Special Issue "Phytochemicals with Signaling, Medicinal and Therapeutic Properties"

Guest Editor
Dr. Swee Ngin Tan
National Institute of Education (NIE), Nanyang Technological University (NTU), Singapore
E-Mail:
Interests: separation science; electrochemistry; phytoremediation and development of green solvent techniques

Guest Editor
Dr. Jean W. H. Yong
National Institute of Education (NIE), Nanyang Technological University (NTU), Singapore
E-Mail:
Interests: growth regulators/hormones and especially cytokinins for plant sciences and cancer-therapy; green life sciences

Guest Editor
Dr. Liya Ge
National Institute of Education (NIE), Nanyang Technological University (NTU), Singapore
E-Mail:
Interests: analytical & bioanalytical chemistry; polymer chemistry & polymer chemical engineering

Dear Colleagues,

As the endogenous constituents of plants, phytochemicals often play essential roles in plant survival, growth and reproduction. A variety of phytochemicals are involved in protection against herbivores, microorganisms, and competitors; regulate growth; and control pollination, fertilization and the rhizosphere environment. Moreover, many isolated phytochemicals and their derivatives also promote human health. Indeed, extensive amount of clinical trials have evaluated phytochemicals for their efficacy in preventing various diseases, such as some types of cancer. The Special Issue on "Phytochemicals with signaling, medicinal and therapeutic properties", therefore, will contain the original research and review articles on the all areas of phytochemicals, mainly including extraction, isolation, characterization, cellular signaling and transport pathways, medicinal applications, and therapeutic effects of phytochemicals.

Dr. Jean W. H. Yong
Dr. Liya Ge
Dr. Swee Ngin Tan
Guest Editors

Submission

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• phytochemicals
• extraction
• characterization
• biological activity
• medicinal property
• therapeutic effect

Title: Supramolecular Self-Assembled Chaos: Lignin’s Barrier to Cost-effective Biofuels
Authors: Komandoor Elayavalli Achyuthan ^1,2, Ann Mary Achyuthan ³, Paul David Adams ^1,4, Blake Alexander Simmons ^1,5 and Anup Kumar Singh ^1,5
Affiliations: ¹ Joint Bioenergy Institute, Emeryville, CA 94450, USA; kachyut@sandia.gov (K.E.A.)
² Biosensors and Nanomaterials Department, Sandia National Laboratories, Albuquerque, NM 87185, USA,
³ Biology Department, Northern New Mexico College, Espanola, NM 87532, USA,
⁴ Lawrence Berkeley National Laboratories, Berkeley, CA 94720 and 5Sandia National Laboratories, Livermore, CA 94550, USA
Abstract: Lignin is a major barrier to the production of cost-effective biofuels. Lignin is the second most abundant biopolymer on Earth; yet its mode of assembly is unclear. Whereas much focus has been on the biochemical machinery catalyzing lignin biosynthesis, post-synthesis assembly is rather opaque. The phenylpropanoid metabolism yields a mixture of molecules that become chaotic due to non-enzymatic reactions such as dehydrogenative free radical polymerization (DHP) of precursor molecules (monolignols), redox shuttle mediators (RSMs) and supramolecular self-assembly. Features most defying an understanding are the non-biologically driven spontaneous self-assemblies yielding the lignin macromolecular polymer with random and highly branched topology and fractal properties. Self-assembly, dynamic self-organization and aggregation give rise to the crosslinked, complex 3-D network of lignin. Attempts to isolate biomass lignin, analogous to Archaeology, become instantly destructive and non-representative of plant physiology. Lack of well documented, authentic plant “ligninases” also frustrates a better understanding of lignin assembly. Supramolecular self-assembly of lignin, nano-mechanical properties of lignin-lignin interactions, aggregation and the association/dissociation kinetics of lignin precursors, all impact biomass deconstruction strategies and the production of cost-effective biofuels.

Title: Bignoniaceae Metabolites as Semichemicals
Authors: Lucía Castillo and Carmen Rossini
Affiliation: Laboratorio de Ecología Química, Facultad de Química, UdelaR, Gral. Flores 2124, Montevideo CP 11880, Uruguay; E-Mail: crossini@fq.edu.uy (C.R.)
Abstract: The family Bignoniaceae (order Lamiales) includes 120 genera with 800 species mainly distributed within tropical and neo-tropical regions of America, Asia and Africa; however, some species are also used as ornamentals worldwide¹. Bignoniaceae species are well known for their ethnobotanical uses² which comprises from applications as insect repellents (i.e. Mansoa sp. extracts) to systemic utilization (i.e. Tecoma stans infusions used as antidiabetic)^2-4. Besides, crude extracts, as well as, secondary metabolites isolated from members of the family have shown to have potential healing uses, such as antimicrobial activity (i.e. antraquinones, flavonoids, phenylpropanoid glycosides isolated from members of the genera Tabebuia and Arrabaidea^5-9), and anti-parasitic activity (i.e. anti-malarial naphtoquinones isolated from the barks of Sterespermum kunthianum¹⁰ and Tabebuia incana¹¹). Indeed, studies of anti-parasitic properties have been driven by the overlap of Bignoniaceae world distribution and the incidence of parasitic diseases. All these pieces of information have been previously reviewed^1-9. In addition, several works have reported on the ecological and evolutionary roles of secondary metabolites found in Bignoniaceae species that mediate interactions among plants and their herbivores. As it is known, the family is recognized for the presence of iridoids¹² which not only exhibit antiinsect properties, but they also are oviposition and feeding stimulants for specialist species^13,14. Moreover, some specialist species have evolved the ability to sequester iridoids and use them as defenses against their predators¹⁵. The aim of this review is to summarize the scientific evidence on extracts and isolated metabolites from Bignoniaceae exhibiting bioactivity with emphasis on those mediating insect-plant interactions.
References: 1. Gentry, A., Bignoniaceae - Part I (Crescentiae and Tourretaeae). The New York Botanical Garden, New York: 1980.
2. Gentry, A., A synopsis of Bignoniaceae ethnobotany and economic botany. Annals of the Missouri botanical garden 1992, 79, (1), 53-64.
3. Lozoya-Meckes, M.; Mellado-Campos, V., Is the Tecoma stans infusion an antidiabetic remedy? Journal of Ethnopharmacology 1985, 14, (1), 1-9.
4. Aguilar-Santamaria, L., Antidiabetic activities of Tecoma stans (L.) Juss. ex Kunth. Journal of Ethnopharmacology 2009, 124, (2), 284-288.
5. Barbosa, J.; Lima, C.; Amorin, E.; de Sena, K.; Almeida, J.; da Cunha, E.; Silva, M.; de Fatima, M.; Braz, R., Botanical Study, phytochemistry and antimicrobial activity of Tabebuia aurea. Phyton (Buenos Aires) 2004, 221-228.
6. Kim, D.; Han, K.; Chung, L.; Kim, D.; Kim, S.; Kwon, B.; Jeong, T.; Park, M.; Ahn, E.; Baek, N., Triterpenoids from the flower of Campsis grandiflora K. Schum. as human Acyl-Cok cholesterol acyltransferase inhibitors. Archives of Pharmacal Research (Seoul) 2005, 28, (550-556).
7. Ali, R. M.; Houghton, P. J.; Hoo, T. S., Antifungal activity of some Bignoniaceae found in Malaysia. Phytotherapy Research 1998, 12, (5), 331-334.
8. Alcerito, T.; Barbo, F. E.; Negri, G.; Santos, D. Y. A. C.; Meda, C. I.; Young, M. C. M.; Chavez, D.; Blatt, C. T. T., Foliar epicuticular wax of Arrabidaea brachypoda: Flavonoids and antifungal activity. Biochemical Systematics and Ecology 2002, 30, (7), 677-683.
9. Lima, C. S. D. A.; Cavalcanti de Amorim, E. L.; Xiato da Fonseca, K.; de Sena, R.; Chiappeta, A. d. A.; Nunes, X. P.; Agra, M. d. F.; Leitao da-Cunha, E. V.; Sobral da Silva, M.; Barbosa-Filho, J. M., Antimicrobial activity of a mixture of two isomeric phenylpropanoid glycosides from Arrabidaea harleyi A.H. Gentry (Bignoniaceae). Revista Brasileira de Ciencias Farmaceuticas 2003, 39, (1), 77-81.
10. Onegi, B.; Kraft, C.; Kohler, I.; Freund, M.; Jenett-Siems, K.; Siems, K.; Beyer, G.; Melzig Matthias, F.; Bienzle, U.; Eich, E., Antiplasmodial activity of naphthoquinones and one anthraquinone from Stereospermum kunthianum. Phytochemistry FIELD Full Journal Title:Phytochemistry FIELD Publication Date:2002 60, (1), 39-44. FIELD Reference Number: FIELD Journal Code:0151434 FIELD Call Number:.
11. Reis de Morais, S. K.; Silva, S. G.; Portela, C. N.; Nunomura, S. M.; Quignard, E. L. J.; Pohlit, A. M., Bioactive dihydroxyfuranonaphthoquinones from the bark of Tabebuia incana A.H. Gentry (Bignoniaceae) and HPLC analysis of commercial pau d' arco and certified T. incana bark infusions. Acta Amazonica 2007, 37, (1), 99-102.
12. Von Poser, G. L.; Schripsema, J.; Henriques, A. T.; Jensen, S. R., The distribution of iridoids in Bignoniaceae. Biochemical Systematics and Ecology 2000, 28, (4), 351-366.
13. Nieminen, M.; Suomi, J.; Van Nouhuys, S.; Sauri, P.; Riekkola, L., Effect of iridoid glycoside content on oviposition host plant choice and parasitism in a specialist herbivore. Journal of chemical ecology 2003, 29, (4), 823-844.
14. Bowers, D., The role of iridoid glycosides in host-plant specificity of checkerspot butterflies. Journal of chemical ecology 1983, 9, (4), 475-350.
15. Bowers, D., Hostplant suitability and defensive chemistry of the catalpa sphinx, Ceratomia catalpae. Journal of chemical ecology 2003, 29, (10), 2359-2366.