Tumor-specific cytotoxicity and type of cell death induced by benzo[b]cyclohept[e][1,4]oxazine and 2-aminotropone derivatives.

A total of twenty benzo[b]cyclohept[e] [1,4]oxazines and their S-analogs, and 2-aminotropone derivatives were investigated for their cytotoxicity against three human normal cells and four tumor cell lines. These compounds showed moderate tumor-specific cytotoxicity. The cytotoxicity was enhanced by bromination at the tropone ring and replacement by formylbenzene.

Tumor-specific cytotoxicity and type of cell death induced by naphtho[2,3-b]furan-4,9-diones and related compounds in human tumor cell lines: relationship to electronic structure.

A total of thirty-nine naphtho[2,3-b]furan-4,9-diones and related compounds were tested for their cytotoxicity against three human normal oral cells (gingival fibroblast, HGF, pulp cell, HPC, periodontal ligament fibroblast, HPLF) and four human tumor cell lines (oral squamous cell carcinoma HSC-2, HSC-3, HSC-4, promyelocytic leukemia HL-60). 2-Acetylnaphtho[2,3-b]furan-4,9-dione [1] was highly cytotoxic to both normal and tumor cells, yielding low tumor-specificity. 2-Acetyl-4,9-dimethoxynaphtho[2,3-b]furan [4], the 2-(3-furanoyl) benzoic acids [5, 6] and the 1,4-naphthoquinones [7, 8] showed much reduced cytototoxicity and low tumor-specificity.

Effect of tropolone, azulene and azulenequinone derivatives on prostaglandin E2 production by activated macrophage-like cells.

We have previously reported that tropolone (T-3), 2,4-dibromo-7-methoxytropone (T-21), diethyl 2-chloroazulene-1,3-dicarboxylate (A-9), 1,3-difluoroazulene (A-11), 3-morpholino-1,5-azulenequinone (AQ-8) and 3,7-dibromo-1,5-azulenequinone (AQ-13) inhibited the nitric oxide (NO) production of lipopolysaccharide (LPS)-activated mouse macrophage-like RAW264.7 cells, with or without the inhibition of inducible NO synthase (iNOS) mRNA and protein expression. In order to confirm the anti-inflammatory potency, possible effects on prostaglandin (PG) E2 production and the expression of enzymes involved in the arachidonic acid pathway were investigated.

Inhibition of LPS-stimulated NO production in mouse macrophage-like cells by benzocycloheptoxazines.

Twenty-six benzocycloheptoxazine derivatives were investigated for their effect on nitric oxide (NO) production by lipopolysaccharide (LPS)-stimulated mouse macrophage-like RAW 264.7 cells. Benzo[b]cyclohepta[e][1,4]thiazine most effectively inhibited the LPS-stimulated NO production at noncytotoxic concentrations.

Tumor-specific cytotoxicity and type of cell death induced by benzocycloheptoxazines in human tumor cell lines.

Twenty-six benzocycloheptoxazine derivatives were investigated for their tumor-specific cytotoxicity and apoptosis-inducing activity against three human normal cells (gingival fibroblast HGF, pulp cell HPC, periodontal ligament fibroblast HPLF) and four human tumor cell lines (squamous cell carcinoma HSC-2, HSC-3, HSC-4, promyelocytic leukemia HL-60). Benzo[b]cyclohepta[e][1,4]thiazine [1] exhibited very weak cytotoxicity, whereas its 6,8,10-tribromo derivative [3] exhibited higher cytotoxicity and tumor specificity (TS = 5.6).

Inhibition of NO production in LPS-stimulated mouse macrophage-like cells by trihaloacetylazulene derivatives.

The effect of 20 trihaloacetylazulene derivatives with one halogen atom, on nitric oxide (NO) production by mouse macrophage-like cells Raw 264.7 was investigated. 2-Methoxyazulenes and 2-ethoxyazulenes exhibited comparable cytotoxicity.

Relationship between electronic structure and cytotoxic activity of azulenequinones and trihaloacetylazulenes.

The relationship between the structure and cytotoxic activity of azulenequinones and trihaloacetylazulenes was investigated based on theoretical calculations. Four different dipole moments (mu(G), mu(ESP-G), mu(W) and mu(ESP-W)) and heats of formation (DeltaH(f)) of the azulenequinones [1-27] and trihaloacetylazulenes [28a,b-40a,b] were separately calculated in gas phase and aqueous solution using the conductor-like screening model/parametric method 3 (COSMO/PM3) method. The cytotoxic activity of azulenequinones was well correlated to DeltaDeltaH(f) HOMO energy and mu(ESP-w).

Factors that affect the type of cell death induced by chemicals.

Surveying about 1000 compounds, we found that several low molecular weight alpha, beta-unsaturated ketones induced non-apoptotic cell death characterized by the formation of autophagosomes, occasionally accompanied by mitochondrial shrinkage. The cytotoxic activity of these compounds was significantly reduced by the addition of N-acetyl-L-cysteine, suggesting their interaction with SH groups of intracellular targeted molecules (the so-called "non-sterically hindered Michael acceptor"). This suggests that the nature of the chemical structure as well as the type of target cells is another factor that determines the type of cell death induced by chemicals.

Tumor-specificity and type of cell death induced by trihaloacetylazulenes in human tumor cell lines.

Twenty trihaloacetylazulene derivatives with one atom of fluorine, chlorine, bromine or iodine was investigated for their tumor-specific cytotoxicity and apoptosis-inducing activity against three human normal cells (gingival fibroblast, HGF; pulp cell, HPC; periodontal ligament fibroblast, HPLF) and four human tumor cell lines (squamous cell carcinoma, HSC-2, HSC-3, HSC-4; promyelocytic leukemia, HL-60). There was no apparent difference in the cytotoxic activity between 2-methoxyazulenes [1a-1e, 2a-2e] and 2-ethoxyazulenes [3a-3e, 4a-4e]. Trichloroacetylazulenes [2a-2e, 4a-4e] generally showed higher cytotoxicity and tumor-specificity (expressed as a TS value) as compared with the corresponding trifluoroacetylazulenes [1a-1e, 3a-3e].

Semisynthesis of isetexane diterpenoid analogues and their cytotoxic activity.

Isetexane diterpene analogues were semisynthesized from demethylsalvicanol isolated from Perovskia abrotanoides (Labiatae). The structure and cytotoxic activity relationships (SAR) of the natural parent diterpene, demethylsalvicanol, and its semisynthetic analogues were studied by using P388 murine leukemia cells.

Inhibition of NO production in LPS-stimulated mouse macrophage-like cells by trihaloacetylazulenes.

The effects of 26 trihaloacetylazulene derivatives on nitric oxide (NO) production by the mouse macrophage-like Raw 264.7 cells was investigated. The trichloroacetylazulenes [1b-13b] generally showed higher cytotoxicity as compared with the corresponding trifluoroacetylazulenes [1a-13a].

Apoptosis-inducing activity of trihaloacetylazulenes against human oral tumor cell lines.

Twenty-six trihaloacetylazulene derivatives were investigated for their tumor-specific cytotoxicity and apoptosis-inducing activity against three human normal cells (HGF, HPC, HPLF) and four human tumor cell lines (HSC-2, HSC-3, HSC-4, HL-60). The trichloroacetylazulenes [1b-13b] generally showed higher cytotoxicity as compared to the corresponding trifluoroacetylazulenes [1a-13a]. The trichloroacetylazulenes [1b-13b] also showed higher tumor-specific cytotoxicity (expressed as TS value) than the corresponding trifluoroacetylazulenes [1a-13a].

Relationship between electronic structure and cytotoxic activity of tropolones.

A structure-activity relationship of the cytotoxic activity of tropolone derivatives was discussed, using theoretical calculations. In order to clearly divide the tropolones into two structurally analogous groups, four different dipole moments (muG, muESP-G, muW and muESP-W) and heats of formation (deltaHf) of the tropolones [1-21] were calculated in the gas-phase and in water-solution by the conductor-like screening model/parametric method 3 (COSMO/PM3). The cytotoxic activities of the tropolones and 2-methoxytropones seem to be related to the three QSAR parameters deltadeltaHf, HOMO energy (EH) and muw.

Relationship between electronic structure and cytotoxic activity of azulenes.

The structure-activity relationship of the cytotoxic activity of azulene and azulene derivatives was discussed, using theoretically calculated results. In order to clearly divide the azulenes into three groups according to their functional groups, the CC50, four different dipole moments (muG, muESP-G, muwand muESP-W) and heats of formation (deltaHf) of the azulenes [1-24] were separately calculated in two states, gas-phase and water, by the conductor-like screening model/parametric method 3 (COSMO/PM3). For the halogenated azulenes and isopropyl azulenes, the cytotoxic activity might follow the three quantitative structure-activity relationship (QSAR) parameters: deltadeltaHf, HOMO energy and muw Whereas, for the other ten compounds [3-5, 7-8, 10, 15-18], the cytotoxic activity might be related to the three QSAR parameters, deltadeltaHf, LUMO energy and muG

Cytotoxicity of abietane diterpenoids from Perovskia abrotanoides and of their semisynthetic analogues.

Seven known abietane diterpenoids and 11-O- and 12-O-acetylcarnosic acids were isolated from a methanol extract of Perovskia abrotanoides (Labiatae). Structure and cytotoxic activity relationships (SAR) of the natural and semisynthetic analogues of the presently isolated abietane diterpenoids were studied by using P388 murine leukemia cells.

Inhibition of LPS-stimulated NO production in mouse macrophage-like cells by azulenequinones.

Azulenequinone derivatives have been reported to display a broad spectrum of biological activities, but study at the cellular level has been limited. The effect of twenty-seven azulenequinone derivatives on nitric oxide (NO) production by mouse macrophage-like cells Raw 264.7 was investigated in this study.

Cytotoxic activity of azulenequinones against human oral tumor cell lines.

We investigated twenty-seven azulenequinone derivatives for their relative cytotoxicity against three human normal cell lines (HGF, HPC, HPLF) and four human tumor cell lines (HSG, HSC-2, HSC-3, HL-60). Parent 1,5-azulenequinone showed potent and some tumor-specific cytotoxicity. Halogenated derivatives of 1,5- and 1,7-azulenequinone showed potent cytotoxicity, but lower tumor-specific cytotoxicity.

Inhibition of LPS-stimulated NO production in mouse macrophage-like cells by azulenes.

We investigated the effect of twenty-seven azulenes on nitric oxide (NO) production by mouse macrophage-like Raw 264.7 cells. No azulene derivative alone induced NO production by the Raw 264.

Inhibition of LPS-stimulated NO production in mouse macrophage-like cells by tropolones.

We investigated the effect of 27 tropolones on nitric oxide (NO) production by mouse macrophage-like Raw 264.7 cells. All of these compounds failed to stimulate the Raw 264.

Relationship between electronic structure and cytotoxic activity of dopamine and 3-benzazepine derivatives.

A structure-activity relationship of dopamine and 3-benzazepine derivatives is discussed, using theoretically calculated results. In order to clearly divide dopamines and 3-benzazepines into a strongly active and a weakly active group, the CC50, two different dipole moments (microESP-G and microESP-W) and heat of formation (deltaHf) of dopamine [1-13] and 3-benzazepine derivatives [14-23] were separately calculated in two states of gas-phase and water-solution by the COSMO/PM3 method. It was found that ten derivatives [1-3, 9, 12-13 and 20-23] (CC50: 0.

Biological activity of barbados cherry (acerola fruits, fruit of Malpighia emarginata DC) extracts and fractions.

Fractionation of barbados cherry (acerola fruit, a fruit of Malpighia emarginata DC.) extracts were performed by organic solvent extractions and column chromatographies, using two extraction methods. Higher cytotoxic activity was concentrated in fractions A4 and A6 (acetone extract), and H3 and HE3 (hexane extract).

Cytotoxic activity of tropolones against human oral tumor cell lines.

Twenty-seven tropolone derivatives were investigated for their tumor-specific cytotoxicity, using 3 normal human cells and 3 human oral tumor cell lines. Tropolone derivatives with phenolic OH group, hinokithiol, its tosylate and methyl ethers have relatively higher tumor specificity. 5-Aminotropolone showed the highest specificity, whereas 2-aminotropone and its derivatives showed little or no specificity.

Cytotoxic activity of azulenes against human oral tumor cell lines.

We investigated 27 azulene derivatives for their relative cytotoxicity against three human normal cells and three human oral tumor cell lines. 2-Acetylaminoazulene [4], diethyl 2-chlorozulene-1,3-dicarboxylate [9] and methyl 7-isopropyl-2-methoxyazulene-1-carboxylate [24] showed higher tumor-specific cytotoxicity than azulene [1] and guaiazulene [2]. Four 1- and 3-halogenated compounds showed lower tumor specificity.

Inhibition of LPS-stimulated NO production in mouse macrophage-like cells by Barbados cherry, a fruit of Malpighia emarginata DC.

The extract of Barbados cherry (acerola fruit), a fruit of Malpighia emarginata DC., has been reported to display diverse biological activities such as prevention of age-related diseases. We investigated here the possible effect of Barbados cherry extract on nitric oxide (NO) production by activated macrophages.

Biological activity of persimmon (Diospyros kaki) peel extracts.

Fractionated extracts of persimmon (Diospyros kaki) peels were studied for cytotoxic activity, multidrug resistance (MDR) reversal activity, anti-human immunodeficiency virus (HIV) activity and anti-Helicobacter pylori (H. pylori) activity. The potent cytotoxic activity against human oral squamous cell carcinoma cells (HSC-2) and human submandibular gland tumor (HSG) cells was found in the acetone fractions (A4 and A5) with IC(50) ranging from 21 to 59 micro g/mL.