Sterine in Trichosanthes kirilowii

Four Δ⁵-sterols and six Δ⁷-sterols were isolated from the seed oil of Trichosanthes kirilowii and identified as campesterol, sitosterol, stigmasterol, Δ⁷-campesterol, Δ⁷-stigmasterol, Δ^7,22-stigmastadienol, 24-ethylcholesta-5,25-diene-3β-ol, 24-ethylcholesta-7,24(25)-diene-3β-ol, 24-ethylcholesta-7,25-diene-3β-ol, and 24-ethylcholesta-7,22,25-trine-3β-ol.     

Triterpene alcohols in the seeds of two Cucumis species of cucurbitaceae

Isomultiflorenol was the major component accompanied by its Δ¹⁷-isomer, multiflorenol, in the triterpene alcohol fractions of the unsaponifiable     

(22E,24S)-5α-Ergosta-7, 22-dien-3β-ol from the seeds of Cucumis sativus

(22E,24S)-5α-Ergosta-7,22-dien-3β-ol isolated from the seeds of Cucumis sativus was shown to be the 24S-epimer, i.e. stellasterol,     

two 3-oxo steroids in Thea sinensis seeds

Spinasterone and 22,23-dihydrospinasterone were isolated from the seed oil of Thea sinensis which contains spinasterol and 22,23-dihydrospinasterol as the two major sterol constituents.     

Trypsin isoinhibitors from Momordica repens seeds

Four trypsin isoinhibitors (CM-1 to CM-4) were purified from Momordica repens seeds by gel filtration on Sephadex G-50 followed by ion exchange chr     

Multiple forms of phytase in germinating cotyledons of Cucurbita maxima

Multiple forms of phytase (myoinositol hexaphosphate phosphohydrolase, EC 3.1.3.8) have been isolated in highly purified forms from germinating Cucurbita maxima cotyledons using acetone and ammonium sulphate fractionation, Sephadex gel filtration and ion exchange chromatography on DEAE- and CM-cellulose. Gel filtration produced two peaks of phytase activity; phytase I (high MW) and phytase II (low MW). Phytase I was further resolved into 4 distinct species on CM-cellulose and these were designated phytase IA, IB, IC and ID, according to their elution order. On the other hand, phytase II remained as a single species with a purification of 35-fold. The MWs of each phytase I species were identical (MW 66 500 ± 4000) and they were twice the MW of phytase II (MW 32 400 ± 4000) indicating that I and II may be structurally related. The properties of various molecular forms were compared. The difference in properties between phytase II and phytase I isoenzymes (IA, IB, IC and ID) was more pronounced than that observed among the isoenzymes of phytase I alone.     

Purification, physicochemical characterization, saccharide specificity, and chemical modification of a Gal/GalNAc specific lectin from the seeds of Trichosanthes dioica

A new galactose-specific lectin has been purified from the extracts of Trichosanthes dioica seeds by affinity chromatography on cross-linked guar gum. The purified lectin (T. dioica seed lectin, TDSL) moved as a single symmetrical peak on gel filtration on Superose-12 in the presence of 0.1 M lactose with an M(r) of 55 kDa. In the absence of ligand, the movement was retarded, indicating a possible interaction of the lectin with the column matrix. In SDS-PAGE, in the presence of beta-mercaptoethanol, two non-identical bands of M(r) 24 and 37 kDa were observed, whereas in the absence of beta-mercaptoethanol, the lectin yielded a single band corresponding to approximately 55,000 Da, indicating that the two subunits of TDSL are connected by one or more disulfide bridges. TDSL is a glycoprotein with about 4.9% covalently bound neutral sugar. Analysis of near-UV CD spectrum by three different methods (CDSSTR, CONTINLL, and SELCON3) shows that TDSL contains 13.3% alpha-helix, 36.7% beta-sheet, 19.4% beta-turns, and 31.6% unordered structure. Among a battery of sugars investigated, TDSL was inhibited strongly by beta-d-galactopyranosides, with 4-methylumbelliferyl-beta-d-galactopyranoside being the best ligand. Chemical modification studies indicate that tyrosine residues are important for the carbohydrate-binding and hemagglutinating activities of the lectin. A partial protection was observed when the tyrosine modification was performed in the presence of 0.2 M lactose. The tryptophan residues of TDSL appear to be buried in the protein interior as they could not be modified under native conditions, whereas upon denaturation with 8 M urea two Trp residues could be selectively modified by N-bromosuccinimide. The subunit composition and size, secondary structure, and sugar specificity of this lectin are similar to those of type-2 ribosome inactivating proteins, suggesting that TDSL may belong to this protein family.     

Alkaloids in seeds of four Erythrina species

The alkaloids present in the seeds of four Erythrina species, E. brucei, E. cochleata, E. thollonia and E. caribaea have been screened by GC/MS. A new alkaloid, erythrocarine, has been isolated from E. caribaea and characterized as a methylenedioxy analogue of the known dienoid alkaloids erysoline and erysonine.     

Prenylated flavonoids from seeds of Calopogonium mucunoides

The seeds of Calopogonium mucunoides furnished 7-O-γ,γ-dimethylallyl-8-methoxy-3′,4′-dioxymethylene-isoflavone, 7-O-γ,γ-dimethylallyl-3′-hydroxy-4′-methoxyisoflavone, 7-O-γ,γ-dimethylallyl-3′,4′-dimethoxyisoflavone and 2S-di[6′',6′'-dimethylpyrano (2′',3′':7,8;2′',3′':4′,3′)]-flavanone whose structures were established by spectroscopic means involving the use of 400 MHz ¹H NMR with double irradiation and INDOR techniques.     

Rhododendron seeds from the Palaeocene of southern England

Seeds closely resembling those of some species of the extant genus Rhododendron L. have been recovered from the Reading Beds near Newbury, Berkshire. The fossils are assigned to Rhododendron newburyanum sp. noV. on the basis of detailed comparisons with seeds of extant Rhododendron species, other Ericaceae, and taxa with seeds of similar morphology.     

Changes in lipid profiles in the developing haustorium of oil palm seeds

Germinated oil palm seeds were placed in special trays in the field and at different intervals the haustoria were harvested. Changes in haustorial lipids were followed until the eighth week after germination. The moisture content decreased while the lipids increased. The haustorial fatty acid profile was similar to that of the palm kernel. Changes in fatty acid composition at different weeks after germination were observed. The major haustorial lipids were triacylglycerols; free fatty acids and diacylglycerols were also present     

Triterpene alcohols in the seeds of solanaceae

Lanost-8-en-3β-ol, lanosterol and 24-methylenelanost-8-en-3β-ol in addition to cycloartanol, cycloartenol, 24-methylenecycloartanol, lupeol, β-amyrin, daturaolone and daturadiol were identified in the seeds of Solanaceae plants. The distribution of the first eight triterpene alcohols in the seeds of eleven plants belonging to seven genera of Solanaceae family was determined.     

Reduced nicotinamide-adenine-dinucleotide-pyrophosphorylase: A novel enzyme in seeds

An enzyme which splits reduced NAD has been partially purified from pea (Pisum sativum, Kelvedon Wonder) seeds. The activity requires orthophosphate and the products are ADP and probably NMN (dihydro NMN?). The enzyme splits the NADH₂ at the pyrophosphate bond and incorporates the phosphate into the AMP residue. NAD, NADP or NADPH₂ could not replace NADH₂. The enzyme is unstable during storage, is activated by Mg²⁺ and by Mn²⁺, and inhibited by Ca²⁺. K⁺, Li⁺ and NH₄⁺ have no effect. The possible role of this enzyme in the synthesis of ATP in seeds at the early stage of germination is discussed.     

The novel peptide composition of the seeds of Trichosanthes dioica Roxb

The seeds of Trichosanthes dioica contain a large amount of peptides in the range of 2-8 kD. These peptides can be resolved in a discontinuous sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) system using Tricine as the trailing ion. The seed proteins contain a number of charge species as determined by isoelectric focusing (IEF) in polyacrylamide gels. The peptides were focused in the basic region as determined by two-dimensional electrophoresis involving IEF and SDS-PAGE. The seed peptides have the unique property of being resistant to the action of silver nitrate, a sensitive reagent commonly used to stain proteins. The seed contains haemagglutinating activity which is inhibited by galactose.     

Glabrachalcone,a chromenochalcone from Pongamia glabra seeds

Glabrachalcone, a new chromenochalcone has been isolated along with a known chromenochalcone from an ethanolic extract of the seed oil of Pongamia glabra. The structure of glabrachalcone has been established as 2′-hydroxy-2,4,5-trimethoxy-6″,6″-dimethylchromeno(4′,3′:2″,3″)chalcone on the basis of spectral evidence and was confirmed by synthesis.