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Synthesis of the I-K Fused Polyether Array of CTX3C and Related Ciguatoxins by Use of a Gold-Catalyzed Cyclization Reaction. Org Lett 2024; 26:775-780. [PMID: 38238251 PMCID: PMC10845158 DOI: 10.1021/acs.orglett.3c03782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 01/04/2024] [Accepted: 01/15/2024] [Indexed: 02/03/2024]
Abstract
The I-K fragment (C31-C49) of the ciguatoxin CTX3C has been synthesized from a simple chiral pool derived tetrahydropyranyl alcohol. An efficient gold-catalyzed cyclization reaction of a γ'-hydroxy ynone has been used to accomplish efficient closure of ring K under mild conditions. The resulting vinylogous ester has been elaborated to give a complete tricyclic fragment bearing the dimethyl-substituted side chain required for assembly of the LM spirocyclic acetal portion of the target.
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Synthesis of the A-F Fragment of the Pacific Ciguatoxin CTX3C by Iterative Ring-Closing Metathesis and Tsuji-Trost Allylation. Chemistry 2023; 29:e202303121. [PMID: 37830907 PMCID: PMC10946863 DOI: 10.1002/chem.202303121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 10/12/2023] [Accepted: 10/13/2023] [Indexed: 10/14/2023]
Abstract
The fully functionalized A-F fragment of the Pacific ciguatoxin CTX3C has been synthesized from a derivative of D-glucal, which serves as the B-ring. Rings A and C were introduced to either side of ring B by ring-closing diene and enyne metathesis (RCM). The seven-membered D-ring and eight-membered E-ring were assembled by iterative use of a six-step reaction sequence in which RCM was used for ring construction and Tsuji-Trost allylation was employed for subsequent stereoselective functionalization. The nine-membered F-ring was formed by use of an RCM reaction and bears the functionality required for attachment of the I-M fragment and subsequent closure of rings G and H.
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3
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Synthetic Studies on Amphidinolide F: Exploration of Macrocycle Construction by Intramolecular Stille Coupling. Org Lett 2022; 24:7600-7604. [PMID: 36223230 DOI: 10.1021/acs.orglett.2c03045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Exploration of an ambitious new strategy for the total synthesis of the cytotoxic marine natural product amphidinolide F is described, which features fabrication of the core structure from four readily accessible fragments and macrocycle construction through C9-C10 bond formation by intramolecular Stille coupling between an alkenyl iodide and alkenyl stannane. Efficient stereoselective synthesis of each of the four building-blocks and subsequent coupling of them to produce the requisite cyclization precursor has been accomplished, but suitable conditions for high-yielding palladium-mediated closure of the macrocycle to produce the fully protected amphidinolide F ring system have yet to be identified.
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Abstract
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The complete carbon
framework of the macrocyclic marine natural
product amphidinolide F has been prepared by a convergent synthetic
route in which three fragments of similar size and complexity have
been coupled. Key features of the syntheses of the fragments include
the stereoselective construction of the tetrahydrofuran in the C1–C9
fragment by oxonium ylide (free or metal-bound) formation and rearrangement
triggered by the direct generation of a rhodium carbenoid from 1-sulfonyl-1,2,3-triazole,
the highly diastereoselective aldol reaction between a boron enolate
and an aldehyde with 1,4-control to prepare the C10–C17 fragment,
and the formation of the tetrahydrofuran in the C18–C29 fragment
by intramolecular nucleophilic ring opening of an epoxide with a hydroxyl
group under acidic conditions.
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Synthesis of the Prototypical Cyclopropyl Dipeptide Mimic and Evaluation of Its Turn-Inducing Capability. J Org Chem 2021; 87:258-270. [PMID: 34913698 DOI: 10.1021/acs.joc.1c02344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The (+) and (-) enantiomers of a new turn-inducing cyclopropyl dipeptide mimic have been synthesized and evaluated. The mimic derives its turn-inducing capabilities solely from the cyclopropyl group and without the conformational biasing that would be provided by side-chain substituents. The mimic and peptide-mimic hybrids prepared from it have been studied using a combination of spectroscopic techniques (NMR, IR, and CD). The dipeptide mimic itself displays intramolecular hydrogen bonding in organic solvents, which differs from that observed in natural peptide turns. In contrast, more elaborate peptide-mimic hybrids exhibit hydrogen bonding characteristics that vary with solvent but are consistent with structures found in the tetrapeptide portion (i → i + 3) of a native β-turn.
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Abstract
We report a simple reductive amination protocol to ligate two peptides, while simultaneously installing a β-turn mimic at the ligation junction. This strategy uses commercially available materials, mild chemical conditions, and a chemoselective ligation reaction of unprotected peptide substrates accessed through standard solid phase methods. This system was implemented in a designed β-hairpin system, and biophysical analysis demonstrates effective mimicry of the β-turn.
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Bidirectional Synthesis of the IJK Fragment of Ciguatoxin CTX3C by Sequential Double Ring-Closing Metathesis and Tsuji-Trost Allylation. Org Lett 2020; 22:3734-3738. [PMID: 32306737 PMCID: PMC7304930 DOI: 10.1021/acs.orglett.0c01238] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
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A novel four-step bidirectional strategy
has been used to synthesize
the IJK fragment of the marine polyether natural product CTX3C from
a simple monocyclic precursor in a concise and efficient manner. The
four-step bidirectional sequence involves ring-closing metathesis,
alcohol oxidation, enol carbonate formation, and palladium-mediated
Tsuji–Trost allylation.
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8
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Total Syntheses of 11-Acetoxy-4-deoxyasbestinin D, 4-Deoxyasbestinin C, Asbestinin-10, -20, -21 and -23. Chemistry 2020; 26:1155-1160. [PMID: 31710141 PMCID: PMC7027880 DOI: 10.1002/chem.201904998] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Indexed: 11/30/2022]
Abstract
Six members of the asbestinin family of marine diterpene natural products have been synthesized in an efficient and stereoselective manner from a single oxa‐bridged intermediate. Five of these natural products have not been synthesized previously and the structures of four of them have been confirmed as those proposed originally or following revisions to the original structures. The fifth natural product—asbestinin‐21—has been shown to be a diastereomer of the compound that had been proposed previously.
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A Short Sequence for the Iterative Synthesis of Fused Polyethers. Helv Chim Acta 2019. [DOI: 10.1002/hlca.201900161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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10
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Evaluation of platelet reactivity during combined antiplatelet therapy in patients with stable coronary artery disease in relation to diabetes type 2 and the GPIIB/IIIA receptor gene polymorphism. JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY 2019; 70. [PMID: 31356179 DOI: 10.26402/jpp.2019.2.01] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 04/29/2019] [Indexed: 11/03/2022]
Abstract
Antiplatelet therapy resistance against acetylsalicylic acid (ASA) and/or clopidogrel in coronary heart disease (CHD) is common with diabetes mellitus. One factor might involve platelet receptor ITGB3 gene polymorphism. We aimed to assess resistance together with platelet reactivity parameters, the polymorphism, plus diabetes type 2 coexistence. The study included 185 patients with CHD, including 58 diabetics, aged 62.3 ± 8.2 years. Patients were treated long-term with ASA, plus clopidogrel, both 75 mg/d. Platelet aggregation was measured with arachidonic acid (ASPI test; ASA-response assessment) or ADP (ADP test; clopidogrel-response assessment). Thromboxane B2 (TXB2) and fibrinogen concentrations were measured and ITGB3 PIA1>A2 variants identified. Increases in PLT, glucose and SBP were demonstrated with dual resistance or to clopidogrel. Regardless of response, diabetics (versus non-diabetics) had elevated platelet aggregation with the ADP test (P = 0.0198), higher TXB2 (P = 0.0501), BMI (P = 0.0003) and SBP (P = 0.0627). ITGB3 PIA1/A1 homozygotes had higher platelet aggregation with the ASPI test (P = 0.0513), and fibrinogen concentrations (P = 0.0133), relative to A2 allele carriers. Significant associations of diabetes with clopidogrel resistance (P = 0.0011) and PIA1/A1 homozygotes with ASA resistance (P = 0.0518) were found. Higher concentrations of TXB2 (P = 0.0223) and higher SBP (P = 0.0063) were found with diabetes (versus non-diabetic) in PIA1/A1 homozygotes. We concluded that diabetes with CHD weakens response to antiplatelet drugs, especially to clopidogrel; and hyperglycaemia, hypertension and obesity might also play an important role. Diabetics' resistance to ASA is associated with increased platelet reactivity, perhaps related to the more frequent ITGB3 PIA1 allele and increased TXB2 generation. The PIA1 allele may be a potential factor for aspirin resistance with elevated fibrinogen concentration.
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Variable gender-dependent platelet responses to combined antiplatelet therapy in patients with stable coronary-artery disease. JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY 2018; 69. [PMID: 30552303 DOI: 10.26402/jpp.2018.4.10] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 08/30/2018] [Indexed: 11/03/2022]
Abstract
Antiplatelet therapy is considered as a standard procedure against atherosclerotic cardiovscular disease but this therapy has limited effect if resistance to acetylsalicylic acid or clopidogrel is present. Important factors associated with resistance are gender; or inflammation possibly associated with membrane microparticles (MP). It was decided to challenge the hypothesis that differential responses to dual antiplatelet therapy are conditioned by gender and/or proinflammatory status. The study involved 160 patients with stable coronary heart disease (118 men, 42 women) aged 65.2 ± 7.8 years. Patients were treated long-term with acetylsalicylic acid (ASA); plus clopidogrel starting 6 days before percutaneous coronary intervention (both 75 mg/day). Response was evaluated using platelet aggregation with either arachidonic acid (the ASPI test; predominantly for ASA response) or adenosine diphosphate (the ADP test; predominantly for clopidogrel response). MP levels were measured as follows: total (MP-total); with TF expression (MP-TF); or platelet-derived microparticles (PDMP), as well as proinflammatory parameters: C-reactive protein (CRP), leukocytes (WBC) and platelet numbers (PLT). Analysis of platelet-aggregation levels with regard to gender revealed higher aggregation in women: with resistance to ASA (ASPI test: P = 0.0383, ADP test: P = 0.0027); resistance to clopidogrel (ASPI test: P = 0.0003; ADP test: P = 0.0566) and with sensitivity to both drugs with the ADP test (P = 0.0190). In women relative to men, regardless of response, significantly higher CRP (P = 0.0012), WBC (P = 0.0244) and PLT numbers (P = 0.0001) were found. In contrast, in men significantly higher concentrations of MP-TF (P = 0.0286) and triglycerides (P = 0.0296) were found in the clopidogrel-resistant group. We conclude that women have an inferior response to dual antiplatelet therapy relative to men, possibly associated with higher platelet reactivity (especially when measured with the ADP test), with a more accentuated proinflammatory status. In contrast, among the factors supporting the resistance in men can be an elevated concentration of MP-TF which, together with the coexistence of hypertriglyceridemia, may constitute an important mechanism of resistance to clopidogrel.
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Tree water balance drives temperate forest responses to drought. Ecology 2018; 99:2506-2514. [PMID: 30144047 DOI: 10.1002/ecy.2499] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 07/13/2018] [Accepted: 07/20/2018] [Indexed: 11/07/2022]
Abstract
Intensifying drought is increasingly linked to global forest diebacks. Improved understanding of drought impacts on individual trees has provided limited insight into drought vulnerability in part because tree moisture access and depletion is difficult to quantify. In forests, moisture reservoir depletion occurs through water use by the trees themselves. Here, we show that drought impacts on tree fitness and demographic performance can be predicted by tracking the moisture reservoir available to trees as a mass balance, estimated in a hierarchical state-space framework. We apply this model to multiple seasonal droughts with tree transpiration measurements to demonstrate how species and size differences modulate moisture availability across landscapes. The depletion of individual moisture reservoirs can be tracked over the course of droughts and linked to biomass growth and reproductive output. This mass balance approach can predict individual moisture deficit, tree demographic performance, and drought vulnerability throughout forest stands based on measurements from a sample of trees.
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Stereoselective Synthesis of Medium-Sized Cyclic Ethers by Sequential Ring-Closing Metathesis and Tsuji–Trost Allylation. Org Lett 2018; 20:2782-2786. [DOI: 10.1021/acs.orglett.8b01082] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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15
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Synthesis of fused tricyclic systems by thermal Cope rearrangement of furan-substituted vinyl cyclopropanes. Org Biomol Chem 2018; 16:3970-3982. [DOI: 10.1039/c8ob00924d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel method for the construction of hexahydroazuleno[4,5-b]furans has been developed in which 1-furanyl-2-alkenylcyclopropanes undergo highly stereoselective thermal Cope rearrangement.
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16
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Total Synthesis of 7-epi
-Pukalide and 7-Acetylsinumaximol B. Chemistry 2017; 23:9761-9765. [DOI: 10.1002/chem.201702591] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Indexed: 11/10/2022]
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Spatial differences of matrix metalloproteinase-2 and matrix metalloproteinase-9 within abdominal aortic aneurysm wall and intraluminal thrombus. JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY : AN OFFICIAL JOURNAL OF THE POLISH PHYSIOLOGICAL SOCIETY 2016; 67:903-910. [PMID: 28195071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 12/27/2016] [Indexed: 06/06/2023]
Abstract
Formation of an abdominal aortic aneurysm is a complex process involving aortic wall degradation. The matrix metalloproteinases (MMPs) mainly involved in this process are MMP-2 and MMP-9. Most aneurysms contain an intraluminal thrombus. It is suggested that the thrombus' thickness correlates with the risk of aneurysm rupture and may be a new prognostic factor. The purpose of the present study was to investigate enzyme protein levels in thick (A1) and thin (B1) segments of the thrombus and aneurysm wall sections A (adjacent to A1) and B (adjacent to B1). Aneurysm samples from one aneurism sac were collected from 36 patients that underwent aneurysm repair. MMP-2, MMP-9 and a tissue inhibitor of metalloproteinases (TIMP-1) were measured using enzyme-linked-immunosorbent assay of protein extract. MMP-9 concentrations were significantly higher in B1 samples compared with A1 (113.4 ± 118.0 versus 63.0 ± 61.2, P = 0.004), A(113.4 ± 118.0 versus 31.7 ± 30.0, P < 0.001) or B (113.4 ± 118.0 versus 39.5 ± 41.5, P < 0.001). Likewise MMP-9/TIMP-1 ratio was elevated in B1 compared with A1 (18.9 ± 27.8 versus 9.1 ± 10.6, P = 0.017), A (18.9 ± 27.8 versus 2.5 ± 2.2, P < 0.001) or B (18.9 ± 27.8 versus 3.6 ± 4.5, P < 0.001). MMP-2 and TIMP-1 were higher in A compared with A1 (18.4 ± 8.5 versus 7.2 ± 7.6, P < 0.001; 14.3 ± 5.9 versus 8.5 ± 5.4, P < 0.001, respectively) and B1 (18.4 ± 8.5 versus 5.2 ± 2.9, P < 0.001; 14.3 ± 5.9 versus 8.9 ± 4.9, P < 0.001, respectively) as well as in B compared with A1 (15.9 ± 7.3 versus 7.2 ± 7.6, P < 0.001; 13.0 ± 5.0 versus 8.5 ± 5.4, P < 0.001, respectively) and B1 (15.9 ± 7.3 versus 5.2 ± 2.9, P < 0.001; 13.0 ± 5.0 versus 8.9 ± 4.9, P = 0.003, respectively). There were significant correlations between thin thrombus TIMP-1 and thrombus thickness (β = -0.24, P = 0.021) and between thin thrombus MMP-9/TIMP-1 ratio and thrombus thickness (β = 1.75, P = 0.003). Our study has revealed that the presence of thrombi with thin segments in the aneurysm sac, associated with higher proteolytic activity, could possibly be used as a potential indicator of a rupture site.
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Expert elicitation of seasonal abundance of North Atlantic right whales Eubalaena glacialis in the mid-Atlantic. ENDANGER SPECIES RES 2015. [DOI: 10.3354/esr00699] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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23
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Synthesis of Cyclopropyl-Substituted Furans by Brønsted Acid Promoted Cascade Reactions. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201500625] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Synthesis of Cyclopropyl-Substituted Furans by Brønsted Acid Promoted Cascade Reactions. Angew Chem Int Ed Engl 2015; 54:5744-7. [DOI: 10.1002/anie.201500625] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Indexed: 11/07/2022]
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Synthesis of four diastereomers of sclerophytin F and structural reassignment of several sclerophytin natural products. Chemistry 2015; 21:4772-80. [PMID: 25663662 DOI: 10.1002/chem.201406051] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Indexed: 11/09/2022]
Abstract
Synthesis of the triol that has been proposed to be the marine natural product sclerophytin F has been completed along with the syntheses of three diastereomers. Comparison of the NMR spectroscopic data for all four compounds to the data reported for the natural product reveals that sclerophytin F is not the 3S diastereomer of sclerophytin A as proposed by Friedrich and Paquette. Re-analysis of the NMR spectroscopic data for known sclerophytin natural products and synthetic analogues leads to the conclusion that sclerophytins E and F are the same compound. This finding has allowed structural reassignment of several other cladiellin natural products.
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Empirical evidence of the efficiency and efficacy of fat taxes and thin subsidies. Cent Eur J Public Health 2015; 22:201-6. [PMID: 25438400 DOI: 10.21101/cejph.a3933] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This study summarizes the empirical literature on fat taxes and thin subsidies to assess their efficiency and efficacy as instruments of public policy to control obesity. Three specific types of taxes are studied in the literature: food group taxes; nutrient taxes; and nutrient index taxes. Anumber of studies use food expenditure data to assess the impact of various taxes on obesity and therefore only indirectly measure the impacts of taxes and subsidies on obesity. These studies generally conclude that food group taxes, nutrient taxes and nutrient index taxes have a small impact on the purchases of food and the nutrients purchased. Other studies use the body mass index as the explanatory variable and thus measure the impacts of taxes on body mass index directly. Nutrient taxes are found to be more effective than food group taxes, although even for nutrient taxes, the effects are small. In general, thin subsidies seem to offer more effective control of obesity than obesity taxes. However, due to the small effects of both fat taxes and thin subsidies, they are not recommended as instruments of food and nutrition policy.
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Abstract
The synthesis of the compound that has been proposed to be the natural product sclerophytin F has been completed from a known vinylogous carbonate. The synthetic strategy relied upon rearrangement of a catalytically generated ylide-like intermediate to produce an oxabicyclo[6.2.1]-5-undecen-9-one and an intermolecular Diels-Alder reaction to construct the complete tricyclic core found in the natural product. Comparison of the spectroscopic data for synthetic material to that reported for sclerophytin F shows that the natural product does not have the revised structure possessing the 3S configuration (*) proposed previously.
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Intramolecular Reactions of Metal Carbenoids with Allylic Ethers: Is a Free Ylide Involved in Every Case? Chemistry 2014; 20:5454-9. [DOI: 10.1002/chem.201304054] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Indexed: 11/09/2022]
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29
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Total Syntheses of Amphidinolides T1, T3, and T4. Angew Chem Int Ed Engl 2013; 52:10072-5. [DOI: 10.1002/anie.201305467] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Indexed: 11/05/2022]
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Total Syntheses of Multiple Cladiellin Natural Products by Use of a Completely General Strategy. J Org Chem 2012; 78:673-96. [DOI: 10.1021/jo302542h] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Organocatalytic Synthesis of Highly Substituted Furfuryl Alcohols and Amines. Angew Chem Int Ed Engl 2012; 51:12128-31. [DOI: 10.1002/anie.201207300] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Indexed: 11/11/2022]
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Possible counter effect in newborns of 1936A>G (I646V) polymorphism in the AKAP10 gene encoding A-kinase-anchoring protein 10. J Perinatol 2012; 32:230-4. [PMID: 21701445 DOI: 10.1038/jp.2011.85] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
OBJECTIVE Cyclic adenosine monophosphate/protein kinase A (PKA) is important in embryonic development. The human AKAP10 gene is polymorphic: 1936A>G results in changes to a PKA-binding domain and increased targeting to mitochondria. Previous studies found G1936 as 'deleterious' in adults, and this study investigates whether this holds true in preterm birth. STUDY DESIGN Study group consisted of 80 preterm newborns (PTNs) born before the 38th gestation week. Control group consisted of 123 full-term healthy newborns born after the 37th gestation week with uncomplicated pregnancies. Genomic DNA was extracted from umbilical blood and AKAP10 genotypes were identified by PCR/restriction enzyme. RESULT Significant differences in frequencies of 1936A>G genotypes/alleles between both groups were found. PTNs had increased frequency (55%) of AA homozygotes (odds ratio, AA versus AG+GG: 2.63 (95% confidence interval: 1.33 to 5.20), P=0.006) after adjustments: mothers with previous PTNs, smoking, first pregnancy, first delivery and Cesarean section. CONCLUSION Results suggest G1936 is preventative factor against preterm birth, in contrast with previously asserted negative effects in adults.
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Abstract
A concise synthesis of the tricyclic core of the marine diterpene natural products labiatin A and australin A has been accomplished. The key ring-forming transformation is a cascade reaction comprising generation of a copper carbenoid from a diazo ketone, intramolecular reaction of the carbenoid with a cyclic ether, and rearrangement of the resulting free oxonium ylide or its metal-bound equivalent with ring expansion of the original cyclic ether.
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Enantioselective total syntheses of three cladiellins (eunicellins): a general approach to the entire family of natural products. Angew Chem Int Ed Engl 2011; 49:9867-70. [PMID: 21082639 DOI: 10.1002/anie.201005508] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Enantioselective Total Syntheses of Three Cladiellins (Eunicellins): A General Approach to the Entire Family of Natural Products. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.201005508] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Synthetic studies on the cornexistins: synthesis of (±)-5-epi-hydroxycornexistin. Org Biomol Chem 2008; 6:4012-25. [DOI: 10.1039/b811245b] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Abstract
The A-E fragment of the marine natural product CTX3C has been prepared in an efficient manner by using a strategy in which two-directional and iterative ring-closing metathesis (RCM) reactions were employed for ring construction.
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Synthesis of the Fused Polyether Core of Hemibrevetoxin B by Two-Directional Ring-Closing Metathesis. Org Lett 2007; 9:1033-6. [PMID: 17311391 DOI: 10.1021/ol0630651] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The tetracyclic fused polyether core of the marine natural product hemibrevetoxin B has been prepared in an efficient manner by using a strategy in which ring-closing metathesis (RCM) reactions were employed for ring synthesis. Simultaneous construction of the A and D rings was accomplished by double two-directional RCM of a tetraene. [reaction: see text]
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Rapid synthesis of medium-ring fused polycarbocyclic systems by rearrangement of carbenoid-derived oxonium ylides. Chem Commun (Camb) 2007:4134-6. [DOI: 10.1039/b709064a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Abstract
BACKGROUND Despite the growing use of error reporting tools, the healthcare industry is inexperienced in receiving, understanding, and analyzing these reports. OBJECTIVE To assess the accuracy and define the epidemiology of medication error reports. DESIGN, SETTING, AND PATIENTS A retrospective cohort study of 581 error reports containing 1010 medication errors reported between July 2001 and January 2003 at a large academic children's institution. MAIN OUTCOME MEASURES Correct classification and types of medication errors. RESULTS Of the 1010 medication errors reviewed, 298 (30%) were prescribing errors, 245 (24%) were dispensing errors, 410 (41%) were administration errors, and 57 (6%) involved medication administration records (MAR). Following expert review, 208 errors (21%) were deleted because they had been inappropriately coded as errors and 97 (10%) were added as they were not initially coded despite having occurred. In addition, 352 medication error reports needed to have the subtype of error reclassified; 207 (59%) of these involved the reporter choosing the non-descript "other" category on the reporting tool (such as "Prescribing other") which was able to be reclassified by expert review. The overall distribution of error type categories did not change significantly with expert review, although only MAR errors were underreported by the reporters. The most common medications were anti-infectives (17%), pain/sedative agents (15%), nutritional agents (11%), gastrointestinal agents (8%), and cardiovascular agents (7%). CONCLUSIONS Despite clear imperfections in the data captured, medication error reporting tools are effective as a means of collecting reliable information on errors rapidly and in real time. Our data suggest that administration errors are at least as common as prescribing errors in children. Further research is needed, not only in the area of computerized physician order entry (CPOE) for children, but also on ways to make the dispensing and administration of medications safer.
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