Flavonoids from pollens and stigmas of male and female flowers of four species of the genusCucurbita

Summary Differences have been found between the flavonoid patterns of pollens and corresponding stigmas ofCucurbita pepo, C. maxima, C. moschata andC. ficifolia. The major flavonoids ahve been identified as isorhamnetin-3-O-rutinoside isolated from stigmas ofC. pepo is absent in this material.Acknowledgments. The author thanks Dr Chr. Karl (Weleda, Schwäbisch Gmünd) for a sample of isorhamnetin and Mr A. D'Urso (Botanic Institute, University of Catania) for help in acquiring the plant material.     

ZNS-aktive Phenylpropylamine vonCatha edulis FORSK. (Celastraceae) kenyanischer Herkunft

Summary The phenylpropylamine fraction ofCatha edulis FORSK. grown in Kenya has been investigated. The major components have been found to be (S)-(–)--aminopropiophenone (1), (+)-norpseudoephedrine (2) and(–)-norephedrine (3). Quantitative ratios of1, 2, 3 in tissues of different age are discussed.

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ZNS-aktive Phenylpropylamine vonCatha edulis FORSK. (Celastraceae) kenyanischer Herkunft

     

Constituents of the digestive gland of molluscs of the genusAplysia. II. Halogenated monoterpenes fromAplysia limacina

Summary The digestive gland of the sea hare Aplysia limacina, collected in the bay of Naples, contains an array of polyhalogenated monoterpenes. The 2 major components are 3,4-erythro-7-dichloromethyl-3-methyl-3,4,8-trichloro-1,5 (E), 7 (Z)-octatriene (1), previously isolated from pacific red alga Plocamium cartilagineum, and the new 3,4-threo-7-dibromomethyl-3-methyl-3,4,8-trichloro-1,5 (E), 7 (E)-octatriene (2), whose structure has been assigned on the basis of analogy and of spectroscopic data. Examination of extracts of local red algae revealed that1 was present in Plocamium coccineum.Acknowledgments. We thank Dr D. J. Faulkner (University of California) for sending us the¹H-NMR-spectra of a series of polyhalogenated monoterpenes, Dr F. Cinelli (Zoological Station) for identification of algae, and Mr A. Crispino (GC) and C. Di Pinto (NMR) for their technical assistance.     

Research Articles¶Naturally occurring 2′-O-methylpurine nucleosides with hypotensive properties

2′-O-Methylinosine (1) has been isolated for the first time and shown to be an intrinsic hypotensive principle. Its probable in vivo precursor, 2′-O-methyladenosine (3), showed stronger and even orally potent hypotensive activity. Resistance of the methyladenosine (3) against adenosine deaminase is thought to contribute to its long-lasting activity. The effect of both nucleosides (1 and 3) was not accompanied with any significant change in heart rate, which is often observed with adenosine. Received 2 October 1997; accepted 28 October 1997     

The structure of gephyrotoxin (GTX) 223AB

Summary The structure 3-butyl-5-propylindolizidine (2), tentatively assigned to a minor alkaloid in skin extracts from a number of poison frogs of the Neotropical genusDendrobates, has been confirmed and its stereochemistry determined as 5E, 9E (2d) by comparison on GC and GC-MS with the four synthetic diastereomers2a-2d.     

Stereoselectivity of oxotremorine antagonists containing a chiral pyrrolidine group

Summary Oxotremorine (Ia) and its succinimide analogue (IIa) have been substituted in the pyrrolidine ring with a methyl group in the 2- or 3-positions. The compounds are oxotremorine antagonists. The 2-methyl-substituted enantiomers show stereoselectivity, the S-isomers being the most active.     

Antimutagenic unusual amino acids from plants

Summary Five unusual amino acids were identified as antimutagens against spontaneous mutation ofSalmonella typhimurium TA100: L-azetidine-2-carboxylic acid (1) from Liliaceae plants, -(methylenecyclopropyl)glycine (2) fromLitchi chinensis seeds, and 2-amino-4-methylhex-5-ynoic acid (3), hypoglycin A (4), and (2S, 4R)-2-amino-4-hydroxyhept-6-ynoic acid (5) fromEuphoria longana seeds. The absolute stereochemistry of5 was determined by its chiral synthesis from L-allylglycine, proving that5 is the C-4 epimer of the amino acid previously isolated from dried longan seeds.This work was partly supported by a Grant-in-Aid form the Ministry of Education, Science, and Culture, Japan, No. 57740283 (to HK).     

Further sesterterpenes from the spongeSpongia nitens: 12-epi-scalaradial and 12,18-diepi-scalaradial

Summary 2 new tetracarbocyclic sesterterpenes, isomers of the previously² described scalaradial (1), have been isolated from the marine spongeSpongia nitens and their structures have been established to be2 and3; during the structural work, evidence on the stereochemistry of1,2 and3 has been obtained.This work is part of the Progetto Finalizzato per l'Oceanografia e i Fondi Marini, C.N.R., Roma. We thank the Zoological Station (Naples) for the collection of the sponge, A. Crispino, C. Di Pinto and A. Milone for their technical assistance and Prof. C. Santacroce for generous gifts of scalaradial.     

Urinary excretion of renal brush border membrane enzymes in leprosy patientseffect of multidrug therapy

Renal function at the brush border membrane level has been studied using characteristic enzymes, such as alkaline phosphatase, leucine-aminopeptidase and gamma-glutamyl transpeptidase. Urinary enzyme studies were performed using leprosy patients, classified on the basis of bacteriological index (BI>3; n=20,BI<3; n=12, BI-ve; n=10) and compared with control subjects (n=10). The role of enzymuria in monitoring WHO-recommended multidrug therapy (MDT) has been evaluated in these patients. A significant increase in the enzyme activities (p<0.01), as well as significant (p<0.01) proteinurea in 24-hour urine samples of both the smear positive groups (BI>3,BI<3) prior to therapy compared to control subjects, indicates proximal tubular functional impairment at brush border membrane level. In the smear negative (BI-ve) grou, no significant difference was observed in enzyme activities as compared with the control group. In a follow-up study (BI>3; n=13, BI<3; n=4) the activities of all the enzymes decreased significantly in all the groups when compared to a corresponding untreated group. The follow-up study was not carried out on the smear negative group. The surprising finding was the differential behaviour of r-glutamyl transpeptidase, whose activity increased significantly (p<0.01) even after therapy inBI>3 group when compared with untreated patients. However in a detailed work-up including hepatic and renal function tests, the serum biochemistry was found to be normal both before and after therapy. Urinary excretion of brush border enzymes seems to be related to bacterial load, and their potential in studying the effect of MDT remains unclear.     

Structure and stereochemistry of attenuol,a new lignan fromKnema attenuata (Wall.) Warb.

Summary A new lignan attenuol has been isolated from the bark ofKnema attenuata (Wall.) Warb. Its structure (I) is deduced on the basis of analytical and spectral data. The compound has been assigned the absolute configuration as 2S,3R-dimethyl-1S-(p-hydroxyphenyl)-6,7-methylenedioxytetralin (III).Contribution No. 487 from the Ciba-Geigy Research Centre.Acknowledgments. We thank Dr H. Fuhrer and Dr P. Moser of Ciba-Geigy Ltd. Basle for the NMR spectral data and ORD determinations and Dr S. Selvavinayakam and his colleagues for the analytical results.     

Naturally occurring heterocycles inducing drought resistance in plants

Summary During screening of animal metabolites which induce drought resistance in plants, two diketopiperazines, cyclo(L-Hyp-L-Pro) (1) and cyclo(L-Hyp-L-Leu) (2), emerged as effective. When rice seeds were pretreated with the cyclic dipeptides (1 and2) during their germination period, the resulting seedlings showed significant resistance to water-stress caused by 0.5–1.5% NaCl solution or 2.5–5.0% mannitol solution.     

Guggulsterol-like steroids from the Mediterranean gorgonianLeptogorgia sarmentosa

Summary Several polyoxygenated steroids (1, 2, 3) have been isolated from the marine gorgonianLeptogorgia sarmentosa. One of these (1) is the known guggulsterol III, previously found in the pharmacologically active resin from the treeCommiphora mukul; the others,2 and3, have not been found before in nature, and are closely related to1. During the structural work apparent anomalies in the CMR-spectra of1 were observed.The authors are grateful to Prof. Sukh Dev for the PMR-spectra of guggulsterol III. Thanks are also due to Zoological Station (Naples), for the collection of the gorgonian, to Centro Metodologie Chimico-Fisiche, Università di Napoli, for recording PMR-spectra on WH-270 Superconducting Spectrometer-Bruker, to Mr C. Di Pinto for the CMR-spectra and to Mr A. Milone for the MS spectral measurements.     

The sperm attractant ofHormosira banksii (Phaeophyceae,Fucales), a seaweed common to Australia and New Zealand

Summary Hormosira banksii is a taxonomically isolated brown seaweed endemic to Australia and New Zealand. The sperm attractant of this species has been isolated and identified as trans-1-vinyl-2-(1E, 3Z-hexadienyl)-cyclopropane (I) (hormosirene).Hormosira is the first organism in which a cyclopropane derivative has been found to act as a hormone in sexual reproduction. The implication of this finding in relation to phylogeny and phytogeography is discussed.Acknowledgment. A substantial part of this work was supported by Deutsche Forschungsgemeinschaft (DFG).     

Two new kaempferol 3,7-diglycosides and kaempferitrin in the fernAsplenium trichomanes

Summary The fronds of the fernAsplenium trichomanes contain kaempferol 3,7-dirhamnoside (1) and the new compounds kaempferol 3-O-a-rhamnoside-7-O-a-arabinoside (2) and kaempferol 3-O-a-arabinoside-7-O-a-rhamnoside (3). The presence of the above flavonoids has been shown by spectroscopic methods and chemical degradations.Acknowledgments. The author thanks Prof. H. Wagner (Institut für pharmazeutische Arzneimittellehre der Universität München, München) for a sample of kaempferol 3,7-dirhamnoside, Dr K. R. Markham (Chemistry Division, D.S.I.R., Petone, New Zealand) for a gift of pectinase and Mr A. D'Urso (Botanic Institute, University of Catania) for help in acquiring the plant material.     

Acyclic diterpenes containing 3 enol acetate groups from the green algaChlorodesmis fastigiata

Summary 2 new diterpenes, chlorodesmin (4) and dihydrochlorodesmin (5), each containing 3 enol acetate groups, have been isolated from Great Barrier Reef collections of the green algaChlorodesmis fastigiata (Chlorophyta, Caulerpales). Didehydrotrifarin (3) was also characterized.     

6,10,14-Trimethylpentadecan-2-one and 6,10,14-trimethyl-5-trans, 9-trans, 13-pentadecatrien-2-one from the androgenic glands of the male crab Carcinus maenas

Summary 2 C₁₈ isoprenoid ketones, hexahydrofarnesylacetone (1) and farnesylacetone (2) have been identified for the first time in lipid extracts from the androgenic glands of the male crab Carcinus maenas, using coupled gas chromatography-mass spectrometry. The 2 compounds prepared by synthesis, are biologically active, inhibiting the incorporation of³H-leucine in Crustaceans ovaries subcultures.We wish to thank Professors H. Charniaux-Cotton and E. Lederer for their permanent interest in this work.     

Zur Stereochemie der Propandioldehydrase-Reaktion

Summary Propanedioldehydrase is shown to convert both (+)-(S)-2-²H-propanediol,3, and (–)-(R)-1-²H₂-propanediol,5, to specimens of deuterated propion-aldehyde, for which the (S)-configuration has been established. Thus, in the propanedioldehydrase reaction migration of hydrogen atoms from C–1 to C–2 always occurs with inversion of configuration.     

Zonaroic acid from the brown seaweedDictyopteris undulata (=zonarioides)

Summary A sesquiterpene-substituted 4-hydroxybenzoic acid, zonaroic acid (5), is described from the brown seaweedDictyopteris undulata (=zonarioides). The absolute stereochemistry in the zonarol (1)-chromazonarol (2) and zonaroic acid (5) series has also been defined. The occurrence of5 along with zonarol (1), the corresponding sesquiterpene-substituted hydroquinone, suggests that 4-hydroxybenzoic acid is the ring precursor as in ubiquinone biogenesis.     

Correlation of anthothecol and hirtin

Summary Hirtin (3) and anthothecol (2) have been correlated by conversion of each to the derivative (10).     

Synthesis of koenigicine

Summary The structure of koenigicine as 8,9-dimethoxy-3,3,5-trimethyl-3, 11-dihydropyrano-[3,2-a] carbazole (1) has been confirmed by synthesis.