Putrescine N-methyltransferases (PMTs) are the first specific enzymes of the biosynthesis of nicotine and tropane alkaloids. PMTs transfer a methyl group onto the diamine putrescine from S-adenosyl-l-methionine (SAM) as coenzyme. PMT proteins have presumably evolved from spermidine synthases (SPDSs), which are ubiquitous enzymes of polyamine metabolism. SPDSs use decarboxylated SAM as coenzyme ...

Hydride transfer from N,N, 1,2,4-pentamethyl-1,4-dihydronicotinamide, 1, to methyl 2-methoxycarbonylimino-phenylacetate, 3, was accomplished in an optical yield 2 95 %. Efficient chirality transfer from reduced NADH models to prochiral carbonyl substrates has i.a. been achieved with pentamethylated 1,4-dihydronicotinamide 1. ’ In comparison with 1,4-dihydroquinoline analogues,’ NADH model 1 is ...

In experiments, the free energy of transferring the peptide group from water to an osmolyte solution is obtained using the transfer free energy of (Gly)n with the added assumption that a constant incremental change in free energy with n implies that each additional unit makes an independent contribution to the free energy. Here we test this assumption and uncover its limitations. Together with ...

With the aim of developing new molecular devices having long-range electron transfer in artificial systems and as photosensitizers, a series of homoleptic ruthenium(II) bisterpyridine complexes bearing one to three anthracenyl units sandwiched between terpyridine and 2-methyl-2-butenoic acid group are synthesized and characterized. The complexes formulated as bis-4'-(9-monoanthracenyl-10-(2-met...

Alkyl sulfate monoesters are involved in cell signaling and structure. Alkyl sulfates are also present in many commercial detergents. Here, we show that monomethyl sulfate acts as an efficient alkylating agent in water, reacting spontaneously with oxygen nucleophiles >100-fold more rapidly than do alkylsulfonium ions, the usual methyl donors in living organisms. These reactions of methyl sulfat...

1. Cell-free extracts of Bacillus subtilis synthesize methionine from serine and homocysteine without added folate. The endogenous folate may be replaced by tetrahydropteroyltriglutamate or an extract of heated Escherichia coli for the overall C(1) transfer, but tetrahydropteroylmonoglutamate is relatively inactive. 2. Extracts of B. subtilis contain serine transhydroxymethylase and 5,10-methyl...

a new proton transfer compound, formulated as (hamp-6-pic)(hpyzd) ∙h2o (1), has been synthesized from the reaction of pyrazine-2,3-dicarboxylic acid (h2pyzd)  and 2-amino-6-methyl pyridine (amp-6-pic), in 1:1 molar ratio. extensive o−h×××o, n−h×××n and o−h×××o hydrogen bonds involving (hamp-6-pic)+ cation, (hpyzd)- anion and co-crystal water molecule٫ static electronic٫ and π…π stacking interac...

a copolymer of styrene and methyl styrene was synthesized by nitroxide - mediated “living” free radical polymerization )nmp). n-bromosuccinimide was used as a brominating agent to obtain a copolymer with bromine as its end group. this brominated copolymer was used as macro initiators for atom transfer  radical  polymerization  (atrp).  chemical  modifcation  of  the  clay  and transformation of...

We report that SeO2 catalyzes the facile oxy-functionalization of (CO)5Re(I)-Me(delta-) with IO4(-) to generate methanol. Mechanistic studies and DFT calculations reveal that catalysis involves methyl group transfer from Re to the electrophilic Se center followed by oxidation and subsequent reductive functionalization of the resulting CH3Se(VI) species. Furthermore, (CO)3Re(I)(Bpy)-R (R = ethyl...