The design and cytotoxic evaluation of some 1-aryl-3-isopropylamino-1-propanone hydrochlorides towards human Huh-7 hepatoma cells

Synthesis of mono Mannich bases of 2-(4-hydroxybenzylidene)-2,3-dihydroinden-1-one and evaluation of their cytotoxicities

Chalcones and Mannich bases are a group of compounds known for their cytotoxicities. In this study restricted chalcone analogue, compound 2-(4-hydroxybenzylidene)-2,3-dihydroinden-1-one MT1, was used as a starting compound to synthesize new mono Mannich bases since Mannich bases may induce more cytotoxicity than chalcone analogue that they are derived from by producing additional alkylating center for cellular thiols. In this study, cyclic and acyclic amines were used to synthesize Mannich bases. All compounds were tested against Ca9-22 (gingival carcinoma), HSC-2, HSC-3 and HSC-4 (oral squamous cell carcinoma) as tumour cell lines and HGF (gingival fibroblasts), HPC (pulp cells) and HPLF (periodontal ligament fibroblasts) human normal oral cells as non tumour cell lines. Cytotoxicity, selectivity index (SI) values and potency selectivity expression (PSE) values expressed as a percentage were determined for the compounds. According to data obtained, the compound MT8 with the highest PSE value bearing N-methylpiperazine moiety seems to be a good candidate to develop new cytotoxic compounds and is suited for further investigation.

Mannich bases in medicinal chemistry and drug design

The biological activity of Mannich bases, a structurally heterogeneous class of chemical compounds that are generated from various substrates through the introduction of an aminomethyl function by means of the Mannich reaction, is surveyed, with emphasis on the relationship between structure and biological activity. The review covers extensively the literature reports that have disclosed Mannich bases as anticancer and cytotoxic agents, or compounds with potential antibacterial and antifungal activity in the last decade. The most relevant studies on the activity of Mannich bases as antimycobacterial agents, antimalarials, or antiviral candidates have been included as well. The review contains also a thorough coverage of anticonvulsant, anti-inflammatory, analgesic and antioxidant activities of Mannich bases. In addition, several minor biological activities of Mannich bases, such as their ability to regulate blood pressure or inhibit platelet aggregation, their antiparasitic and anti-ulcer effects, as well as their use as agents for the treatment of mental disorders have been presented. The review gives in the end a brief overview of the potential of Mannich bases as inhibitors of various enzymes or ligands for several receptors.

N-(2-Benzoyl-eth-yl)propan-2-aminium chloride

In the title salt, C(12)H(18)NO(+)·Cl(-), N-H⋯Cl inter-actions between the free chloride anions and the organic cations connect the mol-ecules into hydrogen-bond dimers, forming a R(2) (2)(8) motif. The dimers are linked by C-H⋯O hydrogen bonds into chains extending along [301]. The carbonyl group is co-planar with the phenyl ring [C-C-C=O torsion angle = -3.3 (7)°]. The side chain has an E conformation.

N-[2-(4-Methyl-benzo-yl)eth-yl]propan-2-aminium chloride

In the title compound, C(13)H(20)NO(+)·Cl(-), the protonated amino N atom is hydrogen bonded to the chloride anion. N-H⋯Cl hydrogen bonds link the anions and cations into dimers, which are connected by C-H⋯O hydrogen bonds, forming supra-molecular chains extending along [100].

N-[2-(4-Bromo-benzo-yl)eth-yl]isopropyl-aminium chloride

The crystal structure of the title compound, C(12)H(17)BrNO(+)·Cl(-), is stabilized by N-H⋯Cl and C-H⋯O hydrogen bonds, forming a three-dimensional network. The inter-actions framework is completed by C-H⋯π contacts between a methyl-ene group and the benzene ring of a symmetry-related mol-ecule.

Synthesis and antifungal evaluation of 1-aryl-2-dimethyl- aminomethyl-2-propen-1-one hydrochlorides

The development of resistance to current antifungal therapeutics drives the search for new effective agents. The fact that several acetophenone-derived Mannich bases had shown remarkable antifungal activities in our previous studies led us to design and synthesize some acetophenone-derived Mannich bases, 1-8 and 2-acetylthiophene-derived Mannich base 9, 1-aryl-2-dimethylaminomethyl-2-propen-1-one hydrochloride, to evaluate their antifungal activities. The designed chemical structures have α,β-unsaturated ketone moieties, which are responsible for the bioactivities of the Mannich bases. The aryl part was C₆H₅ (1); 4-CH₃C₆H₄ (2); 4-CH₃OC₆H₄ (3); 4-ClC₆H₄ (4); 4-FC₆H₄ (5); 4-BrC₆H₄ (6); 4-HOC₆H₄ (7); 4-NO₂C₆H₄ (8); and C₄H₃S(2-yl) (9). In this study the designed compounds were synthesized by the conventional heating method and also by the microwave irradiation method to compare these methods in terms of reaction times and yields to find an optimum synthetic method, which can be applied for the synthesis of Mannich bases in further studies. Since there are limited number of studies reporting the synthesis of Mannich bases by microwave irradiation, this study may also contribute to the general literature on Mannich bases. Compound 7 was reported for the first time. Antifungal activities of all compounds and synthesis of the compounds by microwave irradiation were also reported for the first time by this study. Fungi (15 species) were used for antifungal activity test. Amphotericin B was tested as an antifungal reference compound. In conclusion, compounds 1-6, and 9, which had more potent (2–16 times) antifungal activity than the reference compound amphotericin B against some fungi, can be model compounds for further studies to develop new antifungal agents. In addition, microwave irradiation can be considered to reduce reaction period, while the conventional method can still be considered to obtain compounds with higher reaction yields in the synthesis of new Mannich bases.