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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 325: 125116, 2024 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-39276466

RESUMO

A new probe, 4-(((3',6'-bis(diethylamino)-3-oxospiro[isoindoline-1,9'-xanthen]-2-yl)imino)methyl)phenyl)boronic acid (R4B) was prepared by facile condensation of 4-formylphenylboronic acid and rhodamine B hydrazide. R4B was characterized by spectroscopic methods and single crystal X-ray diffraction. The sensor R4B solution turned pink and emitted orange fluorescence only in the presence of sialic acid but remained colorless and non-fluorescent otherwise. The sugar recognition performance was investigated via UV-vis and fluorescence spectroscopic studies. Our results revealed that R4B has good affinity and selectivity for sialic acid over common monosaccharides, with a detection limit as low as 10-7 M. Furthermore, R4B selectively inhibited growth of human colorectal adenocarcinoma HT-29 (IC50 <20 µM) without significant cytotoxicity to normal human colon fibroblasts CCD-18Co. Treatment with R4B suppressed HT-29 colony formation via mitochondrial apoptosis in a time-dependent manner. Cellular imaging studies also revealed the ability of R4B as a fluorescence dye to detect intracellular sialic acid and showed mitochondria-tracking ability in HT-29 cells. In summary, R4B is a potential theranostic for the detection of intracellular sialic acid during the early incubation period, followed by induction of cancer apoptotic cell death at a later treatment point.

2.
Chem Biodivers ; : e202401086, 2024 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-39289837

RESUMO

Kaempferia parviflora or commonly known as "Kunyit hitam" by locals, is an edible plant, native to tropical regions, has been extensively utilized for culinary and medicinal applications. The present study aimed to investigate the phytochemical composition and biological activities of the rhizomes of K. parviflora. The ethanol crude and fractionated extracts (hexane and chloroform) of the rhizomes were evaluated for their total phenolic content, total steroidal content, as well as antioxidant, anti-obesogenic, and anti-diabetic activities. The chloroform extract demonstrated the highest concentration of plant sterols (432 ± 0.23 mg BSE/g extract) and a substantial amount of phenolic compounds (1.19 × 103 ± 0.41 mg GAE/g extract). Gas chromatography-mass spectrometry (GC/MS) analysis revealed that the chloroform extract of the rhizomes is predominantly composed of bioactive flavonoids including tectochrysin (1), 5,7-dimethoxyflavone (2), 3,5,7-trimethoxyflavone (3), 3,4',5,7-tetramethoxyflavone (4), and 4',5,7-trimethoxyflavone (5). Furthermore, the chloroform extract exhibited the highest overall radical scavenging and α-glucosidase inhibitory activities, which can be attributed to the presence of compounds 1-5 in the extract. Collectively, these findings suggest that the chloroform extract of the rhizomes of K. parviflora is a potentially valuable source of bioactive compounds with antioxidant, anti-obesogenic, and anti-diabetic properties, with potential application in therapeutics and functional foods.

3.
Bioorg Chem ; 146: 107256, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38460334

RESUMO

A new series of indolenines decorated with pyrazolo[3,4-b]pyridines were designed and synthesized in up to 96% yield from the acid-catalyzed cyclocondensation of 1,3-dialdehydes with 3-aminopyrazoles. X-ray crystallography on a representative derivative, 5n, revealed two close to planar conformations whereby the N-atom of the pyridyl residue was syn or anti to the pyrrole-N atom in the two independent molecules of the asymmetric unit. The computational and DNA binding data suggest that 5n is a strong DNA intercalator with the results in agreement with its potent cytotoxicity against two colorectal cancer cell lines (HCT 116 and HT-29). In contrast to doxorubicin, compounds 5k-o have higher druggability (compliance to more criteria stated in Lipinski's rule of five and Veber's rule), higher bioavailability, and better medicinal chemistry properties, indicative of their potential application as chemotherapeutical agents.


Assuntos
Antineoplásicos , Neoplasias Colorretais , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/química , Linhagem Celular Tumoral , Neoplasias Colorretais/tratamento farmacológico , DNA , Ensaios de Seleção de Medicamentos Antitumorais , Estrutura Molecular , Piridinas/farmacologia , Piridinas/química , Relação Estrutura-Atividade , Pirazóis/química , Pirazóis/farmacologia , Indóis/química , Indóis/farmacologia
4.
J Nat Prod ; 87(2): 286-296, 2024 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-38284153

RESUMO

Nine new alkaloids, eugeniinalines A-H (1-8) and (+)-eburnamenine N-oxide (9), comprising one quinoline, six indole, and two isogranatanine alkaloids, were isolated from the stem-bark extract of the Malayan Leuconotis eugeniifolia. The structures and absolute configurations of these alkaloids were established based on the analysis of the spectroscopic data, GIAO NMR calculations, DP4+ probability analysis, TDDFT-ECD method, and X-ray diffraction analysis. Eugeniinaline A (1) represents a new pentacyclic quinoline alkaloid with a 6/6/5/6/7 ring system. Eugeniinaline G (7) and its seco-derivative, eugeniinaline H (8), were the first isogranatanine alkaloids isolated as natural products. The known alkaloids leucolusine (10) and melokhanine A (11) were found to be the same compound, based on comparison of the spectroscopic data of both compounds, with the absolute configuration of (7R, 20R, 21S). Eugeniinalines A and G (1 and 7) showed cytotoxic activity against the HT-29 cancer cell line with IC50 values of 7.1 and 7.2 µM, respectively.


Assuntos
Alcaloides , Antineoplásicos , Apocynaceae , Quinolinas , Humanos , Alcaloides/farmacologia , Apocynaceae/química , Alcaloides Indólicos/farmacologia , Alcaloides Indólicos/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Quinolinas/farmacologia , Alcaloides de Triptamina e Secologanina/química , Alcaloides de Triptamina e Secologanina/farmacologia
5.
Chem Biodivers ; 21(3): e202301836, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38253795

RESUMO

Essential oils have been recognised for their potential benefits in oral care. The aim of this study was to evaluate the antibacterial and antiproliferative activity of essential oils derived from four Zingiberaceae species. A combination of GC/MS and GC-FID was employed to analyse these essential oils. The results showed that ß-myrcene (79.77 %) followed by ethyl-cinnamate (40.14 %), ß-curcumene (34.90 %), and alloaromadendrene (25.15 %) as the primary constituents of Curcuma mangga, Curcuma xanthorrhiza, Kaempferia galanga and Curcuma aeruginosa, respectively. The Zingiberaceae oils were tested for their antibacterial activity against oral bacteria using the disc diffusion test. Curcuma xanthorrhiza oil showed the largest inhibition zones against Streptococcus mitis (19.50±2.22 mm) and Streptococcus sanguinis (15.04±3.05 mm). Similarly, Curcuma mangga oil exhibited significant antibacterial activity against Streptococcus mutans (12.55±0.45 mm) and mixed oral bacteria (15.03±3.82 mm). Furthermore, the MTT viability assay revealed moderate inhibitory activity of these essential oils against H103 and ORL-204 oral cancer cells. The study findings demonstrate that Curcuma xanthorrhiza and Curcuma mangga essential oils have potent antibacterial properties, suggesting their potential use as natural alternatives to synthetic antibacterial agents in oral care products. However, further investigations are necessary to fully explore their therapeutic applications.


Assuntos
Anti-Infecciosos , Óleos Voláteis , Zingiberaceae , Saúde Bucal , Anti-Infecciosos/farmacologia , Antibacterianos/farmacologia , Óleos Voláteis/farmacologia , Curcuma , Bactérias
6.
Mol Divers ; 2023 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-37278911

RESUMO

Five new compounds of benz[e]indole pyrazolyl-substituted amides (2a-e) were synthesised in low to good yields via the direct amide-coupling reaction between a pyrazolyl derivative containing a carboxylic acid and several amine substrates. The molecular structures were determined by various spectroscopic methods, such as NMR (1H, 13C and 19F), FT-IR and high-resolution mass spectrometry (HRMS). X-ray crystallographic analysis on the 4-fluorobenzyl derivative (2d) reveals the amide-O atom to reside to the opposite side of the molecule to the pyrazolyl-N and pyrrolyl-N atoms; in the molecular packing, helical chains feature amide-N‒H⋯N(pyrrolyl) hydrogen bonds. Density-functional theory (DFT) at the geometry-optimisation B3LYP/6-31G(d) level on the full series shows general agreement with the experimental structures. While the LUMO in each case is spread over the benz[e]indole pyrazolyl moiety, the HOMO spreads over the halogenated benzo-substituted amide moieties or is localised near the benz[e]indole pyrazolyl moieties. The MTT assay showed that 2e, exhibited the highest toxicity against a human colorectal carcinoma (HCT 116 cell line) without appreciable toxicity towards the normal human colon fibroblast (CCD-18Co cell line). Based on molecular docking calculations, the probable cytotoxic mechanism of 2e is through the DNA minor groove binding.

7.
Phytochemistry ; 208: 113587, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36646163

RESUMO

Eight undescribed iboga alkaloids, polyneurines A-H, were isolated from the bark of Tabernaemontana polyneura. The structures of these alkaloids were established by interpretation of the MS and NMR data, while the configurations were determined using GIAO NMR calculations and DP4+ probability analysis, TDDFT-ECD method, or X-ray diffraction analysis. Polyneurine A possesses a γ-lactone unit embedded within the iboga skeleton, while polyneurines D and E incorporate a formylmethyl moiety at C-3 of the iboga skeleton. Biosynthetic pathways towards the formation of polyneurines A, C, D, and E were proposed.


Assuntos
Alcaloides , Tabernaemontana , Tabernaemontana/química , Alcaloides Indólicos/química , Alcaloides/química , Cristalografia por Raios X , Estrutura Molecular
8.
Int J Med Mushrooms ; 24(3): 35-50, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35467805

RESUMO

Neurological diseases are increasingly recognized as a health burden worldwide, mainly affecting the elderly population. Sanguinoderma rugosum (=Amauroderma rugosum) is a wild medicinal mushroom traditionally used to alleviate inflammation and prevent seizures. The present study aimed to investigate the neuroprotective and neurorescue effects as well as the possible mechanisms of S. rugosum extracts on glutamate-induced HT-22 mouse hippocampal neuronal cells. The mycelia of S. rugosum were subjected to submerged liquid fermentation followed by solvent extraction and fractionation. The neurotoxicity, neuroprotective, and neurorescue activities of S. rugosum extracts were assessed via the MTT viability assay at 24 and 48 h. The effects of S. rugosum extracts on glutamate-induced oxidative stress and cell death were investigated through flow cytometry. Gas chromatography/mass spectrometry (GC/MS) analysis was conducted to identify the bioactive compounds in the S. rugosum hexane fraction (SR-HF). All extracts were noncytotoxic toward HT-22 cells. Pretreatment with S. rugosum ethanolic extract (SR-EE; 12.5 µg/mL) or SR-HF (100 µg/mL) markedly (P < 0.05) improved the loss of cell viability and attenuated the accumulation of reactive oxygen species production. Pretreatment with SR-HF was also demonstrated to inhibit glutamate-induced cell death. The MTT assay showed that all extracts generally rescued glutamate-induced HT-22 cells at 24 and 48 h. The GC/MS analysis revealed the existence of 11 bioactive components in SR-HF, with linoleic acid, ergosterol, and ethyl linoleate being the main chemical constituents. The current findings suggest that SR-HF could be used as a potential therapeutic intervention to ameliorate oxidative stress and neuroinflammation.


Assuntos
Agaricales , Fármacos Neuroprotetores , Agaricales/química , Idoso , Animais , Sobrevivência Celular , Ácido Glutâmico/toxicidade , Hipocampo , Humanos , Camundongos , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo , Extratos Vegetais/química , Extratos Vegetais/farmacologia
9.
Planta Med ; 88(14): 1325-1340, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35100653

RESUMO

Two iboga-vobasine bisindoles, 16'-decarbomethoxyvoacamine (1: ) and its 19,20-dihydro derivative, 16'-decarbomethoxydihydrovoacamine (2: ) from Tabernaemontana corymbosa exhibited potent cytotoxicity against the human colorectal adenocarcinoma HT-29 cells in our previous studies. Bisindoles 1: and 2: selectively inhibited the growth of HT-29 cells without significant cytotoxicity to normal human colon fibroblasts CCD-18Co. Treatment with bisindoles 1: and 2: suppressed the formation of HT-29 colonies via G0/G1 cell cycle arrest and induction of mitochondrial apoptosis. Owing to its higher antiproliferative activity, bisindole 2: was chosen for the subsequent studies. Bisindole 2: inhibited the formation of HT-29 spheroids (tumor-like cell aggregates) in 3D experiments in a dose-dependent manner, while an in vitro tubulin polymerization assay and molecular docking analysis showed that bisindole 2: is a microtubule-stabilizing agent which is predicted to bind at the ß-tubulin subunit at the taxol-binding site. The binding resulted in the generation of ROS, which consequently activated the oxidative stress-related cell cycle arrest and apoptotic pathways, viz., JNK/p38, p21Cip1/Chk1, and p21Cip1/Rb/E2F, as shown by microarray profiling.


Assuntos
Adenocarcinoma , Antineoplásicos Fitogênicos , Neoplasias Colorretais , Ibogaína , Tabernaemontana , Humanos , Tabernaemontana/química , Células HT29 , Simulação de Acoplamento Molecular , Ensaios de Seleção de Medicamentos Antitumorais , Antineoplásicos Fitogênicos/farmacologia , Estrutura Molecular , Alcaloides Indólicos/farmacologia , Alcaloides Indólicos/química , Ibogaína/farmacologia , Apoptose , Neoplasias Colorretais/tratamento farmacológico , Microtúbulos , Linhagem Celular Tumoral
10.
Spectrochim Acta A Mol Biomol Spectrosc ; 262: 120099, 2021 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-34198119

RESUMO

A new chemosensor 1 was synthesized by reacting rhodamine B hydrazide and 2,3,4-trihydroxybenzaldehyde, which was then characterized by spectroscopic techniques and single crystal X-ray crystallography. Sensor 1 has the ability to sense Co2+/Cu2+ ions by "naked-eye" with an apparent colour change from colourless to pink in different solvent system, MeCN and DMF respectively. Furthermore, it can selectively detect Co2+/Cu2+ among wide range of different metal ions, and it exhibits low detection limit of 4.425 × 10-8 M and 1.398 × 10-7 M respectively. Binding mode of the two complexes were determined to be 1:1 stoichiometry for Co2+ complex and 1:2 stoichiometry for Cu2+ complex through Job's plot, IR spectroscopy, mass spectrometry and 1H NMR spectroscopy. Moreover, reversibility of the sensor 1 as copper (II) ion detector was determined by using EDTA and the results showed that sensor 1 can be reused for at least 6 cycles. Other than that, a low cost chemosensor test strips were fabricated for the convenient "naked-eye" detection of Co2+ and Cu2+ in pure aqueous media. The MTT assay was conducted in order to determine the cytotoxicity of sensor 1 towards human cell lines.


Assuntos
Cobalto , Cobre , Cobalto/toxicidade , Teoria da Densidade Funcional , Corantes Fluorescentes , Humanos , Íons , Rodaminas , Solventes
11.
J Nat Prod ; 84(5): 1524-1533, 2021 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-33872002

RESUMO

A new linearly fused macroline-sarpagine bisindole, angustilongine M (1), was isolated from the methanolic extract of Alstonia penangiana. The structure of the alkaloid was elucidated based on analysis of the spectroscopic data, and its biological activity was evaluated together with another previously reported macroline-akuammiline bisindole from the same plant, angustilongine A (2). Compounds 1 and 2 showed pronounced in vitro growth inhibitory activity against a wide panel of human cancer cell lines. In particular, the two compounds showed potent and selective antiproliferative activity against HT-29 cells, as well as strong growth inhibitory effects against HT-29 spheroids. Cell death mechanistic studies revealed that the compounds induced mitochondrial apoptosis and G0/G1 cell cycle arrest in HT-29 cells in a time-dependent manner, while in vitro tubulin polymerization assays and molecular docking analysis showed that the compounds are microtubule-stabilizing agents, which are predicted to bind at the ß-tubulin subunit at the Taxol-binding site.


Assuntos
Alstonia/química , Antineoplásicos Fitogênicos/farmacologia , Alcaloides Indólicos/farmacologia , Oxindóis/farmacologia , Moduladores de Tubulina/farmacologia , Apoptose/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Células HT29 , Humanos , Mitocôndrias/efeitos dos fármacos , Simulação de Acoplamento Molecular , Estrutura Molecular
12.
Artigo em Inglês | MEDLINE | ID: mdl-32742279

RESUMO

BACKGROUND: The Asiatic pit vipers from the Trimeresurus complex are medically important venomous snakes. These pit vipers are often associated with snakebite that leads to fatal coagulopathy and tissue necrosis. The cytotoxic venoms of Trimeresurus spp.; however, hold great potential for the development of peptide-based anticancer drugs. METHODS: This study investigated the cytotoxic effect of the venom from Trimeresurus purpureomaculatus, the mangrove pit viper (also known as shore pit viper) which is native in Malaysia, across a panel of human cancer cell lines from breast, lung, colon and prostate as well as the corresponding normal cell lines of each tissue. RESULTS: The venom exhibited dose-dependent cytotoxic activities on all cell lines tested, with median inhibition concentrations (IC50) ranging from 0.42 to 6.98 µg/mL. The venom has a high selectivity index (SI = 14.54) on breast cancer cell line (MCF7), indicating that it is significantly more cytotoxic toward the cancer than to normal cell lines. Furthermore, the venom was fractionated using C18 reversed-phase high-performance liquid chromatography and the anticancer effect of each protein fraction was examined. Fraction 1 that contains a hydrophilic low molecular weight (approximately 7.5 kDa) protein was found to be the most cytotoxic and selective toward the breast cancer cell line (MCF7). The protein was identified using liquid chromatography-tandem mass spectrometry as a venom disintegrin, termed purpureomaculin in this study. CONCLUSION: Taken together, the findings revealed the potent and selective cytotoxicity of a disintegrin protein isolated from the Malaysian T. purpureomaculatus venom and suggested its anticancer potential in drug discovery.

13.
J Inorg Biochem ; 208: 111097, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32438269

RESUMO

Two new Schiff base ligands (TE and TF) were prepared from conjugation of testosterone with 4-(4-ethylphenyl)-3-thiosemicarbazide and 4-(4-fluorophenyl)-3-thiosemicarbazide, respectively. Their nickel (NE and NF) and zinc (ZE and ZF) complexes were reported. X-ray crystallography revealed a distorted square planar geometry was adopted by NE. The compounds demonstrated excellent selectivity towards the colorectal carcinoma cell line HCT 116 despite their weak preferences towards the prostate cancer cell lines (PC-3 and LNCaP). Against HCT 116, all these compounds were able to arrest cell cycle at G0/G1 phase and induce apoptosis via mitochondria-dependent (TE, NE, and TF) and extrinsic apoptotic pathway (ZE, NF, and ZF). Moreover, only ZE was able to act as topoisomease I poison and halt its enzymatic reactions although all compounds presented excellent affinity towards DNA.


Assuntos
Neoplasias Colorretais , Complexos de Coordenação , Níquel , Testosterona , Tiossemicarbazonas , Zinco , Morte Celular/efeitos dos fármacos , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Complexos de Coordenação/farmacocinética , Complexos de Coordenação/farmacologia , Células HCT116 , Humanos , Níquel/química , Níquel/farmacocinética , Níquel/farmacologia , Testosterona/química , Testosterona/farmacocinética , Testosterona/farmacologia , Tiossemicarbazonas/química , Tiossemicarbazonas/farmacocinética , Tiossemicarbazonas/farmacologia , Zinco/química , Zinco/farmacocinética , Zinco/farmacologia
14.
J. venom. anim. toxins incl. trop. dis ; 26: e20200013, 2020. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1135156

RESUMO

The Asiatic pit vipers from the Trimeresurus complex are medically important venomous snakes. These pit vipers are often associated with snakebite that leads to fatal coagulopathy and tissue necrosis. The cytotoxic venoms of Trimeresurus spp.; however, hold great potential for the development of peptide-based anticancer drugs. Methods: This study investigated the cytotoxic effect of the venom from Trimeresurus purpureomaculatus, the mangrove pit viper (also known as shore pit viper) which is native in Malaysia, across a panel of human cancer cell lines from breast, lung, colon and prostate as well as the corresponding normal cell lines of each tissue. Results: The venom exhibited dose-dependent cytotoxic activities on all cell lines tested, with median inhibition concentrations (IC50) ranging from 0.42 to 6.98 µg/mL. The venom has a high selectivity index (SI = 14.54) on breast cancer cell line (MCF7), indicating that it is significantly more cytotoxic toward the cancer than to normal cell lines. Furthermore, the venom was fractionated using C18 reversed-phase high-performance liquid chromatography and the anticancer effect of each protein fraction was examined. Fraction 1 that contains a hydrophilic low molecular weight (approximately 7.5 kDa) protein was found to be the most cytotoxic and selective toward the breast cancer cell line (MCF7). The protein was identified using liquid chromatography-tandem mass spectrometry as a venom disintegrin, termed purpureomaculin in this study. Conclusion: Taken together, the findings revealed the potent and selective cytotoxicity of a disintegrin protein isolated from the Malaysian T. purpureomaculatus venom and suggested its anticancer potential in drug discovery.(AU)


Assuntos
Animais , Trimeresurus , Desintegrinas , Citotoxicidade Imunológica , Neoplasias , Venenos de Víboras , Antineoplásicos
15.
J Nat Prod ; 82(11): 3121-3132, 2019 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-31642315

RESUMO

A methanol extract of the stem bark of the Malayan Alstonia penangiana provided seven new bisindole alkaloids, comprising six macroline-sarpagine alkaloids (angustilongines E-K, 1-6) and one macroline-pleiocarpamine bisindole alkaloid (angustilongine L, 7). Analysis of the spectroscopic data (NMR and MS) of these compounds led to the proposed structures of these alkaloids. The macroline-sarpagine alkaloids (1-6) showed in vitro growth inhibitory activity against a panel of human cancer cell lines, inclusive of KB, vincristine-resistant KB, PC-3, LNCaP, MCF7, MDA-MB-231, HT-29, HCT 116, and A549 cells (IC50 values: 0.02-9.0 µM).


Assuntos
Alcaloides/síntese química , Alcaloides/farmacologia , Alstonia/química , Antineoplásicos Fitogênicos/síntese química , Antineoplásicos Fitogênicos/farmacologia , Alcaloides Indólicos/síntese química , Alcaloides Indólicos/farmacologia , Oxindóis/síntese química , Oxindóis/farmacologia , Células A549 , Linhagem Celular Tumoral , Proliferação de Células , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Células HT29 , Humanos , Estrutura Molecular
16.
3 Biotech ; 9(8): 315, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31406637

RESUMO

An ecologically important tropical freshwater microalga, Scenedesmus quadricauda, was exposed to Ni toxicity under two temperature regimes, 25 and 35 °C to investigate the interactive effects of warming and different Ni concentrations (0.1, 1.0 and 10.0 ppm). The stress responses were assessed from the growth, photosynthesis, reactive oxygen species (ROS) generation and metabolomics aspects to understand the effects at both the physiological and biochemical levels. The results showed that the cell densities of the cultures were higher at 35 °C compared to 25 °C, but decreased with increasing Ni concentrations at 35 °C. In terms of photosynthetic efficiency, the maximum quantum yield of photosystem II (F v/F m) of S. quadricauda remained consistent across different conditions. Nickel concentration at 10.0 ppm affected the maximum rate of relative electron transport (rETRm) and saturation irradiance for electron transport (E k) in photosynthesis. At 25 °C, the increase of non-photochemical quenching (NPQ) values in cells exposed to 10.0 ppm Ni might indicate the onset of thermal dissipation process as a self-protection mechanism against Ni toxicity. The combination of warming and Ni toxicity induced a strong oxidative stress response in the cells. The ROS level increased significantly by 40% after exposure to 10.0 ppm of Ni at 35 °C. The amount of Ni accumulated in the biomass was higher at 25 °C compared to 35 °C. Based on the metabolic profile, temperature contributed the most significant differentiation among the samples compared to Ni treatment and the interaction between the two factors. Amino acids, sugars and organic acids were significantly regulated by the combined factors to restore homeostasis. The most affected pathways include sulphur, amino acids, and nitrogen metabolisms. Overall, the results suggest that the inhibitory effect of Ni was lower at 35 °C compared to 25 °C probably due to lower metal uptake and primary metabolism restructuring. The ability of S. quadricauda to accumulate substantial amount of Ni and thrive at 35 °C suggests the potential use of this strain for phycoremediation and outdoor wastewater treatment.

17.
J Nat Prod ; 82(7): 1902-1907, 2019 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-31241923

RESUMO

Three new alkaloids were isolated from the bark extract of the Malayan Kopsia arborea, viz., arbophyllidine (1), an unusual pentacyclic, monoterpenoid indole characterized by an absence of oxygen atoms and incorporating a new carbon-nitrogen skeleton, and arbophyllinines A (2) and B (3), two pentacyclic corynanthean alkaloids incorporating a hydroxyethyl-substituted tetrahydrofuranone ring. The structures of the alkaloids were deduced based on analysis of the MS and NMR data and confirmed by X-ray diffraction analyses. The absolute configuration of arbophyllidine (1) was established based on experimental and calculated ECD data, while that of arbophyllinine A was based on X-ray diffraction analysis (Cu Kα). A reasonable biosynthetic route to arbophyllidine (1) from a pericine precursor is presented. Arbophyllidine (1) showed pronounced in vitro growth inhibitory activity against the HT-29 human cancer cell line with IC50 6.2 µM.


Assuntos
Antineoplásicos/química , Apocynaceae/química , Furanos/química , Alcaloides Indólicos/química , Antineoplásicos/farmacologia , Carbono/química , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Células HT29 , Humanos , Alcaloides Indólicos/farmacologia , Estrutura Molecular , Nitrogênio/química , Análise Espectral/métodos
18.
J Nat Prod ; 82(4): 850-858, 2019 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-30869890

RESUMO

Examination of the EtOH extract of the leaves of the Malayan Tabernaemontana corymbosa resulted in the isolation of four new (1-4) and two known bisindole alkaloids (5, 6) of the Aspidosperma- Aspidosperma type. The structures of these alkaloids were determined based on analysis of the spectroscopic data (NMR and HRESIMS). X-ray diffraction analyses of the related bisindole alkaloids conophylline (5) and conophyllinine (6) established the absolute configurations. Treatment of the bisindole alkaloid conophylline (5) with benzeneselenic anhydride gave, in addition to the known bisindole polyervinine (7) previously isolated from another Malayan Tabernaemontana, another bisindole product, 8, an isolable tautomer of 7. X-ray diffraction analyses yielded the absolute configurations of both bisindoles and in addition showed that polyervinine (7) exists primarily as the neutral dione structure. The bisindoles (1-8) and the related conophylline-type bisindoles (9-13) showed pronounced in vitro growth inhibitory activity against an array of human cancer cell lines, including KB, vincristine-resistant KB, PC-3, LNCaP, MCF7, MDA-MB-231, A549, HT-29, and HCT 116 cells, with IC50 values for the active compounds in the 0.01-5 µM range.


Assuntos
Aspidosperma/química , Proliferação de Células/efeitos dos fármacos , Alcaloides Indólicos/farmacologia , Tabernaemontana/química , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Alcaloides Indólicos/química , Estrutura Molecular , Análise Espectral/métodos
19.
J Nat Prod ; 81(5): 1266-1277, 2018 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-29746134

RESUMO

Examination of the EtOH extract of the Malayan Alstonia penangiana resulted in the isolation of 10 new alkaloids, comprising two ajmaline (1, 2), four macroline oxindole (3-6), and four macroline-akuammiline bisindole alkaloids (7-10). The structures of these alkaloids were determined based on analysis of the spectroscopic data and, in the case of the oxindole 6 and the bisindole alkaloid 7, also confirmed by X-ray diffraction analysis. The bisindole alkaloids 7 and 8 showed pronounced in vitro growth inhibitory activity against an array of human cancer cell lines, including KB, vincristine-resistant KB, PC-3, LNCaP, MCF7, MDA-MB-231, HT-29, HCT 116, and A549 cells with IC50 values in the 0.3-8.3 µM range.


Assuntos
Ajmalina/química , Alcaloides/química , Alstonia/química , Citotoxinas/química , Oxindóis/química , Células A549 , Antineoplásicos Fitogênicos/química , Linhagem Celular Tumoral , Cristalografia por Raios X/métodos , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Células HCT116 , Células HT29 , Humanos , Células KB , Células MCF-7 , Células PC-3 , Vincristina/química
20.
Int J Med Mushrooms ; 20(2): 141-153, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29773006

RESUMO

Five culinary-medicinal mushrooms are commonly available in the Malaysian market: Agaricus bisporus (white and brown), Ganoderma lucidum, Hypsizygus marmoreus, Pleurotus floridanus, and P. pulmonarius. These species were selected for use in the current study, the aim of which was to investigate the antimelanogenesis and anti-inflammatory activity of these mushrooms in an attempt to evaluate their potential use in cosmeceuticals. Mushroom fruiting bodies were extracted with hot water, and the extracts were freeze-dried before testing. The antimelanogenesis activity of the extracts was determined by cell viability assay, measurement of intracellular melanin content, and cellular tyrosinase assay with B16F10 melanoma cells. The anti-inflammatory activity of the mushroom extracts was tested by measuring the levels of nitric oxide (NO), tumor necrosis factor (TNF)-α, and interleukin-10 excreted by RAW264.7 macrophages. Brown A. bisporus reduced intracellular melanin content to the largest extent-up to 57.05 ± 3.90%-without a cytotoxic effect on B16F10 melanoma cells. This extract also reduced cellular tyrosinase activity to 17.93 ± 2.65%, performing better than kojic acid, the positive control. In parallel, the extract from brown A. bisporus, at the highest concentration tested, has appreciable anti-inflammatory activity through reductions of NO and TNF-α levels. The other 5 extracts showed moderate antimelanogenesis and anti-inflammatory activities. In summary, our findings show that A. bisporus (brown) extract has the potential to be used as an ingredient in whitening skincare products and to sooth the inflammatory response on the skin.


Assuntos
Anti-Inflamatórios/farmacologia , Basidiomycota/metabolismo , Melaninas/antagonistas & inibidores , Agaricales/química , Agaricales/metabolismo , Agaricus/química , Agaricus/metabolismo , Animais , Antioxidantes/farmacologia , Basidiomycota/química , Linhagem Celular Tumoral , Cosméticos , Carpóforos/química , Ganoderma/química , Ganoderma/metabolismo , Interleucina-10/análise , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Malásia , Melaninas/metabolismo , Melanoma , Camundongos , Óxido Nítrico/análise , Pleurotus/química , Pleurotus/metabolismo , Polyporaceae/química , Polyporaceae/metabolismo , Células RAW 264.7 , Fator de Necrose Tumoral alfa/análise
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