Perinadine A, a novel tetracyclic alkaloid from marine-derived fungus Penicillium citrinum

[structure: see text] A novel tetracyclic alkaloid, perinadine A (1), was isolated from the cultured broth of the fungus Penicillium citrinum, which was separated from the gastrointestine of a marine fish, and the structure was elucidated on the basis of spectroscopic data including 2D NMR spectra. Biogenetically, perinadine A (1) may be derived from citrinin (4), a well-known mycotoxin, and a scalusamide A-type pyrrolidine alkaloid.     

Agelasine G, a new antileukemic alkaloid from the Okinawan marine sponge Agelas sp.

A new antileukemic alkaloid, agelasine G (1a), has been isolated from the Okinawan marine sponge Agelas sp. and its structure elucidated to be a bromopyrrole alkaloid containing 9-methyladenine and diterpene moieties on the basis of the spectroscopic data.     

Huperzine H, a New Lycopodium Alkaloid from Huperzia serrata

Huper:iaserrata(Thunb.)Trev.isoneofthemostcommonlyusedtraditionalChineseherbalmedicinesforthetreatmentofcontusions,strains,swellingsandschirophremas'etc..Manylycopodiumalkaloidshavebeenisolated2'3fromitincludinghuperzineA,acompoundwhichhasshownpotentialeffectsonAlzheimedisease.Inourinvestigations.threenewlycopodiumalkaloidswereobtainedandreported"'.ThispaperdealswiththeidentificationofhuperzineH--anewlycopodiumalkaloidwithanovelskeleton.HLlperzineHiscolorlessneedleswithIQ].-216(c0.02.CHC…     

Macleayine,a new alkaloid from Macleaya cordata

Macleayine (1),a new natural occurring alkaloid with a unique spiro[furanone-piperidinedione] framework,was isolated from the aerial parts of Macleaya cordata.Its unusual structure was established by extensive spectroscopic analyses,computer-assisted structure elucidation software (ACD/Structure Elucidator),quantum chemistry calculations and ECD calculation.The result of virtual molecular docking predicted the compound can enhance the effects of insulin,and may be used to treat type II diabetes.     

Macleayine,a new alkaloid from Madeaya cordata

Macleayine(1),a new natural occurring alkaloid with a unique spiro[furanone-piperidinedione]framework,was isolated from the aerial parts of Madeaya cordata.Its unusual structure was established by extensive spectroscopic analyses,computer-assisted structure elucidation software(ACD/Structure Elucidator),quantum chemistry calculations and ECD calculation.The result of virtual molecular docking predicted the compound can enhance the effects of insulin,and may be used to treat type II diabetes.     

Nagelamide J, a novel dimeric bromopyrrole alkaloid from a sponge Agelas species

A novel dimeric bromopyrrole alkaloid, nagelamide J (1), with antimicrobial activity has been isolated from an Okinawan marine sponge Agelas species, and the structure and stereochemistry were elucidated from spectroscopic data. Nagelamide J (1) is the first bromopyrrole alkaloid possessing a cyclopentane ring fused to an amino imidazole ring.     

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).     

Amaranzole A, a new N-imidazolyl steroid from Phorbas amaranthus

An unprecedented 24-N-imidazolyl steroidal alkaloid, amaranzole A, was isolated from a tropical sponge, Phorbas amaranthus. The structure was solved by interpretation of MS, NMR, including a novel exciton-coupled CD spectrum due to an allyl imidazole, and comparison with model compounds.     

Ishigadine A,a new canthin-6-one alkaloid from an Okinawan marine sponge Hyrtios sp.

A new indole alkaloid with the canthin-6-one skeleton, ishigadine A, has been isolated from an Okinawan marine sponge Hyrtios sp. The structure of ishigadine A was elucidated on the basis of spectroscopic analyses. Ishigadine A is a new canthin-6-one alkaloid possessing a hydroxy group, a 1,3-dimethyl-4-methylthioimidazolium, and a 1-propylguanidine. Ishigadine A is the third canthin-6-one alkaloid from sponges. Ishigadine A might be generated from l-arginine, l-histidine, and l-tryptophan. Ishigadine A exhibited moderate cytotoxicity against L1210 murine leukemia cells.     

Hypepontine,a new quaternary alkaloid with antimicrobial properties

Abstract

New isoquinoline alkaloid hypepontine (1) together with a five known compounds, were identified in Hypecoum ponticum Velen, the partial synonym of Hypecoum procumbens L. The structure of the new substance was elucidated based on spectroscopic evidence. The tertiary and quaternary alkaloid mixtures as well as the isolated alkaloids were evaluated for their antibacterial and antifungal activity. The result revealed that the crude alkaloid mixture containing quaternary isoquinoline alkaloids showed potent antifungal and antibacterial activity.     

Tacamine,the first example of a new class of indole alkaloids

From the leaves of Tabernaemontana eglandulosa a new alkaloid was isolated, which was assigned structure $\text{1}$ on the basis of speetroscopic evidence.     

Cimicifugadine from Cimicifuga foetida, a new class of triterpene alklaoids with novel reactivity

[structure: see text] An unprecedented triterpene alkaloid glycoside, designated cimicifugadine (1), with a pyridine ring incorporated to a cycloartane triterpenoid nucleus, was isolated from the roots of Cimicifuga foetida. Its structure was established on the basis of extensive spectroscopic measurements and chemical transformation with the absolute configuration at C-24 determined to be S by a modified Mosher method. It demonstrated a novel reactivity in mild acidic media whereby the cyclopropane ring is opened followed by the formation of two isomeric conjugated trienes.     

Structure (x-ray analysis) of Manicoline B,a mixture of two diastereoisomers of a new alkaloid from dulacia guianensis (olacaceae)

Manicoline B, isolated from the root bark of $\text{Dulacia guianensis}$ (Olacaceae), was shown by X-ray analysis to be an equimolecular mixture of two diastereoisomers of a new alkaloid and to have structure (3).     

Structure elucidation and biomimetic synthesis of hostasinine A, a new benzylphenethylamine alkaloid from Hosta plantaginea

Hostasinine A (1), a benzylphenethylamine alkaloid with an unprecedented skeleton featuring a C-4-C-6 linkage and a nitrone moiety, was isolated from Hosta plantaginea. Its structure was established on the basis of spectroscopic data, and was further confirmed by single-crystal X-ray diffraction. The alkaloid was postulated biogenetically from haemanthidine via N-oxidation and aza-aldol-type condensation and was synthesized biomimetically. The inhibitory activities of 1 on acetylcholinesterase (AChE) and two tumor cell lines (K562 and A549) were also evaluated.     

First diamino Daphniphyllum alkaloid, daphnipaxinin, with an unprecedented heterohexacyclic skeleton from Daphniphyllum paxianum

[structure: see text] The first diamino Daphniphyllum alkaloid, daphnipaxinin (1), with an unprecedented hexacyclic fused skeleton, along with a known alkaloid, daphnicyclidin A (2), was isolated from the stem of Daphniphyllum paxianum Rosenth. The structure and absolute stereochemistry of 1 were established by spectral methods, especially two-dimensional NMR techniques and CD analysis.     

Isolation and synthesis of vobparicine,a novel type dimeric indole alkaloid

From the rootbark of Tabernaemontana chippii a novel antimicrobially active dimeric indole alkaloid was isolated which was assigned structure $\text{1}$ on the basis of spectroscopic evidence and its synthesis.     

Puqienine F, a novel veratramine alkaloid from the bulbs of Fritillaria puqiensis

A novel veratramine alkaloid, called puqienine F (1) and possessing a 12,16-epoxy ring, was isolated from the bulbs of Fritillaria puqiensis G. D. Yu et G. Y. Chen (Liliaceae). The structure was elucidated by extensive spectral and X-ray crystallographic analyses.     

Sinoraculine,the Precursor of the Novel Alkaloid Sinoracutine from Stephania cepharantha Hayata

A new alkaloid, sinoraculine, the precursor of the novel alkaloid sinoracutine, was isolated from the leaves and stems of Stephania cepharantha, and its structure was elucidated by spectroscopic analyses.     

Punicagranine,a new pyrrolizine alkaloid with anti-inflammatory activity from the peels of Punica granatum

A novel pyrrolizine alkaloid, 5-(furan-3-carbonyl)-2,3-dihydro-1H-pyrrolizine-7-carboxylic acid, was isolated from the peels of Punica granatum. Its structure was elucidated on the basis of 1D- and 2D-NMR and HR-ESI-MS spectra and then confirmed by X-ray diffraction. It represents a new type of natural pyrrolizine alkaloid, named, punicagranine (1). 1 showed inhibition of nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 cells. To our knowledge, the pyrrolizine alkaloid skeleton was reported in natural products for the first time.     

Hirsutellone F, a dimer of antitubercular alkaloids from the seed fungus Trichoderma species BCC 7579

[structure: see text] Hirsutellone F (7), a novel alkaloid dimer, was isolated together with known monomers, hirsutellones A (1), B (2), and C (3), from the seed fungus Trichoderma sp. BCC 7579. The structure of 7 was elucidated by spectroscopic analysis. Studies on biomimetic chemistry, using the dimer 7, suggested that compound 8 (17,1'-dehydrohirsutellone B) should be the precursor for all hirsutellones.