Shan-Zhai Shang

New Bicyclo[3.1.0]hexane Unit ent-Kaurane Diterpene and Its seco-Derivative from Isodon eriocalyx var. laxiflora

Neolaxiflorin A (1), an unprecedented ent-kaurane diterpenoid with a bicyclo[3.1.0]hexane unit, and its seco-derivative, neolaxiflorin B (2), along with two known compounds 3 and 4 were isolated from the leaves of Isodon eriocalyx var. laxiflora. The absolute configuration of 1 was determined by spectral methods and single crystal X-ray diffraction analysis. Compound 4 and the synthesized compound 5 exhibited significant cytotoxicity.

Biphenyls from Nicotiana tabacum and their anti-tobacco mosaic virus

Five new biphenyls, tababiphenyls A-E (1-5), together with five known ones (5-10), were isolated from the leaves of Nicotiana tabacum, of which compound 1 possessed a seldom reported 6-carbons unit in biphenyls. Their structures were established on the basis of extensive spectroscopic analyses. All compounds were tested for their anti-tobacco mosaic virus (anti-TMV) activities. The results showed that compounds 3 and 5 exhibited high anti-TMV activities with inhibition rate of 48.4% and 32.1%, respectively, which were higher than that of positive control (ningnanmycin). The other compounds also showed potential anti-TMV activities with inhibition rates in the range of 18.6-28.7%, respectively.

Kadcoccitones A and B, Two New 6/6/5/5-Fused Tetracyclic Triterpenoids from Kadsura coccinea

A pair of new triterpenoid epimers, kadcoccitones A (1) and B (2), together with a new biogenetically related compound kadcoccitone C (3), were isolated from Kadsura coccinea. The epimers featured an unprecedented carbon skeleton with a 6/6/5/5-fused tetracyclic ring system unit and a C(9) side chain. Their structures were determined by spectroscopic data, ECD calculation, and single-crystal X-ray diffraction. Compounds 1 and 3 showed anti-HIV-1 activity with an EC(50) value of 47.91 and 32.66 μg/mL, respectively.

Lanostane Triterpenoids from the Stems of Schisandra glaucescens

Ten new triterpenoids, schiglausins A-J (1-10), as well as four known compounds, were isolated from the stems of Schisandra glaucescens. Their structures were elucidated on the basis of spectroscopic methods, including extensive NMR spectra and CD experiment. Compound 8 was determined to be a norlanostane triterpenoid. The crystal structure of compound 1 has been determined using single-crystal X-ray analysis while its absolute configuration was assigned on the basis of the CD spectrum. All isolates were tested for their FXR agonistic and antagonistic effects.

Antiviral sesquiterpenes from leaves of Nicotiana tabacum

Three unreported sesquiterpenes possessing two new skeletons, tabasesquiterpenes A-C (1-3), together with three known sesquiterpenes (3-6) were isolated from the leaves of Nicotiana tabacum. Their structures were determined mainly by spectroscopic methods, including extensive 1D- and 2D-NMR techniques. Compounds 1-6 were evaluated for their anti-tobacco mosaic virus (anti-TMV) activities. The results showed that compound 2 exhibited high anti-TMV activity with inhibition rate of 35.2%, which were higher than that of positive control (ningnanmycin). The other compounds also showed potential anti-TMV activity with inhibition rates in the range of 20.5-28.6%.

Six new lignans from the leaves and stems of Schisandra sphenanthera

Six new lignans, schisphenlignans F-K (1-6), together with ten known ones, were isolated from the leaves and stems of Schisandra sphenanthera. Their structures were elucidated on the basis of spectroscopic methods, including extensive NMR, MS and CD spectra. In addition, some compounds were tested for their acute activity on insulin sensitivity in 3T3-L1 differentiated adipocytes and anti-HIV-1 activity.

Structural Characterization and Antioxidative Activity of Lancifonins: Unique Nortriterpenoids from Schisandra lancifolia

Six unique nortriterpenoids, lancifonins A-F (1-6), were isolated from Schisandra lancifolia. Their absolute configurations were determined by X-ray diffraction and ECD calculation. The conformational analysis of 1 was performed due to the unanticipated changes of Cotton effects in its ECD spectrum. Compounds 5 and 6 possess a unique 7/7 fused carbocyclic core with an internal ester bridge between C-9 and C-14, and 5 exhibited protective activity against H2O2-induced oxidative damage on Caco-2 cells.

Anti-HIV-1 activity of lignans from the fruits of Schisandra rubriflora

This study investigated the 70% aqueous acetone extract of the fruits of Schisandra rubriflora which led to the isolation of eight lignans, including a new isolate, rubrisandrin C (1), and seven known lignans (2–8). The structure of 1 was established by extensive 1D and 2D NMR spectroscopy and its absolute stereochemistry was determined by CD spectrum. Compounds 1–5 and 7–8 were evaluated for their anti-HIV-1 activity that showed inhibitory activity on HIV-1IIIB induced syncytium formation with EC50 values in the range of 2.26∼20.4 μg/mL. Compounds 1 and 7 exerted their obvious protection of HIV-1IIIB inducted MT-4 host cells lytic effects with a selectivity index of 15.4 and 24.6, respectively.

Bioactive phenolics and terpenoids from Manglietia insignis

Four new compounds, maninsigins A-D (1-4), including two new neolignans (1-2) and two new sesquiterpenes (3-4), as well as ten known compounds (5-14), were isolated from the leaves and stems of Manglietia insignis. Their structures were established on the basis of extensive spectroscopic analyses. In addition, some compounds were tested for their cytotoxic and neurite outgrowth-promoting activities, as well as their antagonistic activity toward FXR ligand.

Four new indole alkaloids from Plantago asiatica.

Four new indole alkaloids, plasiaticines A-D (1–4), together with two known ones, were isolated from the seeds of Plantago asiatica. The structures of the new compounds were elucidated on the basis of comprehensive analysis of spectroscopic data. All compounds were tested for their cytotoxic activity, and all compounds except 4 were tested for their acetylcholinesterase (AChE) inhibitory activities.Graphical abstract