Butyric Derivatives Research Articles

Enhancement by stable butyrate derivatives of antitumor and antiviral actions of interferon.

The use of n-butyric acid has been associated with induction of cell differentiation and bypassing of genetic defects in the suppression of malignancy. This biological response modifier satisfies the requirements for specificity and low toxicity, and its use can be considered as an alternative approach to conventional cancer chemotherapy. However, a lack of clinical efficacy has been observed with butyrate and attributed mainly to the rapid metabolism of the compound. Butyric acid pro-drugs derived from monosaccharides such as 3-O-butanoyl-1,2-O-isopropylidene-alpha-D-glucofuranose (MAG = 3but) have consequently been devised. Pharmacokinetic and biological advantages of MAG = 3but have been previously described. In the present report, we have studied the effect of MAG = 3but on murine interferon-alpha, beta (IFN) anticellular, antitumor and antiviral activities. In vitro, it appears that MAG = 3but predisposes malignant MSV cells to a later, complete establishment of the antiproliferative and the cell-differentiating effects of IFN, and the antiviral action of the latter in the same line of cells infected with encephalomyocarditis (EMC) virus. In vivo, combined treatment with MAG = 3but and IFN protects mice effectively against the fatal development of ascitic sarcoma 180 TG and the lethal effect of EMC virus infection.

Metabolism of pyrenyl fatty acids in baby hamster kidney fibroblasts. Effect of the acyl chain length.

Biosynthetic labeling of cellular lipids with a fluorescent pyrenyl fatty acid (PyrxFA) moiety was studied in order to assess the usefulness of this approach in the introduction of fluorescent lipid molecules to living cells for transport and metabolic studies. PyrxFAs containing 4-14 aliphatic carbons were added to the culture medium of baby hamster kidney (BHK) fibroblasts, and their incorporation to various lipid species was monitored by thin layer and high pressure liquid chromatography. The results show that the length of the acyl chain has a remarkable effect on the efficiency of incorporation as well as distribution of the label between lipid species. Accordingly, PyrxFAs can be divided into two groups: the short chain ones including the pyrene butyrate and hexanoate derivatives, which show only modest incorporation to phospholipids and negligible labeling of triglycerides and cholesterol esters, and the long chain PyrxFAs including pyrene octanoate, decanoate, dodecanoate, and myristate derivatives, which incorporate efficiently both to phospholipids, mainly phosphatidylcholine (PC) and -ethanolamine (PE), and neutral lipids, i.e. di- and triglycerides and cholesterol esters. Positional analysis showed that the longer PyrxFAs are esterified preferentially to the sn-1 position of the glycerol moiety of PC and PE while the shorter ones are found exclusively in the sn-2 position indicating that the longer PyrxFAs mimic natural saturated fatty acids whereas the shorter ones may be recognized as polyunsaturated fatty acids by the acylating enzymes. Reverse phase chromatography of PC and PE revealed the presence of a variety of labeled molecular species among which the palmitate and oleate containing species were the major ones. Reverse phase analysis with simultaneous monitoring at the monomer and excimer channels showed the presence of tri- and diglyceride species with either 1 or 2 pyrenyl acyl residues. Analysis of the total cellular fatty acids demonstrated that PyrxFAs are shortened, probably by beta-oxidation in peroxisomes, up to pyrene butyrate. It is concluded that metabolic labeling with PyrxFAs is a promising alternative for studies on intracellular lipid traffic, especially because it allows introduction of fluorescent phospholipid species of very different hydrophobicity into intracellular membrane(s).

Butyrate stimulates the secretion of apolipoprotein (apo) A-I and apo B100 by the human hepatoma cell line Hep G2. Induction of apo A-I mRNA with no change of apo B100 mRNA.

Addition of sodium butyrate to the culture medium of the human hepatoma cell line Hep G2 resulted in a time- and dose-dependent increase in the secretion of apolipoprotein A-I (apo A-I) and apolipoprotein B100 (apo B100). After a 24 h preincubation period, a 2.4- and 2.2-fold increase in the secretion of apo A-I and apo B100 respectively was obtained during the next 24 h in the presence of 2 mM-sodium butyrate. Secretion of albumin, fibrinogen or [35S]methionine-labelled newly synthesized proteins was unaffected or only marginally affected, indicating that the effect of butyrate on apo A-I and apo B100 is not part of a general effect on protein synthesis and secretion. In structure-function studies, butyrate was found to be the most potent inducer among various straight-chain carboxylic acids. Hydroxylated, aminated and otherwise modified butyrate derivatives were inactive. The enhanced accumulation of apo A-I and apo B100 in the culture medium could not be explained by changes in the uptake and degradation of the synthesized apolipoproteins or by alterations in the secretion of possible intracellular pools. In addition, [35S]methionine incorporation studies indicated that synthesis and/or secretion of newly synthesized apo A-I and apo B100 is enhanced in the presence of butyrate. The apo A-I mRNA level was increased 2.3-fold upon treatment with 2 mM-butyrate for 48 h, suggesting regulation at (post-)transcriptional level. In contrast, no change in the level of apo B100 mRNA in butyrate-treated cells was observed, indicating regulation at translational or co- or post-translational level. We propose that the effect of butyrate on the secretion of apo A-I and apo B100 by Hep G2 results from two different regulatory mechanisms.

New stable butyrate derivatives alter proliferation and differentiation in human mammary cells

Two new butyric esters which were devised to extend the half-life of n-butyric acid in vivo, were used to study their effects on a number of phenotypic characteristics including cell morphology, cell proliferation, colony formation, cell-surface antigen and estrogen receptor expression in 3 normal immortalized cell lines and 2 carcinoma cell lines derived from the human mammary gland. When treated with butyric esters, human mammary cells acquired numerous cytoplasmic granules and vacuoles, reminiscent of secretory functions, and increased in volume. Modulation of the expression of membrane-associated antigens recognized by the monoclonal antibodies (MAbs) 115D8, 140C1 and 125B5 was also observed. Furthermore, butyrate derivatives inhibited the proliferation of all the cell lines tested and the colony-forming capacity of those that grew in soft agar. The inhibitory effects were, however, reversible upon removal of butyric esters from the culture medium. In the human breast carcinoma cell line, MCF-7, in which the cytostatic effects of butyric esters were the most pronounced, cells accumulated in the G0/G1 phase of the cell cycle. This cell line was the only one to contain estrogen receptors which decreased in number when treated with butyric esters without any modification in their binding affinity. Moreover, the stimulatory effects of estrogen on MCF-7 cell proliferation were antagonized by butyric esters. Our results demonstrate that many of the proliferative and differentiation changes previously reported for n-butyrates in tumor cells are similarly produced by the new stable butyrate derivatives in normal and malignant human mammary cell lines.

Butyrate-treated chick embryo myoblasts synthesize new proteins

Upon treatment with sodium butyrate, chick embryo myoblasts synthesize two new major proteins, BIP 1 and BIP 2 which have the same molecular weight but differ in charge. These proteins are found free in the cytoplasm. Their synthesis starts within a few hours following addition of butyrate, reaches a constant rate after 40 h in the presence of the drug, and stops upon its removal. At all times BIP 1 and BIP 2 (Butyrate-Induced Proteins) remain at a constant ratio of approx. 2. Their appearance is correlated with the appearance of new species of messenger RNA (mRNA). Only myoblasts seem to synthesize the BIPs upon butyrate treatment. At the present time their function is completely unknown. Evidence is presented that the BIPs are not involved in the inhibition of myotube formation, since a derivative of butyrate, the methylester of butyric acid, can prevent fusion of myoblasts without inducing the synthesis of the BIPs.

Antibiotic activity of a fungal perylene-quinone and some of its derivatives

The photoinducible red pigment of Cercospora beticola Sacc, a derivative of 4,9-dihydroxy-perylene-3,10-quinone (cercosporin), was active against all bacteria tested. G +ve bacteria, particularly members of the genus Clostridium , were most susceptible. Cercosporin exhibited low antifungal activity and appeared to act on yeasts by prolonging the lag phase of growth. The acetate, butyrate, benzoate, maleate and phthalate derivatives of cercosporin were active against a similar range of organisms although the activity of the benzoate derivative against Clostridium acetobutylicum was lowered considerably. All compounds, with the exception of the maleate derivative were active against Chlorella . Cercosporin and its acetate and butyrate derivatives were active against tomatoes post-emergence but the activity was not considered to be of economic interest.

The actions of cyclic AMP, its butyryl derivatives and Na butyrate on the proliferation of malignant trophoblast cells in vitro

Cyclic AMP, and its derivatives N6-monobutyryl cyclic AMP and dibutyryl cyclic AMP, have been found to inhibit the proliferation of trophoblast cells of the BeWo cell line in vitro. Sodium butyrate (1 mM), a possible degradation product of the butyrate derivatives, also inhibited cell proliferation, giving similar growth rates to equimolar dibutyryl cyclic AMP. The inhibition by butyrate was however, not sufficient to account for the action of 1 mM N6-monobutyryl cycli AMP, which, like cyclic AMP, completely inhibited cell proliferation. The potency, specificity and toxicity of the substances were compared. The results suggest different modes of action for cyclic AMP and dibutyryl cyclic AMP.

Observations on the Hydrolysis of p-Nitrophenyl Acylates by Purified Bovine Thrombin

SummaryThe ability of purified bovine thrombin to catalyze the hydrolysis of p-nitrophenyl acetate and p-nitrophenyl butyrate has been studied. The butyrate derivative appears to be hydrolyzed more rapidly than the acetate derivative. An examination of the time course of hydrolysis of these compounds by thrombin shows an initial ‘‘burst” reaction followed by a slower ‘‘steady-state” reaction. The hydrolysis of p-nitrophenyl acylates by thrombin is inhibited by the presence of benzamidine as well as by prior reaction of thrombin with phenylmethylsulfonyl fluoride. It is suggested that bovine thrombin catalyzes the hydrolysis of p-nitrophenyl acylates and that the reaction proceeds via the formation of an acyl-enzyme intermediate.

Biochemische Darstellung stereospezifish Wasserstoff-markierter Verbindungen im präparativen Maßstab III. Gewinnung von [2.3-H*](2R,3R)-Carbonsäuren und Derivaten durch Fermentation oder Austausch mit Clostridium kluyveri / Biochemical Synthesis of Stereospecifically Hydrogen Labelled Compounds in a Preparative Scale III. Preparation of [2,3-H*](2R,3R) -Carbonic Acids and Derivatives by Fermentation or Exchange with Clostridium kluyveri

Clostridium kluyveri ferments crotonate in D2O or H2O/ΗΤΟ and forms [2,3-H] (2R,3R) -butyrate. This was chemically converted to [1,2-H]*(1R,2R) -propylamine, [2-H] (2R) -propylamine, [2-H] (2R) -propionate and [1-H] (1R) -ethylamine. ORD curves of the deuterated compounds have been measured. C. kluyveri ferments also other α,β-enoyl compounds and shows exchange reactions with butyrate homologues and derivatives.

Purification and properties of esterases characteristic of adult rat brain.

1. A method for the partial purification of an esterase fraction, present in the brain of the adult but not the newborn rat, is described. A 54-fold purification was achieved in three steps. 2. When subjected to starch-gel electrophoresis, the purified fraction resolved into three bands of esterase activity. Two of these bands migrate close together and faster than other esterases in the brain. These two esterases are inhibited by p-hydroxymercuribenzoate but not by di-isopropyl phosphorofluoridate. The third band is di-isopropyl phosphorofluoridate-sensitive and migrates just behind the two leading esterases. 3. After treatment with di-isopropyl phosphorofluoridate, to obviate the effects of the di-isopropyl phosphorofluoridate-sensitive esterase, the enzyme preparation hydrolyses alpha-naphthyl acetate, alpha-naphthyl propionate and alpha-naphthyl butyrate, but not cholesteryl acetate. The V(max.) for the naphthyl esters decreased with increase in chain length of the acyl group. The acetate ester is hydrolysed 34 times as fast as the butyrate and about seven times as fast as the propionate derivative. The K(m) values for these three esters, measured at pH7.2 and 37 degrees , are 2.8x10(-4)m, 3.1x10(-4)m and 7.3x10(-5)m for the acetate, propionate and butyrate derivatives respectively. 4. The Hofstee (1952) plots for the kinetic data show a single line, indicating that the two most-rapidly migrating esterases, although electrophoretically separable, are not kinetically distinguishable in the substrate ranges examined.

The growth regulating activity of certain omega-substituted alkyl carboxylic acids in relation to their beta-oxidation within the plant.

The plant growth-regulating activities of homologous series of ω -(4-chlorophenoxy)-, ω -(2:4- dichlorophenoxy)- and ω -(2:4:5-trichlorophenoxy)-alkylcarboxylic acids and of the corresponding ω -(1 -naphthyl)- acids have been assessed in the wheat cylinder, pea curvature and tomato-leaf epinasty tests. In most instances, an alternation in activity was observed as each series was ascended. With some series, however, although the acetic derivative was active, all higher homologues were inactive in certain tests. The results are discussed and shown to be consistent with a possible degradation of the side-chain of these acids by β -oxidation within the plant tissue. Although the evidence indicates that β -oxidase enzyme systems are present in all three types of plant tissue employed, whether or not such enzymes can degrade the side-chain of these acids appears to be related to the type of ring system and to the orientation of nuclear substituents present in the molecule. Thus, for example, 4-chlorophenoxy- and 2:4-dichlorophenoxy-acetic acids and their alternate homologues were active in all three tests, whereas in the case of the ω -(2:4:5-trichlorophenoxy)- series, this typical alternation in growth-regulating activity was shown only in the wheat cylinder test. However, when solutions of alternate homologues of the latter series were pre-treated with wheat coleoptile tissue, they induced growth responses in the pea test. Furthermore, the pre-treated solution of the butyric derivative was shown by chromatographic methods to contain the acetic homologue. The growth-regulating activity of a number of 1-naphthyl-acids with alkyl substituents in the side-chain was also determined. The results are consistent with the view that substitution in the β -position of the side-chain can hinder β -oxidation of these compounds.