Marinoic acid

A novel substance with a bufadienolide-related chemical structure has been isolated from B. marinus skin. This substance is 3P-hydroxy-ll, 12-seco-5p, 14P-bufa-20, 22-dienolide-l 1, 14-olides-12oic acid (called marinoic acid) and shows the Na+/K+-ATPase inhibitory activity characteristic of the bufadienolides (Matsukawa, Akizawa, Morris, Butler Jr and Yoshioka 1996). 

Matsukawa, M., Akizawa, T., Morris, J. F., Butler Jr, V. P. and Yoshioka, M. (1996) Marinoic acid, a novel bufadienolide-based substance in the skin of the giant toad, Bufo marinus. Chem. Pharm. Bull. 44, 255-257. 

Deoxy sugars are of wide occurrence as components of nucleic acids, natural glycosides, and antibiotics, and they were the subject of an earlier article by Hanessian in Volume 21. Here, de Lederkremer and Marino (Buenos Aires) provide a detailed update on the distribution of deoxy sugars in natural products, along with a survey of methods for their synthesis. 

Rist, M. J., and Marino, J. P. (2002). Huorescent nucleotide base analoges as probes of nucleic acid structure, dynamics and interactions. Curr. Org. Chem. 6, 775—793. 

SnCL-catalyzed acetylation by AC2O in dichloroethane at 25°. See Linda and Marino.130 and unpublished results. 9 Reaction with (CF3C0)20 in dichloroethane at 75°. See dementi and Marino.143- 302 h Acetoxymercuration in acetic acid at 50°.121... 

Fig. 6. Plot of log kjko vs ap+ constants for the bromination of 2-substituted thiophenes in acetic acid see Marino.85...

Lallement, G., Carpenteir, P., Collet, A., Pemot-Marino, I., Bauhichon, D., Blanchet, G. (1991b). Effects of soman-induced seizures on different extracellular amino acid levels and on glutamate uptake in rat hippocampus. Brain Res. 563 234-340. 

There have been few transformations of vinylcupiate reagents with acid chlorides (Section 1.13.3.1.1). Marino and Linderman have reported a gener preparation of divinyl ketones useful in a Nazarov sense for the formation of cyclopentenones (Scheme 33). Addition of various cuprate species to ethyl propio-late formed a mixed cuprate which is peibaps best represented as the allene (91). In the case of heterocuprates (89) and (90), acylation proceeded in good yield to form the divinyl ketone. Dimethylcuprate afforded none of the desired product but instead produced 1-acetylcyclohexene. The method was generalized for several different acid chlorides. 

The stereocontrolled total synthesis of (-)-macrolactin A, a 24-membered macrolide, was achieved by J.P. Marino and co-workers/ The key macrocyclization step was carried out using the Yonemitsu modification of the Yamaguchi macroiactonization. In this procedure, the mixed anhydride is added to the highly dilute solution of DMAP rapidly (in one portion) at room temperature. The final step of the total synthesis was the removal of the protecting groups under acidic condition. 

Crupi R, Marino A, Cuzzocrea S (2013) n-3 latty acids Role in neurogenesis and neuroplasticity. Curr Med Chem 20 2953-2963... 

Maurelli S, Bisogno T, De PetrocelUs L, Di Luccia A, Marino G, Di Marzo V (1995) Two novel classes of neuroactive fatty acid amides are substrates for mouse neuroblastoma anandamide amidohydrolase . FEBS Lett 377 82-86... 

In contrast with chlorination, bromination of thiophene always gives substitution products exclusively, and no addition products have been isolated under a variety of experimental conditions. Lauer first studied the kinetics of the reaction of thiophene with molecular bromine however, the reported value for the rate relative to benzene (2 x 10 ) is not reliable, because of the uncorrected value of k for bromination of benzene (for a discussion of this point, see Marino ). Later, the rate of bromination of thiophene relative to benzene in acetic acid was determined as 1.9 x 10 , by comparing the times necessary to achieve 10% reaction in the bromination of thiophene and mesitylene, under the same conditions. ... 

Later, Linda and Marino were able to compare the relative reactivities of all four fundamental systems (furan, thiophene, selenophene, and pyrrole) toward bromination by molecular bromine in acetic acid. Unfortunately, the comparison could not be made on the unsubstituted rings for the following reasons first, the rates of substitution for furan and pyrrole were too high to be followed by standard kinetic techniques second, furan and pyrrole undergo ring fission and/or polymerization under the influence of the hydrobromic acid formed in the reaction finally, furan tends to give addition as well as substitution products in the reaction with bromine. ... 

Later, Butler and Hendry repeated this work, measuring the rates of bromination of some 2-substituted thiophenes (the same derivatives used by Marino plus 2-ethyl, 2-<-butyl, and 2-phenyl) in 85% aqueous acetic acid and in the presence of lithium bromide. The p value obtained was identical (—10.0), showing that it is not affected at all by passing from anhydrous to aqueous acetic acid. 

---