Erythrisenegalone,a prenylated-flavanone from Erythrina senegalensis

The isolation of a new prenylated flavanone, erythrisenegalone, from the stem-bark of Erythrina senegalensis is described. Its structure was established by spectroscopic methods and a few chemical transformations.     

A novel conotoxin, qc16a, with a unique cysteine framework and folding

A novel conotoxin, qc16a, was identified from the venom of vermivorous Conus quercinus. qc16a has only 11 amino acid residues, DCQPCGHNVCC, with a unique cysteine pattern. Its disulfide connectivity was determined to be I-IV, II-III. The NMR structure shows that qc16a adopts a ribbon conformation with a simple beta-turn motif formed by residues Gly6, His7 and Asn8. qc16a causes depression symptom in mice when injected intracranially. Point mutation results showed that Asp1, His7 and Asn8 are all essential for the activity of qc16a. Electrophysiologically, qc16a has no strong effect on the whole-cell currents of neurons and the currents of Drosophila Shaker channels, human BK channels and Na_V1.7 channels. Its specific target still remains to be identified.     

Buchananine,a novel pyridine alkaloid from Cryptolepis buchanani

A new alkaloid, buchananine, was isolated from the stems of Cryptolepis buchanani. Its structure was determined as 6-O-nicotinoyl-α-d-glucopyranose by chemical and spectroscopic investigations.     

2α-iso-Valeroyloxyeperuic acid,a diterpene from Eupatorium petiolare

The diterpene acid 2α-iso-valeroyloxyeperuic acid was isolated from the aerial parts of Eupatorium petiolare. Its structure and stereochemist     

Characterization of a Bacteriocin-Like Substance Produced by a Vaginal Lactobacillus salivarius Strain

A novel bacteriocin-like substance produced by vaginal Lactobacillus salivarius subsp. salivarius CRL 1328 with activity against Enterococcus faecalis, Enterococcus faecium, and Neisseria gonorrhoeae was characterized. The highest level of production of this heat-resistant peptide or protein occurred during the late exponential phase. Its mode of action was shown to be bactericidal. L. salivarius subsp. salivarius CRL 1328 could be used for the design of a probiotic to prevent urogenital infections.     

Ficin E,a serine-centred protease from Ficus elastica

A protease of M, 50 000 was purified from the latex of Ficus elastica. The enzyme has a pI of 3.7 and pH optimum at 6.0. Its activity is dependent on serine and histidine residues. The amino acid composition is reported.     

Preleosibirin,a prefuranic labdane diterpene from ballota nigra subsp. foetida

From the aerial parts of Ballota nigra subsp. foetida a new prefuranic labdane diterpene, preleosibirin, has been isolated. Its structure was established by spectroscopic means and by correlation with the previously known diterpenoid leosibirin.     

Gramodendrine,a bipiperidyl-indole alkaloid from Lupinus arbustus subsp. calcara tus

A new bipiperidyl-indole alkaloid, gramodendrine, was isolated from Lupinus arbustus subsp. calcaratus. Its structure was determined from spect     

Laurebiphenyl,a dimeric sesquiterpene of the cyclolaurane-type from the red alga Laurencia nidifica

Laurebiphenyl, a new, dimeric sesquiterpene of the cyclolaurane-type, was isolated from the red alga Laurencia nidifica. Its structure was determined by spectral and chemical means.     

Vestolide,a guaianolide from vicoa vestita

A new sesquiterpene lactone, vestolide, of the guaiane series was isolated from the aerial parts of Vicoa vestita. Its structure was established on the basis of chemical and spectral evidence.     

Margotianin,a new diterpenoid from Margotia gummifera

From the roots and aerial parts of Margotia gummifera a new natural diterpenic methyl ester, margotianin, has been isolated. Its structure was established as methyl ent-7α-angeloxy-15α-acetoxy-atis-16-en-19-oate almost exclusively by ¹³C NMR spectroscopy.     

Quadranguloside,a cycloartane triterpene glycoside from Passiflora quadrangularis

Quadranguloside, a new cyclopropane triterpene glycoside was isolated from the methanolic extract of the leaves of Passiflora quadrangularis. Its structure has been established as 9,19-cyclolanost-24Z-en-3β,21,26-triol-3,26-di-O-gentiobioside on the basis of hydrolysis and spectral evidence.     

Bullatantriol,a sesquiterpene from annona bullata

Bullatantriol has been isolated from Annona bullata. Its constitution and relative configuration have been established by X-ray analysis. Its absolute configuration has been assigned by chiroptical investigation of the corresponding 7-ketone.     

Teugin,a neo-clerodane diterpenoid from Teucrium fragile

From the aerial part of Teucrium fragile a new neo-clerodane diterpenoid, teugin, has been isolated. Its structure, 15,16-epoxy- 2β,6β-dihydroxy-neo-cleroda-3,13(16),14-triene-18,19:20,12S-diolide, was established mainly by spectroscopic means.     

Koenoline,a further cytotoxic carbazole alkaloid from Murraya koenigii

Koenoline, a carbazole alkaloid, has been isolated from the root bark of Murraya koenigii for the first time as a natural product. Its structure was established as 1-methoxy-3-hydroxymethylcarbazole by analysis of spectroscopic data and was confirmed by partial synthesis from murrayanine isolated from M. siamensis roots. Koenoline exhibited cytotoxic activity against the KB cell-culture test system.     

Ursadiol: a new triterpene diol from Calendula officinalis flowers

A new triterpene diol was isolated from dry Calendula officinalis flowers. Its structure was proved as 3,21-di-OH-ursa-12-en.     

Sarmentosin epoxide,a new cyanogenic compound from Sedum cepaea

A new cyanogenic compound, sarmentosin epoxide, was isolated from the aerial parts of Sedum cepaea. Its structure was established mainly by ¹H     

Grayanoside C,a new diterpene glucoside from Leucothoe grayana

A new diterpene glucoside has been isolated from Leucothoe grayana. Its structure was elucidated by X-ray diffraction analysis of a dehydrated product of the aglycone and conversion of the same to leucothol A.     

Hirsudiol a triterpenoid from cocculus hirsutus

A new triterpenoid alcohol hirsudiol, has been isolated from Cocculus hirsutus. Its structure was determined as 2α,3α-dihydroxyolean-13(18)-ene through spectroscopic studies. Nonacosan-10-ol was also isolated.     

Salviacoccin,a neo-clerodane diterpenoid from Salvia coccinea

A new neo-clerodane diterpenoid, salviacoccin, was isolated from the aerial part of Salvia coccinea. Its structure, 15,16-epoxy-10-hydroxy-neo-cleroda-2,7,13(16), 14-tetraene-17,12R:18,19-diolide, was established by chemical and spectroscopic means and by comparison with closely related compounds.