Asmita V. Patel

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.

Cissampeloflavone, a chalcone-flavone dimer from Cissampelos pareira

From the aerial parts of Cissampelos pareira L. (Menispermaceae), a chalcone-flavone dimer has been isolated which, mainly from NMR spectroscopic and MS data, was proved to be 2-(4-hydroxy-3-methoxyphenyl)-7-(4-methoxyphenyl)-6-(2-hydroxy-4,6-dimethoxybenzoyl)-furano[3,2-g]benzopyran-4-one. This has been assigned the trivial name cissampeloflavone. The compound has good activity against Trypanosoma cruzi and T. brucei rhodesiense and has a low toxicity to the human KB cell line.

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.

Ring substituted 3-phenyl-1-(2-pyrazinyl)-2-propen-1-ones as potential photosynthesis-inhibiting, antifungal and antimycobacterial agents

Four series of ring substituted (E)-3-phenyl-1-(2-pyrazinyl)-2-propen-1-ones were prepared by means of modified Claisen-Schmidt condensation of acetylpyrazines with aromatic aldehydes. The structures were confirmed by elemental analysis, IR, 1H NMR and 13C NMR spectra. The compounds were tested for specific biological properties and some derivatives exhibited photosynthesis-inhibiting, antifungal and antimycobacterial properties. The most pronounced effects were observed with compounds substituted with phenolic groups. Ortho-hydroxyl substituted derivatives were more potent than the corresponding para-hydroxyl substituted analogues.

Chlorogenone and neochlorogenone from the unripe fruits of Solanum torvum

Abstract Either steroidal sapogenins or steroidal alkaloids have been isolated from the unripe fruits of Solanum hazenii , S, meridense , S. scorpioideum , S. sycophanta and S. torvum . Chlorogenone {(25 R )-5α-spirostane-3,6-dione} and its 25 S -epimer, neochlorogenone, were extracted from S. torvum ; this is the first record these compounds as natural products.

Microbiological transformations of hecogenin and diosgenin by Cunninghamella elegans

Abstract Incubation of (25 R )-3β-hydroxy-5α-spirostan-12-one (hecogenin) with the fungus Cunninghamella elegans led to the formation of (25 R )-1β,3β,7β-trihydroxy-5α-spirostan-12-one, (25 R )-3β,7β-dihydroxy-5α-spirostan-12-one and (25 R )-3β-hydroxy-5α-spirostane-7,12-dione. Incubation of (25 R )-spirost-5-en-3β-ol (diosgenin) with the same fungus gave rise to (25 R )-spirost-5-ene-3β,7β,12β-triol and (25 R )-3β,12β-dihydroxy-spirost-5-en-7-one.

Betaine distribution in the Malvaceae

Aerial parts of 26 taxa, distributed in 18 genera and all 5 tribes of the Malvaceae have been examined for the presence of betaines. Glycinebetaine was obtained in high yield (0.5-4.6%, dry weight) from all the plants studied, except Abelmoschus moschatus, in extracts of which glycinebetaine was not detected. Trigonelline was recorded for 16 of the plants tested, but the yields were low (0.005-0.07%, dry weight). Roots and flowers of a few of the species were also examined for betaines. The same compounds as those found in the aerial parts were usually detected, but the glycinebetaine contents of the roots and flowers were considerably lower.

Simultaneous quantification of polyherbal formulations containing Rhodiola rosea L. and Eleutherococcus senticosus Maxim. using rapid resolution liquid chromatography (RRLC)

An RRLC method capable of simultaneous identification and rapid quantification of six biologically active compounds (salidroside, tyrosol, rosarin, rosavin, rosin, rosiridin) in Rhodiola rosea L. and two active compounds (eleutheroside B and eleutheroside E) in Eleutherococcus senticosus Maxim. was developed. The chromatographic analyses were performed on a reversed phase Phenomenex C18 (2)-HST column at 40°C with a neutral mobile phase (purified water and acetonitrile) gradient system at a flow rate of 1.0ml/min and UV detection at 205 and 220nm simultaneously. Baseline separation of eight active compounds was achieved within 8min. This developed method provides good linearity (R>0.9997), precision (RSD<1.99%) and recovery of the bioactive compounds. The RRLC method developed is capable of controlling the quality of R. rosea and E. senticosus raw herbs, commercial extracts, as well as polyherbal formulations containing R. rosea and E. senticosus as ingredients. This RRLC method is accurate and sensitive; in addition, it greatly increases sample analysis throughput with reduced analysis time, which is suitable for routine quality control analysis.

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.

Trans-4-hydroxypipecolic acid betaine from Lamium maculatum

Abstract From the aerial parts of Lamium maculatum L., prolinebetaine, trans -4-hydroxyprolinebetaine, pipecolic acid betaine and trans -4-hydroxypipecolic acid betaine have been isolated. The last of these compounds is a new natural product.