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Comparative study of vacuum arc-remelting and spark plasma sintering processes on microstructure and corrosion behavior of Cp-Ti for biomedical implant applications
(2025-11-01)
Kunbuala, Neeraphat
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Srirussamee, Kasama
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Phamornnak, Chinnawich
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Tunthawiroon, Phacharaphon
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Hankoy, Montree
Titanium (Ti) and its alloys are widely used for biomedical applications due to their excellent mechanical properties and biocompatibility. However, the selection of an appropriate manufacturing process is critical to ensuring the optimal performance of Ti-based implants. This study investigates the effects of two fabrication methods –vacuum arc remelting (VAR) and spark plasma sintering (SPS) – on the microstructure and corrosion behavior of commercially pure titanium (Cp-Ti). VAR-Ti ingots were fabricated using arc-melting with multiple remelting cycles, whereas SPS-Ti specimens were sintered from Ti powders under pressure and pulsed current in a high-vacuum environment. Both specimens were subsequently heat-treated at 800 °C and furnace cooled. Microstructural characterization revealed coarser grains and porosity in VAR-Ti, while SPS-Ti showed refined, uniform α-phase structures. Electrochemical tests, including OCP, polarization, EIS, and ICP-MS, indicated slightly enhanced corrosion resistance in SPS-Ti, attributed to its defect-free microstructure. XPS analysis confirmed TiO<inf>2</inf> surface formation on both samples. Additionally, both materials exhibited high ductility and excellent biocompatibility, with cell viability exceeding ISO 10993-5 thresholds. These findings highlight the advantage of SPS in producing defect-minimized Cp-Ti with improved corrosion behavior for biomedical applications.
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Comparative studies on characterizations and cytotoxicity of oil extracted from Lingzhi (Ganoderma lucidum) G2 spore using Soxhlet extraction and microwave-assisted extraction
(2024-12-01)
Senphan, Theeraphol
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Benjakul, Soottawat
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Sukketsiri, Wanida
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Chotphruethipong, Lalita
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Sriket, Chodsana
This study aimed to compare the characteristics, antioxidant activity, and cytotoxicity of Ganoderma lucidum G2 spore (GLS) oil extracted using two different extraction methods, including Soxhlet extraction (SLE) and microwave-assisted extraction (MAE). The SLE method yielded higher oil content than the MAE method. MAE-extracted oil showed higher lightness (L*) and yellowness (b*) values but lower redness (a*) values. Both methods provided similar fatty acid compositions in GLS oils, including palmitic acid, oleic acid, and linoleic acid as major components. Higher saturated fatty acid content was found in SLE-extracted oil, while MAE-extracted oil had increased levels of mono- and poly-unsaturated fatty acids. The oil obtained from SLE showed slightly higher di- and tri-glycerides than that obtained from MAE (P < 0.05). Furthermore, MAE-extracted oil had high oxidative stability as indicated by lower levels of conjugated diene (CD), peroxide value (PV), thiobarbituric acid-reactive substances (TBARS), and free fatty acids (FFA) as compared to SLE (P < 0.05). MAE-extracted oil had a higher total triterpenoid content than SLE-extracted oil (P < 0.05). Also, MAE-extracted oil showed lower DPPH radical scavenging activity (DPPH-RSA) than SLE-extracted oil (P < 0.05). FTIR spectra of both samples exhibited similar functional groups. Additionally, oils obtained from both processes (at 0.1–10 µg/mL) showed low toxicity on Caco-2 cells (P > 0.05). Therefore, GLS oil with high antioxidant activity and oxidative stability, especially oil extracted by MAE, could be a food supplement for health. Also, the MAE used was a potential implement for extracting oil from GLS.
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Pulsed electric field-assisted extraction of Djenkol (Archidendron pauciflorum) peel: Characterization, suppression of intracellular ROS generation and inflammatory cytokines in LPS-activated RAW264.7 macrophage cells
(2024-06-01)
Sinthusamran, Sirima
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Chotphrethipong, Lalita
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Benjakul, Soottawat
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Hutamekalin, Pilaiwanwadee
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Champoochana, Nidanut
Djenkol (Archidendron pauciflorum) peel is a source of phenolics with an antioxidative activity. Nevertheless, the high extraction efficacy of the target compounds is crucial for the isolation of such compounds. Pulsed electric field (PEF)-assisted extraction is the means that increase the efficacy of extraction via an electroporation mechanism. This research aimed to study the extraction of phenolics with antioxidative activities using the PEF and to investigate the anti-inflammation and antioxidative activities of the Djenkol peel extract (DPE) in RAW264.7 macrophage cells. The PEF at different electric field strengths (E) (4.5 and 6 kV/cm) and times (180, 360, and 540 ms) was implemented to extract the phenolic compounds. The PEF with the E level at 6 kV/cm for 540 ms provided the highest yield, the total phenolic content, and antioxidative activities, compared to other conditions (P < 0.05). The dominant compounds in the DPE were the gallic acid and catechin. When the RAW264.7 cells were treated with the DPE at different levels (0.125, 0.25, 0.5, 0.75 and 1 μg/mL), the DPE at 0.125 and 0.25 μg/mL had no cytotoxicity, compared to the control (P < 0.05). With adding lipopolysaccharide (LPS), the DPE-treated cells at 0.125 μg/mL showed the similar cell viability to that of the control (P < 0.05). Additionally, the use of the DPE, particularly at 0.125 and 0.25 μg/mL, could reduce the TNF-α and IL-6 levels and reactive oxygen species (ROS) generation in the LPS-activated cells. Thus, the DPE could be used as a functional ingredient in food.
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Eremophilane sesquiterpenoids from the endophytic fungus Curvularia lunata BCC76963
(2023-03-21)
Sadorn, Karoon
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Saepua, Siriporn
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Boonyuen, Nattawut
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Auncharoen, Patchanee
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Rachtawee, Pranee
A chemical investigation on broth and mycelia extracts of the endophytic fungus Curvularia lunata BCC76963 led to the isolation of five new eremophilane sesquiterpenoids, curvuleremophilanes A−D (1–4) and septeremophilane I (5), one new conjugated unsaturated fatty acid, (6S,2E,4E)-8-hydroxy-4,6-dimethylocta-2,4-dienoic acid (6), and one new phenylacetic acid derivative, 4′-chlorocurvulin (8), along with ten known compounds. The chemical structures were elucidated based on the analyses of HRESIMS and NMR spectroscopic data. The absolute configurations of eremophilanes were assigned by the evidence from NOESY correlations, chemical conversion, optical rotation values, and ECD spectroscopic data in conjunction with biogenetic considerations. In addition, the absolute stereochemistry of compound 5 was confirmed by X-ray crystallography. Curvuleremophilane A (1), dendryphiellin I (10), chaetopenoid B (11), and bipolaroxin (12) displayed antimalarial activity against Plasmodium falciparum K1 with IC<inf>50</inf> values in a range of 3.64–7.77 μM and antibacterial activity against Bacillus cereus and Staphylococcus aureus with MIC values in a range of 3.13–12.50 and 1.56–25.00 μg/mL, respectively. These compounds, except for compound 11, also showed cytotoxicity against NCI-H187 and Vero cells with respective IC<inf>50</inf> values in a range of 2.76–3.97 and 2.34–4.67 μM.
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Antimalarial and antimicrobial substances isolated from the endophytic actinomycete, Streptomyces aculeolatus MS1-6
(2023-03-01)
Kuncharoen, Nattakorn
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Bunbamrung, Nantiya
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Intaraudom, Chakapong
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Choowong, Wilunda
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Thawai, Chitti
Seven undescribed compounds, including four naphthoquinone terpenoids (aculeolatins A – D), one rare 2-nitropyrrole terpenoid (nitropyrrolin F), and two hydroxamate siderophores (aculeolamides A and B) and one further undescribed compound (2,5,7-trihydroxy-3,6-dimethylnaphthalene-1,4-dione), together with eleven known compounds (arromycin, phenaziterpene A, nitropyrrolin A, heronapyrroles A and B, salaceyin A, 5,7-dihydroxy-2-isopropylchromone, 1-hydroxyphenazine, 1-methoxyphenazine, 1-acetyl-β-carboline, and N-(2-phenylethyl) acetamide), were isolated from the cultures of the endophytic Streptomyces aculeolatus MS1-6. The structures of the isolated compounds were determined using NMR spectroscopy and corroborated using chemical modification. These compounds exhibited a broad spectrum of biological activities, including antimalarial (IC<inf>50</inf> 6.03–9.84 μg/mL), antitubercular (MIC 3.13–6.25 μg/mL), anti-plant pathogenic fungal (MIC 25.0–50.0 μg/mL), and antibacterial (MIC 3.03–50 μg/mL) activities; however, they displayed unremarkable cytotoxicity against cancerous (MCF-7 and NCI–H187) and non-cancerous (Vero) cell lines.
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Quinazoline-based human phosphodiesterase 5 inhibitors exhibited a selective vasorelaxant effect on rat isolated pulmonary arteries involving NO-sGC-cGMP pathway and calcium inhibitory effects
(2022-12-01)
Chatturong, Usana
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Martin, Hélène
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Totoson, Perle
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Ingkaninan, Kornkanok
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Temkitthawon, Prapapan
Phosphodiesterase 5 (PDE5) inhibitors are an attractive option among the currently available therapies in the management of pulmonary arterial hypertension (PAH). Good selectivity for PDE5 is associated with reduced side effects and greater vasorelaxant effect on pulmonary arteries (PA). This study investigated the vasorelaxant effects of a series of quinazoline-based PDE5 inhibitors and their precise mechanisms action using rat isolated PA and aorta, as compared to sildenafil. Their effects on rat hepatocytes (viability and CYP activities) were also evaluated. Compounds 5 and 11 displayed lower human PDE5 IC<inf>50</inf> of the analogs studied here and induced a greater relaxant effect on PA (EC<inf>50</inf> 0.94 ± 0.30 and 1.03 ± 0.23 μM, respectively). As compared to sildenafil (EC<inf>50</inf> = 0.05 ± 0.02 μM on PA), the relaxant effect of 5 and 11 on PA was lower but their selectivity for PA compared to aorta was higher. The effects of 5 and 11 were reduced by NG-nitro-L-arginine methyl ester, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxaline-1-one, but not by indomethacin or potassium channels blockers. They also enhanced the relaxant effect of sodium nitroprusside, and inhibited extracellular Ca2+ influx and intracellular Ca2+release. Compounds 5 and 11 did not reduce hepatocyte viability except at concentration > 10 μM, inhibited CYP3A at 10 μM, like sildenafil, but did not induce CYP1A. In conclusion, this study identified 2 quinazoline analogues with good PDE5 inhibitory activity and good selectivity for the pulmonary vasculature. Their relaxant effect involves both the potentiation of nitric oxide-sGC-cGMP pathway and calcium inhibition. These compounds are potential leads for developing new drugs for PAH.
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Synthesis and cytotoxicity study of gold(III) porphyrin complexes and their derivative in breast cancer cells
(2021-12-01)
Phromsatit, Tossapon
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Arpornmaeklong, Premjit
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Shirosaki, Yuki
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Teerawatananond, Thapong
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Rabablert, Jundee
Gold(III) [Au(III)] complexes exhibit potential anticancer activities. A series of Au(III) porphyrin complexes containing different meso-substituent groups (phenyl, methoxyphenyl, butyloxyphenyl, octyloxyphenyl, and decyloxyphenyl) was synthesized. The synthesized compounds were characterized using mass spectrometry, infrared spectroscopy, UV–visible and fluorescence spectroscopy, and electron paramagnetic resonance spectroscopy. Moreover, the in vitro cytotoxicity of these Au(III) porphyrin complexes was investigated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide surrogate viability assay on an MCF7 human breast cancer cell line. The Au(III) complexes with 5,10,15,20-tetraphenylporphyrin (AuTPP) and 5,10,15,20-tetrakis(4-methyloxyphenyl)porphyrin (AuTOMPP) demonstrated high anticancer activity with IC<inf>50</inf> values against MCF7 cells at 4.30 and 25.35 µM, respectively. The toxicity of the Au(III) porphyrin complexes against the LLC-MK2 rhesus monkey kidney epithelial cell line, a representative normal cell line, was investigated. All the tested Au(III) porphyrin complexes were non-cytotoxic in LLC-MK2 cells. For AuTPP, more than 80% LLC-MK2 cell viability was observed at concentrations lower than 5 μM.
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Abyssomicin derivatives from the rhizosphere soil actinomycete Microbispora rhizosphaerae sp. nov. TBRC6028
(2021-05-01)
Bunbamrung, Nantiya
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Kittisrisopit, Suchada
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Intaraudom, Chakapong
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Dramae, Aibrohim
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Thawai, Chitti
Three undescribed abyssomicin derivatives, including microbimisin, abyssomicins Z1, and Z2, were isolated from the soil actinomycete Microbispora rhizosphaerae sp. nov. TBRC6028. Chemical structures were determined by NMR spectroscopic data (1H, 13C, COSY, HSQC, HMBC, and NOESY spectra) and the absolute configurations were verified by single-crystal X-ray diffraction analyses together with the ECD spectral data. Microbimisin and abyssomicin Z1 exhibited weak antibacterial activity against Bacillus cereus with MIC values of 25.0 and 50.0 μg/mL without cytotoxicity against MCF-7 and Vero cells at the concentration of 50 μg/mL.
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Evaluation of bioactivities of musa sp. Aerial parts extracts
(2021-01-01)
Sriwatcharakul, S.
This research aims to study bioactivity of aerial parts extract from four cultivars of banana; Musa sp. that has been multipurpose plant in Thailand. The determination of phytochemical exhibited that Musa (AA) ‘Lep Mue Nang’ extract had the highest contents of flavonoid and tannin as 515.69 mg QE/g extract and 874.93 mg TAE/g extract, respectively, whereas Musa (AA) ‘Khai’ extract presented the highest level of total phenolic content as 958.49 mg GAE/g extract. Analyzed the efficacy of free radical scavenging by using DPPH radical scavenging assay reveal that the highest antioxidant activity found in Musa (AA) ‘Khai’ extract showed IC50 at 5.76 mg/ml. Cytotoxicity studied of extracts against HeLa cell line by MTT assay at the maximum concentration 10000 μg/ml found that Musa (AA) ‘Khai’ extract had the most cytotoxicity at 82.08%. According to the bioactivities results, Musa (AA) ‘Khai’ extract has potential for remedy aspects to add value of this plant.
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Meroterpenoid pyrones, alkaloid and bicyclic brasiliamide from the fungus Neosartorya hiratsukae
(2020-04-01)
Paluka, Jakkapat
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Kanokmedhakul, Kwanjai
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Soytong, Mayamor
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Soytong, Kasem
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Yahuafai, Jantana
Two new meroterpenoid pyrones, chevalone G (1) and aszonapyrone C (2), a new indole alkaloid, 7-chlorofischerindoline (3) and a new bicyclic brasiliamide, brasiliamide H (4), together with sixteen known compounds, 5–20 were isolated from the fungus Neosartorya hiratsukae. Their structures were established on the basis of spectroscopic evidence. The antibacterial activity and the cytotoxic activity of new compounds were evaluated.

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