The bioassay-guided fractionation of the methylene chloride soluble portion of a methanol extract of Machilus thunbergii bark led to the isolation of four known lignans, machilin A (1), meso-monomethyl dihydroguaiaretic acid (2), nectandrin A (3) and nectandrin B (4), which exhibited potent inhibitory activity on melanin biosynthesis in cultured B-16 mouse melanoma cells (IC(50): 39.9, 15.1, 19.4 and 37.8 microM, respectively).
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http://dx.doi.org/10.1248/bpb.26.1039 | DOI Listing |
Sensors (Basel)
January 2025
Research Centre for Biomedical Engineering, City St George's, University of London, London, EC1V 0HB, UK.
Over the past ten years, there has been an increasing demand for reliable consumer wearables as users are inclined to monitor their health and fitness metrics in real-time, especially since the COVID-19 pandemic. Reflectance pulse oximeters in fitness trackers and smartwatches provide convenient, non-invasive SpO measurements but face challenges in achieving medical-grade accuracy, particularly due to difficulties in capturing physiological signals, which may be affected by skin pigmentation. Hence, this study sets out to investigate the influence of skin pigmentation, particularly in individuals with darker skin, on the accuracy and reliability of SpO measurement in consumer wearables that utilise reflectance pulse oximeters.
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January 2025
Research Centre for Biomedical Engineering, City St George's, University of London, London EC1V 0HB, UK.
The effect of skin pigmentation on photoplethysmography and, specifically, pulse oximetry has recently received a significant amount of attention amongst researchers, especially since the COVID-19 pandemic. With most computational studies observing overestimation of arterial oxygen saturation (SpO) in individuals with darker skin, this study seeks to further investigate the root causes of these discrepancies. This study analysed intensity changes from Monte Carlo-simulated reflectance PPG signals across light, moderate, and dark skin types at oxygen saturations of 70% and 100% in MATLAB R2024a.
View Article and Find Full Text PDFMolecules
January 2025
Anhui Province Key Laboratory of Bioactive Natural Products, School of Pharmacy, Anhui University of Chinese Medicine, Hefei 230012, China.
Natural products and botanicals continue to play a very important role in the development of cosmetics worldwide. The chemical constituents of a fine active fraction of the whole plant extract of Walp., and the tyrosinase and matrix metalloproteinase-1 (MMP-1) inhibitory and antioxidant activities of this fraction were investigated.
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January 2025
Department of Manufacturing Pharmacy, College of Pharmacy and Research Institute for Drug Development, Pusan National University, Busan 46241, Republic of Korea.
Fifteen compounds (-) constructed on a hybrid structure combining a β-phenyl-α,β-unsaturated carbonyl template and a 2-aminothiazol-4(5)-one scaffold were designed and synthesized as potential novel anti-tyrosinase substances. Two compounds ( and ) showed more potent inhibition against mushroom tyrosinase than kojic acid, and the inhibitory activity of (IC value: 1.60 μM) was 11 times stronger than that of kojic acid.
View Article and Find Full Text PDFInsects
January 2025
Department of Plant Protection, College of Agronomy, Jiangxi Agricultural University, Nanchang 330045, China.
(Hendel) is an invasive fruit and vegetable pest, infesting citrus, mango, carambola, etc. We observed that the posterior thoracic scutella of some adults are yellow, some light yellow, and some white in China. Compared with the races with a yellow scutellum (YS) and white scutellum (WS), the race with a light-yellow scutellum (LYS) is dominant in citrus and carambola orchards.
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