Rong-Tao Li

Applanatumin A, a New Dimeric Meroterpenoid from Ganoderma applanatum That Displays Potent Antifibrotic Activity

Applanatumin A (1), a novel meroterpenoid dimer, was isolated from the fungus Ganoderma applanatum. Its structure and absolute configuration were assigned on the basis of spectroscopic and computational data. Notably, 1 possesses a new hexacyclic skeleton containing a spiro[benzofuran-2,1-cyclopentane] motif. A plausible pathway, involving a key Diels-Alder reaction, is proposed for the biosynthesis of 1. Applanatumin A exhibits potent antifibrotic activity in TGF-β1-induced human renal proximal tubular cells.

Cochlearols A and B, Polycyclic Meroterpenoids from the Fungus Ganoderma cochlear That Have Renoprotective Activities

(+)- and (-)-cochlearols A (1) and B (2), two meroterpenoids with novel polycyclic skeletons, were isolated from the fruiting bodies of the fungus Ganoderma cochlear. Their structures and stereochemistry were determined by using spectroscopic, computational and single-crystal X-ray diffraction methods. Cochlearol A is a new normeroterpenoid containing a naturally unusual dioxaspiro[4.5]decane motif. Biological studies showed that (-)-2 is a strong inhibitor of p-Smads, exhibiting renoprotective activities in TGF-β1 induced rat renal proximal tubular cells.

Lyonin A, a New 9,10‐Secograyanotoxin from Lyonia ovalifolia

Phytochemical studies on the branches and leaves of Lyonia ovalifolia yielded a new grayanane diterpenoid, lyonin A (1), together with two known compounds, secorhodomollolides A and D (2 and 3, resp.). The structure of 1 was elucidated by combination of 1D‐ and 2D‐NMR, and MS analyses. Compound 1 turned out to be a new, highly O‐acylated grayanane diterpenoid, of which ring B has undergone an oxidative cleavage between C(9) and C(10), yielding a system differing from the previously reported grayanane type with a 5/7/6/5 ring system. Results of the cAMP regulation activity assay showed that compounds 2 and 3 at 50u2005μM induced a significantly decreased cAMP level in N1E‐115 neuroblastoma cells (p<0.001), indicating neuropharmacological potential.

New grayanol diterpenoid and new phenolic glucoside from the flowers of Pieris formosa

A new grayanol diterpenoid, grayanotoxin XXII (1), and a new phenolic glucoside, benzyl 2-hydroxy-4-O-[β-xylopyranosyl(1″ → 6′)-β-glucopyranosyl]-benzoate (2), were isolated from the flowers of Pieris formosa. Their structures were determined on the basis of spectroscopic analysis and chemical methods.

New cytotoxic and anti-inflammatory compounds isolated from Morus alba L.

Six Diels–Alder adducts (1–6) and nine prenylated flavanones (7–15) were isolated from the root bark of Morus alba L. Among them, soroceal B (1) and sanggenol Q (7) were new compounds. Their structures were elucidated on the basis of extensive spectroscopic methods, including 1D and 2D NMR techniques. Compounds 1–3, 9, 10, 12, 13 and 15 exhibited cytotoxic activity against five human tumour lines and compound 2 inhibited significantly selective cytotoxic activities towards HL-60 and AGS cells with IC50 of 3.4 and 3.6 μM. Compounds 3, 5, 9 and 12 exhibited moderate inhibitory activity against nitric oxide production in LPS-activated RAW264.7.

Pierisformotoxins A-D, Polyesterified Grayanane Diterpenoids from Pieris formosa and Their cAMP-Decreasing Activities

Four highly acylated diterpenoids, designated as pierisformotoxins A–D (1–4, resp.), along with 26 known compounds, were isolated from the flowers of Pieris formosa. Among them, pierisformotoxins A and B (1 and 2, resp.) were new highly acylated grayanane diterpenoids, of which the five‐membered ring A has undergone an oxidative cleavage between C(3) and C(4), followed by lactonization, to give rise to a five‐membered lactone ring between C(3) and C(5), differing from the previously reported grayanane diterpenoids with a 5/7/6/5 ring system. Results of the cAMP‐regulation‐activity assay showed that pierisformotoxin C (3) at 10u2005μM (inhibitory ratio (IR): 10.1%) or 2u2005μM (9.8%), and pierisformotoxin B (2) at 50u2005μM (13.9%) significantly decreased the cAMP level in N1E‐115 neuroblastoma cells (p<0.05).

Neopierisoids A and B, Two New Chlorinated 3,4-seco-Grayanane Diterpenoids with Antifeedant Activity from Flowers of Pieris japonica

Two new chlorinated multiacylated 3,4-seco-grayanane diterpenoids, neopierisoids A and B (1 and 2), were isolated from flowers of the poisonous plant Pieris japonica and were identified from spectroscopic analysis and X-ray diffraction data. Both compounds showed obvious antifeedant activity against Pieris brassicae with an EC50 of 10.07 μg/cm(2) for 1 and 5.33 μg/cm(2) for 2, indications of toxic properties. Chlorinated 3,4-seco-grayanane diterpenoids in P. japonica may play a defensive role against herbivores.

Schisanlactone H and sphenanthin A, new metabolites from Schisandra sphenanthera

From the fruits of Schisandra sphenanthera (Schisandraceae), a new 3,4-seco-lanostane triterpenoid, schisanlactone H (1), and a new monocyclofarnesane sesquiterpenoid, sphenanthin A (2), were isolated. Their structures were elucidated by spectroscopic methods including extensive 1D and 2D NMR techniques.

Two new grayanane diterpenoids from the flowers of Rhododendron molle

A phytochemical investigation of the flowers of Rhododendron molle has yielded two new grayanane diterpenoids, rhodomolleins F and G (1, 2). Compounds 1 and 2 possessed an oxo-bridge between C-5 and C-9, and their structures were elucidated on the basis of interpretation of spectroscopic data, including 1D and 2D NMR techniques.

Minor Compounds from Fungus Ganoderma cochlear

Abstract Objective To study the chemical constituents of the fungus Ganoderma cochlear. Methods The compounds were isolated by using MCI gel CHP 20P, Sephadex LH-20, RP-18 column chromatography, and preparative TLC. The structures were identified by means of spectroscopic methods. Results Two phenolic normeroterpenoid and meroterpenoid, cochlearols C and D ( 1 and 2 ), together with six benzene derivatives, 3-methoxy-4-hydroxy-phenylethanol ( 3 ), 4-hydroxyacetophenone ( 4 ), p -hydroxycinnamic methyl ester ( 5 ), 2-methoxy-4-hydroxybenzaldehyde ( 6 ), 4-hydroxy-3-methoxy benzoic acid ( 7 ), and 2-hydroxy-5-ethoxybenzoic acid ( 8 ), were isolated from the fruiting bodies of Ganoderma cochlear. Conclusion Compounds 1 and 2 are new phenolic normeroterpenoid and meroterpenoid, respectively.