Markhamia lutea

About: Markhamia lutea is a research topic. Over the lifetime, 36 publications have been published within this topic receiving 583 citations.

Antiviral phenylpropanoid glycosides from the medicinal plant Markhamia lutea

Abstract: Three new phenylpropanoid glycosides, named luteoside A (3), luteoside B (4), and luteoside C (5), were isolated together with the known compounds verbascoside (1) and isoverbascoside (2) from the roots of the medicinal plant Markhamia lutea. The structures of the new compounds were determined to be 1-O-(3, 4-dihydroxyphenyl)ethyl beta-D-apiofuranosyl(1-->2)-alpha-l-rhamnopyranosyl(1-->3)-4-O- caffeo yl-6-acetyl-beta-d-glucopyranoside, 1-O-(3,4-dihydroxyphenyl)ethyl beta-d-apiofuranosyl(1-->2)-alpha-l-rhamnopyranosyl(1-->3)-6-O- caffeo yl-beta-d-glucopyranoside, and 1-O-(3,4-dihydroxyphenyl)ethyl beta-D-apiofuranosyl(1-->2)-alpha-l-rhamnopyranosyl(1-->3)-6-O- ferulo yl-beta-d-glucopyranoside, respectively, on the basis of chemical and spectroscopic data. All five phenylpropanoid glycosides exhibited potent in vitro activity against respiratory syncytial virus.

Vertical Distribution of Roots and Soil Nitrate: Tree Species and Phosphorus Effects

Abstract: We hypothesized that trees can rapidly root into subsoil and capture NO 3 , which can accumulate in the subsoil of agricultural soils with high anion sorption. The vertical distribution of root length and inorganic N (NO 3 and NH 4 ) to 3.95-m soil depth was compared for 11-mo-old stands of eucalyptus (Eucalyptus grandis W. Hill ex Maiden), sesbania [Sesbania sesban (L.) Merr.], calliandra (Calliandra calothyrsus Meissner), markhamia [Markhamia lutea (Benth.) Schumann], and grevillea (Grevillea robusta A. Cunn. ex R. Br.) grown at two P levels (no added P and 500 kg added P ha -1 ) on a Kandiudalfic Eutrudox in Kenya. The trees were planted at a I by 1 spacing in a randomized complete block with three replications. Added P had no effect on root length, soil NO 3 , and soil NH 4 even though the soil was low in available P. Total root length was greater for calliandra (15.5 km m -2 ) than other trees (1.2-5.6 km m -2 ). The slope for the model of natural logarithm root length density (cm cm -3 ) as a function of soil depth was affected by tree species (P < 0.01), indicating differences among trees in the tendency for deep rooting. Root length densities, averaged for the two P levels, were ≥0.1 cm cm -3 to depths of 2.2 m with calliandra, 1.8 m with sesbania, 1.2 m with eucalyptus, 0.45 m with grevillea, and 0.3 m with markhamia. Calliandra and sesbania reduced soil NO 3 in the top 2 m by about 150 to 200 kg N ha -1 within 11 mo after establishment and effectively captured subsoil NO 3 . Fast-growing trees with high root length densities can rapidly reduce subsoil NO 3 .

Land use affects the distribution of soil inorganic nitrogen in smallholder production systems in Kenya

Abstract: We hypothesized that the integration of trees and shrubs in agricultural landscapes can reduce NO3– leaching and increase utilization of subsoil N. A field survey was conducted on 14 farms on acid soils in the subhumid highlands of Kenya, where there is little use of fertilizers, to determine the effect of vegetation types (VT) on soil NH4+ and NO3– to 4 m depth. The VT included maize (Zea mays) with poor growth and good growth, Markhamia lutea trees scattered in maize, natural weed fallow, banana (Musa spp.), hedgerow, and eucalyptus woodlot. The effect of VT on NH4+ was small (<1 mg N kg–1). NO3– within a VT was about constant with depth below 0.25 m, but subsoil NO3– varied greatly among VT. Mean NO3–-N concentrations at 0.5–4 m depth were low beneath hedgerow and woodlot (<0.2 mg kg–1), intermediate beneath weed fallow (0.2–0.7 mg kg–1), banana (0.5–1.0 mg kg–1) and markhamia (0.5–1.6 mg kg–1), and high beneath both poor (1.0–2.1 mg kg–1) and good (1.9–3.1 mg kg–1) maize. Subsoil NO3– (0.5–4 m) was agronomically significant after maize harvest with 37 kg N ha–1 m–1 depth of subsoil beneath good maize and 27 kg N ha–1 m–1 depth beneath poor maize. In contrast, subsoil NO3– was only 2 kg N ha–1 m–1 depth beneath woodlot and hedgerow. These results demonstrate that the integration of perennial vegetation and the rotation of annual and perennial crops can tighten N cycling in agricultural landscapes.