scholarly journals Biosynthesis of Pellucidin A in Peperomia pellucida (L.) HBK

2021 ◽  
Vol 12 ◽  
Author(s):  
Marcilio M. de Moraes ◽  
Massuo J. Kato

Peperomia pellucida (L.) HBK (Piperaceae) (“jabuti herb”) is an herbaceous plant that is widespread in the tropics and has several ethnomedicinal uses. The phytochemical study of leaf extracts resulted in the isolation of 2,4,5-trimethoxycinnamic acid, 5,6,7-trimethoxyflavone, 2,4,5-trimethoxystyrene, 2,4,5-trimethoxybenzaldehyde, dillapiol, and sesamin in addition to pellucidin A. The co-occurrence of styrene and cyclobutane dimers suggested the formation of pellucidin A by a photochemical [2+2] cycloaddition of two molecules of 2,4,5-trimethoxystyrene. To investigate this biogenesis, analysis of plant leaves throughout ontogeny and treatments such as drought, herbivory and, exposure to jasmonic acid and UV365 light were carried out. Significant increases in the content of dillapiol (up to 86.0%) were found when P. pellucida plants were treated with jasmonic acid, whereas treatment under UV365 light increase the pellucidin A content (193.2%). The biosynthetic hypothesis was examined by feeding various 13C-labeled precursors, followed by analysis with GC-MS, which showed incorporation of L-(2-13C)-phenylalanine (0.72%), (8-13C)-cinnamic acid (1.32%), (8-13C)-ferulic acid (0.51%), (8-13C)-2,4,5-trimethoxycinnamic acid (7.5%), and (8-13C)-2,4,5-trimethoxystyrene (12.8%) into pellucidin A. The enzymatic conversion assays indicated decarboxylation of 2,4,5-trimethoxycinnamic acid into 2,4,5-trimethoxystyrene, which was subsequently dimerized into pellucidin A under UV light. Taken together, the biosynthesis of pellucidin A in P. pellucida involves a sequence of reactions starting with L-phenylalanine, cinnamic acid, ferulic acid, 2,4,5-trimethoxycinnamic acid, which then decarboxylates to form 2,4,5-trimethoxystyrene and then is photochemically dimerized to produce pellucidin A.

2017 ◽  
Vol 12 (8) ◽  
pp. 1934578X1701200
Author(s):  
Charlotte Thieury ◽  
Rémy Le Guével ◽  
Gaëtan Herbette ◽  
Valérie Monnier ◽  
Nicolas Lebouvier ◽  
...  

A biochemical and phytochemical study of Diospyros macrocarpa Hiern, an endemic plant of New Caledonia, was realized. Indeed, bark and leaf extracts were tested for their cytotoxic and antibiotic activities as well as for their radical scavenging properties. Methanol extracts showed promising radical scavenging activity with an IC50 value of 5.6 ± 0.9 μg/mL for the leaves and 8.1 ± 1.4 μg/mL for the barks. The ethyl acetate extract from the barks showed strong and selective activity against NCI-H727 cancer cell line with an IC50 value of 9.5 ± 0.6 μg/mL.. Two new cyclobutane dimers: macrocarpasin A (1) and B (2) (figure 1) together with six known compounds: yangonin (3), betulinic acid (4), α-amyrin (5), β–amyrin (6), loliolide (7) and oleanderolide (8) were isolated from leaf extracts. Their structures were established by 1D and 2D NMR along with HRMS analyses. Cytotoxic activities of isolated compounds were also evaluated. None of them showed interesting cytotoxicity against the seven tested cancer cell lines.


1979 ◽  
Vol 34 (1-2) ◽  
pp. 5-8 ◽  
Author(s):  
Wim J. Baas ◽  
Gerard J. Niemann

Abstract In Hoya bella latex a number of triterpenols were found, both in the free form and as esters. The main triterpenols were β-amyrin, cycloartenol, lupeol and the rarely occurring isobauerenol; esters of these alcohols which included cinnamic acid, propionic acid and isovaleric acid were identified. A homologous series of alkanes with carbon chain length ranging from C-20 to C-31 was found. In leaf extracts acylated flavonol glycosides as well as free ferulic acid occurred; the concentration of the latter decreased with increasing leaf age.


Author(s):  
Michael Russelle Alvarez ◽  
Paolo Robert Bueno ◽  
Raymond Oliver Cruz ◽  
Richard Macapulay ◽  
Francis Jayson Vallesfin ◽  
...  

Plant-derived digestive enzyme inhibitors particularly those targeted to carbohydrate metabolism has been the focus of recent studies as natural supplements for weight control and diabetes. The present study explores the salivary amylase inhibition activity of Garcinia mangostana (Linn.) pericarp extracts and Carica papaya (Linn.) leaf extracts and fractions, as well as perform phytochemical screening and quantification, and thin layer – and high performance liquid chromatographic profiling. ­Results show that crude extracts and purified fractions were able to inhibit salivary amylase, with C. papaya fraction 1 being the most active at 30.89% inhibition. Phytochemical screening of all extracts tested ­positive for tannins, glycosides, phenolics, flavonoids and alkaloids. Quantification of phenolics showed that extracts contained high levels of phenolics, with C. papaya crude extract having the highest content with 219.0±12.7 mg GAE/g extract followed by G. mangostana crude extract with 247.1±18.0 mg GAE/g extract. Quantification of total flavonoids also showed C. papaya crude extract to contain the highest content with 55.12±0.679 mg QE/g extract. All extracts contained negligible alkaloid content, though. HPLC and TLC profiling showed several peaks and bands, when viewed in 210 nm and UV light, respectively. These results demonstrate in vitro the salivary amylase inhibitory activity of both plants and their potential as antidiabetic drug candidates; however, further studies need to be done, like isolation and structure elucidation of active components and toxicity assays. Keywords: Amylase inhibition, phytochemical quantification, Carica papaya, Garcinia mangostana


2021 ◽  
Vol 11 (8) ◽  
pp. 3542
Author(s):  
Ramida Krumsri ◽  
Kaori Ozaki ◽  
Toshiaki Teruya ◽  
Hisashi Kato-Noguchi

Phytotoxic substances released from plants are considered eco-friendly alternatives for controlling weeds in agricultural production. In this study, the leaves of Afzelia xylocarpa (Kurz) Craib. were investigated for biological activity, and their active substances were determined. Extracts of A. xylocarpa leaf exhibited concentration-dependent phytotoxic activity against the seedling length of Lepidium sativum L., Medicago sativa L., Phleum pratense L., and Echinochloa crus-galli (L.) P. Beauv. Bioassay-guided fractionation of the A. xylocarpa leaf extracts led to isolating and identifying two compounds: vanillic acid and trans-ferulic acid. Both compounds were applied to four model plants using different concentrations. The results showed both compounds significantly inhibited the model plants’ seedling length in a species-dependent manner (p < 0.05). The phytotoxic effects of trans-ferulic acid (IC50 = 0.42 to 2.43 mM) on the model plants were much greater than that of vanillic acid (IC50 = 0.73 to 3.17 mM) and P. pratense was the most sensitive to both compounds. In addition, the application of an equimolar (0.3 mM) mixture of vanillic acid and trans-ferulic acid showed the synergistic effects of the phytotoxic activity against the root length of P. pratense and L. sativum. These results suggest that the leaves of A. xylocarpa and its phytotoxic compounds could be used as a natural source of herbicides.


Author(s):  
Milena Villarini ◽  
Mattia Acito ◽  
Raffaella di Vito ◽  
Samuele Vannini ◽  
Luca Dominici ◽  
...  

(1) Background: Cynara cardunculus L. subsp. scolymus (L.) Hegi, popularly known as artichoke, is an herbaceous plant belonging to the Asteraceae family. Artichoke leaf extracts (ALEs) have been widely used in traditional medicine because of their hepatoprotective, cholagogic, hypoglycaemic, hypolipemic and antibacterial properties. ALEs are also recognized for their antioxidative and anti-inflammatory activities. In this study, we evaluated the cytotoxic, genotoxic, and apoptotic activities, as well as effect on cell growth of ALEs on human colon cancer HT-29 and RKO cells. HT-29 and RKO cells exhibit a different p53 status: RKO cells express the wild-type protein, whereas HT-29 cells express a p53-R273H contact mutant. (2) Methods: Four different ALEs were obtained by sequential extraction of dried artichoke leaves; ALEs were characterized for their content in chlorogenic acid, cynaropicrin, and caffeoylquinic acids. HT-29 and RKO cells were used for in vitro testing (i.e., cytotoxicity and genotoxicity assessment, cell cycle analysis, apoptosis induction). (3) Results: Two out of the four tested ALEs showed marked effects on cell vitality toward HT-29 and RKO tumour cells. The effect was accompanied by a genotoxic activity exerted at a non-cytotoxic concentrations, by a significant perturbation of cell cycle (i.e., with increase of cells in the sub-G1 phase), and by the induction of apoptosis. (4) Conclusions: ALEs rich in cynaropicrin, caffeoylquinic acids, and chlorogenic acid showed to be capable of affecting HT-29 and RKO colon cancer cells by inducing favourable biological effects: cell cycle perturbation, activation of mitochondrial dependent pathway of apoptosis, and the induction of genotoxic effects probably mediated by the induction of apoptosis. Taken together, these results weigh in favour of a potential cancer chemotherapeutic activity of ALEs.


2019 ◽  
Vol 9 (20) ◽  
pp. 5572-5576 ◽  
Author(s):  
M. A. Stephanie Mertens ◽  
Daniel F. Sauer ◽  
Ulrich Markel ◽  
Johannes Schiffels ◽  
Jun Okuda ◽  
...  

We report a chemoenzymatic cascade reaction for stilbene production combining decarboxylation and olefin metathesis with efficient removal of metal contamination.


2009 ◽  
Vol 2 (3) ◽  
pp. 305-312 ◽  
Author(s):  
A. Nesci ◽  
S. Marín ◽  
M. Etcheverry ◽  
V. Sanchis

This research was undertaken to evaluate the effects of the natural phytochemicals trans-cinnamic acid (CA) alone at concentrations of 20 and 25 mM, ferulic acid (FA) at concentration of 30 mM and two mixtures, CA-FA (20+30 mM) and CA-FA (25+30 mM) on natural maize mycoflora, Aspergillus section Flavi population and aflatoxin B1 production. These studies were carried out in maize grain in relation to a water activity of 0.99, 0.97 and 0.94. CA at 25 mM and the mixture CA-FA (25+30 mM) were the most effective treatments at inhibiting natural maize mycoflora at all aw assayed after 11 and 35 days of incubation at 25 °C. In general, 20 mM CA caused complete inhibition of Aspergillus section Flavi population at all aw values tested during all incubation period without an additional inoculum. 20 mM CA and 25 mM CA showed the major inhibitory effect on aflatoxin B1 accumulation of control and Aspergillus section Flavi additionally inoculated during all incubation periods. The data showed that CA and FA could be considered as effective fungitoxicants for natural maize mycoflora and aflatoxigenic fungi in the aw range 0.99 to 0.94. The information obtained shows promise for controlling aflatoxigenic fungi in stored maize.


2018 ◽  
Vol 04 ◽  
pp. 50
Author(s):  
Olajoju. T. Soniran ◽  
Kalu. K. Ngele ◽  
Christopher. O. Alisa ◽  
Damilola. A. Omoboyowa ◽  
Nnabude. H. Agu ◽  
...  

Histopathological studies of the effects of chloroform and methanolic leaf extracts of Ilex kudingcha in Trypanosoma brucei infected albino wistar rats were investigated. The toxicity and phytochemical study were also carried out using standard protocol. T. brucei infected animals were administered orally with 200 and 400 mg/kg b.w. of the extracts and 3.5 mg/kg b.w. of the standard drug (diminazene aceturate). Results on acute toxicity studies (LD50) revealed no sign of lethality up to the dose of 5,000 mg/kg body weight but the liver and kidney histology of infected animals treated with 5,000 mg/kg b.w. of I. kudingcha extracts were observed to be hepatotoxic and nephrotoxic. The methanol extracts showed appreciably high in vivo anti-trypanosomal activities compared to the reference drug. Histological examination of the organs revealed serious pathological lesions in the liver of the infected animals without treatment (negative control). In the positive control animals (infected animals administered standard drug), mild multifocal aggregate of inflammatory leucocytes was observed. In the other experimental animals, no pathological lesion was observed in the liver, kidney, brain, and heart of infected animals treated with the methanolic extract and combined methanol and chloroform extracts. The effectiveness of the methanolic extract at reducing the lesions caused by the parasite is the same compared with the standard drug. Phytochemical analysis of the plant extracts showed that methanol extract contained appreciable high levels of alkaloids, saponin, tannins, phenol, and glycoside while flavonoid was not detected. Hence, the curative properties of methanolic extract of I. kudingcha as observed in the organs indicate its anti-trypanosomal properties but it should be consumed at minimal doses.


2020 ◽  
Vol 11 (4) ◽  
pp. 6017-6022
Author(s):  
Alfred Maroyi

Maerua juncea Pax and M. schinzii Pax have a long history of medicinal use in southern Africa. This study aimed to review the ethnomedicinal uses, phytochemistry and pharmacological properties of the two species. Results of this study are based on data derived from several online databases such as Scopus, Google Scholar, PubMed and Science Direct, and pre-electronic sources such as scientific publications, books, dissertations, book chapters and journal articles. The leaves, roots, stems or whole plant parts of M. juncea and M. schinzii are mainly used as protective charm and tonic, and traditional medicines for fever, heart problems, headache, earache, skin disorders, fatigue and respiratory problems. This study showed that betaines and quaternary ammonium compounds such as 3-hydroxyprolinebetaine, proline betaine and 3-hydroxy-1,1-dimethyl pyrrolidinium had been identified from the aerial parts of M. juncea. In contrast, alkaloids, bitter principles, coumarins, flavonoids, saponins and terpenes have been identified from the leaves of M. schinzii. The leaf extracts and compounds isolated from the species exhibited antibacterial, antifungal, anti-HIV and cytotoxicity activities. There is a need for extensive phytochemical, pharmacological and toxicological studies of crude extracts of M. juncea and M. schinzii to establish the safety profiles of different preparations of the two species.


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