Lycoperine A, A novel C27N3-type pentacyclic alkaloid from Lycopodium hamiltonii, inhibiting acetylcholinesterase

[structure: see text] A novel C(27)N(3)-type pentacyclic Lycopodium alkaloid, lycoperine A (1) consisting of two octahydroquinoline rings and a piperidine ring, was isolated from the club moss Lycopodium hamiltonii. The structure and relative stereochemistry were elucidated on the basis of 2D NMR data and chemical transformation. Lycoperine A (1) exhibited an inhibitory activity against acetylcholinesterase.     

Malycorins A--C, New lycopodium alkaloids from Lycopodium phlegmaria

A novel C(19)N-type Lycopodium alkaloid, malycorin A (1) consisting of a serratinane skeleton with 2-propanol unit has been isolated from the club moss Lycopodium phlegmaria, together with two new C(16)N-type alkaloids, malycorins B (2) and C (3), and the structures and relative stereochemistry were elucidated on the basis of spectroscopic data.     

Sieboldine A, a novel tetracyclic alkaloid from Lycopodium sieboldii, inhibiting acetylcholinesterase

[structure: see text] A novel Lycopodium alkaloid with an unprecedented fused-tetracyclic ring system consisting of an aza-cyclononane ring having a N-hydroxy group, a cyclohexanone, a cyclopentanone, and a tetrahydrofuran ring, sieboldine A (1), was isolated from the club moss Lycopodium sieboldii. The structure and relative stereochemistry were elucidated on the basis of 2D NMR data and X-ray analysis. Sieboldine A (1) exhibited a potent inhibitory activity against acetylcholinesterase and modest cytotoxicity.     

A New Alkaloid from Lycopodium japonicum Thunb.

A new alkaloid, miyoshianine C ( 1 ), was isolated from the whole plants of Lycopodium japonicum Thunb. , together with the known four compounds α‐obscurine ( 2 ), lycodoline ( 3 ), miyoshianine A ( 4 ), and lucidioline ( 5 ). Their structures were elucidated on the basis of in‐depth spectroscopic analysis.     

Nankakurine A, a novel C16N2-type alkaloid from Lycopodium hamiltonii

[sstructure: see text] A novel, fused-tetracyclic Lycopodium alkaloid, nankakurine A (1), consisting of a cyclohexane ring and a 3-aza-bicyclo[3.3.1]nonane ring connected to a piperidine ring through a spiro carbon, was isolated from the club moss Lycopodium hamiltonii. The structure and relative stereochemistry were elucidated on the basis of spectroscopic data.     

Japonicumins A–D: Four New Compounds from Lycopodium japonicum

Three new serratane‐type triterpenoids, japonicumins A–C ( 1 – 3 ), as well as a unique, new C₁₃ terpenoid, japonicumin D ( 4 ), were isolated from the dried whole plants of Lycopodium japonicum, together with the known compound lycoclavanol ( 5 ). Their structures were identified by extensive mass‐spectrometric and spectroscopic (especially 2D‐NMR) experiments. Compounds 1 – 5 exhibited no activity against human‐tumor A 549 cells.     

The Lycopodium alkaloids

Lycopodium alkaloids are quinolizine, or pyridine and alpha-pyridone type alkaloids. Some Lycopodium alkaloids are potent inhibitors of acetylcholinesterase (AChE). Huperzine A (HupA) is reported to increase efficiency for learning and memory in animals, and it shows promise in the treatment of Alzheimer's disease (AD). 201 Lycopodium alkaloids from 54 species of Lycopodium (sensu lato) have been reported so far. This review is intended to to cover the chemical, pharmacological and clinical research on Lycopodium alkaloids reported in the literature from the spring of 1993 to August 2004. Structures of 81 new Lycopodium alkaloids are presented, classified and analyzed. The structural characters and biogenetic relationships of the four major Lycopodium alkaloid groups (lycopodine, lycodine, fawcettimine and miscellaneous) are discussed. Bioactivities of Lycopodium alkaloids, especially HupA, are summarized. In particular, the effect of HupA and other cholinesterase inhibitors (anti-AD drugs) on acetylcholine esterase (AChE) activity in the rat cortex and butylcholine esterase activity are compared. Structure-activity relationships and structure modifications of HupA and its analogs are described. Information on clinical trials with HupA and its derivative ZT-1 is presented. The state of HupA availability and recent advances in in vitro propagation of HupA producing plants are outlined. Finally, hypotheses about Lycopodium alkaloid biosynthetic pathways are discussed.     

Tandem oxidative dearomatization/intramolecular Diels-Alder reaction for construction of the tricyclic core of palhinine A

A concise construction of the 6/6/5 tricyclic core of Lycopodium alkaloid palhinine A (1) has been accomplished. The developed synthetic strategy featured a tandem oxidative dearomatization/intramolecular Diels-Alder reaction to construct C/D rings and an intramolecular 5-exo-trig radical cyclization to install the B ring of palhinine A (1). The developed approach paves the way for the total synthesis of palhinine A (1).     

Lycopladine A, a new C16N alkaloid from Lycopodium complanatum

A new C₁₆N type alkaloid, lycopladine A (1), has been isolated from the club moss Lycopodium complanatum, and the structure and relative stereochemistry of 1 were elucidated on the basis of spectral data.     

Structure elucidation and synthesis of lycoposerramine-B, a novel oxime-containing Lycopodium alkaloid from Lycopodium serratum Thunb

A new alkaloid, lycoposerramine-B (1), containing an oxime function, was isolated from the club moss Lycopodium serratum Thunb. The structure of 1 was elucidated by spectroscopic analysis, including J-resolved HMBC spectroscopy, and confirmed by its synthesis from the known alkaloid, serratinine (3).     

Asymmetric total synthesis of (+)-luciduline: toward a general approach to related Lycopodium alkaloids

As part of a research program directed toward the synthesis of Lycopodium alkaloids, a multigram scale asymmetric synthesis of intermediate 11 was achieved in 11 steps from pyridine (17). In addition to our alkene metathesis strategy, a key feature of this synthetic approach consists of a Fukuyama's Diels-Alder cycloaddition between 1,2-dihydropyridine and acrolein using MacMillan's catalyst (18) on a 50 g scale. This led to a 12-step catalytic asymmetric synthesis of (+)-luciduline (1). A broader subset of Lycopodium alkaloids could also be obtained, as demonstrated by the derivatization of 11 into advanced intermediates for the synthesis of some of these natural products.     

Application of the Helquist annulation in Lycopodium alkaloid synthesis: unified total syntheses of (-)-8-deoxyserratinine, (+)-fawcettimine, and (+)-lycoflexine

A unified strategy for total synthesis of the Lycopodium alkaloids (-)-8-deoxyserratinine (7), (+)-fawcettimine (1), and (+)-lycoflexine (4) is detailed. The key features include a highly efficient Helquist annulation to assemble the cis-fused 6/5 bicycle, facile construction of the aza nine-membered ring system employing double N-alkylation strategy, providing access to the common tricyclic skeleton, asymmetric Shi epoxidation, delivering the desired β-epoxide stereospecifically to furnish (-)-8-deoxyserratinine (7), SmI(2) reduction of dihydroxylation derivative 35 to enable formation of (+)-fawcettimine (1), and a rapid biomimetic transformation of (+)-fawcettimine (1) into (+)-lycoflexine (4) via an intramolecular Mannich cyclization.     

Ten new fawcettimine-related alkaloids from three species of Lycopodium

Ten new fawcettimine-related alkaloids, i.e., lycopoclavamines, lycoposquarrosamine-A, and other hydroxylated fawcettimine derivatives, were isolated from three species of Lycopodium (Lycopodium clavatum, Lycopodium serratum, and Lycopodium squarrosum). The structures of the new alkaloids were elucidated by spectroscopic methods and chemical correlation.     

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.     

A new serratane-type triterpene from Lycopodium phlegmaria

A new serratane-type triterpene, lycophlegmarin (1), has been isolated from Lycopodium phlegmaria L. Four known related triterpenoids were also found from the title plant. The structure of the new compound was elucidated on the basis of detailed spectroscopic analysis and chemical method. Lycophlegmarin exhibited modest growth-inhibitory activity in vitro against human hepatoma cells BEL 7402.     

A biomimetic transformation of serratinine into serratezomine A through a modified Polonovski reaction

Application of a modified Polonovski reaction for serratinine (1) resulted in generation of serratezomine A (2) with a novel seco-serratinine-type skeleton recently isolated from the club moss Lycopodium serratum var. serratum. This biomimetic transformation supports a biogenetic pathway proposed for serratezomine A (2). The absolute stereochemistry of serratezomine A (2) was established by an induced exciton chirality and modified Mosher methods.     

CRYSTAL AND MOLECULAR STRUCTURE OF 1,10-PHENANTHROLINE TETRACARBONYL CHROMIUM AND -MOLYBDENUM COMPLEXES, (C_(12)H_8N_2)M(GO)_4 (M=Cr and Mo)

<正> The crystal and molecular structures of (C12H8N2)Mo(CO)4 and (C12H8N2)Cr(CO)4 are reported. They crystallize in the space group C2/m and are isomorphous with each other. The unit cell dimensions for (C12H8N2 Cr(CO)4 are a=15.404(2), b=12.091(2), c=8.223(2) A, 3=108.70(2)0, and V=1450.6(9) A3, while for (C12H8N2)Mo(CO)4 are a=15.546(6), b=12.086(4), c=8.269(1.) A, β= 107.37(2)0 and V=1482.9(l.5) A3, and both Z=4. Final R=0.040 Rw=0.050 for (C12H8N2)Cr(CO)4 and R=0.034 Rw=0.053 for (C12H8N2)Mo(CO)4.     

石杉碱O的结构鉴定

蛇足石杉[Huperziaserrata(Thunb.)Trev.]中,R~f与石杉碱甲相近部位分离得到一个新生物碱,经IR,MS,1D和2DNMR确定了其化学结构,为一个有内氢键烯醇型新的lycopodine类生物碱,命名为石杉碱O(HuperzineO)。     

Huperzine A: A Mini-Review of Biological Characteristics,Natural Sources,Synthetic Origins,and Future Prospects

Russian Journal of Organic Chemistry - Huperzia serrate is a known medicinal plant that produces the Lycopodium alkaloid Huperzine A (HupA). It has been used to treat such diseases as contusions,...     

Synthesis and Structure of 5-Amino-6-(4-fluorophenylamino)-3-methylthio-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4(5H)-one

The title compound (C18H15FN6OS) has been synthesized and its crystal structure was determined by X-ray analysis. The crystal belongs to monoclinic system, space group P21/n with a = 13.983(10), b = 7.337(5), c = 16.702(12) (A), α = 90, β = 98.277(12), γ = 90°, V = 1696(2)(A)3, Z = 4, Dc= 1.498 g/cm3, Mr = 382.42,μ = 0.224 mm-1, F(000) = 792, the final R = 0.0362 and wR = 0.0878 for 2579 observed reflections with I ＞ 2σ(Ⅰ). In the title compound, the atoms of C(1),C(2), C(3), C(4), C(5), N(1), N(2), N(3), N(4), N(5), N(6), O(1) and S(1) form a fully delocalized system with the average deviation of 0.0307(A). There exists a part of electron delocalization over the planes of Ⅰ (pyrazolo[3,4-d]pyrimidin-4-one moiety), Ⅱ (phenyl moiety) and Ⅲ (p-fluorophenylamine moiety). In the molecule, intermolecular hydrogen bonds between N(6)-H(6)…O(1)and C( 15)-H( 15)…O( 1 ) are observed.