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PubMed1991

Micro-determination of L-gulono-gamma-lactone oxidase activity.

Highly sensitive assay method of L-gulono-gamma-lactone oxidase (GLO) was constructed. In this method, L-ascorbic acid formed in the enzymatic reaction was converted to its bis(dinitrophenyl)hydrazone derivative, and the amount of the latter was determined by high-performance liquid chromatography. Twenty picomoles of ascorbic acid was detected, which makes this method 25 times more sensitive than the previously used dipyridyl one. By the present method, a minute activity of GLO in liver microsomes prepared from rats of the Osteogenic Disorder Shionogi strain (ODS-od/od) could be measured.

Animals↗
PubMed1990

Anthelmintic activity of the macrocyclic lactone F28249-alpha in sheep.

The macrolytic lactone F28249-alpha was titrated in experimentally infected sheep and found to be highly effective against most of the common gastrointestinal nematodes as a single oral dose, given at a rate of 0.025, 0.05, or 0.1 mg/kg. Specifically, maximal activity was evident at even the lowest dosage against adult Haemonchus contortus, Ostertagia circumcinta, Trichostrongylus axei, and T colubriformis and L4 O circumcinta. Activity against Oesophagostomum columbianum was also high at all dosages, with a calculated ED95 of 0.029 mg/kg. Cooperia curticei was eliminated at 0.1 mg/kg, but control was erratic at the lower dosages. The greatest weakness of this compound was its activity against C oncophora. The activity against this parasite was weak (less than or equal to 85%) at all dosages, and the dosage-response curve was flat, suggesting dosages substantially higher than those given would be necessary for high-order control of this species.

Administration, Oral↗
PubMed1988

Isolation and sequence analysis of a complementary DNA encoding rat liver L-gulono-gamma-lactone oxidase, a key enzyme for L-ascorbic acid biosynthesis.

L-Gulono-gamma-lactone oxidase, one of the microsomal flavin enzymes, catalyzes the last step of L-ascorbic acid biosynthesis in many animals; however, it is missing in scurvy-prone animals such as humans, primates, and guinea pigs. A cDNA clone for this enzyme was isolated by screening a rat liver cDNA expression library in lambda gt11 using antibody directed against the enzyme. The cDNA clone contained 2120 nucleotides and an open reading frame of 1320 nucleotides encoding 440 amino acids of the protein with a molecular weight of 50,605. The amino-terminal sequence (residues 1-33) of the enzyme isolated from rat liver completely coincided with the corresponding part of the deduced amino acid sequence. The identity of the cDNA clone was further confirmed by the agreement of the composition of the deduced amino acids with that determined by amino acid analysis of the enzyme. Hydropathy analysis of the deduced amino acid sequence revealed several hydrophobic regions, suggesting that they anchor the protein into the microsomal membrane. The deduced amino acid sequence showed no obvious homology with the flavin-binding regions of other eight flavoenzymes.

Amino Acid Sequence↗
PubMed1986

Natural occurrence of ganglioside lactones. Isolation and characterization of GD1b inner ester from adult human brain.

A new ganglioside containing an inner ester linkage was extracted from adult brain specimens, obtained at the time of surgery on 51-70-year-old subjects, purified, and analyzed. It contains glucose, galactose, N-acetylgalactosamine, an N-acetylneuraminic acid in the molar ratio 1:2:1:2, but, on ion-exchange chromatography, behaves as a monosialoganglioside. Structural analyses showed its basic neutral glycosphingolipid core to be ganglio-N-tetraose ceramide, carrying a disialosyl residue on the 3-position of internal galactose. Sialidase degradation and chemical analysis of the products obtained after alkaline treatments suggested one sialic acid residue to be involved in an ester linkage. Fast atom bombardment-mass spectrometry indicated the presence of an inner ester linkage between the carboxyl group of the external sialic acid residue and a hydroxyl group of the internal one. On these bases, the new ganglioside can be assumed to be a GD1b in lactonic form. This ganglioside is present only in trace amounts in the brain of infants, but its content increases with age, reaching a value of 3.5% of total sialic acid in 51-70-year-old subjects.

Adult↗
PubMed1986

Ulcerogenic and antiulcerogenic effects of a new antiinflammatory drug, the gamma-lactone-N-ethyl derivative of 6-[1S-(3S,4-dihydro-8-hydroxy-1H-2-benzo- pyran-1-one-3-yl)-3-methylbutylamino]-4S,5S-dihydroxy-6-oxo-3S- ammoniohexanoate, on gastrointestinal tract in rats.

6-[1S-(3S,4-Dihydro-8- hydroxy-1H-2-benzo-pyran-1-one-3-yl)- methylbutylamino]-4S,5S-dihydroxy-6-oxo-3S-ammoniohexanoate (AI-77B)-gamma-lactone-N-ethyl derivative (AI-77-C2) is a new antiinflammatory drug with antiulcer activity. In the first part of the present study the ulcerogenicity of this drug was assessed. Acidic antiinflammatory drugs--indomethacin and diclofenac--and basic antiinflammatory drugs--tiaramide and mepirizole--were used for comparison. Although AI-77-C2 was barely ulcerogenic at 7 h after dosing, some lesions developed in both stomach and intestine at 24 h. Repeated administrations over 5 days appeared to increase its ulcerogenicity and general toxicity. Marked gastric ulcers were induced by indomethacin and diclofenac, and severe intestinal ulcers were also produced at 24 h and by their repeated administration. Tiaramide did not induce marked ulcers in any case. Although the ulcerogenicity of mepirizole was weak at 7 h, severe duodenal ulcers developed at 24 h and after the repeated administration. From the results given above, it was concluded that the ulcerogenicity of AI-77-C2 was relatively low. In the next study, the antiulcer activity of AI-77-C2 was examined in several experimental ulcer models. AI-77-C2 showed a marked inhibition of all the models presently employed, i.e., the indomethacin-induced gastric ulcer, the pylorus ligation ulcer, the water immersion stress ulcer, and the acetylsalicylic acid-induced ulcer in rats. It was observed that AI-77-C2 suppressed the gastric secretion and movement. It is therefore concluded that the antiinflammatory drug AI-77-C2 has low ulcerogenicity and potent antiulcer activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Structure-activity relationships for the irreversible blockade of nicotinic receptor agonist sites by lophotoxin and congeneric diterpene lactones.

Lophotoxin, a diterpene lactone paralytic toxin from gorgonian corals of the genus Lophogorgia, inhibits [125I]-alpha-toxin binding to surface nicotinic receptors of BC3H-1 cells by irreversible occupation of the primary agonist sites. In contrast, receptor-bearing membrane fragments or detergent-solubilized receptors prepared from BC3H-1 cells are not susceptible to lophotoxin block. Thus, lophotoxin inhibition requires intact cells. However, when intact cells were incubated with lophotoxin, subsequent membrane-fragment preparation or detergent solubilization of the receptors did not diminish lophotoxin occupation of [125I]-alpha-toxin-binding sites, indicating that lophotoxin binds very tightly to nicotinic receptors. These studies further demonstrate that both surface and nonsurface nicotinic receptors of BC3H-1 cells are susceptible to irreversible occupation by lophotoxin, indicating that the lipophilic toxin freely permeates intact cells. We also examined several structural analogs of lophotoxin, one of which was equipotent with lophotoxin for inhibition of [125I]-alpha-toxin binding to intact cells and, notably, also blocked alpha-toxin binding to detergent-extracted receptor. Furthermore, this active analog inhibited [125I]-alpha-toxin binding to receptor-rich membrane fragments prepared from Torpedo electric organ, a preparation in which lophotoxin was inactive. Structure-activity relationships exhibited by the lophotoxin congeners suggest mechanisms for covalent bonding to the receptor by way of a Michael addition or by Schiff base formation.

Animals↗
PubMedDate not supplied

The central action of 1-p-dimethylaminophenyl-5-allyl-5-(beta-hydroxypropyl) barbituric acid and the corresponding lactone.

1-p-dimethylaminophenyl-5-allyl-5-(beta-hydroxypropyl)barbituric acid (NP) and the probably product of its isomerization alpha-(p-dimethylaminophenyl)allophanyl-alpha-allyl-gamma-methylbutyrolactone (MW) was studied. Behavioral experiments carried out on mice and rats showed that both the acid (NP) and the lactone (MW) suppress the reactivity of the central nervous system, and, to some degree, act like tranquilizing agents.

1-Propanol↗
PubMedDate not supplied

o-Hydroxyphenylethanol, a novel lactone ring-opened metabolite of coumarin.

A novel metabolite of coumarin was isolated by high pressure liquid chromatography from in vitro incubations with a rat liver 10,000g postmitochondrial supernatant fraction. Mass spectral analysis and co-chromatography with authentic reference compound was utilized to identify the lactone ring-opened metabolite as o-hydroxyphenylethanol. Formation of this metabolite required both the microsomal and cytosolic fractions and the maximum rate of production was observed in the presence of both NADPH and NADH. Analysis of urine from rats administered [14C]coumarin established that o-hydroxyphenylethanol was formed in vivo and the amount excreted was about 15% of that of o-hydroxyphenylacetic acid, the major urinary metabolite. Precursor-product relationship studies indicated that o-hydroxyphenylethanol was readily converted to o-hydroxyphenylacetic acid both in vivo and in vitro while the reverse reaction was not observed. The relationships of these results to the currently accepted pathway(s) leading to ring-opened coumarin products are discussed.

Animals↗
PubMed1983

Chromatographic separation of 24(R),25-dihydroxyvitamin D3 and 25-hydroxyvitamin D3-26,23-lactone using a cyano-bonded phase packing.

A high-performance liquid chromatographic system is described for the baseline resolution of 25-hydroxyvitamin D3, 24(R),25-dihydroxyvitamin D3 and 25-hydroxyvitamin D3-26,23-lactone, the three principal circulating metabolites of vitamin D3 in the vitamin D-replete animal. The system is based upon a cyano-bonded phase packing and the solvent hexane--isopropanol--methanol (94:5:1). Of particular interest is the strong retention of carbonyl-containing vitamin D metabolites. The new system can be used for unequivocal analysis of vitamin D metabolites in plasma samples from clinical and animal studies and in the separation and identification of renal metabolites generated in vitro.

24,25-Dihydroxyvitamin D 3↗
PubMed1982

Effect of butylated hydroxyanisole, alpha-angelica lactone, and beta-naphthoflavone on benzo(alpha)pyrene:DNA adduct formation in vivo in the forestomach, lung, and liver of mice.

The effects of alpha-angelica lactone (alpha-AL), butylated hydroxyanisole (BHA), and beta-naphthoflavone (beta-NF) on the amount of benzo(alpha)pyrene (BP) metabolite:DNA adducts formed in the forestomach, lung, and liver of ICR/Ha mice were investigated 48 hr after p.o. administration of BP. BP was administered to mice in amounts known to result in BP-induced neoplasia in certain tissues. Analysis of deoxyribonucleosides by high-pressure liquid chromatography showed that several BP metabolite:DNA adducts were formed in each tissue examined. The major identified adduct in each tissue cochromatographed with the (+/-)-7 beta,8 alpha-dihydroxy-9 alpha,10 alpha-epoxy-7,8,9,10-tetrahydrobenzo(alpha)pyrene (BPDEI):deoxyguanosine adduct. The (+/-)-7 beta,8 alpha-dihydroxy-9 beta,10 beta-epoxy-7,8,9,10-tetrahydrobenzo(alpha)pyrene (BPDEII):deoxyguanosine adduct was detected in each of the tissues. As a percentage of total DNA-associated radioactivity, the BPDEI:DNA and BPDEII:DNA adducts accounted for 14% in the forestomach, 39% in the lung, and 3% in the liver. Another adduct, possibly derived from BP:phenol(s), was detected in lung and liver. Early eluting unidentified DNA-associated radioactivity was also present in each of the tissues and accounted for the majority of the radioactivity (88%) in forestomach, 57% in lung, 97% in liver). Although total DNA-associated radioactivity in liver was approximately 15-fold higher than in lung and 5-fold higher than in forestomach, the specific activities of the BPDEI:adducts and of the BPDEII:adducts were approximately the same in these organs. Addition of alpha-AL or BHA to the diet inhibited BPDEI:DNA adduct formation in the forestomach and liver but not in the lung. The effect of beta-NF was not tissue specific; this aryl hydrocarbon hydroxylase inducer decreased markedly (80 to 90%) BPDEI:DNA adduct formation in all three tissues. The radioactivity associated with the early eluting peaks was also reduced when associated with the early eluting peaks was also reduced when alpha-AL, BHA, or beta-NF was fed to the mice. The inhibition of BPDEI:DNA and BPDEII:DNA adduct formation by alpha-AL, BHA, and beta-NF is discussed in relation to similar studies where these compounds inhibited BP-induced neoplasia.

4-Butyrolactone↗
PubMedDate not supplied

[Pharmacological properties of inulicin, a sesquiterpene lactone from Japanese inula].

Inulicin is a sesquiterpene lactone obtained from Inula Japonica L. (Compositae) possesses a fairly wide spectrum of pharmacological action. In doses from 5 to 60 mg/kg it exerts a certain stimulant action on the central nervous system and smooth muscles of the intestine, displays an anti-inflammatory and anti-ulcer activity on pathological models of different genesis, and has capillary-strengthening diuretic properties. When given in low doses, the drug did not affect cardiac activity, while in high doses it might inhibit it. Inulicin is relatively little toxic. The LD50 for mice is 476 mg/kg intraperitoneally and 1330 mg/kg per os.

Animals↗
PubMed1995

Evaluation of the anticancer property of a new alpha-methylene-gamma-lactone derivative of phthalimide.

The anticancer property of a new alpha-methylene-gamma-lactone derivative of phthalimide (2, NSC 640168) was evaluated in two murine ascitic tumors namely Ehrlich ascites carcinoma (EAC) and sarcoma-180 (S-180) by in vivo screenings and in a battery of human tumor cell lines by in vitro screening. It was found that the compound has exhibited marginal to moderate in vivo activity in EAC and S-180, respectively, and significant in vitro cytotoxicity in SF-268, a human CNS tumor cell line. The compound, however, has not reached the criteria of significant anti-HIV activity.

Animals↗
PubMed1994

[Lipoxygenase oxidation of arachidonic acid in murine splenocytes and its modulation by the lactone ganglioside GM3].

The main arachidonic acid metabolites released into the medium by mouse splenocytes have been identified on the basis of chromatographic and spectral studies as well as by mass spectrometry of the derivatives. In the absence or presence of exogenous arachidonic acid mouse splenocytes produce mainly 12-hydroxy-5,8,10,14-eicosatetraenoic and 12,20-dihydroxy-5,8,10,14-eicosatetraenoic acids. Both products are constantly released by intact cells into surrounding media without stimulation by exogenous substrate or other modulators. For the first time it is shown that exogenously added ganglioside GM3 lactone as well as ganglioside GM3 itself can influence the arachidonic acid metabolism in splenocytes.

Animals↗
PubMed1995

[Reductive effect of the sesquiterpenic lactone "Helenalin " and its metallic derivatives in the formation of the estradiol receptor complex in breast tumor tissue].

Chemotherapy for systemic therapy in breast cancer has been widely used, and has been supported by many varied compounds with different origins and different compositions. Nevertheless, all of them produce several side adverse effects which must be taken into account. For this reason we must study new possibilities in which the administered drug acts selectively on the tumour cell without injuring healthy tissue. For studying its effect, a gamma lactone called "Helenaline" and its metalic derivates He-Co, He-Hg and He-Cu were studied, which chemical composition allows them to react with -SH residues present in the tumour cell receptors, which when interspaced by a previous reaction, could modify its structural composition and finally its affinity by the hormone. The inhibition effect for formation of estradiol-receptor complex in breast tumour tissue using Helenaline 12 n M and 126 n M was studied, obtaining 14% and 56% inhibition effect respectively. When He-Co, He-Hg and He-Cu effect was studied, this effect was raised obtaining 11%, 10.5% and 60% with 12 nM and 44.5%, 74.4% and 86% with 126 nM respectively.

Antineoplastic Agents, Phytogenic↗
PubMed1993

Synthesis and antiscorbutic activity of vitamin C analogue: L-threo-hex-2-enaro-1,4-lactone ethyl ester in the guinea pig.

L-threo-hex-2-enaro-1,4-lactone ethyl ester (II) was synthesized by the modified Fisher's esterification and its sodium salt was obtained almost quantitatively. Confirmation of the compound was made by elementary analysis, as well as IR, UV, MS and NMR spectra. The antiscorbutic activity was compared to that of ascorbic acid and the result showed that (II) did not have Vitamin C activity. The results of this investigation indicate that a close relationship exists between the chemical structure of the C-6 position of ascorbic acid analogues and the development of vitamin C activity.

Alkaline Phosphatase↗
PubMed1993

In vitro biological activities of arglabin, a sesquiterpene lactone from the Chinese herb Artemisia myriantha Wall. (Asteraceae).

The immunomodulating properties of arglabin, a sesquiterpene lactone isolated from Artemisia myriantha Wall. (Asteraceae) were investigated using the murine macrophage tumor line J774.1. Arglabin-stimulated macrophages displayed a strong cytotoxic activity and the lowest doses (1.25 micrograms/mL and 0.125 micrograms/mL) induced a significant stimulation of cell mitochondrial metabolism, which correlated with [3H]TdR uptake by J774.1 cells under the same experimental conditions. In addition, the secretion of cytokines involved in host defence mechanisms--IL-1, TNF-alpha, and IL-2--was investigated upon incubation of J774-1 cells with arglabin. Arglabin triggered the production of the three cytokines from J774-1 cells. However, the pattern of cytokine secretion differed to some extent, according to the methodology used for cytokine measurement: either traditional bioassay or specific immunoassay (ELISA). Our data emphasize a possible proliferative effect of arglabin in the traditional bioassays, at least for the highest concentrations used. The results were verified with specific ELISA immunoassays. Using either method, lower concentrations of arglabin (ranging from 12.5 micrograms/mL to 0.125 micrograms/mL) were the most effective in inducing IL-1, TNF-alpha, or IL-2 secretion. In addition, preliminary data on phagocytosis showed that arglabin enhanced the uptake of fluorescent latex beads by J774.1 cells.

Animals↗
PubMed1998

Effects of macrocyclic lactones on ingestion in susceptible and resistant Haemonchus contortus larvae.

The effects of ivermectin and ivermectin aglycone on pharyngeal uptake of a carbohydrate substrate (3H-inulin) were measured in larvae of a macrocyclic lactone (ML)-susceptible isolate and 2 ML-resistant isolates of Haemonchus contortus. The resistant isolates showed a tolerance (in terms of the concentration of compound required to reduce feeding to 50%) toward ivermectin of approximately 4.5- and 9-fold and toward ivermectin aglycone of approximately 14-fold, compared to the susceptible isolate. This indicates that susceptible and resistant isolates can be readily distinguished on the basis of the sensitivity of pharyngeal uptake to MLs. The use of various metabolic inhibitors in this assay system did not reveal the nature of the resistance mechanism. Pretreatment of resistant larvae with inhibitors of multidrug resistance mechanisms (P-glycoprotein and multidrug resistance protein) and detoxification enzymes (monooxygenases, esterases, and glutathione transferases) did not reduce their level of tolerance to the ivermectin aglycone.

Animals↗