A new neolignan, designated as sisymbrifolin, and carpesterol were isolated from the berries of Solanum sisymbrifolium. Their structures were established mainly on the basis of 2D NMR analyses.

The steroidal composition of four molluscs Meretrix meretrix, Macoma birmanica (bivalves), Cerethidea cingulata, Nassarius stolatus (gastropode) and a sea pen Cavernulina sp., has been ascertained by GC-MS. The isolation of cholest-6-en-5 alpha, 8 alpha-epidioxy-3 beta-ol from M. meretrix, reveals the first reported occurrence of this peroxide in a bivalve.

New bromotyrosine derived secondary metabolites have been isolated from the marine sponge Psammaplysilla purpurea, and the structures assigned on the basis of spectroscopic analyses of their acetates 1a′ and 1b′.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA simple and highly stereoselective route to (.+-.)-podocarpic acidAsish K. Banerjee, Dhanonjoy Nasipuri, and Satyesh C. PakrashiCite this: J. Org. Chem. 1990, 55, 12, 3952–3954Publication Date (Print):June 1, 1990Publication History Published online1 May 2002Published inissue 1 June 1990https://pubs.acs.org/doi/10.1021/jo00299a047https://doi.org/10.1021/jo00299a047research-articleACS PublicationsRequest reuse permissionsArticle Views497Altmetric-Citations5LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

y l c h l o r i d e induced c y c l i r ation and subsequent reduction with sodium c y a n o b o r o h y d r i d e .

A new clerodane diterpene clerodermic acid was isolated from Clerodendron inerme and the structure deduced from spectral data. The known compounds friedelin, 5-hydroxy-7,4′-dimethoxyflavone, salvigenin, acacetin and apigenin were also found.

ChemInformVolume 20, Issue 46 Preparative Organic Chemistry ChemInform Abstract: Bischler-Napieralski Cyclization with Triphenylphosphine-Carbon Tetrachloride: One-Pot Synthesis of Dihydroisoquinolines and β-Carbolines. A. BHATTACHARJYA, A. BHATTACHARJYA Indian Inst. Chem. Biol., Calcutta-700 032, IndiaSearch for more papers by this authorP. CHATTOPADHYAY, P. CHATTOPADHYAY Indian Inst. Chem. Biol., Calcutta-700 032, IndiaSearch for more papers by this authorM. BHAUMIK, M. BHAUMIK Indian Inst. Chem. Biol., Calcutta-700 032, IndiaSearch for more papers by this authorS. C. PAKRASHI, S. C. PAKRASHI Indian Inst. Chem. Biol., Calcutta-700 032, IndiaSearch for more papers by this author A. BHATTACHARJYA, A. BHATTACHARJYA Indian Inst. Chem. Biol., Calcutta-700 032, IndiaSearch for more papers by this authorP. CHATTOPADHYAY, P. CHATTOPADHYAY Indian Inst. Chem. Biol., Calcutta-700 032, IndiaSearch for more papers by this authorM. BHAUMIK, M. BHAUMIK Indian Inst. Chem. Biol., Calcutta-700 032, IndiaSearch for more papers by this authorS. C. PAKRASHI, S. C. PAKRASHI Indian Inst. Chem. Biol., Calcutta-700 032, IndiaSearch for more papers by this author First published: November 14, 1989 https://doi.org/10.1002/chin.198946085Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume20, Issue46November 14, 1989 RelatedInformation

ChemInformVolume 20, Issue 13 Natural Products ChemInform Abstract: A Simplified and Totally Stereoselective Synthesis of Podocarpic Acid Ring System. D. NASIPURI, D. NASIPURI Indian Inst. Chem. Biol., Calcutta 700 032Search for more papers by this authorA. K. BANERJEE, A. K. BANERJEE Indian Inst. Chem. Biol., Calcutta 700 032Search for more papers by this authorS. C. PAKRASHI, S. C. PAKRASHI Indian Inst. Chem. Biol., Calcutta 700 032Search for more papers by this author D. NASIPURI, D. NASIPURI Indian Inst. Chem. Biol., Calcutta 700 032Search for more papers by this authorA. K. BANERJEE, A. K. BANERJEE Indian Inst. Chem. Biol., Calcutta 700 032Search for more papers by this authorS. C. PAKRASHI, S. C. PAKRASHI Indian Inst. Chem. Biol., Calcutta 700 032Search for more papers by this author First published: March 28, 1989 https://doi.org/10.1002/chin.198913287Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume20, Issue13March 28, 1989 RelatedInformation

The binding of aristololactam-beta-D-glucoside to DNA is characterized by hypochromism and bathochromism in the absorption band, quenching of the fluorescence intensity, increase in the positive and negative ellipticity of DNA, enhancement of thermal transition temperature, sign and magnitude of thermodynamic parameters, increase of the contour length of sonicated rod-like DNA and induction of the unwinding-rewinding process of covalently closed superhelical DNA. Binding parameters determined from absorbance and fluorescence titration by Scatchard analysis, according to an excluded-site model, indicate a very high affinity towards DNA. The binding of the alkaloid is an exothermic process with Gibbs free energy of -7.4 kcal/mol, van't Hoff enthalpy of -13.8 kcal/mol and entropy of -21.5 cal/degree/mol at 25 degrees. On the basis of these observations it is concluded that aristololactam-beta-D-glucoside binds to DNA by a mechanism of intercalation.

ChemInformVolume 20, Issue 36 Heterocyclic Compounds ChemInform Abstract: Unusual One-Pot Formation of a Phenylketene Trimer Ester. M. CHAKRABARTY, M. CHAKRABARTY Chem. Dep., Bose Inst., Calcutta 700 009Search for more papers by this authorS. C. PAKRASHI, S. C. PAKRASHI Chem. Dep., Bose Inst., Calcutta 700 009Search for more papers by this author M. CHAKRABARTY, M. CHAKRABARTY Chem. Dep., Bose Inst., Calcutta 700 009Search for more papers by this authorS. C. PAKRASHI, S. C. PAKRASHI Chem. Dep., Bose Inst., Calcutta 700 009Search for more papers by this author First published: September 5, 1989 https://doi.org/10.1002/chin.198936227Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume20, Issue36September 5, 1989 RelatedInformation

AbstractThe title reaction, when conducted in MeOH, leads to the unexpected products (III) and (IV) together with (V) and (VI).

AbstractThe relative stereochemistry of the title compound (VI) is confirmed by its total synthesis starting from the amine (Ia) and 3‐acetylpyridine (II).

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReduction of lactams and thiolactams by sodium borohydride. Application in the synthesis of some alkaloidsS. B. Mandal, V. S. Giri, M. S. Sabeena, and S. C. PakrashiCite this: J. Org. Chem. 1988, 53, 18, 4236–4241Publication Date (Print):September 1, 1988Publication History Published online1 May 2002Published inissue 1 September 1988https://pubs.acs.org/doi/10.1021/jo00253a014https://doi.org/10.1021/jo00253a014research-articleACS PublicationsRequest reuse permissionsArticle Views2178Altmetric-Citations49LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

AbstractReductive desulfurization of the thiolactams (Ia), (II), and (IV) with sodium boranate yields the amines (Ib), (III), and (V).

The indole alkaloid (+)deplancheine (1) has been synthesized utilizing the intermediate 3-acatyl-1,2,6.7,12,12b-hexahydroindolo[2,3-a_kuinolizine(6) prepared in two synthetic steps from readily available startlng materials.(9-Depiancheine (1).en indole slkeloid hawng e m f i g u r a t i o n of ethylidene side chain s t C-3 was first 1 synthesized by Winterfeldt end his co-workers even befare the isolation of the (+)-base from a nature1 source, 2 viz.Alstonia deplanchei (Apocynsceae) by ~esseli&vre Kt who also synthesized the racemic base.Several -other syntheses have since been r e p ~r t e d ~-~, but all of them involved m u l t i s t e p ~ and difficultly ~reparable starting materials.Herein we report some simple and modified syntheses of the t i t l s compound through the key intermediate 3-acetyl-1,2,6,7,12,12bhexshydr01nd~IoI2,3-Jquinolirine (6).7 .Condensation of 3-acetylindole ( a 6 and 3-(1.1-ethylenedioxyethyl)pyridine(1) ~n presence o f iodine a t water-bsth temperature afforded the quaternary iodide salt (9, mp 117-llB0C (H20), i n 65% yield.Reduction of 5 with LiAIH4 i n THF led to the uncyclised product >(61%).Reductive cyclisation could, nevertheless, be brought ebout with ( t ~u ~) 3 L i A l H followed by LiAIH4 reduction t o obtain the desired vinylogous tertiary smids (g8 i n 44% yield.Further reduction with LiAiH4 In THF under reflux afforded only 0.5% of 1 and 3 its &-isomer, contrary to the recent claim of 20% yield.The major products (Scheme 1) o f the reaction i n our hends were identified as 1(40%) and $(26%) besides 9-(4%).The trens ring fusion i n the quinolirlnes (L)-@) was indicated by the characteristic Bohlmann bands.Thal the hydroxyethyl side chain is axial i n 1 and equatorial in :became evidmt from the upfield shift of the signals for C-l(y), C-2(B), C -X d and C 4 6 ) carbons by 5.7, 0.2, 1. 9 and 1.7 ppm i n the 1 3 c nmr spectrum of 1 compared t o those of 8.The above contention was also supported by acetylation of 1 and 8. Thus, where-8 easily underwent acetylation with Ac20/Py a t room temperature, 1 had to be heated e t 1 0 0 T t o give -0-acetylated products 10 and 11 respectively.Presumably, the hydroxy group i n is hydrogen-bonded with the lone pair of nitrogen (Fig.& while it must be free in 1 (FigB).It may be pointed out that the spectrum of 5 howsver, displayed pairs of signals for C-2, C-3, C-4, C-1' and C-2' indicating i t t o be a mixture o f two diastereoisorners.The equatorial orientation of the acetyl group i n 9 ws3 derived from the fact that it furnished g on reduction w i t h NaBH4.Several approaches (Scheme 1) were made t o improve upon the yield of the desired (+)deplancheine (1) from the vinylogoua amide (6) end the results are given as follows : (i) Reduction with LiAIH4-NC13 (?:I) i n diethyl ether under refiux afforded 1 i n 18% yield together w i t h its Z-isomer and 2 i n traces; (ii) Thermal decomposition of the e-tosyi hydrazone derivative (11) of ?(obtained i n 14% yieid from &by LiAiH4 reduction 9 .at room temperature with sodium methoxide in dry diglyme produced 1 i n 65% yield along with a minor amount (-5%) of L-isomer.The best results 80 far have, however, been obtained by (iii) the reaction with triethyloxonium tetrafluoraborate i n M 2 C 1 2 a t room temperature and subsequent reduction o f the resulting imino ether with NaBH4 to furnish 1 i n 23% yieid w i t h 15% of the e n d ether (12).EXPERIMENTAL Mps, taken i n open capillaries, are uncorrected.Ir spectra were recorded i n KBr pellets on a Perkin-Elmer 177 Infrared spectrophotometar; 'H and 1 3 c nmr spectra were measured an s J E M FX-100 F T nmr spectrometer using TMS as internal standard and DMSOd6 as the solvent unless otherwise stated and the mass spectra (El) were taken on a Hitachi R M U d L instrument. 3-Acetyiindoie (2)It was prepared according to the procedure of 5axtan6.'H nmr : 6 2.42 (s,lH), 7.20 (m,W), 7.50 (m,lH), 8.20 (m,lH), 8.22 (s,lH) and 11.76 (s,lH). 341,lEthylenedioxyethvl)pyridineCompound 3 was synthesized following the procedure of Anderson, Jr. and ~e r k e i h a m m e r ~. 'H nmr (CDC13): 6166 (s,Mh 4H), 7.30 (dd,lH, 23 and 5 Hz), 7 8 0 (td,lH, J3 and 2 Hz), 8.56 (dd,lH, J=5 and 2 Hz) and 8.80 (d,lH, J=2 Hz).