The Promiscuity of Squalene Synthase-Like Enzyme: Dehydrosqualene Synthase, a Natural Squalene Hyperproducer?

Dehydrosqualene synthase (CrtM), as a squalene synthase-like enzyme from , can naturally utilize farnesyl diphosphate to produce dehydrosqualene (CH). However, no study has documented the natural production of squalene (CH) by CrtM. Here, based on an HPLC-Q-Orbitrap-MS/MS study, we report that the expression of or in 168 both results in the output of squalene, dehydrosqualene, and phytoene (CH).

Biocatalytic Cascade Synthesis of Enantioenriched Epoxides and Triols from Biomass-Derived Synthons Driven by Specifically Designed Enzymes.

Multi-enzymatic cascades exploiting engineered enzymes are a powerful tool for the tailor-made synthesis of complex molecules from simple inexpensive building blocks. In this work, we engineered the promiscuous enzyme 4-oxalocrotonate tautomerase (4-OT) into an effective aldolase with 160-fold increased activity compared to 4-OT wild type. Subsequently, we applied the evolved 4-OT variant to perform an aldol condensation, followed by an epoxidation reaction catalyzed by a previously engineered 4-OT mutant, in a one-pot two-step cascade for the synthesis of enantioenriched epoxides (up to 98 % ee) from biomass-derived starting materials.

Biocatalytic enantioselective hydroaminations enabling synthesis of -arylalkyl-substituted L-aspartic acids.

N-Substituted l-aspartic acids are important chiral building blocks for pharmaceuticals and food additives. Here we report the asymmetric synthesis of various N-arylalkyl-substituted l-aspartic acids using ethylenediamine-N,N'-disuccinic acid lyase (EDDS lyase) as a biocatalyst. This C-N lyase shows a broad non-natural amine substrate scope and outstanding enantioselectivity, allowing the efficient addition of structurally diverse arylalkylamines to fumarate to afford the corresponding N-arylalkyl-substituted l-aspartic acids in good isolated yield (up to 79%) and with excellent enantiopurity (>99% ee).

Engineering of Multiple Modules to Improve Amorphadiene Production in Using CRISPR-Cas9.

Engineering strategies to improve terpenoids' production in mainly focus on 2-methyl-d-erythritol-4-phosphate (MEP) pathway overexpression. To systematically engineer the chassis strain for higher amorphadiene (precursor of artemisinin) production, a clustered regularly interspaced short palindromic repeat-Cas9 (CRISPR-Cas9) system was established in to facilitate precise and efficient genome editing. Then, this system was employed to engineer three more modules to improve amorphadiene production, including the terpene synthase module, the branch pathway module, and the central metabolic pathway module.

Betacyanins, major components in Opuntia red-purple fruits, protect against acetaminophen-induced acute liver failure.

Acetaminophen (APAP) misuse or overdose is the most important cause of drug-induced acute liver failure. Overdoses of acetaminophen induce oxidative stress and liver injury by the electrophilic metabolite N-acetyl-p-benzoquinone imine (NAPQI). Plant-based medicine has been used for centuries against diseases or intoxications due to their biological activities.

Point-of-care testing system for digital single cell detection of MRSA directly from nasal swabs.

We present an automated point-of-care testing (POCT) system for rapid detection of species- and resistance markers in methicillin-resistant Staphylococcus aureus (MRSA) at the level of single cells, directly from nasal swab samples. Our novel system allows clear differentiation between MRSA, methicillin-sensitive S. aureus (MSSA) and methicillin-resistant coagulase-negative staphylococci (MR-CoNS), which is not the case for currently used real-time quantitative PCR based systems.

Engineered C-N Lyase: Enantioselective Synthesis of Chiral Synthons for Artificial Dipeptide Sweeteners.

Aspartic acid derivatives with branched N-alkyl or N-arylalkyl substituents are valuable precursors to artificial dipeptide sweeteners such as neotame and advantame. The development of a biocatalyst to synthesize these compounds in a single asymmetric step is an as yet unmet challenge. Reported here is an enantioselective biocatalytic synthesis of various difficult N-substituted aspartic acids, including N-(3,3-dimethylbutyl)-l-aspartic acid and N-[3-(3-hydroxy-4-methoxyphenyl)propyl]-l-aspartic acid, precursors to neotame and advantame, respectively, using an engineered variant of ethylenediamine-N,N'-disuccinic acid (EDDS) lyase from Chelativorans sp.

Antifungal and biofilm inhibitory effect of Cymbopogon citratus (lemongrass) essential oil on biofilm forming by Candida tropicalis isolates; an in vitro study.

Ethnopharmacological Relevance: Cymbopogon citratus (lemongrass) essential oil has been widely used as a traditional medicine and is well known for antimicrobial properties. Therefore, it might be a potent anti-infective and biofilm inhibitive against Candida tropicalis infections. Until now, no ideal coating or cleaning method based on an essential oil has been described to prevent biofilm formation of Candida strains on silicone rubber maxillofacial prostheses, voice prostheses and medical devices susceptible to C.

Enantioselective Synthesis of Pharmaceutically Active γ-Aminobutyric Acids Using a Tailor-Made Artificial Michaelase in One-Pot Cascade Reactions.

Chiral γ-aminobutyric acid (GABA) analogues represent abundantly prescribed drugs, which are broadly applied as anticonvulsants, as antidepressants, and for the treatment of neuropathic pain. Here we report a one-pot two-step biocatalytic cascade route for synthesis of the pharmaceutically relevant enantiomers of γ-nitrobutyric acids, starting from simple precursors (acetaldehyde and nitroalkenes), using a tailor-made highly enantioselective artificial "Michaelase" (4-oxalocrotonate tautomerase mutant L8Y/M45Y/F50A), an aldehyde dehydrogenase with a broad non-natural substrate scope, and a cofactor recycling system. We also report a three-step chemoenzymatic cascade route for the efficient chemical reduction of enzymatically prepared γ-nitrobutyric acids into GABA analogues in one pot, achieving high enantiopurity (e.

Real-world comparison of bleeding risks among non-valvular atrial fibrillation patients prescribed apixaban, dabigatran, or rivaroxaban.

Limited real-world data are available regarding the comparative safety of non-vitamin K antagonist oral anticoagulants (NOACs). The objective of this retrospective claims observational cohort study was to compare the risk of bleeding among non-valvular atrial fibrillation (NVAF) patients prescribed apixaban, dabigatran, or rivaroxaban. NVAF patients aged ≥18 years with a 1-year baseline period were included if they were new initiators of NOACs or switched from warfarin to a NOAC.

Brachial artery stiffening in healthy primigravidas is associated with weight gain and increased cardiac output.

Objective: To assess brachial artery distensibility and associated factors in healthy primigravidas.

Methods: We assessed brachial artery distensibility using the DynaPulse 5,000A in 37 women each trimester, and 6-8 weeks and 1-5 years postpartum. Associations with physical and cardiometabolic measures were considered.

Modular Enzymatic Cascade Synthesis of Vitamin B and Its Derivatives.

Access to vitamin B [(R)-pantothenic acid] and both diastereoisomers of α-methyl-substituted vitamin B [(R)- and (S)-3-((R)-2,4-dihydroxy-3,3-dimethylbutanamido)-2-methylpropanoic acid] was achieved using a modular three-step biocatalytic cascade involving 3-methylaspartate ammonia lyase (MAL), aspartate-α-decarboxylase (ADC), β-methylaspartate-α-decarboxylase (CrpG) or glutamate decarboxylase (GAD), and pantothenate synthetase (PS) enzymes. Starting from simple non-chiral dicarboxylic acids (either fumaric acid or mesaconic acid), vitamin B and both diastereoisomers of α-methyl-substituted vitamin B , which are valuable precursors for promising antimicrobials against Plasmodium falciparum and multidrug-resistant Staphylococcus aureus, can be generated in good yields (up to 70 %) and excellent enantiopurity (>99 % ee). This newly developed cascade process may be tailored and used for the biocatalytic production of various vitamin B derivatives by modifying the pantoyl or β-alanine moiety.

Chemoenzymatic Synthesis and Pharmacological Characterization of Functionalized Aspartate Analogues As Novel Excitatory Amino Acid Transporter Inhibitors.

Aspartate (Asp) derivatives are privileged compounds for investigating the roles governed by excitatory amino acid transporters (EAATs) in glutamatergic neurotransmission. Here, we report the synthesis of various Asp derivatives with (cyclo)alkyloxy and (hetero)aryloxy substituents at C-3. Their pharmacological properties were characterized at the EAAT1-4 subtypes.

Cytotoxic Deoxypodophyllotoxin Can Be Extracted in High Purity from Anthriscus sylvestris Roots by Supercritical Carbon Dioxide.

Deoxypodophyllotoxin is present in the roots of . This compound is cytotoxic on its own, but it can also be converted into podophyllotoxin, which is in high demand as a precursor for the important anticancer drugs etoposide and teniposide. In this study, deoxypodophyllotoxin is extracted from roots by supercritical carbon dioxide extraction.

Acetyl-4'-phosphopantetheine is stable in serum and prevents phenotypes induced by pantothenate kinase deficiency.

Coenzyme A is an essential metabolite known for its central role in over one hundred cellular metabolic reactions. In cells, Coenzyme A is synthesized de novo in five enzymatic steps with vitamin B5 as the starting metabolite, phosphorylated by pantothenate kinase. Mutations in the pantothenate kinase 2 gene cause a severe form of neurodegeneration for which no treatment is available.

Ischemic Stroke in Nonvalvular Atrial Fibrillation at Warfarin Initiation: Assessment via a Large Insurance Database.

Background And Purpose: Stroke risk may increase shortly after warfarin initiation in nonvalvular atrial fibrillation patients. Because of the brief period and limited number of events, large samples are needed to study this effect. We compared 30-day rates of ischemic stroke between nonvalvular atrial fibrillation patients initiating warfarin to nonwarfarin comparators using an insurance claims database.

Rapid chemoenzymatic route to glutamate transporter inhibitor l-TFB-TBOA and related amino acids.

The complex amino acid (l-threo)-3-[3-[4-(trifluoromethyl)benzoylamino]benzyloxy]aspartate (l-TFB-TBOA) and its derivatives are privileged compounds for studying the roles of excitatory amino acid transporters (EAATs) in regulation of glutamatergic neurotransmission, animal behavior, and in the pathogenesis of neurological diseases. The wide-spread use of l-TFB-TBOA stems from its high potency of EAAT inhibition and the lack of off-target binding to glutamate receptors. However, one of the main challenges in the evaluation of l-TFB-TBOA and its derivatives is the laborious synthesis of these compounds in stereoisomerically pure form.

Effect of Race and Ethnicity on Antihypertensive Medication Utilization Among Women in the United States: Study of Women's Health Across the Nation (SWAN).

Background: Antihypertensive medication use may vary by race and ethnicity. Longitudinal antihypertensive medication use patterns are not well described in women.

Methods And Results: Participants from the Study of Women's Health Across the Nation (SWAN), a prospective cohort of women (n=3302, aged 42-52), who reported a diagnosis of hypertension or antihypertensive medication use at any annual visit were included.

Stereochemical Control of Enzymatic Carbon-Carbon Bond-Forming Michael-Type Additions by "Substrate Engineering".

The enzyme 4-oxalocrotonate tautomerase (4-OT) promiscuously catalyzes the Michael-type addition of acetaldehyde to β-nitrostyrene derivatives to yield chiral γ-nitroaldehydes, which are important precursors for pharmaceutically active γ-aminobutyric acids. In this study, we investigated the effect of different substituents at the aromatic ring of the Michael acceptor on the catalytic efficiency and stereoselectivity of the 4-OT-catalyzed acetaldehyde addition reactions. Highly enantioenriched ()- and ()-γ-nitroaldehydes and 4-substituted chroman-2-ol could be obtained in good to excellent yields by applying different substituents at appropriate positions of the aromatic substrate.

Change in sexual functioning over the menopausal transition: results from the Study of Women's Health Across the Nation.

Objective: The aim of the study was to identify whether there is a decline in sexual functioning related to the menopausal transition or to hysterectomy.

Methods: In a cohort of 1,390 women aged 42 to 52, with intact uterus and at least one ovary, not using hormone therapy, and pre- or early perimenopausal at baseline, we fit piecewise linear growth curves to 5,798 repeated measurements (seven visits spanning 14.5 y) of a sexual functioning score (range, 5-25) as a function of time relative to date of final menstrual period (FMP) or hysterectomy.

Longitudinal analysis of changes in weight and waist circumference in relation to incident vasomotor symptoms: the Study of Women's Health Across the Nation (SWAN).

Objective: Greater body mass index (BMI) and body fat are associated with vasomotor symptoms (VMS). Thus, weight loss may prevent VMS. We analyzed whether concurrent BMI or waist circumference and/or changes in weight or waist circumference predicted incident VMS and whether these relations differed by menopause stage or race/ethnicity.

Duration of the menopausal transition is longer in women with young age at onset: the multiethnic Study of Women's Health Across the Nation.

Objective: The menopausal transition (MT) is a critical period associated with physiologic changes that influence women's long-term health and longevity. Information is, however, limited regarding factors that influence age at the onset of the MT and its duration (ie, time from MT onset to the final menstrual period).

Methods: We analyzed data for 1,145 women from four sites of the Study of Women's Health Across the Nation who participated in the menstrual calendar substudy, had the start of the MT identified, and had no missing covariate information.

Characterizing the trajectories of vasomotor symptoms across the menopausal transition.

Objective: The aim of the study was to investigate the heterogeneity of temporal patterns of vasomotor symptoms (VMS) over the menopausal transition and identify factors associated with these patterns in a diverse sample of women.

Methods: The Study of Women's Health Across the Nation is a multisite longitudinal study of women from five racial/ethnic groups transitioning through the menopause. The analytic sample included 1,455 women with nonsurgical menopause and a median follow-up of 15.