Wastewater effluent from alkaloid processing plants has the potential adverse environmental influences. Mathematical modelling and simulations were carried out using computational fluid dynamics of mass and momentum transfer in a hollow fibre membrane extractor. Conservation equations were derived for tyramine extraction in the membrane extractor and solved based on the finite element method. Model findings based on the computational fluid dynamics validated well with the experimental data. The results showed that increase in organic-phase flow rate, as well as the fibre length and its porosity, has a positive impact on the performance of the extractor, whereas the enhancement of aqueous-phase flow rate led to the reduction of tyramine extraction.

Cisplatin (CP) is a powerful anticancer agent used in the treatment of a diverse type of cancers. Oxidative stress is one of the most important side effects limiting the use of cisplatin. The protective effects of methanolic extract (ME) and ephedrine (EP), major compound, of Ephedra alata on CP-induced damages were here assessed. Treatment with CP-induced nephrotoxicity and hepatotoxicity characterized by biochemical alterations. In fact, using CP reduced significantly glutathione (GSH) levels, enzymatic activities of superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), and increased malondialdehyde (MDA) content. Nonetheless, CP-treatment induced DNA damage at renal, hepatic, and blood cells and increased interferon gamma (IFNγ) level in serum. Co-treatments of mice with ME normalized relative kidney/body weight, restored biochemical and oxidative stress parameters, reduced DNA damage and IFNγ level. In conclusion, ME exhibited the best protective effect against CP damage compared with ephedrine. This is could be attributed to the presence of polysaccharides, organic acids, flavonoids, and tannins in addition to ephedrine alkaloids. These compounds were reported to play a major role in inhibiting and scavenging free radicals, providing an effective protection against CP- induced oxidative damage. Graphical abstract

Manipulating insect behavior through the deployment of semiochemicals offers a promising opportunity for protecting crops in a sustainable manner. Therefore, there is still a significant opportunity for the development of natural crop protectants as eco-friendly tools in pest management. In this context, the aim of the current investigation is to find a novel prophylactic against the Asian citrus psyllid (ACP) and to gain a better understanding of the host-finding and selection ability of the ACP towards Murraya paniculata seedlings treated with Sophora alopecuroides alkaloids extract (SAAE). Our results indicate that foliar application of SAAE influences the psyllid host-finding and selection process. The behavioral assay with M. paniculata seedlings treated with 15 and 30 mg/mL of SAAE, with masked visual cues, revealed that only 6.6 and 10.4% psyllids were able to locate the host in the vials. The results also indicate that citrus psyllids mainly rely on both visual and olfaction in host-finding and selection. In choice settling experiments, psyllids settled almost completely on control seedlings rather than on seedlings treated with SAAE at a concentration of 30 mg/mL. Chemical analyses of the alkaloids extract revealed the presence of sophocarpine (33.90%), sophoridine (6.23%), anagyrine (2.77%), matrine (2.38%), lupanine (1.68%) aphylline (0.89%), and sophoramine (0.75%). In further behavioral bioassays with the dominant alkaloids sophocarpine and sophoridine, the alkaloids repelled ACP at higher concentrations of 50 and 70 mg/mL as compared to SAAE. Furthermore, the 50 mg/mL (1:1, v/v) combination of sophocarpine and sophoridine displayed a synergistic effect and showed the maximum behavioral effect as compared to the individual alkaloid. Based on our results, SAAE makes M. paniculata seedlings unattractive to the psyllids, and therefore, alkaloids could be used in reducing the colonization of citrus plants, subsequently curtailing HLB infection.

The objective of this study was to evaluate the effects of alkaloid extracts of Prosopis juliflora (Sw.) D.C. pods obtained by two extraction methods as compared with sodium monensin on the gas production kinetic, mitigation of methane, and rumen fermentation products using wheat bran or Tifton 85 hay as substrates, by the semi-automatic in vitro gas production technique. A completely randomized design was adopted, and two natural additives were tested made from mesquite pod (alkaloid extract I and alkaloid extract II) at three levels (3.9, 7.9, and 12 μg), sodium monensin 5 μM (positive control), and no inclusion of additives (negative control). The volume of gases produced by the degradation of the fibrous fraction of wheat bran was influenced by the concentration of the extract I added to the medium, and the amounts of 7.9 and 12 μg were equal to monensin at the lowest value. The degradation rate of the fibrous carbohydrates with additive extract I at 12 μg was lower in relation to monensin. When Tifton 85 hay was utilized, alkaloid extract I provided a shorter colonization time as compared with monensin at the added amounts of 7.9 and 12 μg and higher production of gases from the fibrous fraction but without interfering with the total volume of gases produced during 96 h of fermentation of carbohydrates. In the periods of 12 and 24 h of incubation, utilizing alkaloid extract I, the mean values of methane production with wheat bran and Tifton 85 hay were lower than monensin (p < 0.05) when the respective amounts of 7.9 and 12 μg were added. Alkaloid extract I has similar potential to sodium in reducing production of total gases, methane, and the acetate/propionate ratio.

The effects of supplemental ultraviolet-B (s-UV-B; 3.6 kJ m⁻² day⁻¹ above ambient) radiation were investigated on plant metabolite profile, essential oil content and composition, and free radical scavenging capacities of methanolic extracts of Coleus forskohlii (an indigenous medicinal plant) grown under field conditions. Essential oil was isolated using hydrodistillation technique while alterations in metabolite profile and oil composition were determined via gas chromatography-mass spectroscopy (GC-MS). Leaf and root methanolic extracts were investigated via various in vitro assays for their DPPH radical-, superoxide radical-, hydrogen peroxide-, hydroxyl radical-, and nitric oxide radical scavenging activities, ferrous ion chelating activity, and reducing power. Phytochemical analysis revealed the presence of alkaloids, anthocyanins, coumarins, flavonoids, glycosides, phenols, saponins, steroids, tannins, and terpenoids. Oil content was found to be reduced (by ∼7 %) in supplemental UV-B (s-UV-B) treated plants; the composition of the plant extracts as well as essential oil was also considerably altered. Methanolic extracts from treated plant organs showed more potency as free radical scavengers (their EC₅₀ values being lower than their respective controls). Anomalies were observed in Fe²⁺ chelating activity for both leaves and roots. The present study concludes that s-UV-B adversely affects oil content in C. forskohlii and also alters the composition and contents of metabolites in both plant extracts and oil. The results also denote that s-UV-B treated plant organs might be more effective in safeguarding against oxidative stress, though further studies are required to authenticate these findings.

Catharanthus roseus L. plants were grown under ambient (375 ± 30 ppm) and elevated (560 ± 25 ppm) concentrations of atmospheric CO₂at different rates of N supply (without supplemental N, 0 kg N ha⁻¹; recommended N, 50 kg N ha⁻¹; and double recommended N, 100 kg N ha⁻¹) in open top chambers under field condition. Elevated CO₂significantly increased photosynthetic pigments, photosynthetic efficiency, and organic carbon content in leaves at recommended (RN) and double recommended N (DRN), while significantly decreased total nitrogen content in without supplemental N (WSN). Activities of superoxide dismutase, catalase, and ascorbate peroxidase were declined, while glutathione reductase, peroxidase, and phenylalanine-ammonia lyase were stimulated under elevated CO₂. However, the responses of the above enzymes were modified with different rates of N supply. Elevated CO₂significantly reduced superoxide production rate, hydrogen peroxide, and malondialdehyde contents in RN and DRN. Compared with ambient, total alkaloids content increased maximally at recommended level of N, while total phenolics in WSN under elevated CO₂. Elevated CO₂stimulated growth of plants by increasing plant height and numbers of branches and leaves, and the magnitude of increment were maximum in DRN. The study suggests that elevated CO₂has positively affected plants by increasing growth and alkaloids production and reducing the level of oxidative stress. However, the positive effects of elevated CO₂were comparatively lesser in plants grown under limited N availability than in moderate and higher N availability. Furthermore, the excess N supply in DRN has stimulated the growth but not the alkaloids production under elevated CO₂.

We tested the effects of solvent fractions (FA, FB, FC, and FD), which partitioned by liquid-liquid extraction from the methanol extract of Ulva pertusa, on the growth of red tide microalgae (Karenia mikimitoi, Skeletonema costatum, Alexandrium tamarense, Heterosigma akashiwo, Prorocentrum donghaiense), and FA, FB, and FC exhibited significantly antialgal activity. The chemical constituent analysis showed the existence of bioactive compounds such as phenols and alkaloids. Further, four solvent fractions were applied to silica gel column and repeated preparative TLC to produce 13 samples and their purity qualified as thin-layer chromatographic grade. Among these purified samples, FA₁₁₁, FB₄₁₁, FC₄₁₁, FD₁₁₁, and FD₂₁₁ exhibited stronger antialgal activity. Furthermore, their functional groups were analyzed by colorimetric methods and UV spectra data. FD₁₁₁ and FD₂₁₁ were temptatively identified as alkaloids; the others were initially identified as phenolic acids. This is a preliminary study and the structure identification of these purified samples requires further investigation. While concentration of these purified samples in this algae was very small, they showed excellent effects against red tide microalgae.

Ten compounds (1~10) were successfully isolated from green algae Ulva prolifera through the combination of silica gel column chromatography, Sephadex LH-20 column chromatography and repeated preparative thin-layer chromatography. These ten compounds showed antialgal activity against red tide microalgae. Among them, compounds 3, 6, and 7 showed stronger antialgal activity against red tide microalgae. Furthermore, their structure was identified on the basis of spectroscopic data. There are three glycoglycerolipids: 1-O-octadecanoic acid-3-O-β-D-galactopyranosyl glycerol (2), 1-O-palmitoyl-3-O-β-D-galactopyranosyl glycerol (4), and 1-O-palmitoyl-2-O-oleoyl-3-O-β-D-galactopyranosyl glycerol (5); two monoglycerides: glycerol monopalmitate (1), 9-hexadecenoic acid, 2,3-dihydroxypropyl ester (3); two terpenoids: loliolide (6) and lsololiolide (7); one lipid-soluble pigments: zeaxanthin (8); one sterol: cholest-5-en-3-ol (9); and one alkaloid: pyrrolopiperazine-2,5-dione (10). These compounds were isolated from U. prolifera for the first time, and compounds 2, 3, 5, and 8 were isolated from marine macroalgae for the first time.

The present study, the synthesis of silver nanoparticles (AgNPs) at 90 °C temperature using an aqueous extract from Ficus talboti leaf and the antioxidant and antibacterial activities of the AgNPs obtained. The devised method is simple and cost-effective, and it produces spherical AgNPs of size 11.9 ± 2.3 nm. The synthesized AgNPs was characterized as UV–vis spectrum and obtain a peak at 438 nm. The phytochemical study result shows that the secondary metabolites such as alkaloids, saponins, phenolic compounds, tannin, flavonoids, phytosterol, and glycosides may be responsible for reducing as well as capping silver ions into AgNPs. Transmission electron microscopic (TEM) studies of the particles revealed a dominance of spherical particle AgNPs. The face centered cubic structure of the AgNPs was confirmed by X-ray diffraction (XRD) peaks at 111°, 200°, 220°, and 311°; SAED patterns confirms the plane of silver nanoparticle planes with clear circular spots on the selected area electron diffraction (SAED). Elemental analysis was done by energy dispersive X-ray analysis (EDX). In addition, this study evaluated the in vitro antioxidant and antibacterial properties of the biosynthesized AgNPs that were found to be significant.