Diabetes management primarily aims to achieve a life expectancy and quality of life similar to that of people without diabetes. The key to achieving this goal is the effective prevention and management of both the microvascular and macrovascular complications associated with diabetes. Although glycated hemoglobin levels of less than 7% are recommended to minimize complications, individual targets should be set considering variables such as age, duration of diabetes, risk of hypoglycemia, organ function, support system, general health status, and social background.
View Article and Find Full Text PDFPreviously, we reported two cytotoxic -santonin-amino acid conjugates isolated from the EtOAc layer of . However, a further phytochemical investigation seems to be required because of the few reports of similar derivatives. In this study, we targeted the 1-BuOH layer, which resulted in the isolation of seven new -santonin derivatives (-) together with ten known compounds (-).
View Article and Find Full Text PDFThe Asteraceae family is a promising source of bioactive compounds, such as the famous Asteraceae plants (pyrethrin) and (artemisinin). As a result of our series of phytochemical studies of the subtropical plants, two novel sesquiterpenes, named crossoseamines A and B in this study ( and , respectively), one undescribed coumarin-glucoside (), and eighteen known compounds (-) were isolated from the aerial part of (Asteraceae). The structures of isolated compounds were elucidated by spectroscopic methods, including 1D and 2D NMR experiments (H, C, DEPT, COSY, HSQC, HMBC, and NOESY), IR spectrum, circular dichroism spectrum (CD), and high-resolution electrospray ionization-mass spectrometry (HR-ESI-MS).
View Article and Find Full Text PDFTo this day, since about 50% of all medicines are derived from natural sources, natural product chemistry, especially the search for biologically active natural components, remains extremely important (Newman and Cragg in J Nat Prod 83:770-803, 2020). In this review, we deal with our continuing research work for promising constituents from plants collected in the Ryukyu Archipelago. The isolation of islands in the archipelago by the sea or by straits gives rise to endemic plant species that are unique to the islands.
View Article and Find Full Text PDFTwo previously undescribed megastigmane glucosides, (3S)-3-hydroxy-4-oxo-7,8-dihydro-β-ionone-3-O-β-D-glucopyranoside (1), (3S)-3-hydroxy-4-oxo-β-ionone-3-O-β-D-glucopyranoside (2), an apocarotenoid glucoside named equiseoside A (3) and an unusual aromatic compound with a glucose-fused skeleton named equiseoside B (4), together with 35 known compounds (5-39) were isolated from the aerial parts of Equisetum sylvaticum. The structures of these compounds were elucidated by spectroscopic methods, including 1D and 2D NMR, IR, CD, and HR-MS.
View Article and Find Full Text PDFFive new crotofolanes, named crotocascarins R-V (1-5), one rearranged trinorcrotofolane, crotocascarin δ, and one phorbol derivative were isolated from the EtOAc-soluble fraction of the MeOH extract of the leaves of Croton cascarilloides. Crotocascarins R (1), T (3), and U (4) possessed isobutyric acid as an acyl moiety and crotocascarin B (2) an acetyl group, whereas crotocascarin V (5) was elucidated to be a hydroxylated compound of crotocascarin K at the 9-position. Crotocascarin δ (6) was a trinor rearranged crotofolane with a tertiary hemiketal functional group at the 8-position.
View Article and Find Full Text PDFBackground: A bisresorcinol was isolated as the main constituent of 's trunk (Proteaceae). Recently, resorcinol is applied as an active whitening agent in various cosmetic products. Because of the structural mimic to resorcinol, benefits of the bisresorcinol as an aging-enzyme antagonist were demonstrated in this study.
View Article and Find Full Text PDFFrom the leaves of Ardisia quinquegona, two alkylated tetronic acid derivatives, named ardisiatetrons A and B (1, 2), and four triterpenoids (3-6) were isolated together with one known compound (7) by a combination of various kinds of chromatography. The structure of new methyl migrated triterpene (3) was confirmed by X-ray crystallographic analysis. Compounds 2, 3, and 7 showed moderate anti-Leishmania activity and cytotoxicity towards A549 cells.
View Article and Find Full Text PDFChemical conversion of the extract of natural resources is a very attractive way to expand the chemical space to discover bioactive compounds. In order to search for new medicines to treat parasitic diseases that cause high morbidity and mortality in affected countries in the world, the ethyl acetate extract from the rhizome of (L.) has been chemically converted by epoxidation using dioxirane generated in situ.
View Article and Find Full Text PDFAn investigation into the methanol extracts obtained from the stems of Dodonaea viscosa led to the isolation of one nor-clerodane diterpene (1) and two labdane diterpenes (2, 3), as well as 17 known compounds (4-20). The structures of these compounds were elucidated based on chemical and spectral evidence. The stereochemical structure of the nor-clerodane diterpene was confirmed via its circular dichroism spectrum and calculated electronic circular dichroism spectrum.
View Article and Find Full Text PDFExtensive phytochemical work on the 1-BuOH-soluble fraction of a MeOH extract of the leaves of Symplocos cochinchinensis var. philippinensis resulted in the isolation of 14 new triterpenene saponins, along with four known ones. Their structures were elucidated by comparison of NMR spectroscopic data with related compounds reported in the literature.
View Article and Find Full Text PDFFrom the leaves of Zanthoxylum ailanthoides, four new phenolic glucosides, termed zanthosides A-D (1-4), were isolated. Their structures were elucidated by means of spectroscopic evidence. Zanthoside A was enzymatically hydrolyzed and thus the aglycone obtained was found to be (1'S,2'R)-(-)-trans-decursidinol, isolated from Angelica decursiva.
View Article and Find Full Text PDFTwo new tri-ferulates of sucrose, firmosides A and B (1 and 2, respectively), together with 18 known compounds (3-20), were isolated from the aerial parts of Silene firma. The structures of the isolated compounds were elucidated by various spectroscopic methods, including 1D, 2D NMR, and high-resolution electro-spray ionization-mass spectrometry (HR-ESI-MS). All the isolated compounds were evaluated for their free radical scavenging activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical.
View Article and Find Full Text PDFIn our continuing research for bioactive constituents from natural resources, a new methyl threonolactone glucopyranoside (), a new methyl threonolactone fructofuranoside (), 2 new pyroglutamates ( and ), and 10 known compounds (-) were isolated from the whole plant of (L.) L. The structures of these compounds were determined based on various spectroscopic and chemical analyses.
View Article and Find Full Text PDFThe 1-BuOH-soluble fraction of the methanol (MeOH) extract of Diospyros maritima was separated by chromatographic techniques to give three new oleanane-type and one new ursane-type triterpene glucoside, named ebenamariosides A-D (1-4); two megastigmanes were also isolated. The structures of triterpene glucosides was elucidated with extensive investigation by one and two dimensional NMR spectroscopy and the structures were confirmed by partial enzymatic hydrolyses to give the corresponding mono-glucosides and aglycones. The structures of the megastigmanes, including their absolute stereochemistries, were elucidated by spectroscopic evidence and by the modified Mosher's method.
View Article and Find Full Text PDFThe genus (Rubiaceae) consists of approximately 180 species, of which the greatest species diversity is found in tropical Asia. Some of the species have been used in folk medicine to treat tinnitus, arthritis, fever, and bleeding. (Lour.
View Article and Find Full Text PDFHemichorea is relatively an uncommon clinical presentation while its known etiology are vascular, metabolic, neoplastic, infectious, autoimmune, and inherited disorders. In the acquired case of hemichorea, the most common cause is the cerebrovascular insult, which is often diagnosed by the magnetic resonance (MR) imaging. An 84-year-old woman reported a one-week history of involuntary movements in the left side of her face and left limbs.
View Article and Find Full Text PDFFive eudesmane-type sesquiterpene glycosides, named sonneratiosides A-E (1-5), were isolated from the leaves of Sonneratia alba (Lythraceae). The aglycone of sonneratioside A was identified as cryptomeridiol also known as proximadiol. X-ray crystallographic analysis of sonneratioside A confirmed its structure and its absolute stereochemistry.
View Article and Find Full Text PDFA 43-year-old Japanese woman visited a clinic with a 2-week history of visual loss, hyperemia, and bilateral eye pain. Dilated fundus and optical coherence tomography showed hyperemic optic disc and multifocal serous retinal detachments. Fundus fluorescein angiography revealed optic disc leakage and numerous hyperfluorescent pinpoints of leakage, which are typical of Vogt-Koyanagi-Harada disease (VKHD).
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