Halogenated phlorethols and fucophlorethols from the brown alga Cystophora retroflexa.

From an ethyl acetate fraction of the brown alga Cystophora retroflexa several halogenated phlorotannins were isolated. Most of the compounds are derivatives of diphlorethol penta-acetate and triphlorethol-A hepta-acetate. The majority turned out to be chlorinated and/or brominated. Only one iodinated substance, 2-iodophloroglucinol triacetate, was isolated. The structure of this derivative and the following compounds have been characterized previously: 2([D])-bromodiphlorethol penta-acetate, 3([A1])-bromodiphlorethol penta-acetate, 4([D])-bromo-diphlorethol penta-acetate, 4([D])-chlorodiphlorethol penta-acetate, 3([A1])-chlorotriphlorethol-A hepta-acetate, 4([D])-bromotriphlorethol-A hepta-acetate and 4([D])-chlorobisfucopentaphlorethol-A nonadeca-acetate. Ten halogenated phlorethols and two chlorinated fucophlorethols are described for the first time and characterized as their acetates: 2([B])-bromotriphlorethol-A hepta-acetate, 2([D])-bromotriphlorethol-A hepta-acetate, 2([B]), 2([D])-dibromotriphlorethol-A hepta-acetate, 3([A1]), 5([A1])-dichlorotriphlorethol-A hepta-acetate, 3([A1]), 4([D])-dichlorotriphlorethol-A hepta-acetate, 3([A1])-chloro-4([D])-bromotriphlorethol-A hepta-acetate. 2([B]), 4([D])-dichlorotriphlorethol-A hepta-acetate, 2([D]), 3([A1])-dibromotriphlorethol-A hepta-acetate, 3([A1])-bromo-2([D])-chlorotriphlorethol-A hepta-acetate, 2([D])-bromotetraphlorethol-C nona-acetate, 4([D])-chlorofucotriphlorethol-B dodeca-acetate and 4([D])-chlorobisfucotetraphlorethol-A heptadeca-acetate.

New dammaranes, esterified with malonic acid, from leaves of Betula pendula.

Three known and five new dammarane triterpenes, esterified with malonic acid at C-3 with hemolytic activity were identified from the ethanol-water extract of leaves of Betula pendula Roth: 12-O-acetyl-3alpha,12beta,20(S),24(R)-tetrahydroxydammar-25-en-3-yl hydrogen propanedioate, 12-O-acetyl-3alpha,12beta20(S),24(S)-tetrahydroxydammar-25-en-3-yl hydrogen propanedionate, 12-O-acetyl-3alpha,12beta,17alpha,20(S),24(R)-pentahydroxydammar-25-en-3-yl hydrogen propanedioate, [12beta-acetoxy-4,4,8,10,14-pentamethyl-17-(2-methyl-5-oxotetrahydrofuran2(S)-yl)-hexadecahydrocyclopenta[A]phenanthren-3alpha-yl] hydrogen propanedioate, 12- O-acetyl-3alpha,12beta,20(S),25-pentahydroxydammar-23(E)-en-3-yl hydrogen propanedioate, and one which was new for Betula pendula but found in other Betula species: 12-O-acetyl-20,24-epoxy-3alpha,12beta,20(S),24(R),25-pentahydroxydammar-3-yl hydrogen propanedioate. The structures were elucidated by MS, (1)H-NMR, (13)C-NMR, (1)H-(1)H-COSY, DEPT, (1)H-(13)C-NMR (HMQC, HMBC) experiments.

Phlorotannins from the brown algae Cystophora torulosa and Sargassum spinuligerum.

Phlorotannins often have various toxic effects against a large number of organisms. From the ethyl acetate fraction of the ethanolic extract of the brown alga Cystophora torulosa 33 phlorotannins were obtained. Twenty of them are described in this report: phlorethols and fuhalols, and fucophlorethols and hydroxyfucophlorethols. Seven of them were isolated for the first time. New phlorotannins bearing additional hydroxy groups belong to the hydroxyfucophlorethols. NMR- and MS-data were used for structural elucidation. Several of the substances described for C. torulosa occur in Sargassum spinuligerum as well.

Novel Saponins from Zizyphus spina-christi growing in Egypt.

From the butanol extract of the leaves of Zizyphus spina-christi (L.) Willd. (Rhamnaceae), four saponin glycosides were isolated: Christinin A (1), B (2), C (3), and D (4). Their structures were determined by chemical and spectroscopic evidence. Compound 1, was found to be 3-O-[alpha-L-fucopyranosyl (1 -> 2)-beta-D-glucopyranosyl(1 ->3)-alpha-L-arabinopyranosyl]jujubogenin; the others are the new, 2 being 3-O-[alpha-D-fucopyranosyl(1 -> 2)-¿beta-D- glucopyranosyl-4-sulphate(1 ->3)¿-alpha-L-arabinopyranosyl]jujubogenin, 3 being 3-O-beta-glucopyranosyl(1 -> 2)-alpha-L-rhamnopyranosyl (1 -> 3)-alpha- L-arabinopyranosyl]jujubogenin, and 4 being 3-O-[alpha-L-fucopyranosyl(1 -> 2) -¿beta-D-arabinopyranosyl(1 -> 3)-beta-D-glucopyranosyl(1 -> 3)¿-alpha-L- arabinopyranosy]jujubogenin.

The essential oil of Sideritis syriaca.

The volatile oil of Sideritis syriaca L. has been investigated by means of GC/MS, resulting in the identification of 29 terpenes, fatty acids, esters, and alcohols. The presence of glycosylated derivatives of terpenes could not be established.

Solasodine glycosides of Solanum unguiculatum (A.) Rich.

Besides solasonine, three new glycosides, namely, 3-O-alpha-L-rhamnopyranosyl-(1-->3)-solasodine, 3-O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->4)-beta -D- galactopyranosyl solasodine, and 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-galactopyranosyl solasodine, were isolated from Solanum unguiculatum (A.) Rich. Their structures were determined on the basis of chemical and spectral methods.

Hypoglycemic and antihyperglycemic effects of Zizyphus spina-christi in rats.

Zizyphus is one of the plants commonly used in Egyptian folk medicine for the treatment of different diseases. The present study aims to investigate the effect of the butanol extract of Zizyphus spina-christi leaves as well as christinin-A, its principle saponin glycoside, in normal and streptozotocin-diabetic rats. In normal rats, treatment in both cases for one and four weeks produced insignificant changes in all studied parameters. However, in diabetic rats, both treatments significantly reduced serum glucose level, liver phosphorylase and glucose-6-phosphatase (G-6-pase) activities, and significantly increased serum pyruvate level and liver glycogen content after 4 weeks treatment. There was also marked improvement in glucose utilization in diabetic rats in both cases. Serum insulin and pancreatic cAMP levels showed significant increases in diabetic rats treated for a period of 4 weeks with the butanol extract.

Saponins in the leaves of birch? Hemolytic dammarane triterpenoid esters of Betula pendula.

Three hemolytic dammarane triterpenes, esterified with malonate at C-3 and acetate at C-12, were isolated from the leaves of Betula pendula. Their structures were elucidated by chemical and spectroscopic means. Former reports on the presence of saponins in birch leaf extracts could not be confirmed. The hemolytic activity of the extracts, which was ascribed to saponins, is caused by the dammarane esters instead. A fraction containing a mixture of the dammarane esters did not exhibit diuretic activity when tested p.o. in male Wistar rats.

Essential Oils of Achillea ptarmica.

Using GC and GC/MS, 40 compounds were identified in the essential oils of various organs of ACHILLEA PTARMICA. Three ponticaepoxides and (+)-(4 S,6' R)-beta-sesquiphellandrene could be isolated from the root.

[Alkaline Cleavage of Polymeric Phenols from Sargassum muticum and Pelvetia canaliculata]. / Alkalische Spaltung polymerer Phenole aus Sargassum muticum und Pelvetia canaliculata.

Low-molecular phenolic cleavage products as well as dibenzofurans are obtained by treatment of polymeric polyphenols from SARGASSUM MUTICUM and PELVETIA CANALICULATA (brown algae) with hot aqueous alkali. Similar degradation products were observed in the analogous treatment of model substances (1). Statements about certain structure elements of polymeric material can now be made from rules derived at that time. The polyphenol fraction from S. MUTICUM seems to contain only phlorotannins of the fuhalol type and those from P. CANALICULATA, in addition to a large portion of non-cleavable substances, several compounds of the fucophlorethol type.

Phlorotannins from the Brown Alga Analipus japonicus1.

New phloroglucinol derivatives were isolated from the ethanolic extract of ANALIPUS JAPONICUS (Harv.) Wynne, a north Pacific brown alga. Most of the compounds are fucols, i.e. phlorotannins in which the phloroglucinol units are connected by biaryl bonds. In addition to the four known oligomers difucol hexaacetate, trifucol nonaacetate, and tetrafucol-A and B dodecaacetates, two atropisomeric pentafucol pentadecaacetates, four atropisomeric hexafucol octadecaacetates, a heptafucol uneicosaacetate mixture, the following halogenated compounds could be isolated: bromo- and chlorotrifucol nonaacetate, 5'-bromo- and 5'-chlorotetrafucol-A dodecaacetate as well as 5'-bromo- and 5'-chloropentafucol-A pentadecaacetate. Three other phlorotannin derivatives belong to the phlorethol and fucophlorethol groups, respectively.

The Structures of some Triterpene Saponines from Anagallis arvensis.

5 new triterpene saponines, named anagalloside A, B, C, and desglucoanagalloside A and B, were isolated from the herb of ANAGALLIS ARVENSIS L. (Primulaceae). The structures of the saponines were elucidated by (1)H-, (13)C-NMR spectroscopy, FAB-MS, and the methylating and combined methylating-ethylating analysis methods.

Further Polyenic and Polyynic Carboxamides and Sesamin from Achillea ptarmica.

The amides of various polyenic and polyynic carboxylic acids contained in the lipophilic extract from roots, leaves, and flowers of ACHILLEA PTARMICA were separated into several fractions by DCCC. Further separation was possible by subjecting these fractions to HPLC on silica gel (LiChrosorb) and CN-LiChrosorb. With this procedure, sesamin and 15 acid amides of unsaturated carboxylic acids were found. Structure elucidation of the compounds was carried out by means of UV-, IR-, (1)H-NMR spectroscopy and MS.

Antibiotics from Algae XXXVII. Rhodomelol and Methylrhodomelol from Polysiphonia lanosa1.

From the red alga POLYSIPHONIA LANOSA (L.) Tandy two new bromophenols, methylrhodomelol and rhodomelol were isolaed, and after acetylation and methylation their structure elucidated with the aid of spectroscopic methods and an X-ray crystallographic study.

Antibiotics from Algae. XXXV. Phlorotannins from Ecklonia maxima1.

New phloroglucinol derivatives were isolated from the ethanolic extract of ECKLONIA MAXIMA, a brown alga found off the west coast of South Africa. Most of these compounds contain dibenzo[1,4]dioxin elements. The common basic unit of all the compounds found is eckol, a hexahydroxyphenoxydibenzo[1,4]dioxin composed of 3 phloroglucinol units. Phloroeckol A and B represent four-ringed phloroglucinol derivatives, whereas the only five-ringed substance (furodehydroeckol) displays a furan structure in addition. Six-ringed phloroglucinol derivatives composed of two eckol units joined either symmetrically (such as 7,7'-bieckol, 9,9'-bieckol) or asymmetrically (7,9'-bieckol, dieckol) are found frequently. Apart from these, tetraphlorethol C, a four-ringed tetraphloroglucinol triether which lacks both dioxin and furan structures, also occurs.

Antibiotics from Algae XXXIII1: Phlorotannins of the Brown Alga Himanthalia elongata2,3.

It is possible to obtain approximately 0.2% (relative to dry weight) phenols soluble in ethyl acetate from HIMANTHALIA ELONGATA. After removal of a fraction containing high-molecular weight substances, a total of 17 oligomeric phlorotannins with 2 to 8 aromatic rings can be isolated from the mixture of the acetylated phenol fraction. Apart from 2 derivatives belonging to the fucol group, diphlorethol and a tetraphlorethol not yet fully identified, all the other substances are fucophlorethols. Amongst these substances, a phenoxylated therphenyl derivative and several fucophlorethols with two-fold phenoxy-substituted biphenyl moieties were identified for the first time.