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Results reveal that the reductive cleavage of anisylidene acetals by BH3/Bu2BOTf can selectively produce either regioisomer, simply by adjusting the reaction temperatures and reagent concentrations. Reductive ring opening at low temperatures is determined to be compatible with sensitive functional groups such as allyl and enol ethers and other ketals.

Sulfated epitopes of [alpha]-glucosamine (GlcN sulfoforms) are prepared by using solid-phase synthesis as models of internal glucosamines within heparan sulfate. The fragmentation analysis has distinguished GlcN sulfoforms bearing the relatively rare 3-O-sulfate from isomers with the more common 6-O-sulfate.

The binding of the adaptor protein APPL1 to adiponectin receptors is necessary for adiponectin-induced AMP-activated protein kinase (AMPK) activation in muscle, yet the underlying molecular mechanism remains unknown. Here we show that in muscle cells adiponectin and metformin induce AMPK activation by promoting APPL 1-dependent LKB1 cytosolic translocation. APPL1 mediates adiponectin signaling by directly interacting with adiponectin receptors and enhances LKB1 cytosolic localization by anchoring this kinase in the cytosol. Adiponectin also activates another AMPK upstream kinase Ca2+/calmodulin-dependent protein kinase kinase by activating phospholipase C and subsequently inducing Ca2+ release from the endoplasmic reticulum, which plays a minor role in AMPK activation. Our results show that in muscle cells adiponectin is able to activate AMPK via two distinct mechanisms as follows: a major pathway (the APPL1/LKB1dependent pathway) that promotes the cytosolic localization of LKB1 and a minor pathway (the phospholipase C/Ca2+/Ca2+/calmodulin-dependent protein kinase kinase-dependent pathway) that stimulates Ca2+ release from intracellular stores. [ABSTRACT FROM AUTHOR]

The 22 genetically encoded amino acids (AAs) present in proteins (the 20 standard AAs together with selenocysteine and pyrrolysine), are commonly referred as proteinogenic AAs in the literature due to their appearance in ribosome-synthetized polypeptides. Beyond the borders of this key set of compounds, the rest of AAs are generally named imprecisely as non-proteinogenic AAs, even when they can also appear in polypeptide chains as a result of post-transductional machinery. Besides their importance as metabolites in life, many of D-α- and L-α-"non-canonical" amino acids (NcAAs) are of interest in the biotechnological and biomedical fields. They have found numerous applications in the discovery of new medicines and antibiotics, drug synthesis, cosmetic, and nutritional compounds, or in the improvement of protein and peptide pharmaceuticals. In addition to the numerous studies dealing with the asymmetric synthesis of NcAAs, many different enzymatic pathways have been reported in the literature allowing for the biosynthesis of NcAAs. Due to the huge heterogeneity of this group of molecules, this review is devoted to provide an overview on different established multienzymatic cascades for the production of non-canonical D-α- and L-α-AAs, supplying neophyte and experienced professionals in this field with different illustrative examples in the literature. Whereas the discovery of new or newly designed enzymes is of great interest, dusting off previous enzymatic methodologies by a " back and to the future " strategy might accelerate the implementation of new or improved multienzymatic cascades., (Copyright © 2020 Martínez-Rodríguez, Torres, Sánchez and Ortega.)

Background: The incidence of prostate cancer (PCa) and benign prostatic hypertrophy (BPH) continues to rise in the Western world. The development and growth of the prostate gland depends on androgen stimulation. Dihydrotestosterone (DHT) is the primary androgen responsible for prostate development and also for the pathogenesis of benign prostatic hyperplasia (BPH). DHT is synthesized in prostate from circulating testosterone (T) through the action of 5alpha-Reductase (5alpha-R) (EC 1.3.99.5), which occurs as two isozymes, type-1 and type-2. Both types are expressed in the prostate: type-2 isozyme is predominantly expressed in prostate and is implicated in BPH and PCa; type-1 isozyme is also increased in some prostatic adenocarcinomas. In recent years, various inhibitors of type-2 isozyme or of both type-1 and type-2 isozyme have been used in prostatic diseases., Methods: We present the first published measurements of mRNA levels of steroid 5alpha-R isozymes in the ventral prostate of rats of different androgen status. We used a novel method that combines the high specificity of competitive PCR with the sensitivity of laser-induced capillary electrophoresis (LIF-CE)., Results: We demonstrated that T and DHT androgens control the expression of both 5alpha-R isozymes in rat prostrate., Conclusions: This approach could be of great value for the study of prostate diseases in humans and would allow study at the transcriptional level of the effects of drugs that inhibit either or both of these isozymes., (Copyright 2003 Wiley-Liss, Inc.)