Dataset on the compounds from the leaves of Vietnamese Machilus thunbergii and their anti-inflammatory activity.

Machilus thunbergii has a history of traditional applications including treating dyspepsia, apoplexy, headaches, abdominal pain, abdominal distension, and leg edema [1]. It is also employed for alleviating allergies, inflammation, pain relief, promoting blood circulation, addressing costal chondritis, and sinusitis [2]. Research into the chemical composition of M. thunbergii has revealed the presence of lignans, flavonoids, lactones, and essential oils [1,[3], [4], [5]. While some investigations have explored the inhibitory effects of extracts and lignan compounds from this species on NO production [6], [7], [8], there has been no research into the flavonoids isolated from this plant and their potential for inhibiting NO production, given our reachable referencing. The ethyl acetate (EtOAc) soluble fraction of M. thunbergii leaves was subjected to column chromatography (CC) using silica gel and Sephadex LH-20 for compound isolation. Nuclear magnetic resonance (NMR) data primarily facilitated the determination of isolated compound structures. Anti-inflammatory activity was evaluated against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in macrophage RAW264.7 cells. Anti-inflammatory activity-guided fractionation led to the isolation of twelve secondary metabolites (1-12). The compounds were identified as quercetin (1), kaempferol (2), rhamnetin (3), quercitrin (4), hyperoside (5), reynoutrin (6), guaijaverin (7), afzelin (8), astragalin (9), rutin (10), kaempferol-3-O-rutinoside (11), and rhamnetin-3-O-rutinoside (12). Compounds 3, 5, 6, 9, 11, and 12 were isolated from M. thunbergii for the first time. Evaluation against LPS-induced NO production in macrophage RAW264.7 cells showed that 1-3 exhibited potent inhibitory activity with IC50 values of 15.45, 25.44, and 19.82 µM, respectively. Compounds 4-9 demonstrated IC50 values ranging from 42.15 to 67.42 µM, while 10-12 exhibited inactivity (IC50 > 100 µM).

Vietnamese Dalbergia tonkinensis: A Promising Source of Mono- and Bifunctional Vasodilators.

Hypertension is a risk factor for cardiovascular diseases, which are the main cause of morbidity and mortality in the world. In the search for new molecules capable of targeting KCa1.1 and CaV1.2 channels, the expression of which is altered in hypertension, the in vitro vascular effects of a series of flavonoids extracted from the heartwoods, roots, and leaves of Dalbergia tonkinensis Prain, widely used in traditional medicine, were assessed. Rat aorta rings, tail artery myocytes, and docking and molecular dynamics simulations were used to analyse their effect on these channels. Formononetin, orobol, pinocembrin, and biochanin A showed a marked myorelaxant activity, particularly in rings stimulated by moderate rather than high KCl concentrations. Ba2+ currents through CaV1.2 channels (IBa1.2) were blocked in a concentration-dependent manner by sativanone, 3'-O-methylviolanone, pinocembrin, and biochanin A, while it was stimulated by ambocin. Sativanone, dalsissooside, and eriodictyol inhibited, while tectorigenin 7-O-[ß-D-apiofuranosyl-(1→6)-ß-D-glucopyranoside], ambocin, butin, and biochanin A increased IKCa1.1. In silico analyses showed that biochanin A, sativanone, and pinocembrin bound with high affinity in target-sensing regions of both channels, providing insight into their potential mechanism of action. In conclusion, Dalbergia tonkinensis is a valuable source of mono- and bifunctional, vasoactive scaffolds for the development of novel antihypertensive drugs.

Anti-inflammatory xanthone derivatives from Garcinia delpyana.

Two new xanthones delpyxanthone A (1) and delpyxanthone B (3), together with four known ones, gerontoxanthone I (2), α-mangostin (4), cowanin (5) and cowanol (6) were isolated from the stem bark of Garcinia delpyana. The chemical structures of 1-6 were established mainly using nuclear magnetic resonance (NMR) and mass spectrometry (MS). The anti-inflammatory activity of the isolated compounds was evaluated against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW264.7 cells in vitro. Compounds 1-4 showed significant inhibitory activity against the LPS-induced NO production in RAW264.7 cells with IC50 values ranging from 14.5 to 28.2 µM, but the others were inactive. The results suggested that G. delpyana and its constituents might be potential anti-inflammatory agents on RAW 264.7 cells.[Formula: see text].

Vasorelaxing Activity of R-(-)-3'-Hydroxy-2,4,5-trimethoxydalbergiquinol from Dalbergia tonkinensis: Involvement of Smooth Muscle CaV1.2 Channels.

Dalbergia species heartwood, widely used in traditional medicine to treat various cardiovascular diseases, might represent a rich source of vasoactive agents. In Vietnam, Dalbergia tonkinensis is an endemic tree. Therefore, the aim of the present work was to investigate the vascular activity of R-(-)-3'-hydroxy-2,4,5-trimethoxydalbergiquinol isolated from the heartwood of D. tonkinensis and to provide circular dichroism features of its R absolute configuration. The vascular effects of R-(-)-3'-hydroxy-2,4,5-trimethoxydalbergiquinol were assessed on the in vitro mechanical activity of rat aorta rings, under isometric conditions, and on whole-cell Ba2+ currents through CaV1.2 channels (IBa1.2) recorded in single, rat tail main artery myocytes by means of the patch-clamp technique. R-(-)-3'-Hydroxy-2,4,5-trimethoxydalbergiquinol showed concentration-dependent, vasorelaxant activity on both endothelium-deprived and endothelium intact rings precontracted with the α 1 receptor agonist phenylephrine. Neither the NO (nitric oxide) synthase inhibitor Nω-nitro-L-arginine methyl ester nor the cyclooxygenase inhibitor indomethacin affected its spasmolytic activity. R-(-)-3'-Hydroxy-2,4,5-trimethoxydalbergiquinol-induced vasorelaxation was antagonized by (S)-(-)-Bay K 8644 and unaffected by tetraethylammonium plus glibenclamide. In patch-clamp experiments, R-(-)-3'-hydroxy-2,4,5-trimethoxydalbergiquinol inhibited IBa1.2 in a concentration-dependent manner and significantly decreased the time constant of current inactivation. R-(-)-3'-Hydroxy-2,4,5-trimethoxydalbergiquinol likely stabilized the channel in its closed state, as suggested by molecular modelling and docking simulation to the CaV1.2 channel α 1c subunit. In conclusion, D. tonkinensis species may represent a source of agents potentially useful for the development of novel antihypertensive drugs.

New Records of Potent In-Vitro Antidiabetic Properties of Dalbergia tonkinensis Heartwood and the Bioactivity-Guided Isolation of Active Compounds.

Alpha-glucosidase inhibitory activity has been commonly used for the evaluation of antidiabetic property in vitro. The aim of this study is to investigate and characterize Dalbergia tonkinensis as a potential source of antidiabetic compounds. The screening of the active parts used, such as trunk bark, heartwood, and the leaves of Dalbergia tonkinensis indicated that all these extracted parts used with methanol demonstrated potent α-glucosidase inhibitory activity. The in vitro antidiabetic property of Dalbergia tonkinensis was notably recorded for the first time and showed activity (EC50 = 0.17⁻0.78 mg/mL) comparable to those of reported potent herbal extracts (EC50 = 0.25⁻4.0 mg/mL) and higher activity than that of acarbose, a commercial antidiabetic drug (EC50 = 1.21 mg/mL). The stability tests revealed that the heartwood of Dalbergia tonkinensis extract (HDT) possesses high pH stability with relative activity in the range of 80⁻98%. Further bioassay-guided purification led to the isolation of 2 active compounds identified as sativanone and formononetin from the ethyl acetate fraction and water fraction of HDT, respectively. These α-glucosidase inhibitors (aGIs) show promising inhibition against various types of α-glucosidases. Remarkably, these inhibitors were determined as new mammalian aGIs, showing good effect on rat α-glucosidase. The results suggest that Dalbergia tonkinensis is a potent source of aGIs and suggest promise in being developed as functional food with antidiabetic efficacy. The results of this study also enrich our knowledge concerning current biological activity and constituents of Dalbergia tonkinensis species.