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Significance Liquid manipulation is of significance not only for industrial spraying and drainage facilities, but also for the survival of creatures. Plant leaves perform excellently in rainwater drainage and leaf drying at the apex to avoid damage. Here we demonstrate that apex structure enhances water shedding with high dripping frequencies and low retention volumes. Based on the understanding of the tiny apex structure in controlling water delivery at the plant leaf, the evolutionary law of leaf apex shape could be further revealed. The shape-controlled liquid manipulation mechanism would improve the microfluidic and drainage systems., The rapid removal of rain droplets at the leaf apex is critical for leaves to avoid damage under rainfall conditions, but the general water drainage principle remains unclear. We demonstrate that the apex structure enhances water drainage on the leaf by employing a curvature-controlled mechanism that is based on shaping a balance between reduced capillarity and enhanced gravity components. The leaf apex shape changes from round to triangle to acuminate, and the leaf surface changes from flat to bent, resulting in the increase of the water drainage rate, high-dripping frequencies, and the reduction of retention volumes. For wet tropical plants, such as Alocasia macrorrhiza, Gaussian curvature reconfiguration at the drip tip leads to the capillarity transition from resistance to actuation, further enhancing water drainage to the largest degree possible. The phenomenon is distinct from the widely researched liquid motion control mechanisms, and it offers a specific parametric approach that can be applied to achieve the desired fluidic behavior in a well-controlled way.

Six previously undescribed piperidine alkaloids were isolated from the rhizomes of Alocasia macrorrhiza (L.) Schott. Their structures were elucidated based on 1D and 2D NMR, IR, HR-ESI-MS spectroscopic analysis and the application of a modified Mosher method. All isolated alkaloids were evaluated for cytotoxicity against five human cancer cell lines (CNE-1, Detroit 562, Fadu, MGC-803, and MCF-7) using the MTT method. Only one compound exhibited cytotoxic effects against Detroit 562, Fadu, and MCF-7 cell lines with IC50 values less than 10 μM.

Herein is reported a synthesis of alocasin A (1), an alkaloid component of Alocasia macrorrhiza, a herbaceous plant used in folk medicine throughout southern Asia. A double Suzuki–Miyaura cross-coupling reaction between a 3-borylindole and 2,5-dibromopyrazine was used to assemble the heteroaromatic framework of the natural product. Removal of the protecting groups gave a synthetic sample of 1, the spectroscopic data of which matched those in the isolation report of this compound.

A dynamic model of leaf photosynthesis for C 3 plants has been developed for examination of the role of the dynamic properties of the photosynthetic apparatus in regulating CO 2 assimilation in variable light regimes. The model is modified from the Farquhar-von Caemmerer-Berry model by explicitly including metabolite pools and the effects of light activation and deactivation of Calvin cycle enzymes. It is coupled to a dynamic stomatal conductance model, with the assimilation rate at any time being determined by the joint effects of the dynamic biochemical model and the stomatal conductance model on the intercellular CO 2 pressure. When parametrized for each species, the model was shown to exhibit responses to step changes in photon flux density that agreed closely with the observed responses for both the understory plant Alocasia macrorrhiza and the crop plant Glycine max. Comparisons of measured and simulated photosynthesis under simulated light regimes having natural patterns of lightfleck frequencies and durations showed that the simulated total for Alocasia was within ±4% of the measured total assimilation, but that both were 12-50% less than the predictions from a steady-state solution of the model. Agreement was within ±10% for Glycine max, and only small differences were apparent between the dynamic and steady-state predictions. The model may therefore be parametrized for quite different species, and is shown to reflect more accurately the dynamics of photosynthesis than earlier dynamic models.

A new ceramide alomacrorrhiza A was isolated from the ethanolic extract of the plantAlocasia macrorrhiza (L.) Schott. Its chemical structure was elucidated as (2S, 3S, 4R)-2A/-[(2’R)-2’-hydroxy-hexacosanoyl]-tetradecane-1,3,4-triol based on extensive 1D, 2D NMR, EI-MS, FABMS, HR-FAB-MS spectroscopic data and chemical degradation studies.

The identity, composition and concentration of each of the major lipids found in Alocasia tubers were investigated using a combination of chromatographic procedures. On a weight to weight basis, the neutral lipids, glycolipids and phospholipids comprised 60.5, 19.0 and 20.5% respectively while the total extractable lipids accounted for 0.6% of the dry weight. In addition to the conventional lipid classes of tubers, the presence of tri- and tetragalactosyl diglycerides was confirmed. The predominant fatty acid in each lipid class was linoleic acid with palmitic, oleic and linolenic acids being the other ones. In general, a high degree of unsaturation (66%), similar for most tuber lipids, was established for the component fatty acids of Alocasia.