Lignan and phenylpropanoid glycosides from Fernandoa adenophylla.

From the leaves and branches of Fernandoa adenophylla, a lignan glycoside (fernandoside) and a phenylpropanoid glycoside (2"-O-beta-apiosylverbascoside) were isolated together with 12 known compounds. The structural elucidations were based on analyses of physical and spectroscopic data.     

STEREOLOGICAL STUDY OF ULTRASTRUCTURAL CHANGES IN THE SHOOT APICAL MERISTEM OF NICOTIANA TABACUM DURING FLORAL INDUCTION

Shoot apices of a short-day sensitive line of Nicotiana tabacum L. cv. NCTG-22 have been examined by electron microscopy for ultrastructural changes which occurred in the central zone over a 17-day period during the transition from vegetative to reproductive growth. Plants were grown in controlled-environment chambers of the NCSU Phytotron and exposed to an inductive photoperiod after a 6-wk juvenile phase. Ultrastructural changes were investigated from photomicrographs using a semi-automatic stereological procedure and a microcomputer. After exposure to only one inductive cycle cell and nuclear cross sectional areas in short-day plants were significantly larger than in long-day controls. Subsequently, under short days cross sectional areas of cells, nuclei, vacuoles and proplastids decreased, while mitochondrial cross sectional area and relative volume increased during the course of the induction period. In induced apices as cross sectional areas and relative volumes of vacuoles and proplastids decreased, their profile numbers increased. The reduction in cross sectional areas of cells and most organelles was associated with an increase in rate of leaf initiation and size of the apical dome. The demand for sufficient energy input to maintain the surge in growth and activity preceding floral initiation was reflected by the significant increases in cross sectional area, profile numbers and density of the mitochondria population. Even though the transition period is quite long for Nicotiana, cells and organelles in the central zone were observed to progress through similar changes in morphology that are known to occur in Sinapis and Xanthium which exhibit a more rapid and absolute response to photo-induction.     

Lignan, phenolic and iridoid glycosides from Stereospermum cylindricum

A lignan glycoside [(+)-cycloolivil 4'-O-beta-d-glucopyranoside], a phenolic glycoside [3,4-dimethoxyphenyl 1-O-beta-d-xylopyranosyl-(1-->6)-beta-d-glucopyranoside] and a iridoid glycoside (stereospermoside) were isolated from the leaves and branches of Stereospermum cylindricum, together with (+)-cycloolivil, (+)-cycloolivil 6-O-beta-d-glucopyranoside, (-)-olivil, (-)-olivil 4-O-beta-d-glucopyranoside, (-)-olivil 4'-O-beta-d-glucopyranoside, vanilloloside, decaffeoyl-verbascoside, isoverbascoside, 3,4,5-trimethoxyphenyl 1-O-beta-d-xylopyranosyl-(1-->6)-beta-d-glucopyranoside, ajugol, verminoside, and specioside. The structure elucidations were based on spectroscopic evidence.     

The effect of fluorescent labeling on calcium-induced fusion of fusogenic carrot protoplasts

Various fluorescent compounds — carboxyfluorescein, scopoletin, fluorescein isothiocyanate (FITC), rhodamine B isothiocyanate (RITC), rhodamine 123, and rhodamine B ethyl ester — were used to study their effects on calcium-induced fusion of fusogenic carrot (Daucus carota L.) protoplasts. These protoplasts normally fused at a high percentage (50–60%) in response to 10 mM calcium, pH 6.0; however, if cells had been labeled with scopoletin, FITC, or RITC, fusion was greatly reduced. In contrast, labeling with carboxyfluorescein, rhodamine 123, or rhodamine B ethyl ester had no detectable effect on calcium-induced fusion. The two rhodamine dyes are shown to be localized in mitochondria.Abbreviations EGTA ethyleneglycol-bis-(-aminoethyl ether) N,N-tetraacetic acid - FITC fluorescein isothiocyanate - RITC rhodamine isothiocyanate - PE phosphatidylethanolamine     

Lignan and megastigmane glycosides from Sauropus androgynus

A lignan diglycoside, (-)-isolariciresinol 3alpha-O-beta-apiofuranosyl-(1-->2)-O-beta-glucopyranoside, and a megastigmane glucoside, sauroposide, were isolated from the aerial part of Sauropus androgynus together with (+)-isolariciresinol 3alpha-O-beta-glucopyranoside, (-)-isolariciresinol 3alpha-O-beta-glucopyranoside, (+)-syringaresinol di-O-beta-glucopyranoside, guanosine and corchoionoside C. The structural elucidations were bases on analyses of physical and spectroscopic data.     

Benzoxazinoid glucosides from Acanthus ilicifolius

From the aerial parts of Acanthus ilicifolius, two benzoxazinoid glucosides, 7-chloro-(2R)-2-O-beta-D-glucopyranosyl-2H-1,4-benzoxazin-3(4H)-one and (2R)-2-O-beta-D-glucopyranosyl-5-hydroxy-2H-1,4-benzoxazin-3(4H)-one have been isolated, together with six known compounds. The structural elucidations were based on the analyses of spectroscopic data.     

Canthin-6-one and beta-carboline alkaloids from Eurycoma harmandiana

Two alkaloids, canthin-6-one 9-O-beta-glucopyranoside and 7-hydroxy-beta-carboline 1-propionic acid, were isolated from the roots of Eurcoma harmandiana together with the five known canthin-6-one alkaloids, 9-hydroxycanthin-6-one, 9-methoxycanthin-6-one, 9,10-dimethoxycanthin-6-one, canthin-6-one and canthin-6-one N-oxide, and the two known beta-carboline alkaloids, beta-carboline 1-propionic acid and 7-methoxy-beta-carboline 1-propionic acid. Their structures were based on analyses of spectroscopic data.     

Megastigmane, aliphatic alcohol and benzoxazinoid glycosides from Acanthus ebracteatus.

From the aerial part of Acanthus ebracteatus, a megastigmane glycoside (ebracteatoside A), three aliphatic alcohol glycosides (ebracteatosides B-D), as well as 7-chloro-(2R)-2-O-beta-D-glucopyranosyl-4-hydroxy-2H-1,4-benzoxazin-3(4H)-one (7-Cl-DIBOA-Glc) were isolated together with 22 known compounds. Structural elucidations were based on analyses of spectroscopic data.     

Effect of auxins on spermidine uptake into carrot protoplasts

The effect of an auxin, indole-3-acetic-acid (IAA), on spermidine uptake into protoplasts of carrot ( Daucus carota L. cv. Ingrid) was studied. In the presence of 1 m M Ca²⁺, IAA (10⁻⁷ to 10⁻⁴ M ) enchances [¹⁴C]-spermidine uptake into carrot protoplasts, while no stimulation occurs in the absence of Ca²⁺. The time course of the uptake with and without IAA is very rapid and reaches saturation within 1 to 2 min. Preincubation of protoplasts with IAA inhibits the spermidine uptake. La³⁺, known not to penetrate the plasmalemma, exerts the same effect as Ca²⁺, but gives lower uptake values than Ca²⁺. The application of vanadate, an ATPase inhibitor, strongly inhibits IAA-stimulated spermidine uptake, suggesting that an energy-dependent mechanism may be involved in this transport. Neither spermidine nor Ca²⁺ alone stimulate IAA uptake. The synthetic auxin 2,4-dichlorophenoxyacetic acid, yields the same results as IAA with regard to time course of spermidine uptake with and without preincubation while, unlike IAA, no significant effect was observed on the Ca²⁺ -induced increase of spermidine uptake.