Cytotoxic activities of mono and bis Mannich bases derived from acetophenone against Renca and Jurkat cells

Mannich bases of acetophenones have been disclosed to have antitumour and cytotoxic activities. 1-Phenyl-3-dimethylaminopropan-1-one hydrochloride, 1, and related piperidino, 2, and morpholino, 3, derivatives, and compound 4, which is a quaternary form of 1, were synthesized as mono Mannich bases derived from acetophenone. They were converted to corresponding bis Mannich bases, 5-8, to see whether it increases the bioactivity. The biological activity of the compounds was examined by cytotoxicity against mouse renal carcinoma (Renca) and transformed human T-lymphocyte (Jurkat) cell lines. Conversion of mono Mannich bases to corresponding bis Mannich bases remarkably increased the cytotoxicity in most cases. Quaternization procedure also improved the bioactivity in mono derivatives against Jurkat cells. Bis mannich bases 5-7 were found to be more active than 5-fluorouracil (6-23 fold) and melphalan (1.25-5 fold) against Renca cells. Except 2 and 8, the compounds synthesised were found to be more active than 5-fluorouracil (1.2-33 fold) against Jurkat cells.     

Antifungal activity of some mono, bis and quaternary Mannich bases derived from acetophenone

The development of resistance to current antifungal therapeutics drives search for new effective agents. Some Mannich bases have antifungal activity, but no information is available regarding the antifungal activity of acetophenone derived Mannich bases. Mono Mannich bases of acetophenone 1-3 were synthesized and converted into their corresponding bis derivatives, 5-7. Representative quaternary derivatives 4 and 8 were also synthesized. Antifungal activities of the compounds were evaluated using some yeasts and dermatophytes in vitro. Mono Mannich base 3 and quaternary compounds 4 and 8 were found to be 2-16 times more potent than the reference compound amphotericin B against dermatophytes: Trichophyton rubrum, Trichophyton mentagrophytes, and Microsporum canis. Compounds 4 and 8 were also found to be 2 times more effective compared with amphotericin B against the yeast Saccharomyces cerevisiae. Quaternization procedure improved the biological activity dramatically, whereas conversion of mono Mannich bases to corresponding bis derivatives generally did not affect antifungal activity. Our results suggest that acetophenone derived mono Mannich base 3 and quaternary derivatives 4 and 8 may serve as leading compounds for further studies to develop new antifungal agents with their highly potent antifungal activity.     

Synthesis of new arylaminoquinoxalines and their antimalarial activity in mice.

2-Arylaminoquinoxalines were prepared by the condensation of 2-chloroquinoxaline with the appropriate Mannich bases in the presence of HCl. To synthesize the Mannich bases, 4-acetamidophenol was reacted with formaldehyde and dialkylamine to yield 3-[(dialkylamino) methyl]-4-hydroxyacetanilide, followed by hydrolysis. Antimalarial activities of the new arylaminoquinoxalines were evaluated against the rodent malaria parasite Plasmodium yoelii at a dose of 75 mg kg(-1). Three compounds synthesized (2-[3-[(diethylamino) methyl]-4-hydroxyanilino]-quinoxaline dihydrochloride (2b), 2-[3-[(pyrrolidinyl) methyl]-4-hydroxyanilino]-quinoxaline dihydrochloride (2f), and 2-[3-[(piperidinyl) methyl]-4-hydroxyanilino]-quinoxaline dihydrochloride (2g)) showed moderate antimalarial activity.     

Studies on arylfuran derivatives. Part XI. Synthesis, characterisation and biological studies on some Mannich bases carrying 2,4-dichlorophenylfurfural moiety

A series of 3-substituted-4-[5-(2,4-dichlorophenyl)-2-furfurylidine]amino-5-me rcapto-1, 2,4-triazoles (3) are synthesised. Aminomethylation of 3 with formaldehyde and a primary/secondary amine furnished Mannich bases 4 and 5. Both Schiff bases 3 and Mannich bases 4 and 5 are characterised on the basis of IR, 1H NMR, mass spectral data and elemental analysis. All the newly synthesised compounds are tested for their antibacterial activities. Some of the selected compounds are also tested for their fungicidal and herbicidal properties.     

Toxicity of some bis Mannich bases and corresponding piperidinols in the brine shrimp (Artemia salina) bioassay

Some acetophenone-derived bis Mannich bases were synthesized: bis[beta-benzoylethyl]ethylamine hydrochloride (IIa), bis[beta-(p-methylbenzoyl)ethyl]ethylamine hydrochloride (IIb), bis[beta-(p-chlorobenzoyl)ethyl]ethy- lamine hydrochloride (IId), bis[(2-thienylcarbonyl)ethyl]ethylamine hydrochloride (IIe); some corresponding piperidinol derivatives: 3-benzoyl-1-ethyl-4-phenyl-4-piperidinol hydrochloride (IIIa), 1-ethyl-3-(p-methyl- benzoyl)-4-(p-methylphenyl)-4-piperidinol hydrochloride (IIIb), 1-ethyl-3-(p-methoxybenzoyl)-4-(p-methoxy- phenyl)-4-piperidinol hydrochloride (IIIc), 1-ethyl-3-(p-chlorobenzoyl)-4-(p-chlorophenyl)-4-piperidinol hydrochloride (IIId), 1-ethyl-4-(2-thienyl)-3-(2-thienylcarbonyl)-4-piperidinol hydrochloride (IIIe); and some representative quaternary piperidinols: 3-benzoyl-1-ethyl-4-hydroxy-1-methyl-4-phenylpiperidinium iodide (IIIf), 1-ethyl-4-hydroxy-1-methyl-3-(p-methylbenzoyl)-4-(p-methylphenyl)piperidinium iodide (IIIg). Toxicity was tested by the brine shrimp bioassay as an intermediate test before further in vivo animal experiments. Piperidine derivatives were found to be more potent than bis Mannich bases. Quaternary piperidine derivatives IIIf and IIIg and also non-quaternary piperidine derivatives IIIb, IIIe, IIIc and IIId were more toxic than 5-fluorouracil in brine shrimp bioassay. Except for IIe, bis Mannich bases were not effective. Quaternization and conversion of bis Mannich bases to corresponding piperidines improved the toxicity. The lipid solubility of the compounds may not affect the toxicity. From these findings the quaternary piperidine derivatives IIIf and IIIg could be used in further drug development and also for in vivo experiments.     

Synthesis of some Mannich bases with dimethylamine and their hydrazones and evaluation of their cytotoxicity against Jurkat cells

1-Aryl-3-dimethylamino-1-propanone hydrochlorides type mono Mannich bases, D series, and corresponding hydrazone derivatives, K series, were synthesized and their cytotoxicity was tested against Jurkat cells (transformed human T-lymphocytes). The aryl part was changed as phenyl in D1 and K1, 4-methylphenyl in D2 and K2, 4-methoxyphenyl in D3 and K3, 4-hydroxyphenyl in D4 and K4, 4-chlorophenyl in D5 and K5, 3-methoxyphenyl in D6 and K6, 4-fluorophenyl in D7 and K7, 4-bromophenyl in D8 and K8, 3-hydroxyphenyl in D9 and K9, and 2-acetylthiophene in D10 and K10. Of the compounds synthesized, K2, K3, K5, K6, K7, K8, K9, and K10 are reported for the first time. Cytotoxic activities of the D and K series were compared with each other to see alterations in bioactivity depending on the chemical structures in Jurkat cells. Cytotoxicities of the compounds synthesized were also compared with the reference compound, 5-fluorouracil (CAS 148-82-3). Mono Mannich bases, D1 (3.60 times), D2 (4.45 times), D3 (2.46 times), D4 (3.52 times), D5 (5.18 times), D6 (3.20 times), D7 (3.23 times), D8 (3.95 times), D9 (3.36 times) and D10 (3.99 times) had 2.46-5.18 times higher cytotoxic potency than the reference compound 5-fluorouracil against Jurkat cells, while hydrazones K1 (4.92 times), K2 (4.65 times), K3 (6.04 times), K4 (6.34 times), K5 (4.67 times), K6 (5.12 times), K7 (5.39 times), K8 (8.31 times), K9 (4.65 times) and K10 (8.65 times) had 4.65-8.65 times higher cytotoxic potency than the reference compound 5-fluorouracil against the same cell line. On the other hand, hydrazone compounds K1 (1.37 times), K3 (2.46 times), K4 (1.80 times), K6 (1.60 times), K7 (1.67 times), K8 (2.11 times), K9 (1.38 times), and K10 (2.17 times) had 1.37-2.46 times higher cytotoxic potency than their corresponding mono Mannich bases. The results of this study suggest that hydrazones were better compounds compared with the corresponding mono Mannich bases in terms of cytotoxicity, and they may serve as model compounds to develop new cytotoxic agents for further studies.     

Chemical and pharmacological research on derivatives of 1H-naphtho/2,1-b/pyran. V. Behavior of some 1-oxo-3-dialkylamino-1H-naphtho/2,1-b/pyrans substituted in the Mannich reaction]

1-Oxo-3-dialkylamino-1H-naphtho [2,1-b] pyrans substituted in positions 5, 8 or 9 with halogen, alkyl, alkoxycarbonyl, hydroxyl, methoxyl, by the Mannich reaction will yield the corresponding 2-dialkylamino-methyl derivatives when a correct amount of acetic acid is present in the reaction mixture. Excess acid will give rise to the formation of substituted 1-oxo-2-[(1'-oxy-3'-oxo-3'H-naphtho [2',1'-b']pyran-2'-yl)methyl]-3-dialkylamino-1H-naphtho [2,1-b] pyrans when the group in the 3 position is dimethylamino or N-pyrrolidyl. In a few cases Mannich bases were accompanied by an appreciable quantity of substituted 2,2'-methylenebis (1-oxo-3-dialkylamino-1H-naphtho-E12,1-B] PYRANS). Therefore, these compounds were synthesized with excellent yields by treating Mannich bases with acetic anhydride. The behavior of some compounds in the acidic hydrolysis was also considered. Some Mannich bases of 1-oxo-3-dialkylamino-9 methoxy-1H-naphtho-[2,1-b] pyrans showed a more specific anticonvulsant activity than the parent compounds.     

Antifungal evaluation of bis Mannich bases derived from acetophenones and their corresponding piperidinols and stability studies

The development of resistance to current antifungal therapeutics drives the search for effective new agents. The fact that some acetophenone-derived Mannich bases had shown antifungal activities in our previous studies led us to design and synthesize acetophenone-derived bis Mannich bases, B1-B5, bis(beta-aroylethyl)methylamine hydrochlorides, to evaluate their antifungal activity. These bis Mannich bases were then converted to the corresponding piperidinols, C1-C5, which are structural isomers of bis derivatives, 3-aroyl-4-aryl-1-methyl-4-piperidinol hydrochlorides, to see alterations in biological activity. A stability study of B1 and Cl was also carried out to estimate whether they alkylate the thiols. All compounds studied have shown antifungal activity, especially against dermatophytes (Trichophyton rubrum, Trichophyton mentagrophytes, Trichophyton tonsurans, and Microsporum canis), in the concentration range studied (2-128 microng/ml). The activity was especially apparent against T. tonsurans. All compounds had at least equal antifungal activity compared with the reference compound amphotericin-B against T. tonsurans. Bis Mannich bases were generally found to be more potent compounds than their structural isomer piperidinols. The results of our stability studies suggest that thiol alkylation may contribute to the antifungal activity of the Mannich bases synthesized. Even though all compounds showed antifungal activity against dermatophytes, bis Mannich bases B1, B2, B4, and B5 appear to have potential for developing novel antifungal agents against dermatophytes.     

Synthesis,SAR Study and Evaluation of Mannich and Schiff Bases of Pyrazol-5(4H)-one Moiety Containing 3-(Hydrazinyl)-2-phenylquinazolin-4(3H)-one

In the present investigation, a series of 12 Mannich bases (QP1-12) and 5 Schiff bases (QSP1-5) of pyrazol-5(4H)-one moiety containing 3-(hydrazinyl)-2-phenylquinazolin-4(3H)-one has been synthesized and characterized by physicochemical as well as spectral means. The synthesized Mannich and Schiff bases were screened for their preliminary antimicrobial activity against Gram-positive and Gram-negative bacterial as well as fungal strains by the determination of zone of inhibition. Mannich bases (QP1-12) were found to be more potent antibacterial agents against Gram-positive bacteria, whereas Schiff bases (QSP1-5) were more potent against Gram-negative bacteria and fungi. Minimum inhibitory concentration result demonstrated that Mannich base compound (QP7) having ortho -OH and para -COOH group showed some improvement in antibacterial activity (minimum inhibitory concentration of 48.88×10⁻³ μM/ml) among the tested Gram-positive organisms and it also exhibit minimum inhibitory concentration of value of 12.22×10⁻³ μM/ml for Klebsiella pneumoniae. The antitubercular activity of synthesized compounds against Mycobacterium tuberculosis (H₃₇Rv) was determined using microplate alamar blue assay. Compound QP11 showed appreciable antitubercular activity (minimum inhibitory concentration of 6.49×10⁻³ μM/ml) which was more active than the standard drugs, ethambutol (minimum inhibitory concentration of 7.60×10⁻³ μM/ml) and ciprofloxacin (9.4×10⁻³ μM/ml). Compounds QP11, QP9, QSP1, QSP2, and QSP5 have good selective index and may be selected as a lead compound for the development of novel antitubercular agents.     

Synthesis, characterization and in vitro cytotoxic properties of some new Schiff and Mannich bases in Hep G2 cells

A series of 5-substituted-4-amino-3-mercapto-1,2,4-triazoles were synthesized and were treated with various 3-substituted pyrazole aldehydes to obtain a series of new Schiff bases (3a–l). Few of the selected Schiff bases were converted into Mannich bases by reaction with diphenylamine/morpholine in presence of formaldehyde in ethanol media (4a–e, 5a–e). These newly synthesized compounds were characterized by elemental analysis, IR, NMR and mass spectrometry studies. A comparative study on the cytotoxic activities of few selected Schiff and Mannich bases was done in HepG2 cells using MTT assay. Few of the screened Schiff bases, 3a, 3d, 3e, 3g and 3h showed dose dependent cytotoxic activity, 3a being the most potent with an IC₅₀ value of 0.018 g/l comparable to the standard drug doxorubicin. Among the Mannich bases, 5b was the most active with an IC₅₀ value of 0.034 g/l. The Schiff bases were found to be more active, when compared to Mannich bases derived from them. The morpholine derived Mannich bases were more potent than those obtained from diphenyl amine.     

(Aminomethyl)aryloxy]acetic acid esters. A new class of high-ceiling diuretics. 1. Effects of nitrogen and aromatic nuclear substitution

A series of Mannich bases and aminomethyl derivatives of ethyl [2,3-dichloro-4-(4-hydroxybenzoyl)phenoxy]acetate were synthesized and tested for saluretic and diuretic activities. The effects of nitrogen and aromatic nuclear substitution, reorientation of the aminomethyl group relative to that of the phenolic hydroxyl group, and replacement of either the phenolic hydroxyl or the aminomethyl group by other functional groups are described. Ethyl [2,3-dichloro-4-[3-(aminomethyl)-4-hydroxybenzoyl]phenoxy]acetate (27) was found to be a very potent, high-ceiling diuretic.     

咪唑并［2,1-b］［1,3,4］噻二唑及杂环氨曼尼希碱盐酸盐的合成及抗菌活性

为了进一步优化由噻二唑核稠合的水溶性稠杂环化合物的合成方法及抗菌活性，本文用2-(4-甲氧苯基)-5-氨基-1,3,4-噻二唑(2)与α-氯代-4-氯苯乙酮(3)缩合得6-(4-氯苯基)-2-(4-甲氧苯基)-咪唑并［2,1-b］［1,3,4］噻二唑(4)，4与取代哌嗪发生亲核取代反应得到6-(4-取代哌嗪-1-苯基)-2-(4-甲氧苯基)-咪唑并［2,1-b］-［1,3,4］噻二唑(5)，5与杂环氨进行曼尼希反应并与盐酸成盐得目标化合物6-(4-取代哌嗪-1-苯基)-2-(4-甲氧苯基)-5-杂环氨基甲基-咪唑并［2,1-b］［1,3,4］噻二唑盐酸盐(1)。用试管二倍稀释法评价了15个新化合物的体外抗菌活性，结果表明，随着极性基团的引入，抗菌活性显著提高，提示该类化合物的结构修饰值得进一步研究。     

4-色满酮Mannich碱类化合物的合成及其抗炎活性

目的设计合成一些4-色满酮Mannich类化合物,并且考察其抗炎活性.方法以取代的4-色满酮为原料,经过Mannich反应合成4-色满酮Mannich碱类化合物,并测定了目标化合物的抗炎活性.结果合成了17种4-色满酮Mannich碱类化合物,并经元素分析、红外光谱、核磁共振氢谱确证这些化合物的结构,药理活性筛选结果表明:大多数化合物具有显著的抗炎活性.     

2-羟基-3-甲基-环戊-2-烯酮 Mannich 碱衍生物的合成及其抗癌活性

以２羟基３甲基环戊２烯酮为母体化合物设计合成了１０个双Ｍａｎｎｉｃｈ碱衍生物，４个单Ｍａｎｎｉｃｈ碱衍生物．体外细胞毒性试验和ＤＮＡ合成抑制试验结果表明：脂肪胺、杂环胺双Ｍａｎｎｉｃｈ碱活性较强，优于阳性对照药５Ｆｕ；二甲胺单Ｍａｎｎｉｃｈ碱活性较强，而芳胺类Ｍａｎｎｉｃｈ碱活性很弱，ＩＣ５０值大于５０ｍｇ／Ｌ．     

抗疟新药的研究:笨骈[g]喹嘛氨基酚双Mannich碱类化合物的合成

前文报道了一类具有对-氨基酚双Mannich碱的杂环类化合物,其中以4-[3,5-双(次甲基四氢吡咯基)-4-羟基苯胺基]苯骈[g]喹啉(I)对鼠伯氏疟原虫的作用最显著;鼠疟试验,未发现它与氯喹有交叉抗药性。这个化合物的母核是苯骈[g]喹啉,它与目前国外正在研究的一种抗疟新药dabequing的母核类同,前者为苯骈[g]喹啉环4位上接有双Mannich碱     

Evaluation of antimicrobial activities of several mannich bases and their derivatives

The aim of this study was to evaluate the antimicrobial activities of several Mannich bases and their derivatives against pathogenic bacteria and fungi. 3-Dimethylamino-1-phenyl-1-propanone hydrochloride (Ig1) as mono-Mannich base, bis(beta-aroylethyl)methylamine hydrochlorides (B1, B5) as bis-Mannich bases, 3-aroyl-4-aryl-1-methyl-4-piperidinol hydrochlorides (C1, C5) as piperidinol derivatives, which are structural isomers of bis-Mannich bases, N,N'-Bis(3-dimethylamino-1-phenylpropylidene)hydra zine dihydrochlorides (D1) as azine derivative of mono-Mannich base Ig1, and some representative quaternary derivatives (Ig4 and C6), which are quaternary derivatives of Ig1 and C1, respectively, have been synthesized. Aryl parts were phenyl in B1 and C1, and 2-thienyl in B5 and C5. Bis-Mannich bases and quaternary Mannich bases were found to be effective antifungal derivatives. Quaternary mono-Mannich base Ig4 has shown twice the amount of higher antifungal potency against the human pathogenic fungus Microsporum canis compared with the reference drug amphotericin-B and it had equal potency against many other fungi species pathogenic in humans and plants. Ig4 was effective against Staphylococcus aureus among the bacteria tested. Preparation of bis-Mannich bases and qua ternization procedure seemed suitable chemical modifications to prepare effective antifungal compounds. Especially quaternary derivatives Ig4, and to some extent C6, seem to be model compounds to develop new antimicrobial agents for further studies.     

Mannich-Basen von Hydroxy-indolen, 2. Mitt

Mannich Bases of Hydroxyindoles, II¹ The 2-hydroxy-cyclohept[b]indolones 2a-c react with bis(dimethylamino)methane to yield the phenol Mannich bases 3a-c . The 1,3-benzoxazine derivatives 5a-c are synthesized from 2a,b,d and hexahydrotriethyl-1,3,5-triazine 4 . Reaction of 6-hydroxyindole 6 with triazine 4 yields benzoxazine 7 .     

Effects of Mannich bases on cellular glutathione and related enzymes of Jurkat cells in culture conditions.

Jurkat cells were exposed to representative acetophenone-derived mono Mannich bases 2 and 3 and also cyclic Mannich base C1 in culture conditions to see the alterations in the most abundant cellular thiol, glutathione and also some of the enzymes in its metabolic pathway. Jurkat cells were exposed to the compounds for 24 h in cell culture medium with fetal bovine serum (1%) at 37 degrees C under a humidified atmosphere of 95% air and 5% CO2. Mannich bases generally increased total glutathione level (123-151% of control). Glutathione S-transferase (GST) activity also increased (150-363% of control), while glutathione disulfide reductase (GRD) activity was not affected. The increase in cellular glutathione level may possibly result from de novo glutathione synthesis. The consumption of the glutathione due to alkylation by Mannich bases might have stimulated the enzymes in the gamma-glutamyl cycle in our experimental design, where the cells had nutrients and time to react with their feedback mechanisms. A remarkable increase in GST activity might be a compensatory up-regulation to detoxify Mannich bases by conjugating them with cellular thiols.     

2-Phenylpyrroles as conformationally restricted benzamide analogues. A new class of potential antipsychotics. 2

A series of 2-phenylpyrrole Mannich bases was synthesized and screened in pharmacological models for antipsychotic activity and extrapyramidal effects. Structure modifications of 5-(4-fluorophenyl)-2-[[4-(2-methoxyphenyl)-1-piperazinyl]methyl]pyrrole (1), the prototype of a new class of sodium-independent atypical dopamine D-2 antagonists, resulted in 2-[[4-(7-benzofuranyl)-1-piperazinyl]methyl]-5-(4-fluorophenyl)pyrrole (15), which was an even more potent and selective D-2 antagonist than the parent compound. The excellent oral activity in the apomorphine-induced climbing behavior and the conditioned avoidance response tests and the absence of catalepsy make this compound particularly promising as a potential antipsychotic with a low propensity to induce acute extrapyramidal side effects.     

Synthesis and anti-HIV activity of nevirapine prodrugs

The synthesis, in vitro anti-HIV activity and stability studies of the N-Mannich bases of nevirapine are reported. Among the synthesized compounds, 5-{[4-(4-chlorophenyl)piperazin-1 -yl]methyl}-1-cyclopropyl-4-methyl-5,11-dihydro-6H-dipyrido[2,3-e:3',2'-b][1,4]diazepin-6-one (3) was found to be the most potent compound with EC50 of 0.0159 microM against HIV-1 replication and CC50 of >1000 microM against CEM cell lines with selectivity index of >62893. Compound 3 was five times more active than nevirapine (EC50 of 0.09 microM). In vitro hydrolysis of the Mannich bases in phosphate buffer (pH 7.4) indicated that these agents were relatively stable with t1/2 ranging from 15 to 240 min.