Explorations of Caffeic Acid Derivatives: Total Syntheses of Rufescenolide, Yunnaneic Acids C and D, and Studies toward Yunnaneic Acids A and B

Yunnaneic acids A–D, isolated from the roots of Salvia yunnanensis, are hexameric (A and B) and trimeric (C and D) assemblies of caffeic acid that feature an array of synthetically challenging and structurally interesting domains. In addition to being caffeic acid oligomers, yunnaneic acids A and B are formally dimeric and heterodimeric adducts of yunnaneic acids C and D. Herein we report the first total syntheses of yunnaneic acids C and D featuring the formation of their bicyclo[2.2.2]­octene cores in a single step from simple precursors via an oxidative dearomatization/Diels–Alder cascade that may have biogenetic relevance. In addition, exploitation of the key intermediate resulting from this cascade reaction has enabled rapid access to the structurally related caffeic acid metabolite rufescenolide through an unexpected Lewis acid-mediated reduction. Finally, we report the results of extensive model studies toward forming the dimeric yunnaneic acids A and B. These explorations indicate that the innate reactivities of the monomeric fragments do not favor spontaneous formation of the desired dimeric linkages. Consequently, enzymatic involvement may be required for the biosynthesis of these more complex family members

Explorations of Caffeic Acid Derivatives: Total Syntheses of Rufescenolide, Yunnaneic Acids C and D, and Studies toward Yunnaneic Acids A and B

Yunnaneic acids A–D, isolated from the roots of Salvia yunnanensis, are hexameric (A and B) and trimeric (C and D) assemblies of caffeic acid that feature an array of synthetically challenging and structurally interesting domains. In addition to being caffeic acid oligomers, yunnaneic acids A and B are formally dimeric and heterodimeric adducts of yunnaneic acids C and D. Herein we report the first total syntheses of yunnaneic acids C and D featuring the formation of their bicyclo[2.2.2]­octene cores in a single step from simple precursors via an oxidative dearomatization/Diels–Alder cascade that may have biogenetic relevance. In addition, exploitation of the key intermediate resulting from this cascade reaction has enabled rapid access to the structurally related caffeic acid metabolite rufescenolide through an unexpected Lewis acid-mediated reduction. Finally, we report the results of extensive model studies toward forming the dimeric yunnaneic acids A and B. These explorations indicate that the innate reactivities of the monomeric fragments do not favor spontaneous formation of the desired dimeric linkages. Consequently, enzymatic involvement may be required for the biosynthesis of these more complex family members

Explorations of Caffeic Acid Derivatives: Total Syntheses of Rufescenolide, Yunnaneic Acids C and D, and Studies toward Yunnaneic Acids A and B

Yunnaneic acids A–D, isolated from the roots of Salvia yunnanensis, are hexameric (A and B) and trimeric (C and D) assemblies of caffeic acid that feature an array of synthetically challenging and structurally interesting domains. In addition to being caffeic acid oligomers, yunnaneic acids A and B are formally dimeric and heterodimeric adducts of yunnaneic acids C and D. Herein we report the first total syntheses of yunnaneic acids C and D featuring the formation of their bicyclo[2.2.2]­octene cores in a single step from simple precursors via an oxidative dearomatization/Diels–Alder cascade that may have biogenetic relevance. In addition, exploitation of the key intermediate resulting from this cascade reaction has enabled rapid access to the structurally related caffeic acid metabolite rufescenolide through an unexpected Lewis acid-mediated reduction. Finally, we report the results of extensive model studies toward forming the dimeric yunnaneic acids A and B. These explorations indicate that the innate reactivities of the monomeric fragments do not favor spontaneous formation of the desired dimeric linkages. Consequently, enzymatic involvement may be required for the biosynthesis of these more complex family members

Explorations of Caffeic Acid Derivatives: Total Syntheses of Rufescenolide, Yunnaneic Acids C and D, and Studies toward Yunnaneic Acids A and B

Yunnaneic acids A–D, isolated from the roots of Salvia yunnanensis, are hexameric (A and B) and trimeric (C and D) assemblies of caffeic acid that feature an array of synthetically challenging and structurally interesting domains. In addition to being caffeic acid oligomers, yunnaneic acids A and B are formally dimeric and heterodimeric adducts of yunnaneic acids C and D. Herein we report the first total syntheses of yunnaneic acids C and D featuring the formation of their bicyclo[2.2.2]­octene cores in a single step from simple precursors via an oxidative dearomatization/Diels–Alder cascade that may have biogenetic relevance. In addition, exploitation of the key intermediate resulting from this cascade reaction has enabled rapid access to the structurally related caffeic acid metabolite rufescenolide through an unexpected Lewis acid-mediated reduction. Finally, we report the results of extensive model studies toward forming the dimeric yunnaneic acids A and B. These explorations indicate that the innate reactivities of the monomeric fragments do not favor spontaneous formation of the desired dimeric linkages. Consequently, enzymatic involvement may be required for the biosynthesis of these more complex family members

Explorations of Caffeic Acid Derivatives: Total Syntheses of Rufescenolide, Yunnaneic Acids C and D, and Studies toward Yunnaneic Acids A and B

Yunnaneic acids A–D, isolated from the roots of Salvia yunnanensis, are hexameric (A and B) and trimeric (C and D) assemblies of caffeic acid that feature an array of synthetically challenging and structurally interesting domains. In addition to being caffeic acid oligomers, yunnaneic acids A and B are formally dimeric and heterodimeric adducts of yunnaneic acids C and D. Herein we report the first total syntheses of yunnaneic acids C and D featuring the formation of their bicyclo[2.2.2]­octene cores in a single step from simple precursors via an oxidative dearomatization/Diels–Alder cascade that may have biogenetic relevance. In addition, exploitation of the key intermediate resulting from this cascade reaction has enabled rapid access to the structurally related caffeic acid metabolite rufescenolide through an unexpected Lewis acid-mediated reduction. Finally, we report the results of extensive model studies toward forming the dimeric yunnaneic acids A and B. These explorations indicate that the innate reactivities of the monomeric fragments do not favor spontaneous formation of the desired dimeric linkages. Consequently, enzymatic involvement may be required for the biosynthesis of these more complex family members

Explorations of Caffeic Acid Derivatives: Total Syntheses of Rufescenolide, Yunnaneic Acids C and D, and Studies toward Yunnaneic Acids A and B

Yunnaneic acids A–D, isolated from the roots of Salvia yunnanensis, are hexameric (A and B) and trimeric (C and D) assemblies of caffeic acid that feature an array of synthetically challenging and structurally interesting domains. In addition to being caffeic acid oligomers, yunnaneic acids A and B are formally dimeric and heterodimeric adducts of yunnaneic acids C and D. Herein we report the first total syntheses of yunnaneic acids C and D featuring the formation of their bicyclo[2.2.2]­octene cores in a single step from simple precursors via an oxidative dearomatization/Diels–Alder cascade that may have biogenetic relevance. In addition, exploitation of the key intermediate resulting from this cascade reaction has enabled rapid access to the structurally related caffeic acid metabolite rufescenolide through an unexpected Lewis acid-mediated reduction. Finally, we report the results of extensive model studies toward forming the dimeric yunnaneic acids A and B. These explorations indicate that the innate reactivities of the monomeric fragments do not favor spontaneous formation of the desired dimeric linkages. Consequently, enzymatic involvement may be required for the biosynthesis of these more complex family members

Explorations of Caffeic Acid Derivatives: Total Syntheses of Rufescenolide, Yunnaneic Acids C and D, and Studies toward Yunnaneic Acids A and B

Yunnaneic acids A–D, isolated from the roots of Salvia yunnanensis, are hexameric (A and B) and trimeric (C and D) assemblies of caffeic acid that feature an array of synthetically challenging and structurally interesting domains. In addition to being caffeic acid oligomers, yunnaneic acids A and B are formally dimeric and heterodimeric adducts of yunnaneic acids C and D. Herein we report the first total syntheses of yunnaneic acids C and D featuring the formation of their bicyclo[2.2.2]­octene cores in a single step from simple precursors via an oxidative dearomatization/Diels–Alder cascade that may have biogenetic relevance. In addition, exploitation of the key intermediate resulting from this cascade reaction has enabled rapid access to the structurally related caffeic acid metabolite rufescenolide through an unexpected Lewis acid-mediated reduction. Finally, we report the results of extensive model studies toward forming the dimeric yunnaneic acids A and B. These explorations indicate that the innate reactivities of the monomeric fragments do not favor spontaneous formation of the desired dimeric linkages. Consequently, enzymatic involvement may be required for the biosynthesis of these more complex family members

PENGARUH KEPEMIMPINAN, LINGKUNGAN KERJA DAN STRES KERJA TERHADAP TURNOVER INTENTION PADA KARYAWAN BANK MUAMALAT KC YOGYAKARTA

This study aims to explain the influence of leadership, work environment, and work stress on turnover intention on employees of Bank Muamalat KC Yogyakarta. The dependent variable in this study is turnover intention. While the independent variables are leadership, work environment, and work stress. The sampling used is 56 employees. The sampling method uses purposive sampling using several criteria. Data collection techniques are done by distributing questionnaires and interviews. The analytical tool used is multiple linear regression techniques. The results of the analysis state that leadership and work environment do not have a effect on turnover intention. While job stress has a positive and significant effect on turnover intention

Discovery and Optimization of a Novel Macrocyclic Amidinourea Series Active as Acidic Mammalian Chitinase Inhibitors

Our research group has been involved for a long time in the development of macrocyclic amidinoureas (MCAs) as antifungal agents. The mechanistic investigation drove us to perform an in silico target fishing study, which allowed the identification of chitinases as one of their putative targets, with 1a showing a submicromolar inhibition of Trichoderma viride chitinase. In this work, we investigated the possibility to further inhibit the corresponding human enzymes, acidic mammalian chitinase (AMCase) and chitotriosidase (CHIT1), involved in several chronic inflammatory lung diseases. Thus, we first validated the inhibitory activity of 1a against AMCase and CHIT1 and then designed and synthesized new derivatives aimed at improving the potency and selectivity against AMCase. Among them, compound 3f emerged for its activity profile along with its promising in vitro ADME properties. We also gained a good understanding of the key interactions with the target enzyme through in silico studies

Identification of New Fyn Kinase Inhibitors Using a FLAP-Based Approach

The abnormal activity of Fyn tyrosine kinase has been shown to be related to various human cancers. Furthermore, its involvement in signaling pathways that lead to severe pathologies, such as Alzheimer’s and Parkinson’s diseases, has also been demonstrated, thus making Fyn an attractive target for the discovery of potential novel therapeutics for brain pathologies and tumors. In this study we evaluated the reliability of various screening approaches based on the FLAP software. By the application of the best procedure, the virtual screening workflow was used to filter the Gold and Platinum database from Asinex to identify new Fyn inhibitors. Enzymatic assays revealed that among the eight top-scoring compounds five proved to efficiently inhibit Fyn activity with IC₅₀ values in the micromolar range. These results demonstrate the validity of the methodologies we followed. Furthermore, the five active compounds herein described may be considered as interesting leads for the development of new and more efficient Fyn inhibitors