Bing-Xin Zhao

Flueggines A and B, Two New Dimeric Indolizidine Alkaloids from Flueggea virosa

Two unprecedented C,C-linked dimeric indolizidine alkaloids, flueggines A (1) and B (2), were isolated from the twigs and leaves of Flueggea virosa. The structures and absolute configurations were elucidated by means of NMR, single-crystal X-ray diffraction, and CD analyses. Compound 1 is the first example of Securinega alkaloids bearing an isoxazolidine ring, the plausible biogenetic pathway of which is also proposed. Compound 2 exhibited growth inhibitory activity against MCF-7 and MDA-MB-231 human breast cancer cells.

Virosaines A and B, two new birdcage-shaped Securinega alkaloids with an unprecedented skeleton from Flueggea virosa.

Two new Securinega alkaloids, virosaines A (1) and B (2), were isolated from the twigs and leaves of Flueggea virosa. The structures and absolute configurations were elucidated by means of NMR, X-ray diffraction, and CD analyses. Compounds 1 and 2 represent the first examples of Securinega alkaloids bearing a 7-oxa-1-azabicyclo[3.2.1]octane ring system, whose plausible biogenetic pathways were also proposed.

The application of click chemistry in the synthesis of agents with anticancer activity

The copper(I)-catalyzed 1,3-dipolar cycloaddition between alkynes and azides (click chemistry) to form 1,2,3-triazoles is the most popular reaction due to its reliability, specificity, and biocompatibility. This reaction has the potential to shorten procedures, and render more efficient lead identification and optimization procedures in medicinal chemistry, which is a powerful modular synthetic approach toward the assembly of new molecular entities and has been applied in anticancer drugs discovery increasingly. The present review focuses mainly on the applications of this reaction in the field of synthesis of agents with anticancer activity, which are divided into four groups: topoisomerase II inhibitors, histone deacetylase inhibitors, protein tyrosine kinase inhibitors, and antimicrotubule agents.

Chrysamides A–C, Three Dimeric Nitrophenyl trans-Epoxyamides Produced by the Deep-Sea-Derived Fungus Penicillium chrysogenum SCSIO41001

Three dimeric nitrophenyl trans-epoxyamides, chrysamides A-C (1-3), were obtained from the deep-sea-derived fungus Penicillium chrysogenum SCSIO41001. Their structures were characterized by spectroscopic analysis, electronic circular dichroism computations, and X-ray single-crystal diffraction analysis. Notably, compound 1 possesses a novel centrosymmetric dimer skeleton featuring an unprecedented 7-oxa-2,5-diazabicyclo[2.2.1]heptane ring system, which represents the first example of dimeric nitrophenyl trans-epoxyamide in nature. Compound 3 suppresses the production of proinflammatory cytokine interleukin-17. A possible biosynthetic pathway of 1-3 was proposed.

Guapsidial A and Guadials B and C: Three New Meroterpenoids with Unusual Skeletons from the Leaves of Psidium guajava

A novel sesquiterpene-based Psidium meroterpenoid, possessing an unusual coupling pattern, and two new monoterpene-based meroterpenoids with unprecedented skeletons were isolated from the leaves of Psidium guajava. Their structures and absolute configurations were elucidated by spectroscopic, X-ray diffraction, and computational methods. The plausible biosynthetic pathway of these meroterpenoids as well as their cytotoxicities toward HepG2 and HepG2/ADM cells were also discussed.

(+)- and (-)-Cajanusine, a Pair of New Enantiomeric Stilbene Dimers with a New Skeleton from the Leaves of Cajanus cajan

A pair of new enantiomeric stilbene dimers, (+)- and (-)-cajanusine [(+)-1 and (-)-1], with a unique coupling pattern were isolated from the leaves of Cajanus cajan . Their structures including absolute configurations were elucidated on the basis of comprehensive spectroscopic and single-crystal X-ray diffraction analyses, as well as CD calculations. The plausible biogenetic pathway of 1 was also proposed. Additionally, (±)-1, (+)-1, and (-)-1 exhibited inhibitory activities on the growth of human hepatocellular carcinoma cells.

Suffrutines A and B: A Pair of Z/E Isomeric Indolizidine Alkaloids from the Roots of Flueggea suffruticosa

Suffrutines A (1) and B (2), a pair of novel photochemical Z/E isomeric indolizidine alkaloids, with a unique and highly conjugated C20 skeleton, were isolated from the roots of Flueggea suffruticosa. The structures were elucidated by extensive analysis of NMR spectra and single-crystal X-ray diffraction. The light-induced isomerization and hypothetical biogenetic pathway to 1 and 2, as well as their activity for regulating the morphology of Neuro-2a cells are also discussed.

Five new stilbene glycosides from the roots of Polygonum multiflorum

Five new stilbene glycosides (1–5), together with six known ones, were isolated from the roots of Polygonum multiflorum. Their structures were elucidated on the basis of spectroscopic analysis and chemical evidence.

A new α-pyrone from the deep-sea actinomycete Nocardiopsis dassonvillei subsp. dassonvillei DSM 43111(T)

Abstract A new α-pyrone, nocapyrone S (1), together with five known compounds (2-6), were isolated from the deep-sea actinomycete Nocardiopsis dassonvillei subsp. dassonvillei DSM 43111(T). Their structures were determined by spectroscopic analyses. The absolute configuration of 1 was established by quantum approaches. Cytotoxic activity of 1 was evaluated against K562, MCF-7, SGC7901, A375, Hela, and HepG2 cell lines.

Two new euglobals from the leaves of Eucalyptus robusta

Two new euglobals, R1 (1) and R2 (2), together with eight known euglobals (3–10) were isolated from the leaves of Eucalyptus robusta. Their structures were established by means of spectroscopic analysis and single-crystal X-ray diffraction. Euglobal R1 (1) represents a new skeleton of formyl-isovaleryl phloroglucinol-coupled β-phellandrene.