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A facile and straightforward method was developed to construct the fused tetracyclic 3-spirooxindole skeleton, which exists widely in natural products. The formation of the tetracyclic 3-spirooxindole structure was achieved through a transition-metal-free intramolecular cross-dehydrogenative coupling of pyridinium, which were formed in situ by the(More)
A small focused library which comprised of l-AA lactone derivatives was built with a facile method. This reported method was optimized by modifying the acidity of the solvent. As a result, 12 l-AA lactones were synthesized. Among these lactones, lactones 8–12 were new compounds. The cytotoxicity of these synthetic compounds were investigated.
Interstitial leukocyte migration plays a critical role in inflammation and offers a therapeutic target for treating inflammation-associated diseases such as multiple sclerosis. Identifying small molecules to inhibit undesired leukocyte migration provides promise for the treatment of these disorders. In this study, we identified vibsanin B, a novel(More)
Inspired by natural 11β-HSD1 inhibitors hupehenols A - E, a ring-focused strategy was applied for the synthesis of 35 structurally diverse dammarane-type derivatives. These derivatives were effectively prepared from protopanaxadiol based on the modification of rings A and D. Among these compounds, ten were identified as selective 11β-HSD1 inhibitors (IC50(More)
Euphorbia peplus has been used in traditional medicine to treat asthma and psoriasis. Three highly modified diterpenoids, namely, pepluacetal (1) and pepluanol A-B (2-3), have been isolated and identified from this plant. Compounds 1-3 exhibit unprecedented 5/4/7/3, 5/6/7/3, and 5/5/8/3 ring systems, respectively. Their structures with absolute(More)
A novel segetane diterpenoid (1) and four jatrophane diterpenoids (2-5) were isolated from an acetone extract of Euphorbia peplus. Due to quantity limitations, we prepared 1 via a Diels-Alder reaction, an approach motivated by this compound's biosynthetic pathway and successfully performed X-ray analysis of 1. Furthermore, in an in vitro activity test, 1(More)
Sauruchinenols A (1) and B (2), two novel monocyclic diterpenes with unique carbon skeleton, as well as two new structurally related diterpenes, sauruchinenols C (3) and D (4), were isolated from the aerial part of Saururus chinensis. Their structures were elucidated based on the analysis of spectroscopic data. A hypothetical biogenetic pathway for(More)
Direct transformation of bulk crystals to single-crystalline crystallographically oriented semiconductor nanowire arrays is presented. Real-time imaging during in situ environmental scanning electron microscopy experiment clearly demonstrates that the nanowire arrays form through a selective vaporization process with respect to the crystallography of(More)
Vibsatins A (1) and B (2), a pair of 14,15,16,17-tetranorvibsane-type diterpenoids that feature a bicyclo[4.2.1]nonane moiety formed by a new C-13/C-2 bond, were isolated from the twigs and leaves of Viburnum tinus cv. variegatus. The structures and absolute configurations were elucidated by a combination of NMR spectra, optical rotation, and X-ray(More)
Two new lactone-containing selaginellins T and U (1 and 2) together with eleven known selaginellin derivatives (3 and 7-16) were isolated from the whole plant of Selaginella tamariscina. The structure of tautomeric selaginellin U along with its biogenetic pathway was confirmed and proposed by a cross-validation of the semisynthesis of compound 4 from(More)