Isomeric Lactones Research Articles

Frequency-dependent nonlinear optical response and refractive index investigation of lactone-derived thermochromic compounds

Nonlinear optical (NLO) switchable materials play a crucial role in the fields of electronics and optoelectronics. The selection of an appropriate switching approach is vital in designing such materials to enhance their NLO response. Among various approaches, thermos-switching materials have shown a 4-fold increase in NLO response compared to other photo-switching materials. In this study, we computationally investigated the geometric, electronic, and nonlinear optical properties of reversible lactone-based thermochromic compounds using the ωB97XD/6-311+G (d,p) level of theory. Molecular orbital studies are employed to analyze the electronic properties of the close and open isomers of these compounds, while time-dependent density functional theory (TD-DFT) analysis is utilized to evaluate their molecular absorption. Our findings reveal that the π-electronic conjugation-induced delocalization significantly influences the ON-OFF switchable nonlinear optical response of the lactone-based thermochromic compounds. Notably, among all compounds, the open isomer of lactone 2 exhibits the highest hyperpolarizability value (6596.69 au). Furthermore, we extended our analysis to investigate the frequency-dependent second and third-order hyperpolarizabilities. The most pronounced frequency-dependent NLO response is observed at 532 nm. Additionally, we calculated the refractive index of these thermochromic compounds to further assess their nonlinear optical response. The open isomer of lactone 1 demonstrates the highest refractive index value (3.99 × 10−14 cm2/W). Overall, our study highlights the excellent potential of reversible thermochromic compounds as NLO molecular thermos-switches for future applications.

Organic decomposition and synthesis reactions in lactated solution exposed to nonequilibrium atmospheric pressure plasma

AbstractLactate is used in the food and pharmaceutical industries and is a crucial intermediate for synthesis. Plasma‐activated lactate (PAL) in Ringer's solution was recently shown to have effective antitumor action. Small molecule aldehydes, ketones, and organic acids were produced from lactate during plasma exposure, and five‐membered conjugated lactone isomers of furanone (C5H6O2) were detected formed by interactions of lactate or its fragments with •OH, organic radicals, and H2O2. 2,3‐Dimethyl‐tartaric acid may be the effective component in PAL for the selective killing of cancer but not normal cells and possible pathways for its synthesis are provided. Aqueous reaction mechanisms are explained, including dehydration, esterification, hydrolysis, and dimerization. This study will help develop novel cancer therapies and further plasma organic chemistry.

Stereoselective synthesis of whisky lactone isomers catalyzed by bacteria in the genus Rhodococcus.

Whisky lactone is a naturally occurring fragrance compound in oak wood and is widely used as a sensory additive in food products. However, safe and efficient methods for the production of its individual enantiomers for applications in the food industry are lacking. The aim of this study was to develop an efficient and highly stereoselective process for the synthesis of individual enantiomeric forms of whisky lactones. The proposed three-step method involves (1) column chromatography separation of a diastereoisomeric mixture of whisky lactone, (2) chemical reduction of cis-and trans-whisky lactones to corresponding syn-and anti-diols, and (3) microbial oxidation of racemic diols to individual enantiomers of whisky lactone. Among various bacteria in the genera Dietzia, Gordonia, Micrococcus, Rhodococcus, and Streptomyces, R. erythropolis DSM44534 and R. erythropolis PCM2150 effectively oxidized anti-and syn-3-methyl-octane-1,4-diols (1a-b) to corresponding enantiomerically pure cis-and trans-whisky lactones, indicating high alcohol dehydrogenase activity. Bio-oxidation catalyzed by whole cells of these strains yielded enantiomerically pure isomers of trans-(+)-(4S,5R) (2a), trans-(-)-(4R,5S) (2b), and cis-(+)-(4R,5R) (2d) whisky lactones. The optical density of bacterial cultures and the impact of the use of acetone powders as catalysts on the course of the reaction were also evaluated. Finally, the application of R. erythropolis DSM44534 in the form of an acetone powder generated the enantiomerically enriched cis-(-)-(4S,5S)-isomer (2c) from the corresponding syn-diol (1b). The newly developed method provides an improved approach for the synthesis of chiral whisky lactones.

Isoalantolactone Enhances the Antitumor Activity of Doxorubicin by Inducing Reactive Oxygen Species and DNA Damage.

Colon cancer is one of the most common cancer in the world. Doxorubicin (DOX) is a classical anti-tumor drug which widely used in treatment of cancers, however, high toxicity limited its further clinical application. Thus, it is urgent to find new drugs with low toxicity and high efficiency to treat colon cancer. Isoalantolactone (IATL), an isomeric sesquiterpene lactone isolated from the plant of inula helenium, has been reported to have anti-cancer activity against a variety of cancer cells. However, the function of IATL in colon cancer remains unclear. Here, we demonstrated that IATL inhibited colon cancer cell growth by increasing cellular reactive oxygen species (ROS) production. Further study showed that ROS accumulation contributed to DNA damage and JNK signaling pathway activation. In addition, we found that IATL markedly enhanced DOX-induced cell cytotoxicity in colon cancer cells. IATL in combination with DOX significantly increased the ROS production, induced DNA damage and activated JNK signaling pathway. Taken together, our data suggested that combined treatment with IATL and DOX may serve as a potential therapeutics for colon cancer.

4-Phenylnaphtho[2,3-c]furan-1(3H)-one, 9-Phenylnaphtho[2,3-c]furan-1(3H)-one and 3a,4-Dihydro-9-phenylnaphtho[2,3-c]furan-1(3H)-one Crystal Structures

The crystal structures are reported for two unsubstituted arylnaphthalene lactones, 4-phenylnaphtho[2,3-c]furan-1(3H)-one (2), 9-phenylnaphtho[2,3-c]furan-1(3H)-one (3) and a non-aromatic dihydro arylnaphthene lactone, 3a,4-dihydro-9-phenylnaphtho[2,3-c]furan-1(3H)-one (5). There are only minor differences in the geometrical parameters of these structures. However, in certain cases, both isomers of arylnaphthalene lactones (termed Type I and Type II) were found in the same asymmetric unit cell.

Chemical Variation among Castes, Female Life Stages and Populations of the Facultative Eusocial Sweat Bee Halictus rubicundus (Hymenoptera: Halictidae)

In eusocial insects, chemical communication is crucial for mediating many aspects of social activities, especially the regulation of reproduction. Though queen signals are known to decrease ovarian activation of workers in highly eusocial species, little is known about their evolution. In contrast, some primitively eusocial species are thought to control worker reproduction through physical aggression by the queen rather than via pheromones, suggesting the evolutionary establishment of chemical signals with more derived sociality. However, studies supporting this hypothesis are largely missing. Socially polymorphic halictid bees, such as Halictus rubicundus, with social and solitary populations in both Europe and North America, offer excellent opportunities to illuminate the evolution of caste-specific signals. Here we compared the chemical profiles of social and solitary populations from both continents and tested whether (i) population or social level affect chemical dissimilarity and whether (ii) caste-specific patterns reflect a conserved queen signal. Our results demonstrate unique odor profiles of European and North American populations, mainly due to different isomers of n-alkenes and macrocyclic lactones; chemical differences may be indicative of phylogeographic drift in odor profiles. We also found common compounds overproduced in queens compared to workers in both populations, indicating a potential conserved queen signal. However, North American populations have a lower caste-specific chemical dissimilarity than European populations which raises the question if both use different mechanisms of regulating reproductive division of labor. Therefore, our study gives new insights into the evolution of eusocial behavior and the role of chemical communication in the inhibition of reproduction.

Bacterial Whole Cells Synthesis of Whisky Lactones in a Solid-State Fermentation Bioreactor Prototype

Agro-industrial side streams such as oilseed cakes were used as a medium in solid-state fermentation (SSF) for microbial oxidation of anti- and syn-3-methyl-octane-1,4-diols to obtain corresponding trans- and cis-whisky lactones. In preliminary screening transformations, a wide range of whole bacterial cells were tested on the basis of oxidation activity, which is rarely described in the literature, in contrast to the widely studied lipolytic activity on SSF. Among the different oil cakes tested, biotransformations carried out on linseed cake were characterized by the highest conversion and stereoselectivity. Several preparative-scale oxidations performed in a self-constructed SSF bioreactor catalyzed by Rhodococcus erythropolis DSM44534, Rhodococcus erythropolis PCM2150 and Gordonia rubripertincta PCM2144 afforded optically active trans-(+)-(4S,5R), cis-(+)-(4R,5R) and cis-(-)-(4S,5S) isomers of whisky lactones, respectively. Bacteria of the Rhodococcus, Gordonia, Dietzia and Streptomyces genera carried out transformations with complete conversion after three days. Various extraction methods were applied for the isolation of the products, and among them, the combination of steam distillation with simple extraction were the most efficient. Biotransformations were conducted under precise control of conditions in a bioreactor based on a Raspberry Pi Zero W. The proposed low-cost (ca. USD 100) bioreactor is a standalone system that is fully autoclavable and easy to use.

Artificial vs natural Stachybotrys infestation-Comparison of mycotoxin production on various building materials.

The genus Stachybotrys belongs to filamentous fungi found in indoor environment, mostly on cellulose-rich substrates after water-damage. The major purpose of this study was to investigate the influence of different building materials in case of mold infestation on the mycotoxin production of Stachybotrys species. Fifteen Stachybotrys mycotoxins including satratoxins, phenylspirodrimanes, and recently discovered stachybotrychromenes were in the focus of the investigations. Artificial and natural infestations were compared to determine whether environmental factors, for example, time of growth, temperature, humidity, and material additives have an influence on the observed mycotoxin profiles. It turned out that mycotoxin profiles from Stachybotrys spp. on building materials can be influenced by cellulose, paints, and paste of the materials. The total toxin levels of artificially and naturally contaminated gypsum board samples ranged up to 30µg/cm2 , whereas wallpaper samples showed total toxin levels in the range of 20-66µg/cm2 . A naturally infested sample disclosed the conversion of the dialdehyde components to the corresponding lactone isomers under the influence of light.

Typicality Assessment of Onions (Allium cepa) from Different Geographical Regions Based on the Volatile Signature and Chemometric Tools.

Onion (Allium cepa L.) is one of the main agricultural commodities produced and consumed around the world. In the present work, for the first time, the volatile signature of onions from different geographical regions of Madeira Island (Caniço, Santa Cruz, Ribeira Brava, and Porto Moniz) was tested with headspace solid-phase microextraction (HS-SPME/GC-qMS) and chemometric tools, showing that the volatile signature was affected by the geographical region of cultivation. Sulfur compounds, furanic compounds, and aldehydes are the most dominant chemical groups. Some of the identified volatile organic metabolites (VOMs) were detected only in onions cultivated in specific regions; 17 VOMs were only identified in onions cultivated at Caniço, eight in Porto Moniz, two in Santa Cruz, two in Ribeira Brava, while 12 VOMs are common to all samples from the four regions. Moreover, some VOMs belonging to sulfur compounds (dipropyl disulfide, 3-(acetylthio)-2-methylfuran), furanic compounds (dimethylmethoxyfuranone, ethyl furanone, acetyloxy-dimethylfuranone), and lactones (whiskey lactone isomer), could be applied as potential geographical markers of onions, providing a useful tool to authenticate onions by farming regions where the influence of latitude seems to be an important factor for yielding the chemical profile and may contribute to geographical protection of food and simultaneously benefiting both consumers and farmers.

Reactions of cyclic β-alkoxyvinyl α-keto esters with heteroaromatic NCC-binucleophiles

Reactions of five- and six-membered cyclic β-alkoxyvinyl α-keto esters and NCC-binucleophiles are described. The following binucleophiles were studied: heteroaromatic amines (pyrazoles, isoxazole, uracils, and isoquinolinone) and 2-(benzimidazolyl)acetonitrile. It was found that condensation proceeded regioselectively in the case of five-membered cyclic enone. Fused α-pyridine carboxylates, likely formed in situ, underwent lactonization, which resulted in six-membered lactones in moderate to excellent yields (53–91%). Only in the case of 3-unsubstituted 5-aminopyrazole, formation of γ-pyridine carboxylate followed by cyclization to isomeric lactone was observed. On the contrary, six-membered cyclic enone was reactive only toward heterocyclic amines under optimized conditions and provided open-chain α-pyridine carboxylates in 40–80% yield.

Subcritical Water Extraction of Sesquiterpene Lactones from Inula racemose

AbstractInula racemose, a traditional Tibetan medicine with strong antifungal and anti‐inflammatory activities, contains large amounts of sesquiterpene lactones. In the current study, subcritical water extraction was employed for the efficient extraction sesquiterpene lactones from I. racemose. Various parameters, such as extraction time (23.2‐56.8 min), temperature (129.5‐230.5 °C) and SW flow rate (1.3‐4.7 mL/min) was investigated for optimizing the recovery of the targeted compounds. The optimal conditions for SWE were determined as follows: extraction time of 45 min, extraction temperature of 190 °C, and SW flow rate of 3.0 mL/min, and a recovery of 71.97% was achieved. Four sesquiterpene lactone isomers were separated by prep‐HPLC from the SWE extract and identified as igalan, isoalantolactone, alantolactone, and alloantolactone. A comparison of SWE with traditional extraction technologies showed that subcritical water could be a green and efficient substitution for the extraction of sesquiterpene lactones from I. racemose.

Impact of Genetic Variation on Pravastatin Systemic Exposure in Pediatric Hypercholesterolemia.

This study investigated the impact of SLCO1B1 genotype on pravastatin systemic exposure in children and adolescents with hypercholesterolemia. Participants (8-20years) with at least one allelic variant of SLCO1B1 c.521T>C (521TC, n=15; 521CC, n=2) and wild-type controls (521TT, n=15) completed a single oral dose pharmacokinetic study. Interindividual variability of pravastatin acid (PVA) exposure within SLCO1B1 genotype groups exceeded the approximately twofold difference in mean PVA exposure observed between SLCO1B1 genotype groups (P>0.05, q>0.10). The 3'α-iso-pravastatin acid and lactone isomer formation in the acidic environment of the stomach prior to absorption also was variable and affected PVA exposure in all genotype groups. The SLCO1B1 c.521 gene variant contributing to variability in systemic exposure to PVA in our pediatric cohort was comparable to previous studies in adults. However, other demographic and physicochemical factors seem to also contribute to interindividual variability in the dose-exposure relationship.

Isomerization of Linear to Hyperbranched Polymers: Two Isomeric Lactones Converge via Metastable Isostructural Polyesters to a Highly Branched Analogue.

We report here the Zn(II)-catalyzed convergence of two metastable and isostructural polyesters to an isomeric polymer having a hyperbranched architecture. Ring-opening transesterification polymerization (ROTEP) of 4-carbomethoxyvalerolactone (CMVL) under Brønsted catalysis is known to give the linear polyester PCMVL. We show here that this can be isomerized to the equilibrated (and highly branched) polyester EQ-PCMVL. Analysis of the fragments obtained from eliminative degradation of EQ-PCMVL were critical in the formulation of its structure. The isomerization of PCMVL to EQ-PCMVL is a direct consequence of the presence of the second ester functional group in the CMVL ester-lactone, a rarely studied class of monomer. Zn(II)-catalysis of the ROTEP of the isomeric β-lactone, 2-(2-carbomethoxyethyl)propiolactone (isoCMVL), as well as isomerization of the isostructural linear homopolymer derived from that isomeric monomer, led to the same EQ-PCMVL. These results suggest a new strategy for the introduction of branching into various polyesters.

Diels-Alder cycloaddition versus ring-opening esterification: A computational study of the mechanism of formation of oxa-norbonene lactones from the reaction of furfuryl alcohol and itaconic anhydride

Abstract The reactions of furfuryl alcohol with itaconic anhydride can proceed via four plausible pathways – two pathways involving initial Diels-Alder cycloaddition followed by lactonization and two pathways involving initial esterification followed by intramolecular Diels-Alder cycloaddition – to afford two distinct norbornene products bearing either a five- or six-membered butyrolactone ring respectively. DFT calculations reported herein show that the first-step Diels-Alder cycloaddition reactions have barriers of 8.5 and 11.8 kcal/mol which are far lower than the barriers of 29.6 and 36.9 kcal/mol for the esterification pathways. The calculated energies for the experimentally observed five- and six membered oxa-norbornene lactone isomers are exergonic with reaction energies of −17.1 and −12.8 kcal/mol respectively. Thermodynamically the five-membered isomer is more stable adduct than the six-membered adduct. Thus the most preferred pathway is the one involving initial [4 + 2] cycloaddition followed by lactonization to form the five-membered butylrolactone ring. Substitution of methyl groups on the carbon bearing the hydroxyl group shows that the substituents do not affects the reaction pathways markedly.

Rapid screening and identification of sesquiterpene lactones in Kudiezi injection based on high-performance liquid chromatography coupled with linear ion trap-orbitrap mass spectrometry

Sesquiterpene lactones are considered as the major active compounds in Kudiezi injection in virtue of their special structures and activities. Herein, an analytical method was developed for rapid screening and identification of sesquiterpene lactones in Kudiezi injection using high-performance liquid chromatography coupled with linear ion trap-orbitrap mass spectrometry (HPLC-LTQ-Orbitrap) in negative ion mode. First, two sesquiterpene lactone reference standards were analyzed to obtain their characteristic ESI-MS/MS fragmentation patterns. Second, based on extracted ion chromatography (EIC) data-mining method and characteristic fragmentation pathways analysis, sesquiterpene lactones in Kudiezi injection were rapidly screened and identified. Finally, an important parameter Clog P was adopted to discriminate the isomers of sesquiterpene lactones. As a result, 50 sesquiterpene lactones were characterized, including 9 sesquiterpene lactone aglycones, 39 sesquiterpene lactone glycosides, and 2 amino acid-sesquiterpene lactone conjugates. Among them, 13 compounds were tentatively identified as new compounds. The results demonstrated that the established method would be a rapid, effective analytical tool for screening and identification of sesquiterpene lactones in the complex system of natural medicines.

Microbial synthesis of a useful optically active (+)-isomer of lactone with bicyclo[4.3.0]nonane structure

Lactone 2a of a bicyclo[4.3.0]nonane structure is a good starting material for synthesis of many attractive compounds. Enantiomerically enriched (−)-(3aR,7aS)-lactone 2a is produced by whole cells of bacteria. In order to examine the impact of the absolute configuration on biological activity we evaluated the process affording the opposite isomer. To this purpose Candida pelliculosa ZP22 characterized by high dehydrogenase activity was used. The goal of presented work was to perform bioreactor scale microbial one-pot oxidation of diol with selected yeast strain C. pelliculosa ZP22 to obtain chiral (+)-(3aS,7aR)-lactone 2a. The idea was to influence on alcohol dehydrogenase activity by increasing the activity of pro-(+)-ADH and simultanously diminishing the activity of pro-(−)-ADH. The optimization of biotransformation conditions involved the manipulation of the nutritional and physical parameters. Selection of the optimal medium in order to improve yield and process enantioselectivity was based on a two-level factorial design methodology. We have also studied the relationship between microbial growth and biosynthesis of lactone 2a. Preparative oxidation of diol 3a (400 mg/L, 2.9 mM) catalyzed by C. pelliculosa ZP22 in an optimized conditions afforded enantiomerically enriched (+)-(3aS,7aR)-isomer of lactone 2a with the isolated yield (30%).

5,6-δ-DHTL, a stable metabolite of arachidonic acid, is a potential EDHF that mediates microvascular dilation

ObjectiveProminent among the endothelium-derived hyperpolarizing factors (EDHFs) are the Cytochrome P450 (CYP) epoxygenase-derived arachidonic acid metabolites—the epoxyeicosatrienoic acids (EETs), that are known as vasodilators in the microcirculation. Among the EET isomers, 5,6-EET undergoes rapid lactonization in aqueous solution to the more stable 5,6-δ DHTL (5,6-dihydroxytrienoic lactone) isomer. It is unclear whether this metabolic transformation maintains its vasodilator potential and what is the mechanism of action. Thus, the aim of this study was to investigate the capacity of the lactone isomer, 5,6- δ DHTL, to induce dilation of arterioles and explore the endothelial Ca2+ response mechanism. Approach and resultsIn isolated human microvessels 5,6- δ DHTL induced a dose dependent vasodilation, that was inhibited by mechanical denudation of the endothelial layer. This 5,6- δ DHTL -dependent dilation was partially reduced in the presence of L-NAME (NOS inhibitor) or the NO-scavenger, cPTIO (by 19.7%, which was not statistically significantly). In human endothelial cells, 5,6- δ DHTL induced an increase in intracellular Ca2+([Ca2+]i) in a dose dependent manner. This increase in [Ca2+]i was similar to that induced by the 5,6-EET isomer, and significantly higher than observed by administering the hydrolytic dihydroxy isomer, 5,6-DHET. Further experiments aimed to investigate the mechanism of action revealed, that the 5,6-δ DHTL-mediated ([Ca2+]i elevation was reduced by IP3 and ryanodine antagonists, but not by antagonists to the TRPV4 membrane channel. Similar to their effect on the dilation response in the arteries, NO inhibitors reduced the 5,6-δ DHTL-mediated ([Ca2+]i elevation by 20%. Subsequent 5,6-δ DHTL -dependent K+ ion efflux from endothelial cells, was abolished by the inhibition of small and intermediate conductance KCa. ConclusionsThe present study shows that 5,6-δ DHTL is a potential EDHF, that dilates microvessels through a mechanism that involves endothelial dependent Ca2+ entry, requiring endothelial hyperpolarization. These results suggest the existence of additional lactone-containing metabolites that can be derived from the PUFA metabolism and which may function as novel EDHFs.

ChemInform Abstract: Four New Isomeric Sesquiterpene Lactone Dimers from Carpesium faberi.

AbstractGuaianodilactones A—D (I)—(IV) are isolated from the title plant.

Microbial Stereoselective One-Step Conversion of Diols to Chiral Lactones in Yeast Cultures

It has been shown that whole cells of different strains of yeast catalyze stereoselective oxidation of meso diols to the corresponding chiral lactones. Among screening-scale experiments, Candida pelliculosa ZP22 was selected as the most effective biocatalyst for the oxidation of monocyclic diols 3a–b with respect to the ratio of high conversion to stereoselectivity. This strain was used in the preparative oxidation, affording enantiomerically-enriched isomers of lactones: (+)-(3aR,7aS)-cis-hexahydro-1(3H) -isobenzofuranone (2a) and (+)-(3aS,4,7,7aR)-cis-tetrahydro-1(3H)-isobenzofuranone (2b). Scaling up the culture growth, as well as biotransformation conditions has been successfully accomplished. Among more bulky substrates, bicyclic diol 3d was totally converted into enantiomerically-pure exo-bridged (+)-(3aR,4S,7R,7aS)-cis-tetrahydro-4,7-methanoisobenzofuran -1(3H)-one (2d) by Yarrovia lipolytica AR71. Microbial oxidation of diol 3f by Candida sake AM908 and Rhodotorula rubra AM4 afforded optically-pure cis-3-butylhexahydro-1(3H) -isobenzofuranone (2f), however with low conversion.

Abstract 13716: Pharmacokinetics of Pravastatin in Pediatric Dyslipidemia Patients: Clinical Impact of Genetic Variation on Statin Disposition

Background: In adults, genetic variation of the drug transporter, organic anion transporting polypeptide (OATP1B1) encoded by the gene SLCO1B1, decreases hepatic uptake of statins. This leads to increased circulating statin concentrations in plasma, thereby placing patients at higher risk for adverse events and decreased efficacy. Expression of OATP transporters in mice changes during development, raising the question of whether in humans the genotype-phenotype relationship observed in adults is relevant in the developing child. Methods: Participants (8-21 years) with at least one allelic variant of SLCO1B1 c.521 T>C (521TC; n=8) and wild type controls (521TT; n=5) were enrolled in a single oral dose pharmacokinetics (PK) study. Pravastatin and isomers were quantified by liquid chromatography tandem mass spectrometry. A model-independent PK approach was used to define the peak plasma concentration (Cmax), area under the curve (AUC) during the sample period and AUC to infinity. Results: 521TC subjects had a nearly 3-fold increase in Cmax (177.62 vs. 56.53 ng/ml; p=0.001) and AUC (389.81 vs. 139.57 ng/ml*h; p=0.004) compared to 521TT controls (Fig. 1). Formation of the 3-alpha-iso-pravastatin acid and lactone isomers in the acidic environment of the stomach prior to absorption was variable in both groups. There was a linear relationship between pravastatin acid AUC and the ratio of pravastatin acid to total analyte (pravastatin acid, 3-alpha-iso-pravastatin, and corresponding lactones) AUC amongst genetic variants (R=0.8961) that does not appear to be present in the control. Conclusion: The impact of the SLCO1B1 c.521 gene variant on pravastatin PK in adults was replicated in our pediatric cohort. However, other physicochemical factors appear to contribute to variability in the dose-exposure relationship. This data must be replicated in a larger cohort, and the pharmacodynamic consequences assessed, before implementing OATP1B1 driven dosing guidelines.