N-(9,11-Dimeth­oxy-4-oxo-2,3,4,6,7,11b-hexa­hydro-1H-pyrido[2,1-a]isoquinolin-3-yl)benzamide

The title schulzeine derivative, C22H24N2O4, crystallizes with two crystallographically independent mol­ecules of almost identical conformation in the asymmetric unit. The tricyclic core of schulzeine has a fused-three-ring system comprising the tetra­hydro­isoquinoline and δ-lactam moieties. In both mol­ecules, the pyridine ring adopts a twisted-boat conformation, whereas the lactam ring is in a boat conformation. The two meth­oxy groups are slightly twisted from the attached benzene ring [C—O—C—C torsion angles = −21.3 (2) and −20.5 (2)° in mol­ecule A, and −6.3 (2) and −16.2 (2)° in mol­ecule B] and the benzamide moiety is in a (−)-synclinal conformation with respect to the lactam ring. In the crystal, mol­ecules are linked into V-shaped dimers by inter­molecular N—H⋯O hydrogen bonds and weak C—H⋯O inter­actions. These dimers are stacked into V-shaped columns along the a axis. Adjacent columns are further linked in an anti­parallel manner. C—H⋯π inter­actions are also observed

Isolation of linobiflavonoid, a novel biflavonoid from Linostoma pauciflorum Griff

A novel biflavonoid, that we have named linobiflavonoid, and the known biscoumarin ether, daphnoretin, were isolated from the root extracts of Linostoma pauciflorum Griff. The structure of linobiflavonoid was determined from interpretation of its NMR spectroscopic data and from a comparison of this data with those of known biflavonoids and biflavones. The known flavones, 5,4\u27-dihydroxy- 7,3\u27,5\u27-trimethoxyflavone and 5,4\u27-dihydroxy-7-methoxyflavone along with stigmasterol were isolated from the vines of the same plant. 4\u27-Dihydroxy-7,3\u27-5\u27-trimethoxyflavone was active against Mycobacterium tuberculosis (MIC 3.13 mu M) and KB-oral cavity cancer (IC50 17.41 mu M). (C) 2011 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved

Cytotoxic Sesterterpenes from Thai Marine Sponge <i>Hyrtios erectus</i>

Four sesterterpenes, erectusolides B, C, D, and seco-manoalide-25-methyl ether, two 2-furanone derivatives, erectusfuranones A and B, together with thirteen known sesterterpenes, (6Z)-neomanoalide-24-acetate, two diastereomers of 24-O-methylmanoalide, luffariolide B, manoalide, (6E)- and (6Z)-neomanoalide, seco-manoalide, scalarafuran, 12-acetylscalarolide, 12-epi-O-deacetyl-19-deoxyscalarin, 12-epi-scalarin, and 12-O-deacetyl-12-epi-scalarin, three indole alkaloids, 5-hydroxy-1H-indole-3-carbaldehyde, hyrtiosine A, and variabine B, and one norterpene, cavernosine were isolated from the marine sponge Hyrtios erectus. Their structures were determined by means of spectroscopic methods and the absolute configurations of the asymmetric centers were determined using the modified Mosher&#8217;s method. The cytotoxic activities for the isolated compounds have been reported

A new dihydrobenzofuran lignan and potential <i>α</i>-glucosidase inhibitory activity of isolated compounds from <i>Mitrephora teysmannii</i>

<p>A new dihydrobenzofuran lignan, (2<i>R</i>,3<i>S</i>)-2-(3′,4′-dimethoxyphenyl)-5-(3-hydroxypropyl)-7-methoxy-2,3-dihydrobenzofuran-3-methyl acetate, named as mitredrusin (<b>1</b>), was isolated from the leaves of <i>Mitrephora teysmannii</i> (Annonaceae) together with 12 known compounds including a related dihydrobenzofuran lignan: (−)-3′,4-di-<i>O</i>-methylcedrusin (<b>2</b>), four polyacetylenic acids: 13(<i>E</i>)-octadecene-9,11-diynoic acid (<b>3</b>), 13(<i>E</i>),17-octadecadiene-9,11-diynoic acid (<b>4</b>), octadeca-9,11,13-triynoic acid (<b>5</b>) and octadeca-17-en-9,11,13-triynoic acid (<b>6</b>), five lignans: (−)-eudesmin (<b>7</b>), (−)-epieudesmin (<b>8</b>), (−)-phillygenin (<b>9</b>), magnone A (<b>10</b>) and forsythialan B (<b>11</b>) and two megastigmans: (3<i>S</i>,5<i>R</i>,6<i>S</i>,7<i>E</i>,9<i>R</i>)-7-megastigmene-3,6,9-triol (<b>12</b>) and annoionol A (<b>13</b>). The chemical structures of these compounds were established on the basis of their 1-D and 2-D NMR spectroscopic data. All compounds were evaluated for their <i>α</i>-glucosidase inhibitory activity. Among these isolates, polyacetylenic acids <b>3</b> and <b>4</b> showed more than 20-fold much higher activity compared with that of the antidiabetic drug acarbose.</p

Isolation of linobiflavonoid, a novel biflavonoid from Linostoma pauciflorum Griff.

A novel biflavonoid, that we have named linobiflavonoid, and the known biscoumarin ether, daphnoretin, were isolated from the root extracts of Linostoma pauciflorum Griff. The structure of linobiflavonoid was determined from interpretation of its NMR spectroscopic data and from a comparison of this data with those of known biflavonoids and biflavones. The known flavones, 5,4\u27-dihydroxy- 7,3\u27,5\u27-trimethoxyflavone and 5,4\u27-dihydroxy-7-methoxyflavone along with stigmasterol were isolated from the vines of the same plant. 4\u27-Dihydroxy-7,3\u27-5\u27-trimethoxyflavone was active against Mycobacterium tuberculosis (MIC 3.13 mu M) and KB-oral cavity cancer (IC50 17.41 mu M). (C) 2011 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved