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Objective: To evaluate the monogalactosyl diglyceride (MGDG) and digalactosyl diglyceride (DGDG) from Clinacanthus nutans (C. nutans) for their in vitro antiviral activities against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) by plaque reduction assay. Methods: MGDG and DGDG were extracted with chloroform from C. nutans leaves. MGDG and DGDG were separated from chloroform crude extract using column chromatography, characterized by thin layer chromatography and quantified by high performance liquid chromatography. The anti HSV-1 and 2 activity against pre-treatment and post-treatment of the compounds was evaluated using plaque reduction assay. The cytotoxicity of the extract and the compounds on Vero cells were performed by MTT assay. Results: MGDG and DGDG obtained by column chromatography showed identical profiles as standard MGDG and standard DGDG using thin layer chromatography and high performance liquid chromatography. MGDG and DGDG from C. nutans showed 100% inhibition of HSV-1 replication at the post step of infection at noncytotoxic concentration with IC50 values of 36.00 and 40.00 μg/mL, and HSV-2 at 41.00 and 43.20 μg/mL, respectively. Moreover, MGDG and DGDG from C. nutans were demonstrated to have anti-herpes simplex activity at the same level as standard synthetic compounds. In contrast, pre-treatment of Vero cells with MGDG and DGDG before HSV-1 and HSV-2 infection did not show inhibitory effect against these viruses. MGDG and DGDG exhibited antiviral activity against HSV-1 with selectivity index of 26.00 and 23.00 and HSV-2 of 23.30 and 21.30. Conclusions: MGDG and DGDG from C. nutans, a traditional Thai herbal medicine illustrated inhibitory activity against HSV-1 and HSV-2, probably by inhibiting the late stage of multiplication, suggesting their promising use as anti-HSV agents.

Objective To evaluate the monogalactosyl diglyceride (MGDG) and digalactosyl diglyceride (DGDG) from Clinacanthus nutans ( C. nutans ) for their in vitro antiviral activities against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) by plaque reduction assay. Methods MGDG and DGDG were extracted with chloroform from C. nutans leaves. MGDG and DGDG were separated from chloroform crude extract using column chromatography, characterized by thin layer chromatography and quantified by high performance liquid chromatography. The anti HSV-1 and 2 activity against pre-treatment and post-treatment of the compounds was evaluated using plaque reduction assay. The cytotoxicity of the extract and the compounds on Vero cells were performed by MTT assay. Results MGDG and DGDG obtained by column chromatography showed identical profiles as standard MGDG and standard DGDG using thin layer chromatography and high performance liquid chromatography. MGDG and DGDG from C. nutans showed 100% inhibition of HSV-1 replication at the post step of infection at noncytotoxic concentration with IC 50 values of 36.00 and 40.00 μg/mL, and HSV-2 at 41.00 and 43.20 μg/mL, respectively. Moreover, MGDG and DGDG from C. nutans were demonstrated to have anti-herpes simplex activity at the same level as standard synthetic compounds. In contrast, pre-treatment of Vero cells with MGDG and DGDG before HSV-1 and HSV-2 infection did not show inhibitory effect against these viruses. MGDG and DGDG exhibited antiviral activity against HSV-1 with selectivity index of 26.00 and 23.00 and HSV-2 of 23.30 and 21.30. Conclusions MGDG and DGDG from C. nutans , a traditional Thai herbal medicine illustrated inhibitory activity against HSV-1 and HSV-2, probably by inhibiting the late stage of multiplication, suggesting their promising use as anti-HSV agents. [ABSTRACT FROM AUTHOR]

Current year needles from 5 yr-old Norway spruce trees, which had been exposed to either episodes of atmospheric O3 or periodic mistings with stimulated acid rainwater throughout three summer periods, were analyzed for changes in molar percentages and ratios of fatty acids isolated from different lipids at the time of maximum winter hardening. No significant changes due to acidic mistings were detected but significant decreases on the degree of unsaturation of both C16 and C18 fatty acids, the molar percentage of δ5, 9, 12, 15 18:4, and the molar ratio of δ5, 918:2 to δ9, 1218:2 in monogalactosyl diglyceride (MGDG) due to summer O3 exposures were found. Molar percentages and ratios to a significant effect of summer O3 on the δ5- and δ12-desaturases acting upon phosphatidyl choline (PC) in the endoplasmic reticulum, The replacement of the δ6-subset of C18 fatty acids by an equivalent δ5-series throughout was confirmed by gas cromatography and mass spectrometry. Molecular modelling also showed that the δ5-forms, which resembled the δ9-isomers, are very different in shape to the δ6-series and this may account, in part, for the extremely low winter temperatures from which Norway spruce needles may recover. [ABSTRACT FROM AUTHOR]

Glycolipids, neutral lipids and chlorophyll of chloroplasts of pine needles (Pinus sylvestris L) and apple bark tissue (Malus sylvestris Mill. cv Golden Delicious) were determined in a series of experiments in which growth temperature and daylength were changed. Trees were exposed to 0 and 20°C and to daylength conditions of 9 and 14 h. All 16 possible combinations were studied by transfer of the trees from the original condition to each of the other conditions. There was no direct relation between cold hardiness and glycolipid composition in apple bark and pine chloroplasts, when temperature and/or daylength were changed. Glycolipid and neutral lipid composition seemed to be strongly determined by the sequence of the imposed sets of daylength and temperature, and the effects of these factors on lipids strongly differed from that on cold hardiness. When the treatments were given in seasonal order, the corresponding changes in chloroplast glycolipids matched those reported in the literature for needles collected in the forest the year around. Glycolipid synthesis could well be under phytochrome control. [ABSTRACT FROM AUTHOR]

Artificial aggregates of bacteriochlorophyll c (BChl c) were formed in an aqueous medium in the presence of a lipid, monogalactosyl diglyceride (MGDG), and the optical properties of those aggregates were studied by absorption and circular dichroism (CD) mainly. Four BChl c homologs, ([E,E]BChl c, [P,E]BChl c, [E,M]BChl c and [I,E]BChl c), were isolated from the green photosynthetic bacterium Chlorobium limicola strain 6230. Above 0.0004%, MGDG induced a red-shift of the absorption maxima of BChl c aggregates. At 0.003% MGDG BChl c aggregates showed absorption maxima in the range of 724 to 745 (±3) nm with a shift of 12 to 24 (±3) nm depending on the homolog species. Four kinds of BChl c-MGDG aggregates showed characteristic CD spectra. [E,M]BChl c gave rise to a CD spectrum similar to that of chlorosomes, while the other three gave spectra of opposite sign. These aggregates are sensitive to 1-hexanol treatment; in a saturating amount (0.85%) of 1-hexanol, all the homologs gave a monomer-like absorption spectrum peaking at 670nm. At an intermediate concentration (0.5%), [E,M]BChl c showed an enhanced CD intensity, as observed in native chlorosomes. Resonance Raman spectra of the monomer-like BChl c samples indicated that the keto vibrational band at ca. 1640 cm was considerably weakened by the 0.85% 1-hexanol treatment, however the 1680 cm band characteristic of a free keto group did not appear. These results indicate that the artificial aggregates formed by purified BChl c homologs and MGDG are good models for studying chlorosomes structure. [ABSTRACT FROM AUTHOR]

During greening of detached leaves from dark-grown barley seedlings, the linolenic acid content of the lipids increases in the early stages of the formation of the chloroplast lamellar system. Primarily the fraction containing monogalactosyl diglyceride is enriched with linolenic acid.Incorporation of 14C-labeled acetate into the leaf lipids of detached whole leaves is low, but increases 10- to 20-fold during greening. Increasing percentages of label appear in linolenic acid during the first 15 hr of greening, whereafter they remain constant.A constant, relatively high amount of acetate is incorporated into lipids when slices of leaves at various stages of greening are incubated by submersion in acetate solution, a treatment that blocks further chlorophyll synthesis during incubation. At the initial greening stages 75% of the label is channeled into steroids and other unsaponifiable lipids, but in advanced stages of chloroplast development 75% of the incorporated acetate is built into phospho-, sulfo- and galacto-lipids, and only 25% is channeled into unsaponifiable lipids.Experimental variation of the physiological conditions of the tissue during incubation resulted in differences in the amount of label found in the various phospho- and galacto-lipids. The amounts of labeling of the individual fatty acids in the lipid classes studied differ markedly and could be changed by varying the conditions of incubation. Labeling of linolenic acid was found to be highest in the monogalactosyl diglyceride fraction at all stages of greening.

The capacity of leaf slices from light-grown seedlings of wild type barley and 10 xantha mutants at six different gene loci to incorporate acetate-14C into various lipids has been investigated. The fatty acid composition of the leaf lipids in these lethal mutants was similar to that of the wild type, but the fatty acid labeling pattern in the individual lipid classes can be drastically altered by these mutations, which affect chloroplast differentiation. A genetic block in chlorophyll synthesis, caused by mutations in the xan-f locus, leads to a repression of the formation of chloroplast membranes and of acetate incorporation into phospho-, sulfo-, and galacto-lipids (the acetate being preferentially channeled into a lipid fraction containing steroids and free fatty acids). Two leucine “auxotrophs” at different loci, which in the absence of leucine in the growth medium produce giant grana and accumulate some chlorophyll, differed considerably in the amount of labeling of their polar lipids during incubation.Leaves of xan-a11, containing plastids with little chlorophyll, highly disorganized membrane systems, and large bodies with osmiophilic deposits, were nonetheless equal to wild type in their capacity to incorporate acetate-14C into phospho-, sulfo-, and galacto-lipids. The mutants at the xan-m locus have plastids with undispersed prolamellar bodies and osmiophilic packages of grana-like membranes associations. Leaf slices of these mutants synthesized considerably more linolenic acid-14C, which was incorporated into monogalactosyl diglycerides, than did slices of the wild type. This led to a labeling pattern of the fatty acids in the monogalactolipids which was remarkably similar to their endogenous fatty acid composition.

Monogalactosyl and digalactosyl diglycerides were separated from leaf and Chlorella vulgaris lipid extracts by thin-layer chromatography with Silica Gel G as the stationary phase and acetone-acetic acid-water as the mobile phase. Phospholipids are completely removed and with two-dimensional development can themselves be fractionated.

Current year needles from 5 yr-old Norway spruce trees, which had been exposed to either episodes of atmospheric O 3 , or periodic mistings with simulated acid rainwater throughout three summer periods, were-analyzed for changes in molar percentages and ratios of fatty acids isolated from different lipids at the time of maximum winter hardening. No significant changes due to acidic misting were detected but significant decreases in the degree of unsaturation off both C 16 and C 18 , fatty acids, the molar percentage of δ 5,9,12,15 , and the molar ratio δ 5,9 18: 2 to δ 9,12 18:2 in monogalactosyl diglyceride (MGDG) due to summer 0 3 exposures were found. Molar percentages and ratios of fatty acids did not change much in other lipids bur these changes in plastidie MGDG could be traced to a significant effect of summer O 3 on the δ 4 - and δ 12 -desaturases acting upon phosphatidyl choline (PC) in the endoplasmic reticulum. The replacement of the δ 6 -subset of C 18 fatty acids by an equivalent δ 5 -series throughout was confirmed by Gas chromatography and mass spectrometry Molecular modelling also showed that the δ 5 forms, which resembled the δ 5 -isomers, are very different in shape to the δ 5 -series and this may account, in part, for the extremely low winter temperatures from which Norway spruce needles may recover.