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2.
Chemistry ; 19(30): 10004-16, 2013 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-23775936

RESUMEN

Ladder polyether natural products are a class of natural products denoted by their high functional-group density and large number of well-defined stereocenters. They comprise the toxic component of harmful algal blooms (HABs), having significant negative economic and environmental ramifications. However, their mode of action, namely blocking various cellular ion channels, also denotes their promise as potential anticancer agents. Understanding their potential mode of biosynthesis will not only help with developing ways to limit the damage of HABs, but would also facilitate the synthesis of a range of analogs with interesting biological activity. 1,3-Dioxan-5-ol substrates display remarkable 'enhanced template effects' in water-promoted epoxide cyclization processes en route to the synthesis of these ladder polyether natural products. In many cases, they provide near complete endo-to-exo selectivity in the cyclization of epoxy alcohols, thereby strongly favoring the formation of tetrahydropyran (THP) over tetrahydrofuran (THF) rings. The effects of various Brønsted and Lewis acidic and basic conditions are explored to demonstrate the superior selectivity of the template over the previously reported THP-based epoxy alcohols. In addition, the consideration of other synthetic routes are also considered with the goal of gaining rapid access to a plethora of potential starting materials applicable towards the synthesis of ladder polyethers. Finally, cascade sequences with polyepoxides are investigated, further demonstrating the versatility of this new reaction template.


Asunto(s)
Alcoholes/química , Productos Biológicos/química , Dioxanos/química , Compuestos Epoxi/química , Productos Biológicos/síntesis química , Ciclización , Compuestos Epoxi/síntesis química , Furanos/síntesis química , Furanos/química , Humanos , Piranos/síntesis química , Piranos/química , Estereoisomerismo , Agua/química
3.
J Law Med Ethics ; 51(S2): 35-40, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38433675

RESUMEN

This commentary highlights the scientific history of the NIH-Moderna COVID-19 vaccine and corroborates Sarpatwari's theme of private capture of value created by the public. The commentary also identifies missteps by the Trump and Biden Administrations and offers policy recommendations: better contracts with and incentives for pharmaceutical manufacturers and a not-for-profit "public option" for pharmaceutical development.


Asunto(s)
Vacuna nCoV-2019 mRNA-1273 , Vacunas , Humanos , Desarrollo de Medicamentos , Políticas , Programas Informáticos
4.
J Law Med Ethics ; 51(4): 961-971, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38477274

RESUMEN

In recent months, pharmaceutical manufacturers have brought legal challenges to a provision of the 2022 Inflation Reduction Act (IRA) empowering the federal government to negotiate the prices Medicare pays for certain prescription medications. One key argument made in these filings is that price negotiation is a "taking" of property and violates the Takings Clause of the US Constitution. Through original case law and health policy analysis, we show that government price negotiation and even price regulation of goods and services, including patented goods, are constitutional under the Takings Clause. Finding that the IRA violates the Takings Clause would radically upend settled constitutional law and jeopardize the US's most important state and federal health care programs.


Asunto(s)
Medicare , Medicamentos bajo Prescripción , Anciano , Estados Unidos , Humanos , Negociación , Política de Salud , Costos de los Medicamentos
5.
JAMA Health Forum ; 3(5): e221096, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35977259

RESUMEN

Importance: New formulations of prescription drugs can improve convenience and tolerability for patients, but they also constitute manufacturer strategies to extend brand-name drug market exclusivity periods. Objective: To examine whether new formulations of brand-name novel drugs were associated with novel drugs' sales and/or therapeutic value, as well as characterize first new formulations' approval timing relative to the novel drug's generic approval. Design Setting and Participants: This cross-sectional study used the Drugs@FDA database to identify all novel tablet and capsule drugs approved by the US Food and Drug Administration (FDA) between 1995 and 2010 and followed through December 31, 2021. Exposures: Novel drugs' blockbuster status, defined as annual sales of $1 billion or greater, and therapeutic value, measured by (1) accelerated approval status, (2) World Health Organization Model Lists of Essential Medicines inclusion, (3) innovativeness, and (4) clinical usefulness. Main Outcomes and Measures: Approval of a new formulation and timing relative to a novel drug's first generic's approval. Results: Among the 206 novel drugs in tablet or capsule form approved by the FDA from 1995 to 2010, 81 (39.3%) were followed by an FDA-approved new formulation, and 167 (81.1%) had a generic version as of December 31, 2021. In multivariable analyses, new formulations were statistically significantly more likely among blockbuster drugs vs not (58.2% vs 27.6%; adjusted odds ratio [AOR], 4.72; 95% CI, 2.26-9.87; P < .001) and those granted accelerated approval vs not (50.0% vs 37.6%; AOR, 5.48; 95% CI, 1.52-19.67; P = .009), and less likely among orphan products vs not (11.8% vs 44.8%; AOR, 0.13; 95% CI, 0.03-0.52; P = .004). Essential medicine listing vs no listing (47.8% vs 36.9%; AOR, 1.32; 95% CI, 0.52-3.34; P = .56), first-in-class or advance-in-class status vs addition-to-class status (37.8% vs 40.5%; AOR, 0.71; 95% CI, 0.32-1.58; P = .40), and categorization as clinically useful vs not useful (40.9% vs 44.8%; AOR, 0.81; 95% CI, 0.34-1.92; P = .64) were not associated with increased likelihood of a new formulation. First new formulations were statistically significantly less likely to be approved after the novel drug's first generic approval (84.6% vs 15.4%; P < .001). Conclusions and Relevance: In this cross-sectional study of novel drugs in tablet or capsule form approved by the FDA between 1995 and 2010, manufacturers pursued new formulations of best-selling brand-name drugs and those granted accelerated approval but did so less frequently once generic competitors entered the market. Other measures of therapeutic value were not associated with new formulations.


Asunto(s)
Aprobación de Drogas , Medicamentos bajo Prescripción , Estudios Transversales , Medicamentos Genéricos/uso terapéutico , Humanos , Comprimidos , Estados Unidos , United States Food and Drug Administration
6.
J Am Chem Soc ; 133(6): 1902-8, 2011 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-21235230

RESUMEN

A detailed kinetic study of the endo-selective epoxide-opening cascade reaction of a diepoxy alcohol in neutral water was undertaken using (1)H NMR spectroscopy. The observation of monoepoxide intermediates resulting from initial endo and exo cyclization indicated that the cascade proceeds via a stepwise mechanism rather than through a concerted one. Independent synthesis and cyclization of these monoepoxide intermediates demonstrated that they are chemically and kinetically competent intermediates in the cascade. Analysis of each step of the reaction revealed that both the rate and regioselectivity of cyclization improve as the cascade reaction proceeds. In the second step, cyclization of an epoxy alcohol substrate templated by a fused diad of two tetrahydropyran rings proceeds with exceptionally high regioselectivity (endo:exo = 19:1), the highest we have measured in the opening of a simple trans-disubstituted epoxide. The origins of these observations are discussed.


Asunto(s)
Compuestos Epoxi/química , Agua/química , Alcoholes/química , Ciclización , Cinética , Estereoisomerismo , Especificidad por Sustrato
7.
J Law Med Ethics ; 49(3): 456-485, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34665102

RESUMEN

Based on an analysis of relevant laws and policies, regulator data portals, and information requests, we find that clinical data, including clinical study reports, submitted to the European Medicines Agency and Health Canada to support approval of medicines are routinely made publicly available.


Asunto(s)
Aprobación de Drogas , Informe de Investigación , Canadá , Europa (Continente) , Humanos , Estados Unidos , United States Food and Drug Administration
8.
Chem Soc Rev ; 38(11): 3175-92, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19847350

RESUMEN

This tutorial review traces the development of endo-regioselective epoxide-opening reactions in water. Templated, water-promoted epoxide-opening cyclization reactions can offer rapid access to subunits of the ladder polyethers, a fascinating and complex family of natural products. This review may be of interest to those curious about the ladder polyethers and their hypothesized biogenesis, about organic reactions in water, and about the development and application of cascade reactions in organic synthesis.


Asunto(s)
Compuestos Epoxi/química , Compuestos Orgánicos/síntesis química , Agua/química , Catálisis , Ciclización , Polímeros/síntesis química
9.
J Am Chem Soc ; 131(19): 6678-9, 2009 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-19402635

RESUMEN

Water is an effective promoter of the endo-selective opening of trisubstituted epoxides, enabling related cascades leading to a variety of substituted ladder polyether structures. When used in conjunction with a tetrahydropyran-templated nucleophile, water can overcome the powerful electronic directing effect of a methyl substituent at either site of the epoxide, making water a uniquely versatile medium and promoter of epoxide opening.


Asunto(s)
Productos Biológicos/síntesis química , Compuestos Epoxi/química , Metano/química , Agua/química , Ciclización , Toxinas Marinas/biosíntesis , Toxinas Marinas/síntesis química , Toxinas Marinas/química , Oxocinas/síntesis química , Oxocinas/química
10.
Tetrahedron ; 65(33): 6648-6655, 2009 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-20161178

RESUMEN

This report describes a number of new synthetic approaches towards methyl-substituted mono- and diepoxy alcohols that serve as substrates for endo-selective epoxide-opening cascades. The key transformations involve the manipulation of alkynes. Highlighted are the directed methylmetalation of bishomopropargylic alcohols, the bromoallylation of alkynes, and Pd-catalyzed cross-coupling between an alkenyl boronate ester and allylic bromides.

11.
Res Integr Peer Rev ; 4: 26, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31867126

RESUMEN

BACKGROUND: The Freedom of Information Act (FOIA) provides access to unreleased government records that can be used to enhance the transparency and integrity of biomedical research. We characterized FOIA requests to Department of Health and Human Services (HHS) agencies, including request outcomes, processing times, backlogs, and costs. METHODS: Using HHS FOIA annual reports, we extracted data on the number of FOIA requests received and processed by HHS agencies between 2008 and 2017, as well as request outcomes. Processing times were reported in three time increments, < 1-20, 21-60, or 61+ days, and trends in backlog status were also described. Information about costs and fees collected were aggregated. RESULTS: Between 2008 and 2017, 69.6% of 530,094 HHS FOIA requests were received by the Centers for Medicare and Medicaid Services (CMS), 18.9% by the Food and Drug Administration (FDA), and 11.6% by all other HHS agencies. During this period, CMS processed 374,728 requests, FDA 114,938, and other HHS agencies 61,890. CMS and FDA reduced backlogged requests by 9396 (89.7%) and 4289 (65.3%), respectively, leaving backlogs of 1081 and 2279 requests at the end of 2017. CMS fully or partially granted 60.3% of requests whereas FDA fully or partially granted 72.4%. Of all requests to CMS, 82.0% were considered simple and 18.0% complex; 82.2% of simple requests and 54.9% of complex requests were processed in 20 days, and 5.6% and 29.9% were processed in 61+ days. In contrast, 60.2% of requests to FDA were considered simple and 39.8% complex; 28.8% of simple requests and 9.0% of complex requests were processed in 20 days, and 58.3% and 81.5% were processed in 61+ days. The costs to HHS associated with FOIA requests totaled $446.4 million ($809 per processed request), increasing from $28.1 million ($423 per request) in 2008 to $53.3 million ($1544 per request) in 2017. In total, HHS collected $8.5 million in fees (1.9% of total costs). CONCLUSIONS: FOIA is frequently used to obtain information about HHS and its agencies. With growing costs, minimal fees collected, and lengthy processing times, HHS agencies' FOIA programs might be made more efficient through greater proactive record disclosure.

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