Xing-De Wu

Lycopalhine A, a novel sterically congested Lycopodium alkaloid with an unprecedented skeleton from Palhinhaea cernua

A novel sterically congested Lycopodium alkaloid named lycopalhine A (1) that possesses a fused hexacyclic (5/5/5/6/6/6) ring system comprising a 5,9-diaza-tricyclo[6.2.1.0(4,9)]undecane moiety and a tricyclo[5.2.1.0(4,8)]decane moiety was isolated from Palhinhaea cernua L. The structure and absolute configuration were determined by spectroscopic and computational methods.

Terpenoids and Norlignans from Metasequoia glyptostroboides

Four new terpenoids, metaseglyptorin A (1), metasequoic acid C (2), 12α-hydroxy-8,15-isopimaradien-18-oic acid (3), and (-)-acora-2,4(14),8-trien-15-oic acid (4), and three new norlignans, metasequirins D-F (5-7), were isolated from Metasequoia glyptostroboides, together with 15 known compounds. Structures of the new compounds were determined by analysis of their spectroscopic data, and the absolute configuration of 7 was established by the modified Mosher method. All of the compounds were evaluated for cytotoxicity against five human tumor cell lines.

Isopalhinine A, a Unique Pentacyclic Lycopodium Alkaloid from Palhinhaea cernua

A new pentacyclic (5/6/6/6/7) Lycopodium alkaloid named isopalhinine A (1), which possesses a sterically congested architecture built with a tricyclo[4.3.1.0(3,7)]decane (isotwistane) moiety and a 1-azabicyclo[4.3.1]decane moiety, and palhinines B (2) and C (3) were isolated from Palhinhaea cernua. The structure and absolute configuration of 1 were elucidated by a combination of NMR spectra, optical rotation calculation, and X-ray diffraction experiment. A possible biogenetic pathway was also proposed.

Lycospidine A, a New Type of Lycopodium Alkaloid from Lycopodium complanatum

Lycospidine A (1), the first example of a Lycopodium alkaloid which contains an unprecedented five-membered A ring, was isolated from Lycopodium complanatum. The unique five-membered A ring in 1 indicates that carbons 2-5 in 1 are presumably derived from proline instead of the lysine biosynthetically, which suggests that 1 represent a new class of Lycopodium alkaloid. In addition, the unique structural feature and biosynthetic origin of 1 shed new insight into the structural diversity of Lycopodium alkaloid analogue libraries potentially accessible by engineered biosynthesis.

Isolation and Complete Structural Assignment of Lycopodium Alkaloid Cernupalhine A: Theoretical Prediction and Total Synthesis Validation

Cernupalhine A (1) is a trace Lycopodium alkaloid (0.7 mg) possessing a new C17N skeleton with an unusual hydroxydihydrofuranone motif newly isolated from Palhinhaea cernua L. Its complete structural assignment, including absolute stereochemistry, was established through a combination of high-field NMR techniques and computational methods and further unequivocal confirmation by the first asymmetric total synthesis. Following the first total synthesis of lobscurinine (3), 1 was achieved via regio- and stereoselective cyanide ion addition and subsequent acid treatment.

A cytotoxic cardenolide and a saponin from the rhizomes of Tupistra chinensis

A new cardenolide tupichinolide (1) and a new steroidal saponin tupichinin A (2), together with seven known compounds, were isolated from the rhizomes of Tupistra chinensis. Their structures were established using spectroscopic analysis and chemical methods. Compound 1 was the first cardenolide isolated from Tupistra chinensis and exhibited potent cytotoxicity against five human cancer cell lines: HL-60, SMMC-7721, A-549, MCF-7 and SW480.

New clerodane diterpenoids from the twigs and leaves of Croton euryphyllus

Three new nor-clerodane diterpenoids, crotoeurins A-C (1-3), together with four known ones were isolated from the twigs and leaves of Croton euryphyllus. Among them, crotoeurin A (1) is a new nor-clerodane diterpenoid dimer with a unique cyclobutane ring via a [2+2] cycloaddition. Their structures were elucidated by spectroscopic analyses and the stereochemistry of 1 was confirmed by single-crystal X-ray diffraction analysis. Compounds 1-3 exhibited neurite outgrowth-promoting activity on NGF-mediated PC12 cells at concentration of 10μM.

Chemical constituents from the aerial parts of Musella lasiocarpa

Phytochemical investigation of the aerial parts of the monotypic plant, Musella lasiocarpa, led to the isolation of four rare bicyclic diarylheptanoids, musellarins B-E (2–5), two new phenylphenalenones, 2-methoxy-9-(3′,4′-dihydroxyphenyl)-1Hphenalen-1-one (9), 2-methoxy-9-(3′-methoxy-4′-hydroxyphenyl)-1H-phenalen-1-one (10), a new acenaphtylene derivative, trans-(1S,2S)-3-(4′-methoxyphenyl)-acenaphthene-1,2-diol (13), and two new sucrose esters, 1,2′,3′,4′,6′-O-pentaacetyl-3-O-trans-pcoumaroylsucrose (16), 1,2′,3′,4′,6′-O-pentaacetyl-3-O-cis-p-coumaroylsucrose (17), together with nine known compounds. In addition, (4E,6E)-1-(3′,4′-dihydroxyphenyl)-7-(4″-hydroxyphenyl)-hepta-4,6-dien-3-one (15) was isolated for the first time from a natural source. The structures of new compounds were elucidated by analysis of their spectroscopic data. Compounds 2, 6, 8–10, 12, and 14 were cytotoxic toward several of the human tumor cell lines (HL-60, SMMC-7721, A-549, MCF-7, and SW480). Of these, the new compound 9 was the most potent one, with IC50 values of 5.8, 10.3, 6.3, 3.3, and 2.3 µM, respectively.

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.

Sesquiterpenoids from Tussilago farfara and Their Inhibitory Effects on Nitric Oxide Production

Tussilagone (TSL) and its allied sesquiterpenoids were considered as the main active principles of the flower buds of Tussilago farfara, which has been widely used in China as an antitussive herbal medicine. Six new bisabolane-type sesquiterpenoids, tussfararins A-F (1-6), along with 12 known sesquiterpenoids, were isolated from the flower buds of T. farfara. Structures of the new compounds were elucidated by extensive spectroscopic analysis. The biological analysis showed that compounds 1, 3, 6, and 7 inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells with IC50 values of 13.6-24.4 µM.