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Bioactive polar natural compounds from garlic and onions
No full textBioactive natural compounds from garlic and onions have been the focus of
researches for decades, firstly due to their pharmacological effects, and secondly due
to their defence properties against plant diseases. In fact, garlic and onion, belonging
to Allium genus, are among the oldest food plants known since ancient times and
used as ingredient of many recipes and for therapeutic properties. These plants are
well known to produce bioactive apolar sulphur compounds but less is known about
their polar natural compounds, such as phenols, sapogenins and saponins, that are
more stable to cooking, So, we continued our work on the discovery of polar bioactive
metabolites from Allium with the isolation of a number of sapogenins and saponins
from the wild onion species Allium elburzense, Allium hirtifolium, Allium atroviolaceum,
and Allium minutiflorum, and, more recently, from the cultivated white onion, Allium
cepa, and garlic, Allium sativum.
In particular, the sapogenins and saponins isolated from A. elburzense and A.
hirtifolium, named elburzensosides and hirtifoliosides respectively, exhibited significant
antispasmodic properties. In addition, the saponins named minutosides isolated from
A. minutiflorum showed promising antimicrobial activity. More recently the
phytochemical analysis of A. cepa and A. sativum has been undertaken and afforded
the characterization of saponins, phenols and N-cynnamic amides which showed
significant antifungal activit
The analysis of onion and garlic
No full textOnion (Allium cepa L.) and garlic (Allium sativum L.), among the oldest cultivated plants, are used both as a food and for medicinal applications. In fact, these common food plants are a rich source of several phytonutrients recognized as important elements of the Mediterranean diet, but are also used in the treatment and prevention of a number of diseases, including cancer, coronary heart disease, obesity, hypercholesterolemia, diabetes type 2, hypertension, cataract and disturbances of the gastrointestinal tract (e.g. colic pain, flatulent colic and dyspepsia). These activities are related to the thiosulfinates, volatile sulfur compounds, which are also responsible for the pungent of these vegetables. Besides these low-molecular weight compounds, onion and garlic are characterized by more polar compounds of phenolic and steroidal origin, often glycosilated, showing interesting pharmacological properties. These latter compounds, compared to the more studied thiosulfinates, present the advantages to be not pungent and more stable to cooking. Recently, there has been an increasing scientific attention on such compounds. In this paper, the literature about the major volatile and non-volatile phytoconstituents of onion and garlic has been reviewed. Particular attention was given to the different methodology developed to perform chemical analysis, including separation and structural elucidation. (c) 2005 Elsevier B.V. All rights reserved
Natural Products in Cancer Prevention and Therapy, a selection of topics presented in the 2nd Edition PSE Symposium (Naples, Italy, 25th to 28th of June 2013))
No full textBiogenetical related highly oxygenated macrocyclic diterpenes from sea spurge Euphorbia paralias
No full textA new tricyclic diterpenoid, named pre-segetanin (1), and two new diterpenes, named segetanin A and B (2 and 3), the latter based on the rare segetane skeleton, have been identified from the whole plant of sea spurge along with four known segetane diterpenes (4-7). Among them, pre-segetanin (1) has an unprecedented carbon skeleton, whose isolation provides a first insight into the biosynthesis of diterpenoids with a segetane skeleton. The stereostructure elucidation of the isolated metabolites was determined by extensive spectroscopic analysis, including 1D and 2D NMR (COSY, TOCSY, HSQC, HMBC, and ROESY) and HRFABMS experiments
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