Ming-He Yang

Betaines and tertiary sulphonium compounds from 62 species of marine algae

Abstract From all 62 species of marine algae studied, either betaines or a tertiary sulphonium analogue or a mixture of the two types of compounds were extracted. Thus from this and earlier studies it would appear that either one or both of these classes of compounds are a constant feature of marine algae. Some compounds, in particular glycinebetaine, γ-aminobutyric acid betaine, prolinebetaine and 3-dimethyl-sulphoniopropionate, have a common and widespread distribution, whereas other compounds, e.g. β-prolinebetaine, trans-4- hydroxy-β-prolinebetaine , N- acetyllamine , δ-aminovaleric acid betaine and α-alaninebetaine, appear to have a very restricted occurrence. From Ptilota serrata, γ-aminobutyric acid betaine, methyl ester, was isolated and characterized; this is the first record of this substance as a natural product. It was not detected in any of the other algae investigated. The yields of betaines and tertiary sulphonium compounds obtained by extraction of the algae were low, especially from the Phaeophyceae. Apart from Chaetomorpha capillaris, for which 2% (of dry weight) of glycinebetaine was recorded, the yield of the major betaine or tertiary sulphonium compound from the other species investigated was less than 1% (of dry weight) and frequently less than 0.1%. The similarity of the betaines and their tertiary sulphonium analogues found in different species of the same genus show that these compounds have taxonomic significance at the genetic level.

Betaine distribution in the labiatae

Abstract Seventy-nine species and three hybrids of Labiatae have been examined for the presence of betaines, which were isolated from and characterised for all the plants tested in six of the eight subfamilies (Ajugoideae, Teucrioideae, Viticoideae, Lamioideae, Pogostemonoideae and Scutellarioideae). However, unlike the Lamioideae, all species of which had relatively high betaine levels, those members tested of the other major subfamily, the Nepetoideae, either gave low betaine yields or these compounds were not detected. The three species examined representing the Chloanthoideae contained compounds which reacted with Dragendorffs reagent, but their structures could not be determined because of the small quantities isolated. The betaines found in different species of the same genus were very similar, supporting the view that these compounds have taxonomic significance at the generic level.

Betaines in coastal plants

Abstract Aerial parts of 63 flowering plant species distributed in 43 genera and 22 families have been examined for the presence of betaines and tertiary sulphonium compounds. The plants tested were collected primarily either from salt marshes or close to the sea, but other species in either the same genus or family as plants collected from the coastal area were included in the study. Betaines were isolated from all but six of the species collected, but tertiary sulphonium compounds were not detected in any. High concentrations of betaines were found in all species of Chenopodiaceae examined as well as in 12 other species in other families, most notably Sesuvium portulacastrum (Aizoaceae), Avicennia marina (Verbenaceae) and Spartina×townsendii (Gramineae). Most of the species tested contained betaines in low concentrations (0.0009–0.10% dry weight). The qualitative distribution of betaines within different species of any one genus was consistently the same.

Formaldehyde, as its dimedone adduct, fromAscophyllum nodosum

Formaldehyde, as its dimedone adduct (formaldemethone), has been isolated fromAscophyllum nodosum and characterised by thin-layer and overpressured layer chromatography, and from proton nuclear magnetic resonance spectroscopic and electron impact mass spectrometric data. Formaldemethone was detected in extracts of both fresh and dry alga. It is postulated that during dynamic methylation and demethylation processes in the cells, hydroxymethyl groups may be formed, which dependent on pH, are in equilibrium with either free formaldehyde or ions such as iminium, oxonium and thionium; these species will react with dimedone to form formaldemethone. The amount of formaldehyde captured by the dimedone reagent increases as the concentration of dimedone is increased, until a maximum is reached.

Growth of a dissociated, filamentous stage of Codium species in laboratory culture

Unialgal cultures were established from isolated utricles for all five Codium species occurring in the British Isles and growth studies performed under different conditions of temperature (10-30 °C), photon irradiance (0-175 µmol m-2 s-1) and salinity (0-100% seawater growth medium). The species studied were C. fragile ssp. tomentosoides, C. fragile ssp. atlanticum, C. adhaerens, C. bursa, C. tomentosum and C. vermilara. All cultures developed into growth forms comprised of branched, dissociated, coenocytic filaments. All grew rapidly in culture, although the conditions for optimum growth sometimes differed for the individual entities. The development of typical Codium plants, with utricles, similar to the parental material, occurred only occasionally. The rapid growth of the dissociated, filamentous forms in laboratory culture led to the provision of sufficient quantities of plant material to enable detailed studies to be made of the lectins present in several of the species.

Crabbine, an aporphine alkaloid from Corydalis lutea

Abstract From Corydalis lutea , (+)-bicuculline, (+)-adlumidine, (−)-corypalmine, (−)-isocorypalmine and isocorydine have been isolated, along with a new aporphine alkaloid, the structure of which has been deduced from 1 H and 13 C NMR spectroscopic and mass spectrometric evidence. The trivial name crabbine has been assigned to the new compound.

Coumarleucasin and leucasone from Leucas inflataroots

Abstract From the acetone extract of the roots of Leucas inflata , four coumarins (siderin,coumarsabin, 8-methoxycoumarsabin and coumarleucasin) and one chromone were isolated. Oneof the coumarins, coumarleucasin (5-formyl-4,7,8-trimethoxy-3-methylcoumarin), and thechromone, leucasone {2,8-dimethyl (2,2-dimethylethenyl)-5,6-benzo-4-pyrone}, have not beenreported previously.

Rubragenin, chenogenin and wallogenin, steroidal sapogenins from Cordyline rubra

Abstract Three new steroidal sapogenin triols have been isolated from the leaves of Cordyline rubra. NMR spectroscopic and mass spectrometric data prove the compounds to be (22S,25R)-5α-furostan-22,25-epoxy-1β,3α,26-triol (rubragenin), (22R,25R)-5α-furostan-22,25-epoxy-1β,3α,26-triol (wallogenin), and (22R,25R)-5α-spirostane-1β, 3α,25-triol (chenogenin). Wallogenin is epimeric at C-22 to all the previously reported ‘furanose’ F-ring sapogenins.

Formaldehyde from marine algae

Abstract Formaldehyde, as its dimedone adduct (formaldemethone), has been isolated and fully characterized from the marine algae Ulva lactuca , Codium fragile ssp. tomentosoides (Chlorophyta) and Palmaria palmata (Rhodophyta). Formaldemethone has also been detected by TLC (thin-layer chromatography) and quantitatively estimated by OPLC (overpressured layer chromatography) in extracts of all the other species of seaweeds tested, which included representatives of the green, red and brown algae. It was concluded that formaldehyde is probably a constituent of all marine algal species.

Two furostane sapogenins from Cordyline rubra

From the leaves of Cordyline rubra two new steroidal sapogenins have been isolated. NMR and IR spectroscopic and mass spectrometric data prove the compounds to be 1β,3α-dihydroxy-furost-5-ene and 1β,3α,26-trihydroxy-5α-furostane.