Phytochemistry Reviews (v.15, #1)

Steroidal saponins from the genus Allium by Danuta Sobolewska; Klaudia Michalska; Irma Podolak; Karolina Grabowska (1-35).
Steroidal saponins are widely distributed among monocots, including the Amaryllidaceae family to which the Allium genus is currently classified. Apart from sulfur compounds, these are important biologically active molecules that are considered to be responsible for the observed activity of Allium species, including antifungal, cytotoxic, enzyme-inhibitory, and other. In this paper, literature data concerning chemistry and biological activity of steroidal saponins from the Allium genus has been reviewed.
Keywords: Allium ; Steroidal saponins; Saponins activity

A review through recovery, purification and identification of genipin by Ana Mayela Ramos-de-la-Peña; Catherine M. G. C. Renard; Julio Montañez; María de la Luz Reyes-Vega; Juan Carlos Contreras-Esquivel (37-49).
Genipin is a secoiridoid that may be obtained directly from Genipa americana and after geniposide hydrolysis from Gardenia jasminoides fruits. It is well known that genipin is a high added value product which has a great potential for its application in different fields, such as medicine and food industry. A lack of information and research about the development of novel methods for the environmental friendly recovery and purification of genipin exists, focused on the green recovery of genipin through emerging technologies that lead to the sustainable extraction. In the present review, the available methods for recovery of genipin and geniposide are enlisted and described, as well as the reaction mechanism of genipin, and the developed methods for genipin and geniposide identification and quantification based on HPLC analysis. Moreover, this work reveals the scarcity of available identification methods for genipin, that should be taken into account to fulfill the recovery and quantification process of genipin.
Keywords: Genipa americana ; Geniposide; Natural cross-linker; HPLC

Huperzine A from Huperzia serrata: a review of its sources, chemistry, pharmacology and toxicology by Ana Ferreira; Márcio Rodrigues; Ana Fortuna; Amílcar Falcão; Gilberto Alves (51-85).
The use and popularity of herbal medicines has been increasing worldwide. In fact, today, the traditional Chinese medicine offers a vast repertory for pharmaceutical research, as is the case of Huperzia serrata, a member of Huperziaceae family. This review reports the Lycopodium alkaloids that have been isolated from this plant. However, it was mainly focused on the huperzine A (HupA), a promising therapeutic option in several acute and chronic disorders. The major therapeutic interest described for HupA has been directed to the treatment of acetylcholine-deficit dementia, including Alzheimer’s disease. However, HupA was also shown to be effective on cerebrovascular dementia and other neurodegenerative disorders with an ischemic component, as well as on other kind of cognitive impairments; the value of HupA on myasthenia gravis, organophosphate poisoning and schizophrenia has also been described. In addition, many other pharmacological properties have been ascribed to HupA, namely its anti-inflammatory, antinociceptive and anticonvulsant properties, which was recently identified, promoting a growing interest on HupA research. Furthermore, its particular chemical structure and the fact that HupA is well tolerated in humans, even at doses well above those clinically required, along with its favorable pharmacokinetics, also boosted an intense research in the pharmaceutical industry. Therefore, several HupA-related features are addressed in this review, including not only its therapeutic properties, but also its chemistry, biological and chemical sources, structure–activity relationship, pharmacokinetics and toxicology, which are discussed in detail covering the literature published from 1962 to 2014.
Keywords: Huperziaceae; Huperzia serrata ; Lycopodium alkaloids; Huperzine A; Alzheimer’s disease

Naturally occurring chalcones and their biological activities by Zsuzsanna Rozmer; Pál Perjési (87-120).
The aim of this review is to summarize the various naturally occurring chalcone compounds which have been isolated from different plants. Chalcones considered as obligate intermediated in flavonoid biosynthesis but they do not accumulate to appreciable degree in most plants. The largest number of natural chalcones has been isolated from species of the Leguminosae, Asteraceae and Moraceae families. Chalcone accumulating plants have often been used in traditional medicine and chalcones have therefore been studied and reported to possess many beneficial biological effects including anti-inflammatory, antimicrobial, antifungal, antioxidant, cytotoxic, antitumor and chemopreventive activities. Previously published reviews on this topic survey the biological activities of natural and synthetic chalcones but there are no comprehensive contributions on occurrence and biological activities of natural chalcones. The present study provides an overview of hydroxy or/and methoxy-substituted chalcones, methylated, prenylated, geranylated and other monomeric derivatives, chromeno- and furanochalcones, dimeric chalcones and dihydrochalcone derivatives focusing on their biosynthesis, natural sources and biological activities. On the basis of 608 references, this review covers the phytochemistry and biological activity of natural chalcones, describing 646 compounds have been appeared in the literature since 1975. The summary is aimed to initiate further pharmacobotanical, biotechnological and medicinal studies on the field of chalcone research.This contribution reviews some of the general aspects of naturally occurring chalcones including their chemical categories, focusing on plant sources and biological activities. The review covers the major works appeared in the literature from 1975 up to 2014, relating to 608 references and 646 compounds.
Keywords: Flavonoids; Chalcones; Dihydrochalcones; Natural occurence; Biological activity

Furan fatty acids: their role in plant systems by Ibandalin Mawlong; M. S. Sujith Kumar; Dhiraj Singh (121-127).
Furan fatty acids (F-acids) are heterocyclic fatty acids having a furan ring in their structure. Most existing studies on F-acids are related to either fish or other marine animals. Even though F-acids have been detected in many plant species, not much work has been done exclusively in plants of economic importance, especially oilseed crops. This review focuses mainly on the functions and roles of F-acids in plants. In plants, they are bound to phospholipids by substituting PUFA and function as free radical scavengers suggesting their role in defense against oxidative stress. Owing to their antioxidative property F-acids are highly unstable and their photooxidative products can contribute to the flavor of edible oils.
Keywords: Furan fatty acids; PUFA; Antioxidants

Tools for biotechnological production of useful phytochemicals from adventitious root cultures by Hosakatte Niranjana Murthy; Vijayalaxmi S. Dandin; Kee-Yoeup Paek (129-145).
Adventitious roots are natural roots which develop from the differentiated cells of any organ such as leaf, root or stem. These roots are attractive source of phytochemicals due to their genetic and biosynthetic stability. Their stability offers new scope for the in vitro production of valuable secondary metabolites. In the past two decades, adventitious roots have been induced from different plant systems and the suspension cultures have been established. However, the special morphology of adventitious roots hampers the scale-up processes, which needs modifications with the existing bioreactors to facilitate proper mixing, aeration and which can overcome shear stress. Various modifications have been done with the stirred tank and air-lift bioreactors and successfully used for the cultivation of adventitious roots. The progress made in this area is tremendous, in few cases adventitious root cultures are succeeded up to commercial scale with step-wise viz. small scale to large-scale by establishing the standards with various parameters which affect the biomass accumulation and metabolite productivity. This review addresses the recent progresses made in this area and discusses the potential applications and limitations.
Keywords: Adventitious roots; Bioreactors; Elicitation; Secondary metabolites; Scale-up process

The Brazilian Amaryllidaceae as a source of acetylcholinesterase inhibitory alkaloids by Jean Paulo de Andrade; Raquel B. Giordani; Laura Torras-Claveria; Natalia Belén Pigni; Strahil Berkov; Mercè Font-Bardia; Teresa Calvet; Eduardo Konrath; Kelly Bueno; Liana G. Sachett; Julie H. Dutilh; Warley de Souza Borges; Francesc Viladomat; Amelia T. Henriques; Jerald J. Nair; José Angelo S. Zuanazzi; Jaume Bastida (147-160).
Nine Brazilian Amaryllidaceae species were studied for their alkaloid composition and acetylcholinesterase (AChE) inhibitory activity via GC–MS and a modified Ellman assay, respectively. A total of thirty-six alkaloids were identified in these plants, of which Hippeastrum papilio and H. glaucescens exhibited the highest galanthamine content and the best IC50 values against AChE. Furthermore, Hippeastrum vittatum and Rhodophiala bifida also showed notable AChE inhibitory effects. X-ray crystallographic data for four galanthamine-type compounds revealed significant differences in the orientation of the N-methyl group, which are shown to be related to AChE inhibition.
Keywords: Galanthamine; GC–MS; Hippeastrum ; Sanguinine; X-ray crystallography