium (ma), and rat liver (rl). A novel, simple, and feasible methodology was developed for the synthesis of the titled compounds. Amongst these, compound 8 6‐phenyl‐2‐(2‐(1‐(thiophen‐2‐yl) ethylidene)hydrazinyl) pyrimidin‐4(3H)‐one exhibited 17.74 μM activity against pcDHFR. J. Heterocyclic Chem., (2010).
A comparative study of incisor procumbency and mandibular morphology in vampire bats
Authors: Davis Jillian S. , Nicolay Christopher W. , Williams Susan H. 
Published: April 2010

AbstractThe three species of vampire bats (Phyllostomidae: Desmodontinae), Desmodus rotundus, Diaemus youngi, and Diphylla ecaudata, are the only mammals that obtain all nutrition from vertebrate blood (sanguinivory). Because of the unique challenges of this dietary niche, vampire bats possess a suite of behavioral, physiological, and morphological specializations. Morphological specializations include a dentition characterized by small, bladelike, non‐occlusive cheek teeth, large canines, and extremely large, procumbent, sickle‐shaped upper central incisors. The tips of these incisors rest in cuplike pits in the mandible behind the lower incisors (mandibular pits). Here, we use microCT scanning and high‐resolution radiography to describe the morphology of the mandible and anterior dentition in vampire bats, focusing on the relationship between symphyseal fusion, mandibular pit size, incisor size, and procumbency. In Desmodus and Diaemus, highly procumbent upper incisors are associated with relatively small mandibular pits, an unfused mandibular symphysis with substantial bony interdigitations linking the dentaries, and a diastema between the lower central incisors that helps to facilitate the lapping of blood from a wound. In Diphylla, less procumbent upper incisors are associated with relatively large mandibular pits, a completely fused mandibular symphysis, and a continuous lower toothrow lacking a central diastema. We hypothesize that symphyseal morphology and the presence or absence of the diastema are associated with the angle of upper incisor procumbency and mandibular pit development, and that spatial constraints influence the morphology of the symphysis. Finally, this morphological variation suggests that Diphylla utilizes a different feeding strategy as compared to Desmodus and Diaemus, possibly resulting from the functional demands of specialization on avian, rather than mammalian, blood. J. Morphol., 2010. © 2010 Wiley‐Liss, Inc.
Shape of articular surface of crocodilian (Archosauria) elbow joints and its relevance to sauropsids
Authors: Fujiwara Shin‐ichi , Taru Hajime , Suzuki Daisuke 
Published: April 2010

AbstractThe determination of area and shape of articular surfaces on the limb bones of extinct archosaurs is difficult because of postmortem decomposition of the fibrous tissue and articular cartilages that provide the complex three‐dimensional joint surfaces in vivo. This study aims at describing the shape of the articular cartilages in the elbow joints of six crocodilian specimens; comparing its structure with that of four birds, three testudines, and five squamates; and comparing the shapes of the surfaces of the calcified and the articular cartilages in the elbow joints of an Alligator specimen. The shapes of the articular cartilages of crocodilian elbow joint are shown to resemble those of birds. The humerus possesses an olecranon fossa positioned approximately at the midportion of the distal epiphysis and bordering the margin of the extensor side of the articular surface. The ulna possesses a prominent intercotylar process at approximately the middle of its articular surface, and splits the surface into the radial and ulnar cotylae. This divides the articular cartilage into an articular surface on the flexor portion, and the olecranon on the extensor portion. The intercotylar process fits into the olecranon fossa to restrict elbow joint extension. Dinosaurs and pterosaurs, phylogenetically bracketed by Crocodylia and Aves (birds), may have possessed a similar olecranon fossa and intercotylar process on their articular cartilages. Although these shapes are rarely recognizable on the bones, their impressions on the surfaces of the calcified cartilages provide an important indication of the extensor margin of the articular surfaces. This, in turn, helps to determine the maximum angle of extension of the elbow joint in archosaurs. J. Morphol., 2010. © 2010 Wiley‐Liss, Inc.