Cambial Variants Combine Successive Cambia and Intraxylary Phloem in Convolvulaceae in Taiwan

Secondary stem growth develops different cambial variants in Convolvulaceae. Here, the cambial variant features of 17 species in seven genera (Convolvulaceae) in Taiwan are presented. The xylem rings produce various successive cambial types and the primary xylem and intraxylary phloem are produced in the outer and inner pith, respectively. The two Argyreia species have round or elliptical stems with continuous secondary xylem and phloem rings. In the eight Ipomoea species, secondary growth has two to four layers of successive cambia and xylem, dispersed with parenchyma tissue, except for I. nil and I. violacea with one layer of successive cambia. The first secondary xylem segments are separated by few or many xylem rays: I. cairica and I. obscura have three to five xylem rays and I. triloba has numerous xylem rays. The first secondary xylem of Erycibe henryi is divided by numerous rays in small stems, but develops more layers, as adjacent segments separated by xylem rays, in larger stems. Owing to continuous vascular bundle division, it has a dissected xylem. The secondary growth of Distimate tuberosa and Operculina turpethum produces two layers of successive cambia;the secondary successive cambium is divided evenly by rays into many arcs/segments. The stem thickness of I. pes-caprae subsp. brasiliensis increases via concentric successive cambia. Owing to shallowly lobed stems with directional successive cambia, I. obscura and I. triloba stems are irregularly shaped. I. littoralis and Stictocardia tilifolia stems are triangular without directional successive cambia. I. hederifolia and Merremia gemella stems have two to three deep lobes. Parenchyma proliferation results in thicker cortex with mucilaginous canals. The xylem vessels are dispersed and diffuse-porous;the vasicentric paratracheal parenchyma around them is common to all species. A bracketed key was developed comparing the secondary xylem structures of the 17 species, providing a basis for further morphological studies.

Secondary metabolite credentials ofEvolvulus alsinoides by high performance thin layer chromatography(HPTLC)

Plants and plant-based products are the bases of many modern pharmaceuticals that are current in use today for various diseases.The aim of the study was to investigate the biochemical constituents and high performance thin layer chromatography（HPTLC） finger printing of the ethanolic extract of Evolvulus alsinoides.Phytochemical screening was done by standard procedures and HPTLC method was also established to analyze alkaloids,flavonoids and phenolic compounds from the ethanolic extract of Evolvulus alsinoides.Preliminary phytochemical screening showed that ethanol extracted more secondary metabolites than other solvents.HPTLC fingerprinting analysis showed the presence of various alkaloids,flavonoids and phenols（quercetin） in the ethanolic extract.It can be concluded that Evolvulus alsinoides may serve as a source of potent antioxidants that may be used in the prevention of various diseases such as cancer,diabetes and cardiovascular diseases due to the presence of phenolic compounds.HPTLC finger print of Evolvulus alsinoides may be useful in the differentiation of the species from adulterants and act as a biochemical marker for this medicinally important plant in the pharmaceutical industry and plant systematic studies.

Comparison of Flavonoid Profiles between Leaves and Stems of <i>Calystegia soldanella</i>and <i>Calystegia japonica</i>

Two species of Calystegia, C. soldanella and C. japonica which both are vine perennials belong to Convolvulaceae habituated in extremely different environment. In order to elucidate the effect of flavonoids to tolerate environmental stress we chose a sand-dune plant C. soldanella, under unfavorable conditions such as nutrients deficiency, strong irradiance, and broad differences of temperature during day and night and compared this plant with C. japonica habituated under mild environment. Several kinds of flavonoids were found in both plants. Especially, quercetin glycosides and kaempferol glycosides were found as major flavonols in both plants. In C. soldanella, kaempferol 3-O-galacto-sidee-7-O-glucoside, kaempferol 3-O-digalactoside-7-O-glucoside, kaempferol 3-O-galactoside-7-O-galactoside and 4’-hydroxyflavone 7-O-glucoside were found. While in C. japonica, quercetin 3-O-galactoside 7-O-glucuronide, quercetin 3,7-O-digalactoside and kaempferol 3-O-galactoside 7-O-glucoside were found. Also, kaempferol glycoside was a major flavonol in C. soldanella, in contrast to quercetin glycoside as major flavonol in C. japonica. The content of total phenolic compounds was similar in two species but the content of total flavonoid compounds was higher by 1.5 times in C. japonica than that of C. soldanella.

In Vitro Free Radical Scavenging Activity of Ethanolic Extract of the Whole Plant of Evolvulus Alsinoides(L.) L.

Objective： To identify the free radical scavenging activity of ethanolic extract of Evolvulus alsinoides. Methods： The free radical scavenging activity was evaluated by in vitro methods like reducing power assay, total antioxidant activity, 2,2-diphenyl-l-picrylhydrazyl （DPPH） reduction, superoxide radical scavenging activity, 2,2＇-azinobis-（3-ethylbenzothiazoline-6-sulfonic acid） （ABTS＊） scavenging activity, hydroxyl radical scavenging assay, and nitric oxide radical scavenging assay, which were studied by using ascorbic acid as standard. Results： The extract showed significant activities in all antioxidant assays compared with the reference antioxidant ascorbic acid. The total antioxidant activity as well as the reducing power was also found to increase in a dose-dependent manner. Conclusion： Evolvulus alsinoides may act as a chemopreventive agent, providing antioxidant properties and offering effective protection from free radicals.