Hypolipidemic Agents of Phthalimide Derivatives 6. Effects of Aromatic vs. Non-Aromatic Imides

A number of substituted phthalimide, 1, 8-naphthalimide, succinimide and glutarimide derivatives demonstrated significant hypolipidemic activity at 20 mg/kg/ day, I.P. after 16 days dosing. The N-(n-pentyl) succinimide proved to be the most potent analogue of the new compounds, lowering serum triglyceride levels 51 % and serum cholesterol 47 % after 16 days dosing in mice. For the N-substituted derivatives, i. e., n-butyl, butanone, and propionic acid, of these four cyclic imides, there appeared to be no obvious trend in ability to reduce serum lipid levels. In general, the 1,8-naphthalimide and glutarimide derivatives appeared to be less active than phthalimide and succinimide. However, the -phenylsuccinimide afforded less activity than the -phenylglutarimide. Most of the derivatives at 20mg/kg/day demonstrated improved activity over clofibrate at 150mg/kg/day.     

Hypolipidemic activity of phthalimide derivatives. 3. A comparison of phthalimide and 1,2-benzisothiazolin-3-one 1,1-dioxide derivatives to phthalimidine and 1,2-benzisothiazoline 1,1-dioxide congeners

Previously it has been observed that N-substituted phthalimide derivatives with chain lengths of four carbon or oxygen atoms showed potent hypolipidemic activity in rodents at 20 (mg/kg)/day ip. The 1,2-benzisothiazolin-3-one 1,1-dioxide (saccharin) nucleus, itself, had also been observed to be active at the same dose. An investigation was undertaken to examine a series of 1,2-benzisothiazolin-3-one 1,1-dioxide analogues for their hypolipidemic activity in mice and to compare them to their respective phthalimide congeners. In addition, a series of 1,2-benzisothiazoline 1,1-dioxide and phthalimidine analogues was prepared, and their hypolipidemic activity was compared to the phthalimide analogues. These studies show that the respective congeners of 1,2-benzisothiazolin-3-one 1,1-dioxide compared favorably to phthalimide congeners in reducing serum triglyceride and cholesterol levels in male CF1 mice at 20 (mg/kg)/day ip. Of the saccharin derivatives, 3-oxo-1,2-benzisothiazoline-2-propionic acid 1,1-dioxide was the most effective in lowering serum cholesterol levels by 53% after 16 days dosing and 3-oxo-1,2-benzisothiazoline-2-valeric acid 1,1-dioxide lowered serum triglycerides 56% after 14 days dosing. The 1,2-benzisothiazoline 1,1-dioxide and phthalimidine compounds were less active as hypolipidemic agents than their 1,2-benzisothiazolin-3-one 1,1-dioxide and phthalimide analogues, respectively.     

Synthesis of new cyclic imides derivatives with potential hypolipidemic activity

Abstract  

Certain new nitrogen-substituted derivatives of cyclic imides phthalimide (a), 1,8-naphthalimide (b), and diphenimide (c), were synthesized aiming to obtain potent hypolipidemic agents. Thus, 2-(N-imido) propanoic acids, 2-(N-phthalimido)-2-methylpropionic acid, and their ethyl esters were synthesized (Target derivative A). Also their corresponding N-substituted-2-(N-imido) propionamides and 2-(N-phthalimido)-2-methylpropionamides were prepared (Target derivative B). In addition, N-phthalimidomethyleneoxy acetate was prepared. Some of the newly prepared compounds were subjected to 3D studies and were found to be superimposed on Clofibrate, which is the first generation of fibrate drugs. The preliminary evaluation of hypolipidemic activity of the newly prepared compounds against triton WR-1339-induced hyperlipidemia in rat showed that several derivatives have demonstrated significant lowering of serum total cholesterol and triglyceride levels at dose of 150 mg/kg/i.p. comparing with Fenofibrate which is one of the second generations of fibrate drugs.     

Effects of imide analogs on enzymes required for cholesterol and fatty acid synthesis

Twelve imide analogs were examined for their ability to lower serum cholesterol and triglyceride levels in mice. Potent activity was observed for compounds containing a phthalimide or saccharin ring structure. The ability to lower serum cholesterol appears to be related to the ability to suppress acetyl-CoA synthetase activity. The availability of acetyl-CoA in the cytoplasm is a key regulatory component for cholesterol and fatty acid synthesis. The capacity to reduce serum triglycerides was related directly to the ability of the compound to inhibit acetyl-CoA carboxylase activity, the regulatory enzyme of fatty acid synthesis.     

Computer assisted structure-activity correlations. Evaluation of benzo(de)isoqinoline-1,3-diones and related compounds as antitumor agents

Computer assisted evaluations of benzo(de)isoquinoline-1,3-diones and related compounds screened for antitumor activity against P388 lymphocytic leukemia and L1210 lymphoid leukemia are presented. Two important features necessary for good anticancer activity are the nature of the imide side-chain and the type of substituent on the aromatic portion. Based on these considerations 1H-benzo(de)isoquinoline-1,3(2H)dione,5-amino-2-(2-dimethyl-aminoethyl) (NSC 308847) has been selected for preclinical toxicology studies.     

Hypolipidemic activity of indan-1,3-dione derivatives in rodents

A series of 2-substituted indan-1,3-dione derivatives, including alkyl (C-1-C-5), mono- and disubstituted phenyl, and other 2-aryl derivatives, were tested for hypolipidemic activity of CF1 male mice at 20 mg/kg per day. These derivatives reduced both serum cholesterol and triglycerides after 16 days of administration intraperitoneally. 2-(4-Methoxyphenyl)indan-1,3-dione was one of the more active compounds with 41% reduction of serum cholesterol and 58% reduction of serum triglyceride levels on day 16. This activity was confirmed in the rat after oral administration. 2-(2-Methylphenyl)- and 2-(4-chlorophenyl)indan-1,3-dione were effective in reducing serum triglyceride levels 58% and 53%, respectively, in mice. Serum cholesterol on day 16 was effectively reduced 46% by 2-(2,4-dimethylphenyl)indan-1,3-dione. The indan-1,3-dione derivatives were more effective than clofibrate in lowering lipid levels in mice. A more detailed study on the effects of 2-(4-methoxyphenyl)indan-1,3-dione demonstrated that key enzymes in the de novo synthesis of lipids were inhibited by the drug lowering tissue levels of lipids but raising those in the feces. The alterations in lipid content of rat lipoprotein fractions by the drug appeared favorable.     

Synthesis, hypolipidemic, and anti-inflammatory activities of arylphthalimides

Phthalimide and some N-substituted cyclic imides may be potent hypolipidemic agents, capable of reducing plasma cholesterol, and triglyceride levels. In this work, N-phenylphthalimide (5a), N-(2-nitrophenyl)phthalimide (5b), N-(3-nitrophenyl)phthalimide (5c), N-(4-nitrophenyl)phthalimide (5d), N-(4-bromophenyl)phthalimide (5e), N-(4-amidaphenyl)phthalimide (5f), N-(4-methylthiophenyl)phthalimide (5g), and N-(4-chlorophenyl)phthalimide (5h) were synthesized, and their effects on reducing lipid levels and as acute antiinflammatory agents in 3-month-old male Swiss mice were compared with phthalimide. To access their safety, the drugs were administered to determine the acute toxicity (LD₅₀ value). In addition, the acute anti-inflammatory activity was evaluated via carrageenan-induced edema; and the effective dose was determined for compounds that showed the best anti-inflammatory activity in comparison with ibuprofen. The compound (5g) proved to be a more active hypolipidemic compound than phthalimide, at a dose level of 20 mg kg^?1 day^?1. The derivative (5g) reduced the plasmatic triglycerides and cholesterol levels by 54 and 41 %, respectively, while the percentages of reduction were 43 and 30 %, respectively, with phthalimide. The hypocholesterolemic and hypotriglyceridemic activities of the (5g) derivative were similar to that obtained with the commercially available drug, pravastatin. The anti-inflammatory activity of compound (5b) was similar to ibuprofen and aspirin at 250 mg kg^?1. Taken together, it was demonstrated that the new phthalimide derivatives were able to increase HDL-cholesterol levels, along with reducing the cholesterol and triglyceride levels and carrageenan-induced edema in mice. Therefore, they may offer promise in the future as new hypolipidemic and anti-inflammatory agents.     

Synthesis of ethyl 2-(4-chlorophenyl)-5-(2-furyl)-4-oxazoleacetate, a hypolipidemic agent, and related compounds

A series of 2-aryl and 2-alkyl derivatives of 5-furyl-4-oxazoleacetic acid and their homologues having alkyl groups at the alpha-position of the acids were synthesized and evaluated for their hypolipidemic activities in Sprague-Dawley rats. On the basis of the structure-activity relationships and subacute toxicities, ethyl 2-(4-chlorophenyl)-5-(2-furyl)-4-oxazoleacetate (35) was selected as a candidate compound for development. Compound 35 reduced serum cholesterol and triglyceride levels by 23% and 35%, respectively, at a dose of 0.05% in a diet in normal rats, and it was about 10 times more active in hereditary hyperlipidemic rats (THLR/1) than in normal rats. Compound 35 inhibited platelet aggregation in vitro and also normalized hyperaggregability of hyperlipidemic plasma platelet ex vivo.     

Antihyperlipidemic activity of saccharin analogues in rodents

Saccharin analogues were observed to be potent antihyperlipidemic agents at 20 mg/kg/day in rodents, significantly reducing both serum cholesterol and triglyceride levels in both normal and atherogenic mice. The saccharin analogues suppressed in vitro and in vivo liver enzymatic activity of acetyl-CoA synthetase, citrate lyase, and mitochondrial citrate exchange leading to a reduction of available cytoplasmic acetyl-CoA, which is required for the synthesis of cholesterol and fatty acids. Liver acetyl-CoA carboxylase, phosphatidate phosphohydralase, and glycerol-3-phosphate acyl transferase activities were markedly reduced by the saccharin analogues. Suppression of these enzymes would lead to a reduction of triglyceride synthesis. The saccharin analogues accelerated bile excretion of cholesterol metabolites and increased the fecal excretion of the cholesterol, triglycerides, neutral lipids, and phospholipids. The liver and plasma lipoprotein lipid content (including cholesterol, triglycerides, and neutral lipids) was markedly reduced by the saccharin analogues, whereas phospholipid content was elevated. The reduction of lipid content of serum chylomicron, very low-density, low-density, and high-density lipoprotein fractions by the saccharin analogues indicates that these agents may be useful in controlling hyperlipidemic diseases where specific lipoprotein fractions are elevated.     

Synthesis of New Nonclassical Acridines,Quinolines, and Quinazolines Derived from Dimedone for Biological Evaluation

New nonclassical acridines, quinolines, and quinazolines were prepared starting from cyclic β‐diketones, namely dimedone, through application of Hantzsch addition, Michael addition, and Mannich reactions, respectively. The antimicrobial activity revealed that decahydroacridin‐1,8‐dione 2e bearing a 3‐nitrophenyl group and hexahydroquinoline 4e having a 2,4‐dichlorophenyl moiety were the most active compounds against both Gram‐positive and ‐negative bacteria based upon using the disc diffusion method. Cytotoxic activity studies for decahydroacridin‐1,8‐diones 2a–e against liver carcinoma cells (HepG₂) using the MTT cell viability assay revealed that decahydroacridin‐1,8‐dione bearing a 4‐methylphenyl moiety 2d showed a higher cytotoxic activity (IC₅₀ = 4.42 µg/mL) than the other derivatives.     

Hypolipidemic Activity and Toxicity of 3-Methoxy-N,N′-diaminophthalamide in Rodents

3-Methoxy-N,N′-diaminophthalamide was observed to be a potent hypolipidemic agent in rodents. Serum cholesterol and triglyceride levels in rats were significantly reduced as were lipid contents of the liver, small intestine, and aorta wall. VLDL and LDL cholesterol levels were significantly reduced. Unfortunately, HDL cholesterol levels were also markedly reduced. Furthermore, acute toxicity studies showed that the compound caused marked increases in serum CP kinase activity with doses of 40 and 100 mg/kg/day in mice. This is not a property of the 2,3-dihydrophthalazine-1,4-dione, the resultant product of the N,N′-diaminophthalamides. Apparently, closing the ring results in a safer compound with elevations in HDL cholesterol levels, a desirable characteristic in effective hypolipidemic agents.     

Selective irreversible inhibitors of aldose reductase.

A series of 5-substituted-1,3-dioxo-1H-benz[de]isoquinoline-2(3H)-acetic acid analogues have been examined as irreversible inhibitors of aldose reductase. The 5-alpha-bromoacetamide and 5-alpha-iodoacetamide analogues 5 and 6 gave irreversible inhibition of aldose reductase while the 5-alpha-chloroacetamide analogue 3 did not show this type of inhibition. Protection studies indicate that irreversible inhibitions are occurring at the inhibitor binding site. Comparative irreversible inhibition studies with rat lens aldose reductase (RLAR) and rat kidney aldehyde reductase (RKALR) indicate that 5-alpha-haloacetamide analogues 5 and 6 are much more effective inhibitors of RLAR.     

The Effects of Phthalimide and Saccharin Derivatives on Low-Density Lipoprotein (LDL) and High-Density Lipoprotein (HDL) Receptor Activity and Related Enzyme Activities

The hypolipidemic agents, phthalimide, saccharin, o-(N-phthalimido) acetophenone, N-(p-chlorobenzoyl) sulfamate, and o-chlorobenzylsulfonamide affected low-density lipoprotein (LDL) and high-density lipoprotein (HDL) receptor activity and lipoprotein degradation. In isolated rat hepatocytes, rat aorta foam cells, and human fibroblasts, LDL receptor activity, which is dependent on apo-B and -E, was inhibited by the drugs in a dose-dependent manner. LDL degradation was accelerated in the hepatocytes, while it was inhibited in aorta cells and fibroblasts. The drugs enhanced HDL receptor activity, dependent on apo-E and -Al, and HDL degradation in the hepatocytes, whereas in fibroblasts and aorta cells HDL receptor binding and degradation were suppressed. In parallel, activities of acyl Co A acyl transferase, sn-glycerol-3-phosphate acyl transferase, and heparin-induced lipoprotein lipase decreased and activities of HMG–CoA reductase and cholesterol oleate-ester hydrolase increased. In fibroblasts the presence of drugs enhanced HDL binding of intracellular cholesterol. In vivo studies demonstrated that phthalimide and saccharin treatment enhanced the clearance of HDL and decreased the clearance of LDL from the serum of rats. The results suggest that the mode of action of the agents is to modulate the lipoprotein receptor and, thereby, the clearance of lipids from peripheral tissue as part of the hypolipidemic activity.     

Succinimide and saccharin-based enzyme-activated inhibitors of serine proteases.

The inhibition of human leukocyte elastase (HLE), and other serine proteases, by succinimide and saccharin-based compounds is reviewed. The succinimide compounds are unique in that the inactivating species is generated within the enzyme active site via a molecular rearrangement. The related saccharin derivatives also inactivate serine proteases by an enzyme-activated mechanism. Those factors effecting the potency, selectivity and stability of these important classes of inhibitor are discussed.     

The Hypolipidemic Activity of l-N-3-Methylphthalimido-butan-3-semicarbazone in Rodents

l-N-(3-Methylphthalimido)butan-3-one semicarbazone demonstrated potent hypolipidemic activity in normal rats and mice and hyperlipidemic diet-induced mice. The compound decreased tissue lipid levels and increased the fecal excretion of cholesterol and triglycerides. After 2 weeks of administration, serum lipoprotein levels were modulated so that very low-density lipoprotein (VLDL) and low-density lipoprotein (LDL) cholesterol concentrations were reduced and high-density lipoprotein (HDL) cholesterol concentrations were elevated to levels unprecedented by the cyclic imide derivatives previously tested. The VLDL triglyceride content was also reduced. Hepatic in vitro enzymatic studies demonstrated that the compound suppressed the activity of enzymes in the early synthesis of fatty acids and cholesterol and the regulatory enzymes for the de novo synthesis of triglycerides.     

Pharmacokinetics and metabolism of the antitumor drug amonafide (NSC-308847) in humans

Pharmacokinetics and urinary excretion of Amonafide (5-amino-2-[2-(dimethylamine)ethyl]-1H-benz[de]isoquinoline-1,3-(2H)- dione) were examined in seven patients who were administered 400 mg/m2 of drug as a 30-min infusion on a daily schedule for 5 consecutive days. Amonafide concentrations in plasma and urine were determined using reversed phase HPLC. Amonafide was eliminated from plasma with a terminal half-life of 3.5 hr. Renal excretion accounted for 23% of the administered dose. Amonafide pharmacokinetic parameters after the initial dose (day 1) were similar to those calculated after the fifth daily dose. Amonafide undergoes a significant amount of metabolism and eight urinary metabolites have been identified using a thermospray liquid chromatography-mass spectrometry (LC/MS) technique. Various N-acetylated species appear to be the major metabolites, although no evidence of N-acetylation was found in urine obtained from two patients. Two of the primary metabolites, the N(N5)-acetyl and N'(N1)-oxide metabolites of Amonafide, were tested in vitro for cytotoxicity against P388 murine leukemia cells. In this test system, the N-acetyl metabolite was observed to be only slightly less cytotoxic than the parent compound. The N'-oxide of Amonafide, however, proved to be inactive. These results are discussed together with the pharmacokinetic and metabolism data of this new investigational antitumor drug.     

Hypolipidemic activity of N,N-dimethyl-n-octadecylamine borane in rodents

N,N-Dimethyl-n-octadecylamine borane proved to be an effective hypolipidemic agent in rodents, lowering both serum cholesterol and triglyceride levels by greater than 40% after 16 d of administration. The agent lowered serum lipid levels by inhibiting the enzymatic activity of rate-limiting enzymes of both de novo cholesterol and triglyceride pathways in the liver. The reduction led to lower levels of lipids in the liver and small intestine tissues, with a reduction of the cholesterol and triglyceride levels of the serum low density lipoprotein (LDL) fraction. Concurrently, the cholesterol level of high density lipoproteins (HDL) was significantly elevated in rats after 14 d of treatment. The drug caused an increased rate of cholesterol clearance from the body, essentially via the feces. The ability of the agent to modulate the cholesterol levels of LDL and HDL fractions suggests that the agent should be an effective agent for the treatment of hyperlipidemic states in humans.     

Hypolipidemic activity of 5-aryl-3-methylvaleric acid derivatives

Several 5-aryl-3-methylvaleric acid derivatives have been shown to be more potent hypolipidemic agents than the previously reported 5-(4-biphenylyl)-3-methylvaleric acid (1). The most active compound in this series was 5-(4-phenylsulfonylphenyl)-3-methylvaleric acid (10) which lowered serum cholesterol levels 45% and serum triglyceride levels 60% in normal rats. Significant lowering of the serum triglyceride levels was the predominant effect noted with most of the compounds tested.     

Synthesis and Hypolipidemic Activity of 3-Imino-l-oxoisoindolines in Rodents

A series of substituted 3-imino-l-oxoisoindolines derivatives demonstrated significant hypolipidemic activity, lowering both serum cholesterol and triglycerides levels after 16 days of dosing at 20 mg/kg/ day ip in CF₁ mice. 2-Butyl-3-butylimino-l-oxoisoindoline lowered serum cholesterol levels 52% and serum triglyceride 42%. 2-Pentyl-3-imino-l-oxoisoindoline lowered serum cholesterol levels 42% and serum triglyceride 61%. These derivatives resulted in better activity than the parent compound, 3-imino-1-oxoisoindoline. These studies showed that compounds with N-alkyl substitution of nitrogen atoms in the ring and outside the ring possessed potent hypolipidemic activity at the low dose of 20 mg/kg/day ip in normolipidemic CF₁ mice. Studies with 2-butyl-3-butylimino-l-oxoisoinodine in rats showed that serum cholesterol was reduced 60% and serum triglyceride 43% after 14 days of dosing at 20 mg/kg/day, orally. Treatment with this agent lowered lipid levels in the liver and aorta tissue, with increases in lipid levels in the small intestine tissue. Higher levels of cholesterol and phospholipids were excreted in the feces of treated animals compared to the control. Cholesterol levels of the very low-density lipoprotein (VLDL) and high-density lipoprotein (HDL) fractions were reduced, whereas the HDL cholesterol levels were elevated significantly. This ratio of low-density lipoprotein (LDL) cholesterol:HDL cholesterol levels suggests that the agent may be effective in treating hyperlipidemic states in humans.     

Bicyclol, a synthetic dibenzocyclooctadiene derivative, decreases hepatic lipids but increases serum triglyceride level in normal and hypercholesterolaemic mice

Bicyclol is used for the treatment of chronic hepatitis B in China. In this study, the effects of bicyclol (100 or 300 mg kg(-1), p.o.) on serum and liver lipid contents were investigated in both normal and experimentally induced hypercholesterolaemic mice. Hypercholesterolaemia was induced by either oral administration of cholesterol/bile salt or feeding a diet containing lard/cholesterol. Daily administration of bicyclol for 7 days dose-dependently increased the serum triglyceride level (29-80%) but slightly decreased the hepatic total cholesterol level (12-17%) in normal mice. Co-administration of bicyclol with cholesterol/bile salt decreased the hepatic triglyceride and total cholesterol levels (7-15% and 25-31%, respectively), when compared with the drug-untreated and cholesterol/bile salt-treated group. Bicyclol treatment for 7 days decreased hepatic triglyceride (5-76%) and total cholesterol (5-48%) levels in mice fed with high-fat/cholesterol diet. In contrast, bicyclol treatment increased the serum triglyceride level (18-77%) in mice treated with cholesterol/bile salt or fed with high-fat/cholesterol diet. Bicyclol treatment also caused an increase in hepatic index of normal and hypercholesterolaemic mice (3-32%). The results indicate that bicyclol treatment can invariably decrease hepatic lipid levels and increase serum triglyceride levels in normal and hypercholesterolaemic mice.