title: Acantholactam and pre-neo-kauluamine, manzamine-related alkaloids from the Indonesian marine sponge Acanthostrongylophora ingens.
abstract: Two new manzamine alkaloids, acantholactam (3) and pre-neo-kauluamine (4), were isolated from the marine sponge Acanthostrongylophora ingens along with manzamine A (1) and neo-kauluamine (2). Acantholactam contains a γ-lactam ring N-substituted with a (Z)-2-hexenoic acid moiety and is proposed to be biosynthetically derived from manzamine A by oxidative cleavage of the eight-membered ring. Compound 4 was converted to the dimer 2 during storage, suggesting nonenzymatic dimer formation. Among the four isolated compounds, 1, 2, and 4 showed proteasome inhibitory activity.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kumamoto University , Oe-honmachi 5-1, Kumamoto 862-0973, Japan.
authors.forename: Ahmed H
authors.initials: AH
authors.lastname: El-Desoky
authors.forename: Hikaru
authors.initials: H
authors.lastname: Kato
authors.forename: Keisuke
authors.initials: K
authors.lastname: Eguchi
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Kawabata
authors.forename: Yukio
authors.initials: Y
authors.lastname: Fujiwara
authors.forename: Fitje
authors.initials: F
authors.lastname: Losung
authors.forename: Remy E P
authors.initials: RE
authors.lastname: Mangindaan
authors.forename: Nicole J
authors.initials: NJ
authors.lastname: de Voogd
authors.forename: Motohiro
authors.initials: M
authors.lastname: Takeya
authors.forename: Hideyoshi
authors.initials: H
authors.lastname: Yokosawa
authors.forename: Sachiko
authors.initials: S
authors.lastname: Tsukamoto
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000818:Animals; D002227:Carbazoles / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D002243:Carbolines; D007214:Indonesia; D008264:Macrophages / Q000187:drug effects; D008386:Marine Biology; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D009792:Oceans and Seas; D011161:Porifera / Q000737:chemistry*; D011480:Protease Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D000470:Alkaloids; D002227:Carbazoles; D002243:Carbolines; D011480:Protease Inhibitors; C000591099:acantholactam; C436388:neo-kauluamine; C078290:manzamine A