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1.
ChemistryOpen ; : e202400139, 2024 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-39171770

RESUMO

Alcohols are common alkylating agents and starting materials alternative to harmful alkyl halides. In this study, a simple, benign and efficient pathway was developed to synthesize 1,3-diphenylpropan-1-ols via the ß-alkylation of 1-phenylethanol with benzyl alcohols. Unlike conventional borrowing hydrogen processes in which alcohols were activated by transition-metal catalyzed dehydrogenation, in this work, t-BuONa was suggested to be a dual-role reagent, namely, both base and radical initiator, for the radical coupling of aromatic alcohols. The cross-coupling reaction readily proceeded under transition metal-free conditions and an inert atmosphere, affording 1,3-diphenylpropan-1-ol with an excellent yield. A good functional group tolerance in benzyl alcohols was observed, leading to the production of various phenyl-substituted propan-1-ol derivatives in moderate-to-good yields. The mechanistic studies proposed that the reaction could involve the formation of reactive radical anions by base-mediated deprotonation and single electron transfer.

2.
Front Microbiol ; 15: 1441330, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39211319

RESUMO

Burkholderia pseudomallei (Bp) causes the tropical disease melioidosis that afflicts an estimated 165,000 people each year. Bp is a facultative intracellular pathogen that transits through distinct intracellular stages including attachment to host cells, invasion through the endocytic pathway, escape from the endosome, replication in the cytoplasm, generation of protrusions towards neighboring cells, and host cell fusion allowing Bp infection to spread without exiting the intracellular environment. We have identified a TetR-like transcriptional regulator, BP1026B_II1561, that is up-regulated during the late stages of infection as Bp protrudes toward neighboring cells. We have characterized BP1026B_II1561 and determined that it has a role in pathogenesis. A deletional mutant of BP1026B_II1561 is attenuated in RAW264.7 macrophage and BALB/c mouse models of infection. Using RNA-seq, we found that BP1026B_II1561 controls secondary metabolite biosynthesis, fatty acid degradation, and propanoate metabolism. In addition, we identified that BP1026B_II1561 directly controls expression of an outer membrane porin and genes in the shikimate biosynthetic pathway using ChIP-seq. Transposon mutants of genes within the BP1026B_II1561 regulon show defects during intracellular replication in RAW264.7 cells confirming the role of this transcriptional regulator and the pathways it controls in pathogenesis. BP1026B_II1561 also up-regulates the majority of the enzymes in shikimate and tryptophan biosynthetic pathways, suggesting their importance for Bp physiology. To investigate this, we tested fluorinated analogs of anthranilate and tryptophan, intermediates and products of the shikimate and tryptophan biosynthetic pathways, respectively, and showed inhibition of Bp growth at nanomolar concentrations. The expression of these pathways by BP1026b_II1561 and during intracellular infection combined with the inhibition of Bp growth by fluorotryptophan/anthranilate highlights these pathways as potential targets for therapeutic intervention against melioidosis. In the present study, we have identified BP1026B_II1561 as a critical transcriptional regulator for Bp pathogenesis and partially characterized its role during host cell infection.

3.
Am J Clin Nutr ; 120(1): 80-91, 2024 07.
Artigo em Inglês | MEDLINE | ID: mdl-38960579

RESUMO

BACKGROUND: In 2019, the EAT-Lancet Commission proposed a healthy dietary pattern that, along with reductions in food waste and improved agricultural practices, could feed the increasing global population sustainably. We developed a Planetary Health Diet Index (PHDI) to quantify adherence to the EAT-Lancet reference diet. OBJECTIVES: We aimed to assess associations between PHDI and total and cause-specific mortality in 3 prospective cohorts of males and females in the United States. METHODS: We followed 66,692 females from the Nurses' Health Study (1986-2019), 92,438 females from the Nurses' Health Study II (1989-2019), and 47,274 males from the Health Professionals Follow-up Study (1986-2018) who were free of cancer, diabetes, and major cardiovascular diseases at baseline. The PHDI was calculated every 4 y using a semiquantitative food frequency questionnaire. Hazard ratios (HRs) were calculated using multivariable proportional-hazards models. RESULTS: During follow-up, we documented 31,330 deaths among females and 23,206 among males. When comparing the highest with the lowest quintile of PHDI, the pooled multivariable-adjusted HRs were 0.77 [95% confidence interval (CI): 0.75, 0.80] for all-cause mortality (P-trend < 0.0001). The PHDI was associated with lower risk of deaths from cardiovascular diseases (HR: 0.86; 95% CI: 0.81, 0.91), cancer (HR: 0.90; 95% CI: 0.85, 0.95), respiratory diseases (HR: 0.53; 95% CI: 0.48, 0.59), and neurodegenerative diseases (HR: 0.72; 95% CI: 0.67, 0.78). In females, but not males, the PHDI was also significantly associated with a lower risk of deaths from infectious diseases (HR: 0.62; 95% CI: 0.51, 0.76). PHDI scores were also associated inversely with greenhouse gas emissions and other environmental impacts. CONCLUSIONS: In 3 large United States-based prospective cohorts of males and females with up to 34 y of follow-up, a higher PHDI was associated with lower risk of total and cause-specific mortality and environment impacts.


Assuntos
Dieta Saudável , Humanos , Feminino , Masculino , Estudos Prospectivos , Pessoa de Meia-Idade , Adulto , Estados Unidos/epidemiologia , Fatores de Risco , Estudos de Coortes , Causas de Morte , Idoso , Dieta , Mortalidade
4.
Org Biomol Chem ; 22(26): 5296-5300, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38896038

RESUMO

The synthesis of medicinally relevant N-aryl-substituted 2-aminobenzothiazoles often uses 2-aminothiophenol derivatives, which are not commercially abundant, as starting materials. Herein, we report a method for the annulation of C3-substituted nitroarenes and aryl isothiocyanates towards the synthesis of 2-aminobenzothiazoles. Reactions proceeded in the presence of cobalt ferrite nanoparticles as a catalyst, DABCO as a base, and DMF as a promoter. The cobalt ferrite nanoparticles could be recovered after each run and reused up to 3 times while the product yield was not diminished. Our method appears to be the first example of the direct use of substituted nitroarenes for yielding 2-aminobenzothiazoles.

5.
JMIR Form Res ; 8: e56373, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38857065

RESUMO

BACKGROUND: Physical inactivity is associated with adverse health outcomes among Asian Americans, who exhibit the least adherence to physical activity guidelines compared with other racial and ethnic groups. Mobile app-based interventions are a promising approach to promote healthy behaviors. However, there is a lack of app-based interventions focused on improving physical activity among Asian Americans whose primary language is not English. OBJECTIVE: This pilot study aimed to assess the feasibility and acceptability of a 5-week intervention using a culturally and linguistically adapted, evidence-based mobile phone app with an accelerometer program, to promote physical activity among Chinese-, Tagalog-, or Vietnamese-speaking Americans. METHODS: Participants were recruited through collaborations with community-based organizations. The intervention was adapted from a 12-month physical activity randomized controlled trial involving the app and accelerometer for English-speaking adults. Sociodemographic characteristics, lifestyle factors, and physical measurements were collected at the baseline visit. A 7-day run-in period was conducted to screen for the participants who could wear a Fitbit One (Fitbit LLC) accelerometer and complete the app's daily step diary. During the 4-week intervention period, participants wore the accelerometer and reported their daily steps in the app. Participants also received daily messages to reinforce key contents taught during an in-person educational session, remind them to input steps, and provide tailored feedback. Feasibility measures were the percentage of eligible participants completing the run-in period and the percentage of participants who used the app diary for at least 5 out of 7 days during the intervention period. We conducted poststudy participant interviews to explore overall intervention acceptability. RESULTS: A total of 19 participants were enrolled at the beginning of the study with a mean age of 47 (SD 13.3; range 29-70) years, and 58% (n=11) of them were female. Of the participants, 26% (n=5) were Chinese, 32% (n=6) were Vietnamese, and 42% (n=8) were Filipino. All participants met the run-in criteria to proceed with the intervention. Adherence to the app diary ranged from 74% (n=14) in week 2 to 95% (n=18) in week 4. The daily average steps per week from accelerometers increased each week from 8451 (SD 3378) steps during the run-in period to 10,930 (SD 4213) steps in week 4. Participants reported positive experiences including an increased motivation to walk and the enjoyment of being able to monitor their physical activity. CONCLUSIONS: This is the first pilot study of a multicomponent intervention and evidence-based mobile phone app to promote physical activity among Asian Americans who use apps in traditional Chinese, Tagalog, or Vietnamese, which demonstrated high feasibility and acceptability. Future work focused on multilingual mobile apps to address disparities in physical inactivity among Asian Americans should be considered.

6.
RSC Adv ; 14(23): 16389-16399, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38774621

RESUMO

In this work, we introduce a novel defective analogue of the representative 6-connected zirconium-based metal-organic framework (MOF-808), by employing 5-sulfoisophthalic acid monosodium salt (H2BTC-SO3Na) as a defect inducer via a mixed-linker approach. The structural integrity and different physicochemical properties were investigated by various characterization techniques, including powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and nitrogen physisorption at 77 K. Additionally, proton nuclear magnetic resonance (1H-NMR), energy-dispersive X-ray (EDX), and inductively coupled plasma optical emission spectroscopy (ICP-OES) were employed to confirm the presence of 6.9 mol% of the 5-sulfoisophthalate ligand within the highly crystalline MOF-808 structure. The defective material exhibited significant enhancements in the removal efficiency of various organic dyes, including approximately 64% and 77% for quinoline yellow and sunset yellow, and 56% and 13% for rhodamine B and malachite green, compared to its pristine counterpart. Importantly, the defective MOF-808 showed a remarkable selectivity toward anionic species in binary-component dyes comprising both anionic and cationic dyes.

7.
J Am Coll Emerg Physicians Open ; 5(3): e13168, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38699223

RESUMO

Objectives: This study aimed to assess the effectiveness of a continuous quality improvement initiative at the University of Florida Health Physicians practice in reducing the time to administer factor replacement therapy (FRT) for hemophilia patients presenting with bleeding in the emergency department (ED). Methods: The study, a quasi-experimental, interventional design, was conducted between January 2020 and January 2023. The intervention, implemented in September 2021, involved training ED physicians, creating a specialized medication order set within the electronic health record (EHR), and a rapid triage system. The effectiveness was measured by comparing the time from ED arrival to factor administration before and after the intervention and benchmarking it against the National Bleeding Disorders Foundation's Medical and Scientific Advisory Council (MASAC)-recommended 1-hour timeline for factor administration. An interrupted time series (ITS) analysis with a generalized least squares model assessed the intervention's impact. Results: A total of 43 ED visits (22 pre-intervention and 21 post-intervention) were recorded. Post-intervention, the average time from ED arrival to factor administration decreased from 5.63 to 3.15 hours. There was no significant increase (27% vs. 29%) in the patients receiving factor within 1-hour of ED arrival. The ITS analysis predicted a 20-hour reduction in the average quarterly time to administer factor by the end of the study, an 84% decrease. Conclusions: The quality improvement program decreased the time to administer FRT for patients with hemophilia in the ED. However, the majority of patients did not achieve the 1-hour MASAC-recommended timeline for factor administration after ED arrival.

8.
Cancer Rep (Hoboken) ; 7(2): e1971, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38351528

RESUMO

BACKGROUND: Cancer is the leading cause of death among Asian Americans, who often face barriers to cancer care. Cancer supportive care needs among Asian Americans remain understudied. AIMS: We examined cancer supportive care needs and participant factors correlated with these needs, identified profiles of supportive care needs, and examined whether needs profiles are associated with quality of life among Asian American adults. METHODS AND RESULTS: We recruited 47 Asian American adults with colorectal, liver, or lung cancer who spoke Chinese, English, or Vietnamese, and were starting or undergoing cancer treatment. We assessed cancer supportive care needs in four domains: cancer information, daily living, behavioral health, and language assistance. Hierarchical cluster analysis was used to identify clusters of participants based on their supportive need profiles to further examine the association between need profiles and quality of life (QoL) assessed by the Functional Assessment of Cancer Therapy. Participants (mean age = 57.6) included 72% males and 62% spoke English less than very well. Older participants (age ≥ 65) and those with annual income <$50K reported higher daily living needs. Men and younger participants (age < 50) reported higher behavioral health needs. We found three clusters displaying distinct cancer supportive need profiles: Cluster 1 (28% of the sample) displayed high needs across all domains; Cluster 2 (51%) had low needs across all domains; and Cluster 3 (21%) had high needs for cancer information and daily living. Cluster 1 participants reported the lowest QoL. CONCLUSION: Cancer supportive care needs among Asian American patients with colorectal, liver, and lung cancer were associated with patient characteristics and QoL. Understanding cancer supportive care needs will inform future interventions to improve care and QoL for Asian American patients with cancer. CLINICALTRIALS: gov Identifier: NCT03867916.


Assuntos
Neoplasias Colorretais , Neoplasias Hepáticas , Neoplasias Pulmonares , Navegação de Pacientes , Portais do Paciente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Asiático , Neoplasias Colorretais/terapia , Internet , Neoplasias Pulmonares/terapia , Qualidade de Vida , Neoplasias Hepáticas/terapia
9.
IJID Reg ; 10: 174-178, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38322246

RESUMO

Objectives: The emergence and spread of SARS-CoV-2 have stimulated ongoing research into the virus transmission dynamics, circulating variants, and potential mutations. This study was conducted to understand the genomic dynamics of the epidemic in Nigeria. Design: Whole genome sequencing was conducted on SARS-CoV-2 samples collected during the first and second outbreaks using the Oxford Nanopore MinION sequencing platform. Phylogenetic analysis was conducted, and genomes were grouped into different pangolin lineages. Results: The study revealed four circulating SARS-CoV-2 variants. The Alpha (B.1.1.7) variant was the most prevalent (32.7%), followed by Beta (B.1 B.1.1, L.3, and B.1.1.318) (30.8%), Eta (B.1.525) (28.9%), and Delta (B.1.617, AY.1, AY.109, and AY.36) (7.7%). Phylogenetic analysis revealed three clusters with four Nextstrain clades (20I, 20B, 21D, and 21J). The Alpha lineages (B.1.1.7) clustered with references from Italy. The Beta lineages (Clade 20B) (B.11, B.11318, and L3) and sub-lineage B.11 were distinct. Sub-lineage B.11318 is clustered with references from the USA, whereas sub-lineage L3 is clustered with references from Russia, the Philippines, Australia, and Japan. The 21D and 21J, belonging to two Pango lineages, Eta (B.1525) and Delta (B.1.617 and AY.109), showed high genetic similarity. Conclusion: The phylogenetic relatedness of the lineages suggests multiple virus introduction, which could be a source of more virulent, locally adapted variants.

10.
J Org Chem ; 89(5): 3202-3210, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38329896

RESUMO

We report a method for using elemental sulfur to facilitate the cyclization of aryl hydrazones and aryl isothiocyanates, affording biorelated 2-imino-1,3,4-thiadiazoles. Reactions progressed in the presence of elemental sulfur, N-methylmorpholine base, and DMSO solvent, while were tolerant of a wide range of functionalities including halogen, nitro, cyano, methylsulfonyl, and heterocyclic groups. The method appears to offer a general pathway for using simple, cheap, and stable reagents to afford triaryl-substituted 2-imino-1,3,4-thiadiazoles under relatively mild conditions.

11.
Org Biomol Chem ; 22(6): 1234-1244, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38240351

RESUMO

Herein we report a method for affording 2-benzyl benzoxazoles from substituted styrenes and 2-nitrophenols. The success of this method relies on the use of simple reagents, namely elemental sulfur and DABCO. A combination of identical reagents was utilized for the annulation of styrenes with N,N-dialkyl-3-nitroanilines to afford 2-benzyl benzothiazoles. Overall, benzoxazoles and benzothiazoles bearing useful functionalities such as halogens, amines, and heterocyclic groups were isolated in moderate to good yields. Our methods are a rare example of divergent transformations of substituted nitroarenes towards 2-benzyl benzoxazoles and benzothiazoles.

12.
Nutr Metab Cardiovasc Dis ; 34(2): 326-333, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38000991

RESUMO

BACKGROUND AND AIMS: Metabolic syndrome (MtS) is associated with increased risk of many health disorders, especially cardiovascular diseases. In Vietnam, study examining MtS is meager and especially lacking for the workforce. We estimated the prevalence of MtS and its associated factors among Vietnamese employees. METHODS AND RESULTS: We analyzed secondary data of annual health check of employees of 300 Vietnamese companies from the Vinmec Healthcare System. We used three definitions for MtS: International Diabetes Federation (IDF), National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III), and NCEP ATP III-Asia. Of 57,997 participants evaluated, 48.5 % were males and 66.2 % were younger than 40 years old. The unadjusted MtS prevalence was 8.4 % (IDF), 10.2 % (NCEP ATP III), and 16.0 % (NCEP ATP III-Asia). The age-sex adjusted prevalence of MtS (NCEP ATP III-Asia) was 21.8 % (95 % confidence interval (CI): 21.4 %, 22.2 %). MtS prevalence increased with age, reached 49.6 % for age ≥60. The aging related increase was more remarkable in females than males (prevalence ratio (PR) (95 % CI) for age ≥60 comparing to age <30 years old in males vs. females was 4.0 (3.6, 4.3) vs. 20.1 (17.7, 22.9)). High blood triglyceride (83.4 %) and abdominal obesity (74.5 %) were the predominant contributors to MtS. CONCLUSION: In this relatively young Vietnamese working population, 16 % had MtS with high triglyceride and abdominal obesity being the predominant contributors. These findings emphasize the need for developing effective high triglyceride and abdominal obesity prevention and control programs to curb the emerging epidemic of metabolic disorders in the workforce.


Assuntos
Síndrome Metabólica , Adulto , Feminino , Masculino , Humanos , Síndrome Metabólica/diagnóstico , Síndrome Metabólica/epidemiologia , Síndrome Metabólica/prevenção & controle , Vietnã/epidemiologia , Obesidade Abdominal/diagnóstico , Obesidade Abdominal/epidemiologia , Prevalência , Obesidade , Triglicerídeos , Trifosfato de Adenosina
13.
Chaos ; 33(10)2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37844292

RESUMO

Networks with different levels of interactions, including multilayer and multiplex networks, can display a rich diversity of dynamical behaviors and can be used to model and study a wide range of systems. Despite numerous efforts to investigate these networks, obtaining mathematical descriptions for the dynamics of multilayer and multiplex systems is still an open problem. Here, we combine ideas and concepts from linear algebra and graph theory with nonlinear dynamics to offer a novel approach to study multiplex networks of Kuramoto oscillators. Our approach allows us to study the dynamics of a large, multiplex network by decomposing it into two smaller systems: one representing the connection scheme within layers (intra-layer), and the other representing the connections between layers (inter-layer). Particularly, we use this approach to compose solutions for multiplex networks of Kuramoto oscillators. These solutions are given by a combination of solutions for the smaller systems given by the intra- and inter-layer systems, and in addition, our approach allows us to study the linear stability of these solutions.

14.
JAMA Netw Open ; 6(8): e2329913, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37594759

RESUMO

Importance: The potential role of living alone in either facilitating or hampering access to and use of services for older adults with cognitive impairment is largely unknown. Specifically, it is critical to understand directly from health care and social services professionals how living alone creates barriers to the access and use of supportive health care and social services for racially and ethnically diverse patients with cognitive impairment. Objective: To identify the potential role of living alone in the access and use of health care and social services for diverse patients with cognitive impairment by investigating professionals' perceptions of caring for such patients who live alone in comparison with counterparts living with others. Design, Setting, and Participants: This qualitative study of 76 clinicians, social workers, and other professionals used semistructured interviews conducted between February 8, 2021, and June 8, 2022, with purposively sampled professionals providing services to diverse patients with cognitive impairment in Michigan, California, and Texas. Main Outcomes and Measures: Clinicians, social workers, and other professionals compared serving patients with cognitive impairment and living alone vs counterparts living with others. An inductive content analysis was used to analyze the interview transcripts. Results: A total of 76 professionals were interviewed (mean [SD] age, 49.3 [12.7] years); 59 were female (77.6%), 8 were Black or African American (11%), and 35 were White (46%). Participants included physicians, nurses, social workers, and home-care aides, for a total of 20 professions. Participants elucidated specific factors that made serving older adults living alone with cognitive impairment more challenging than serving counterparts living with others (eg, lacking an advocate, incomplete medical history, requiring difficult interventions), as well as factors associated with increased concerns when caring for older adults living alone with cognitive impairment, such as isolation and a crisis-dominated health care system. Participants also identified reasons for systematic unmet needs of older adults living alone with cognitive impairment for essential health care and social services, including policies limiting access and use to public home-care aides. Conclusions and Relevance: In this qualitative study of professionals' perspectives, findings suggest that living alone is a social determinant of health among patients with cognitive impairment owing to substantial barriers in access to services. Results raised considerable concerns about safety because the US health care system is not well equipped to address the unique needs of older adults living alone with cognitive impairment.


Assuntos
Disfunção Cognitiva , Utilização de Instalações e Serviços , Acessibilidade aos Serviços de Saúde , Ambiente Domiciliar , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , População Negra , Disfunção Cognitiva/terapia , Serviço Social , Assistentes Sociais , Atenção à Saúde , Estados Unidos , Adulto , Atitude do Pessoal de Saúde , Brancos
15.
J Am Geriatr Soc ; 71(9): 2924-2934, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37317827

RESUMO

BACKGROUND: Participation and active engagement in meaningful activities support the emotional and physical well-being of older adults. In 2020, the onset of the COVID-19 pandemic altered lives, including the ability to participate in meaningful activities. This study compared meaningful activity engagement before and at the beginning of the COVID-19 pandemic in a nationally representative, diverse sample >65 years between 2015 and 2020. METHODS: We described the proportions and characteristics of National Health and Aging Trends Study participants and their engagement in four activities: visiting friends or family, attending religious services, participating in clubs/classes/other organized activities, and going out for enjoyment. We used mixed effects logistic regressions to compare probabilities of activity engagement before 2020 and in 2020, adjusting for age, sex, functional status, income, geographic region, anxiety-depression, and transportation issues. RESULTS: Of 6815 participants in 2015, the mean age was 77.7 (7.6) years; 57% of participants were female; 22% were Black, 5% Hispanic, 2% were American Indian, and 1% were Asian; 20% had disability; and median income was $33,000. Participation in all four activities remained consistent between 2015 and 2019 and declined in 2020. Significant differences existed in attending religious services (p < 0.01) and going out for enjoyment (p < 0.001) by race and ethnicity, before and after the start of COVID-19. Black and Hispanic participants experienced the largest decline in attending religious services (-32%, -28%) while Asian and White participants experienced the largest decline in going out for enjoyment (-49%, -56%). CONCLUSIONS: Potential quality of life tradeoffs should be considered to a greater extent in future pandemic emergencies.


Assuntos
COVID-19 , Pandemias , Humanos , Feminino , Idoso , Masculino , Qualidade de Vida , COVID-19/epidemiologia , Etnicidade , Envelhecimento
16.
Chem Sci ; 14(25): 6904-6914, 2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37389248

RESUMO

Lanthipeptides are ribosomally synthesized and post-translationally modified peptides that are generated from precursor peptides through a dehydration and cyclization process. ProcM, a class II lanthipeptide synthetase, demonstrates high substrate tolerance. It is enigmatic that a single enzyme can catalyze the cyclization process of many substrates with high fidelity. Previous studies suggested that the site-selectivity of lanthionine formation is determined by substrate sequence rather than by the enzyme. However, exactly how substrate sequence contributes to site-selective lanthipeptide biosynthesis is not clear. In this study, we performed molecular dynamic simulations for ProcA3.3 variants to explore how the predicted solution structure of the substrate without enzyme correlates to the final product formation. Our simulation results support a model in which the secondary structure of the core peptide is important for the final product's ring pattern for the substrates investigated. We also demonstrate that the dehydration step in the biosynthesis pathway does not influence the site-selectivity of ring formation. In addition, we performed simulation for ProcA1.1 and 2.8, which are well-suited candidates to investigate the connection between order of ring formation and solution structure. Simulation results indicate that in both cases, C-terminal ring formation is more likely which was supported by experimental results. Our findings indicate that the substrate sequence and its solution structure can be used to predict the site-selectivity and order of ring formation, and that secondary structure is a crucial factor influencing the site-selectivity. Taken together, these findings will facilitate our understanding of the lanthipeptide biosynthetic mechanism and accelerate bioengineering efforts for lanthipeptide-derived products.

17.
RSC Adv ; 13(26): 18156-18159, 2023 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-37333726

RESUMO

A method for the annulation of 2-nitrophenols with aryl isothiocyanates is reported. The reactions proceeded in the presence of an iron(iii) acetylacetonate catalyst, elemental sulfur, NaOH as a base, and DMSO as a solvent. Derivatives of 2-aminobenzoxazoles bearing nitro, cyano, acetyl, sulfone, secondary amine, and pyrrolyl groups were successfully isolated.

19.
Zootaxa ; 5255(1): 113-135, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-37045263

RESUMO

The Metaphire peguana species-group was revised from the earthworm fauna of Vietnam. As a result, a total of seven species/subspecies have been assigned to this species-gro+up, namely M. peguana peguana (Rosa, 1890), M. peguana laisonensis Nguyen & Nguyen, 2017, M. bahli (Gates, 1945), M. doiphamon Bantaowong & Panha, 2016, M. dorsomultitheca Nguyen & Nguyen, 2015, M. kiengiangensis Nguyen & Trinh, 2015, and M. nhuongi Nguyen, 2016. The species, M. pacseana (Thai & Samphon, 1988) was removed from the group. The species-group was diagnosed by having spermathecal pores in 6/7/8/9, sometimes 5/6/7/8/9 or 7/8/9; bithecate or polythecate; genital markings paired in 17/18 and 18/19 or in xvii and xix; accessory glands paired, coelomic, strongly covered by muscular-walled bursae; septum 10/11 only present ventrally; and intestinal caeca simple. The K2P genetic distances between the group members varies from 12.9% to 20.7%. The phylogenetic analysis clearly supports the members of this species-group.


Assuntos
Oligoquetos , Animais , Oligoquetos/genética , Vietnã , Filogenia
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