Reactive oxygen/nitrogen species generated in the human body can cause oxidative damage associated with many degenerative diseases such as atherosclerosis, dementia, coronary heart diseases, aging, and cancer. There is a great interest in developing new antioxidants from Ganoderma fungus due to its low toxicity. As part of our ongoing search for antioxidative constituents from the fruiting bodies of Ganoderma lucidum, the chemical constituents were investigated and seven secondary metabolites, including one new lanostane triterpene (1), two known aromatic meroterpenoids (6–7), and four known triterpenes (2–5), were isolated by a series of chromatographic methods. The structures of the seven compounds were elucidated by spectroscopic techniques. The isolated compounds were tested in vitro for antioxidant potencies and neuroprotective activities against H2O2 and aged Aβ-induced cell death in SH-SY5Y cells. As a result, compounds 1, 6, and 7 exhibited potent antioxidant and neuroprotective activities. Additionally, all isolated compounds were tested for radical scavenging activities. Compounds 6 and 7 showed the comparable free radical scavenging activities with the standard drug in both ABTS (2, 2’-azobis (3-ethylbenzothiazole-6-sulfonaic acid)) and ORAC (oxygen radical absorbance capacity) experiments. The results from this study suggested that G. lucidum and its metabolites (especially the meroterpenoids) may be potential functional food ingredients for the antioxidation and prevention of neurogenerative diseases.
Three new cucurbitane triterpenoids 1–3 and one new steroidal glycoside 4, were isolated together with ten known compounds from Momordica charantia. The structures of new compounds were determined to be 19(R)-n-butanoxy-5β,19-epoxycucurbita-6,23-diene-3β,25-diol 3-O-β-glucopyranoside (1), 23-O-β-allopyranosylecucurbita-5,24-dien-7α,3β,22(R),23(S)-tetraol 3-O-β-allopyranoside. (2), 23(R),24(S),25-trihydroxycucurbit-5-ene 3-O-{[β-glucopyranosyl(1→6)]-O-β-glucopyranosyl}-25-O-β-glucopyranoside (3), and 24(R)-stigmastan-3β,5α,6β-triol-25-ene 3-O-β-glucopyranoside (4), respectively. Their structures were elucidated by the combination of mass spectrometry (MS), one and two-dimensional NMR experiments and chemical reactions.
Fucoidans and alginates extracted from Sargassum graminifolium showed significant activities of anti-food allergy and regulating intestinal microbiota, and the relationship between intestinal microbiota and anti-food allergies effects was close.
Three series of compounds were designed, synthesized and evaluated for their in vitro anticancer activity against a procaspase-3 over-expression cancer cell line (U937) and a procaspase-3 no-expression cancer cell line (MCF-7) to rule out off-target effects. Biological evaluation led to the identification of a series of benzothiazole derivatives bearing a pyridine-semicarbazone moiety, 8j and 8k, with promising anticancer activity and remarkable selectivity. Further mechanism studies revealed that compounds 8j and 8k could induce apoptosis of cancer cells by activating procaspase-3 to caspase-3, and compound 8k exhibited the strongest procaspase-3 activation activity. Structure–activity relationships (SARs) revealed that the presence of benzothiazole and an N,N,O-donor set is crucial for the anticancer activity and selectivity, and reducing the electron density of the N,N,O-donor set results in a dramatic decline in the anticancer activity and selectivity. Furthermore, toxicity evaluation (zebrafish) in vivo and metabolic stability studies (human, rat and mouse liver microsomes) were performed to provide reliable guidance for further PK/PD studies in vivo.