A new phaeophytin, ligulariaphytin A, together with five known phaeophytins, were isolated from the aerial parts of Ligularia knorringiana. The structure of ligulariaphytin A was elucidated as 13¹-hydroxy-13¹,13²-peroxyphaeophorbide A ethyl ester, and the five known compounds were identified as 13²-hydroxyphaeophorbide A ethyl ester, 17³-ethoxyphaeophorbide A, phaeophytin B, phaeophytin A, and ...

A formal enantioselective synthesis of benazepril.HCl (4), an anti- hypertensive drug, is reported. Our synthesis employed an asymmetric aza-Michael addition of L-homophenylalanine ethyl ester (LHPE, 1) to 4-(2-nitrophenyl)-4-oxo- but-2-enoic acid methyl ester (6) as the key step to prepare (2S,3'S)-2-(2-oxo-2,3,4,5- tetrahydro-1H-benzo[b]azepin-3-ylamino)-4-phenylbutyric acid ethyl ester (8), ...

The use of nicotinic acid derivatives in the field of medicinal, biomedical industries, production of cosmetics, pesticides, agro chemical industries and its biological activities have been studied extensively over the past decades. In this chapter, one of such nicotinic acid derivative called Nicotinic Acid Ethyl Ester (also known ethyl nicotinate, Ethyl 3-pyridinecarboxylate and 3-pyridinecar...

Fatty acid ethyl esters are secondary metabolites produced by Saccharomyces cerevisiae and many other fungi. Their natural physiological role is not known but in fermentations of alcoholic beverages and other food products they play a key role as flavor compounds. Information about the metabolic pathways and enzymology of fatty acid ethyl ester biosynthesis, however, is very limited. In this wo...

The distribution of ethyl esters, triglycerides, diglycerides, monoglycerides and glycerol between the ester and glycerol phase was investigated after the ethanolysis of rapeseed oil at various reaction conditions. The determination of these substances in the ester and glycerol phases was carried out by the GC method. The amount of ethyl esters in the glycerol phase was unexpectedly high and th...

Surfactin originated from genus Bacillus is composed of a heptapeptide moiety bonded to the carboxyl and hydroxyl groups of a β-hydroxy fatty acid and it can be chemically modified to prepare the derivatives with different structures, owing to the existence of two free carboxyl groups in its peptide loop. This article presents the chemical modification of surfactin esterified with three differe...

1. Rat-liver supernatant preparations are capable of achieving the biological sulphation of l-tyrosine methyl ester, the reaction proceeding maximally at a substrate concentration of 30 mm and at pH 7.0. 2. Two sulphated products are formed, one of which has been identified as l-tyrosine O-sulphate. On the basis of indirect evidence the other product can be assumed to be l-tyrosine O-sulphate m...

The investigations by Xath, Chitale, and Belavady (1) showed that when n-glucose1 and an equimolar amount of sodium acetoacetate is fed to germinating mung beans or injected into rats (a), the production of n-ascorbic acid is greater than with glucose alone. It was further observed (2) that a condensation product of glucose and acetoacetate (glucose cycloacetoacetate ethyl ester) can be easily ...