Cucurbitane-type triterpenoids from the vines of Momordica charantia and their anti-inflammatory, cytotoxic, and antidiabetic activity

The recent advance and prospect of natural source compounds for the treatment of heart failure

Heart failure is a continuously developing syndrome of cardiac insufficiency caused by diseases, which becomes a major disease endangering human health as well as one of the main causes of death in patients with cardiovascular diseases. The occurrence of heart failure is related to hemodynamic abnormalities, neuroendocrine hormones, myocardial damage, myocardial remodeling etc, lead to the clinical manifestations including dyspnea, fatigue and fluid retention with complex pathophysiological mechanisms. Currently available drugs such as cardiac glycoside, diuretic, angiotensin-converting enzyme inhibitor, vasodilator and β receptor blocker etc are widely used for the treatment of heart failure. In particular, natural products and related active ingredients have the characteristics of mild efficacy, low toxicity, multi-target comprehensive efficacy, and have obvious advantages in restoring cardiac function, reducing energy disorder and improving quality of life. In this review, we mainly focus on the recent advance including mechanisms and active ingredients of natural products for the treatment of heart failure, which will provide the inspiration for the development of more potent clinical drugs against heart failure.

Four cucurbitane glycosides taimordisins A–D with novel furopyranone skeletons isolated from the fruits of Momordica charantia

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Four new cucurbitane-type triterpenoids glycosides were isolated from the fresh fruit of Momordica charantia and determined by NMR, HRESIMS, and biosynthesis.

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Taimordisins A and B possess rare bicyclic-fused and trifuso-centro-fused ring systems at side chain of the cucurbitane-type triterpenoids at the first time.

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Taimordisins A-D showed the inhibition of NO production by LPS-stimulated in RAW264.7 macrophage cells.

Four novel triterpene glycosides, taimordisins A–D (1–4), were discovered from fresh fruits of Taiwanese Momordica charantia. The chemical framework and relative stereochemistry of these four natural products were isolated, purified, and determined by using various separation and spectroscopy techniques. Each of them features a unique bicyclic-fused or trifuso-centro-fused ring system. Notably, 1 and 2 are cucurbitane-based compounds possessing a new C-24 and C-2″ carbon–carbon linkage with 5-hydroxy-2-(hydroxymethyl)tetrahydro-4H-pyran-4-one and 6-(hydroxymethyl)tetrahydro-4H-pyran-3,4,4-triol units, respectively, and represented an unprecedented molecular skeleton. In terms of biosynthesis, they all originate from a common precursor 3-hydroxycucurbita-5,24-dien-19-al-7,23-di-O-β-glucopyranoside. Of two sugar moieties, the one at 23-O-β-glucopyranoside grants each individual congener uniqueness likely through microbial symbiont-mediated intramolecular transformation into two major types of furo[2,3-b]pyranone and furo[3,2-c]pyranone derivatives. These new products possess desirable anti-inflammatory biological activities in addition to being generally regarded as safe.

Pimarane, abietane, and labdane diterpenoids from Euphorbia pekinensis Rupr. and their anti-tumor activities

Chemical investigation of the roots of Euphorbia pekinensis Rupr. led to the isolation of five undescribed labdane diterpenoids "(4S, 5S, 9R, 10S, 13R)-18-O-galloyl-labda-8(17), 14(15)-dien-13-ol; (4S, 5S, 9R, 10S, 13R)-13-hydroxy-labda-8(17), 14(15)-dien-18-one; (4S, 5S, 9R, 10S, 13R)-18-O-acetyl-labda-8(17), 14(15)-dien-13-ol; (4S, 5S, 9R, 10S)-labda-8(17), 13(16), 14(15)-trien-18-ol; (5R, 6R, 9R, 10S, 13R)-labda-8(17), 14(15)-dien-6,13-diol", two undescribed pimarane diterpenoids "(2R, 5S, 9R, 10S, 12R, 13R)-2,12-dihydroxy-isopimara-7,15-dien-3-one; (5S, 9R, 10S, 12R, 13R)-2, 12-dihydroxy-isopimara-1, 7, 15-trien-3-one)", together with nine known diterpenoids, including three pimarane-type "(3β,11α,13α)-3,11-dihydroxypimara-7,15-diene-2,12-dione; (11R, 12S)-2,11,12-trihydroxy-ent-isopimara-1,7,15-trien-3-one; isopimara-7,15-dien-3β-ol)", five abietane-type "helioscopinolide A-C; helioscopinolide E; helioscopinolide I″, and one lathyrane-type "jolkinol B". The structures of these compounds were elucidated by analysis of HRESIMS, 1D NMR, 2D NMR, and X-ray diffraction. These sixteen compounds were evaluated for cytotoxic activity in vitro against three human cancer cell lines, U-937, LOVO, and K-562. Jolkinol B exhibited IC₅₀ of 3.60 μM and 8.44 μM against U-937 and LOVO cell lines, (4S, 5S, 9R, 10S, 13R)-18-O-galloyl-labda-8(17), 14(15)-dien-13-ol displayed IC₅₀ of 5.92 μM against U-937 cell lines, isopimara-7,15-dien-3β-ol showed IC₅₀ of 0.87 μM against K-562 cell lines.