Lycopodine-Type Alkaloids from Lycopodium japonicum

Three new lycopodine-type alkaloids,4a-hydroxyanhydrolycodoline(1),4a,6a-dihydroxyanhydrolycodoline(2),and 6-epi-8b-acetoxylycoclavine(3),and an artifact,lycoposerramine G nitrate(4),along with seventeen related known compounds,were isolated from the club moss Lycopodium japonicum Thunb.ex Murray(Lycopodiaceae).Their structures were elucidated by extensive spectroscopic methods as well as X-ray analysis.Compounds 1–4 were evaluated for their acetylcholine esterase inhibitory activity.

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)-1H-phenalen-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-p-coumaroylsucrose(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 2.3μM,respectively.

Lycodine-Type Lycopodium Alkaloids from the Whole Plants of Huperzia serrata

t Three new lycodine-type Lycopodium alkaloids,namely 1-methyllycodine(1),8a-hydroxy-15,16-dehydro-desN-methyl-a-obscurine(2),N-methyl-16-hydroxyhuperzine B(3),and one new natural lycodine-type Lycopodium alkaloid,N-methylhuperzine A(4),along with 11 known analogues(5–15),were isolated from the whole plants of club moss Huperzia serrata.The structures of 1–4 were elucidated on the basis of NMR spectroscopic and mass spectrometry data.Among them,compound 1 was the first lycodine-type alkaloid possessing a methyl group at C-1.In addition,the structure of 5 was confirmed by the single-crystal X-ray crystallography data and its^(13)C NMR was reported for the first time in current study.Compounds 1–5 were tested their BACE1 inhibitory activity.

Carinatines A and B,Lycopodium Alkaloids from Phlegmariurus carinatus

Carinatine A(1),a C16N2-type Lycopodium alkaloid possessing a 5/6/6/6 ring system formed by a new C-4/C-12 bond,and carinatine B(2),the first derivative of lycojaponicumin C,along 16 known compounds,were isolated from the whole plant of Phlegmariurus carinatus.Their structures were elucidated based on the spectroscopic data.The two new isolates were no inhibitory activity for the acetylcholinesterase(AChE).

New Lycopodium alkaloids from Lycopodium obscurum

Three new Lycopodium alkaloids,obscurumines C-E(1-3),along with nine known compounds,were isolated from the club moss Lycopodium obscurum L.Structures of the new compounds were determined on the basis of their spectroscopic analysis and the relative configurations of 1 were established by X-ray crystallographic analysis.All the new isolates were tested for the acetylcholinesterase(AChE)inhibitory activity.

(±)-Evodiakine,A Pair of Rearranged Rutaecarpine-Type Alkaloids From Evodia rutaecarpa

(±)-Evodiakine(1a and 1b),a pair of rearranged rutaecarpine-type alkaloids with an unprecedented 6/5/5/7/6 ring system,were isolated from the nearly ripe fruits of Evodia rutaecarpa.Separation of the enantiomers have been achieved by chiral HPLC column.The structures of(±)-evodiakine were unambiguously elucidated by 1D and 2D NMR spectra,mass spectrometry,and single-crystal X-ray diffraction.Their absolute configurations were determined by comparison of experimental and calculated electronic circular dichroism spectra.A hypothetical biogenetic pathway for(±)-evodiakine was also proposed.Compounds 1a,1b,and the racemate(1)were tested for their cytotoxic and anti-inflammatory activities.

Isolation,Structural Assignment of Isoselagintamarlin A from Selaginella tamariscina and Its Biomimetic Synthesis

Isoselagintamarlin A(1),a selaginellin analogue featured a rare benzofuran unit,was isolated from Selaginella tamariscina.Its complete structural assignment was established through a combination of high-feld NMR technique and biomimetic synthesis.Notably,isoselagintamarlin A(1)was successfully synthesized via sequential oxidations and intramolecular cyclization.

Lycoplanines B-D,Three Lycopodium Alkaloids from Lycopodium complanatum

A novel Ci7N Lycopodium alkaloid(LA),lycoplanine B(1),containing an unusual formyl group,along with two new LAs,lycoplanines C(2)and D(3),were isolated from the whole plant of Lycopodium complanatum.Their structures were elucidated by extensive NMR techniques,including 1D-and 2D-NMR experiments,as well as comparing their spectral data with those of the known analogues.A possible biogenetic pathway for 1 was also proposed.

Euglobal-IIIa, a novel acylphloroglucinol-sesquiterpene derivative from Eucalyptus robusta: absolute structure and cytotoxicity

Euglobal-IIIa (1), a novel acylphloroglucinol-sesquiterpene derivative, and a known analogue, have been isolated from leaves of Eucalyptus robusta. The structures was elucidated by extensive spectroscopic data and by comparison with data reported in literature, while the absolute configuration of 1 was determined by the X-ray diffraction analysis. Compound 1 exhibited comparable cytotoxicity with that of cisplatin against five human cancer cell lines HL-60, SMMC-7721, A-549, MCF-7, and SW480 with IC50 values of 15.7, 15.5, 17.6, 14.3, and 21.8 μM, respectively.

Lyconadins G and H,Two Rare Lyconadin-Type Lycopodium Alkaloids from Lycopodium complanatum

Two rare lyconadin-type Lycopodium alkaloids,lyconadins G(1)and H(2),together with four known ones(3–6),were isolated from Lycopodium complanatum.The structures were determined on the basis of their spectroscopic analyses,and the absolute configuration of 1 was established by an X-ray crystallographic analysis.It is the first time to establish the absolute configuration of lyconadin-type Lycopodium alkaloid by an X-ray diffraction experiment.In addition,these findings may provide more information for the biosynthesis of lyconadins.