Structure of renifolin and reconfirmation of the structure of pirolatin

The ¹H and ¹³C NMR spectral analysis of the glucoside renifolin, isolated from Pyrola renifolia, demonstrated the so far unknown binding site of the glucose moiety to be at C-8 and hence its structure as 8-β-D-glucosyloxy-2,7-dimethyl-1,4-dihydronaphthalen-5-ol. The earlier reported structure for the glucoside pirolatin, isolated from Pyrola japonica, was also reconfirmed by the ¹³C NMR spectral analysis.     

Oriciopsin,a new ring-D cleaved tetranortriterpenoid,and flindersiamine from Oriciopsis glaberrima

A novel ring-D cleaved tetranortriterpenoid, oriciopsin and flindersiamine have been isolated from the whole plant extracts of Oriciopsis glaberrima. The structure of the new limonoid was determined from its ¹H NMR and ¹³C NMR spectra and by mass spectrometry.     

Isolimonic acid,a new citrus limonoid

Isolimonic acid was isolated as its methyl ester from seeds of Citrus aurantium, C. reticulata and C. paradisi, and its structure was determined by ¹H and ¹³C NMR. The isomeric limonoid ichangin was also isolated from C. aurantium and C. paradisi.     

A diterpenoid of the atis-16-ene class from Elaeoselinum foetidum

A new diterpenoid has been isolated from the root of Elaeoselinum foetidum. Its structure was established as ent-15α-senecioxy-atis-16-en-19-oic acid mainly by ¹H NMR ¹³C NMR spectroscopic studies of its methyl ester derivative.     

Fungal macrolides: Structure determination and biosynthesis of achaetolide,a lactone from Achaetomium cristalliferum

The structure of a new ten-membered lactone, achaetolide, isolated from cultures of Achaetomium cristalliferum is deduced from its mass and NMR spectra and from the study ofsomederivatives. The ¹³C NMR spectra of achaetolide enriched with [1-¹³C], [2-¹³C] and [1, 2-¹³C] acetate established its formation from eight intact acetate units via a precursor octaketide chain.     

A diterpenoid from Elaeoselinum foetidum

A new diterpene acid has been isolated from the roots of Elaeoselinum foetidum. Its structure was established as ent-7α-senecioxy-15α-hydroxy-atis-16-en-19-oic acid by ¹H NMR and ¹³C NMR spectroscopic studies of its methyl ester derivative and confirmed by correlation with a margotianin derivative.     

Nigrifortine,a diketopiperazine metabolite of Penicillium nigricans

The structure of a novel diketopiperazine metabolite, named nigrifortine, isolated from cultures of Penicillium nigricans is deduced from its ¹H NMR, mass and UV spectra together with biosynthetic reasoning.     

Acalyphin,a cyanogenic glucoside from Acalypha indica

A new cyanogenic glucoside, acalyphin, was isolated from the aerial parts of Acalypha indica and its structure identified mainly by ¹H NMR and     

15-hydroxyblennin A,a new lactarane-type sesquiterpene lactone isolated from Lactarius torminosus

15-Hydroxyblennin A, a new lactarane-type sesquiterpene lactone was isolated from Lactarius torminosus mushrooms. Through spectroscopic (IR, ¹H NMR, ¹³C NMR, MS, UV) investigation and comparison with data for other known lactaranolides its structure was deduced as 3.     

Wampetin,a furocoumarin from Clausena wampi

A new furocoumarin wampetin has been isolated from Clausena wampi (syn. Clausena lansium). The structure was established from ¹H NMR, ¹³C NMR, MS and chemical data.     

New indanone compounds from Onychium japonicum

A new indanone glucoside pteroside M has been isolated from fronds of Onychium japonicumPteridaceae. The structure of its aglycone pterosin M has been established by ¹³C NMR, PMR spectra and degradation with nitric acid.     

Caffeoyltryptophan from green robusta coffee beans

A new compound, caffeoyltryptophan, was isolated from the coffee beans Coffea canephora and its structure was determined by FD mass, IR and ¹H NMR spectroscopy.     

La 12′-hydroxyisostrychnobiline: Nouvel alcaloïde du Strychnos variabilis

The structure of a new bisindole alkaloid, 12′-hydroxyisostrychnobiline, has been proposed from the analysis of its 300 MHz ¹H NMR spectrum and comparison of the spectroscopic data with those of various monomeric and dimeric alkaloids, previously isolated from the same Strychnos species     

A new sesquiterpenoid from Sclerorhachis platyrachis (Boiss.) Podlech ex Rech.f

A new eudesmane-type sesquiterpenoid together with two known flavonoids were isolated from the chloroform extract of the aerial part of Sclerorhachis platyrachis. The structure of the new compound was deduced from its comprehensive spectroscopic analysis including IR, EI-MS, ¹H NMR, ¹³C NMR, DEPT, COSY, HMBC and HMQC and was shown to be 4R^*-hydroxy-6S^*-tigloyloxyeudesma-7S^*-11 (13)-en-12-oic acid (1). Finally, the structure of the new compound was unambiguously confirmed by single-crystal X-ray analysis. The structure of known compounds 2 and 3 were identified by comparison of their spectral data with those reported in the literature.     

3-O-caffeoyl-4-O-feruloylquinic acid from green robusta coffee beans

An additional compound, 3-O-caffeoyl-4-O-feruloylquinic acid, has been isolated from unroasted coffee beans (Coffea canephora var. robusta) and its structure determined by FD mass and ¹H NMR spectroscopy.     

Garuganin III,a macrocyclic biphenyl ether from Garuga pinnata

The structure of garuganin III, a novel macrocyclic biphenyl ether isolated from Garuga pinnata, was established by spectroscopic analyses, including ¹H NMR and ¹³C NMR decoupling experiments and chemical transformations     

Alkaloids of Alstonia lenormandii,a structural revision of 10-methoxycompactinervine

Thirteen alkaloids have been isolated from the leaves and from the stem bark of two varieties of Alstonia lenormandii: variety lenormandii and variety minutifolia from New Caledonia. They are 10,11-dimethoxy-1-methyldeacetylpicraline, its 3′,4′,5′-trimethoxybenzoate and its benzoate, 10,11-dimethoxy-1-methylpicraline, akuam-miline, picraline, lochnericine, 11-methoxyakuammicine, 11-methoxy- and 12-methoxycompactinervine, 12-methoxy-19α,20α-epoxyakuammicine, gentianine and 3′,4′,5′-trimethoxycinnamamide. The compactinervine which is methoxylated at C-12 was previously isolated from A. lanceolata and assigned the structure 10-methoxycompactinervine; this has been revised in the present work by the analysis of high field ¹H and ¹³C NMR. The corresponding epoxide is a novel alkaloid isolated only in the minutifolia variety. Its structure has been established by spectral means and by chemical correlations.     

Sulcatine,a norsesquiterpene from the fungus Laurilia sulcata

The structure of sulcatine, a novel protoilludene norsesquiterpene isolated from a culture of Laurilia sulcata, has been assigned on the basis of a detailed study of its ¹H NMR and ¹³C NMR spectra and chemical evidence. The relative configuration was deduced from the observed ¹H {¹H} nuclear Overhauser effects (NOEs) and from the values of ¹H¹H coupling constants. The application of the exciton chirality method on the dibenzoate permitted establishment of the absolute configuration of sulcatine as 2S,3R,7S,8S,9R.     

6β-Hydroxyipolamiide,an iridoid glucoside from Stachytarpheta mutabilis

A new iridoid glucoside has been isolated from Stachytarpheta mutabilis and assigned the structure and configuration of 6β-hydroxyipolamiide on the basis of ¹H NMR and ¹³C NMR evidence. The conversion of this compound into penta- acetyllamiol proved the above assignment.     

Liquidambin,an ellagitannin from Liquidambar formosana

A new ellagitannin, named liquidambin, which could be biogenetically closely correlated with casuarinin and pedunculagin, has been isolated from the leaves of Liquidambar formosana. Its structure was determined as 5-O-galloyl-2,3,4,6-di-O-(S)-hexahydroxydiphenoyl-d-glucose. The structural equilibration due to hydration of the aldehyde group of the glucose core in this tannin was shown from its ¹H and ¹³C NMR spectra.