Lignin, a major component of lignocellulose, is the largest source of aromatic building blocks on the planet and harbors great potential to serve as starting material for the production of biobased products. Despite the initial challenges associated with the robust and irregular structure of lignin, the valorization of this intriguing aromatic biopolymer has come a long way: recently, many creative strategies emerged that deliver defined products via catalytic or biocatalytic depolymerization in good yields. The purpose of this review is to provide insight into these novel approaches and the potential application of such emerging new structures for the synthesis of biobased polymers or pharmacologically active molecules. Existing strategies for functionalization or defunctionalization of lignin-based compounds are also summarized. Following the whole value chain from raw lignocellulose through depolymerization to application whenever possible, specific lignin-based compounds emerge that could be in the fu...

Bright Side of Lignin Depolymerization: Toward New Platform Chemicals

Phytochemical composition and antimicrobial activities of the essential oils from Satureja subspicata Vis. growing in Croatia

Medical Ethnobotany of the Yucatec Maya: Healers’ Consensus as a Quantitative Criterion. Economic Botany 53(2):144–160, 1999. There is an urgent need to obtain information on the relative importance of a taxon used medicinally as compared to others within the same culture. This was achieved through a documentation of the current indigenous medical uses of 320 species in three Yucatec Maya communities during 18 months of fieldwork. The 1549 individual reports documented were divided into nine groups, which classify indigenous uses. The frequency of usage of the individual plants reported was employed in the analysis of the ethnobotanical importance of the respective taxa. Species cited more frequently in a group of indigenous uses are regarded to be of greater ethnobotanical importance than those cited only by a few informants. In order to obtain information on possible biological, pharmacological and toxicological effects of some particularly important species, the scientific literature on these taxa was evaluated systematically. The study is the basis for phytochemical and pharmacological evaluations of the traditional uses.

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Medical ethnobotany of the Yucatec Maya: Healers’ consensus as a quantitative criterion

Introduction

There has been increasing interest dedicated to the phenolic compounds with a view to their antioxidant and healthy properties. Recent studies have focused on plants from the Lamiaceae family with special interest in phenolic compounds antioxidant potential.



Objective

The metabolite profile of methanolic extracts from two Lamiacea medicinal plants was investigated.



Materials and Methods

Mentha pulegium and Origanum majorana methanolic extracts were analysed using reversed-phase ultra-high-performance liquid chromatography (RP-UHPLC) coupled to electrospray ionisation quadrupole time-of-flight mass spectrometry (ESI-QTOF-MS) detection in the negative ion mode.



Results

A total of 85 metabolites were characterised from different families, such as organic acids and derivatives, amino acids and derivatives, nucleosides, phenolic compounds as well as other polar metabolites, by using the MS and MS/MS information provided by the QTOF-MS. However, the total phenols and flavonoids were also quantified spectrophotometrically and they registered higher amounts in Mentha pulegium than in Origanum majorana extract. Gallocatechin was the major compound in M. pulegium extract whereas quercetin dimethyl ether, jaceidin and dihydrokaempferide were the major ones in O. majorana extract.



Conclusion

The distribution of phenolic compounds in the methanolic extract showed a variation among studied plants. Mentha pulegium can be considered as a source of gallocatechin. Copyright © 2015 John Wiley & Sons, Ltd.

LC-MS-based metabolite profiling of methanolic extracts from the medicinal and aromatic species Mentha pulegium and Origanum majorana.

The micromorphology of trichomes of 56 Teucrium L. species belonging to the 9 sections of the genus in the Mediterranean area was surveyed by scanning electron microscopy (SEM) of leaves, calyx, corolla and nutlets. 25 trichome types are described, 12 of them are new. Thin walled hairs are the exclusive type found in the corolla and are the most widespread type on the abaxial side of the leaves. Subsessile glandular hairs, 2-4-celled, are found on the nutlet and leaves of the semi-shrubby and paleoendemic species. The presence of short or elongated, generally adpressed simple thick-walled slighuy conical hairs provides an additional character to clarify the boundaries between sect. Chamedrys (Mill.) Schreb, and sect. Polium (Mill.) Schreb. Branched non-glandular hairs are confined to sect. Polium subsect Polium , except for the rare branched hair conical and thick-walled type found in Teucrium barbarum Jahand. & Maire (sect. Chamaedrys ) and T. heterophyllum L`Her. from sect. Teucrium . This last section is well defined by the absence of simple slighuy conical thick-walled hairs and the glandular hairs in the corolla. Sect. Teucriopsis Benth, is of particular interest for the exclusive presence of branched and peltate glandular hairs on the nutlets surface. Sect. Chamedrys is a homogeneous group, distinguished from the other sections by an indumentum formed only by trichomes types evolved from the simple slighuy conical thick-walled hairs. This section overlaps, in the presence of glandular sub-sessile hair on the nutlets surface, with sects. Isotriodon Boiss, and sect. Polium subsect. Rotundifolia Cohen ex Valdes Berm. & Sanchez Crespo. The trichomes type of the calyx teeth, abaxial side of the leaf and latero-posterior corolla lobes can be used as a distinctive taxonomic character at specific and infra-specific level. This study supports Bentham's delimitauon of sections with the addiuons subequently made by Boissier.

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Syed Z. Husain

Papers

A micromorphological study of some representative genera in the tribe saturejeae lamiaceae

The distribution of methylated flavones in the Lamiaceae

The glycoflavone vicenin-2 its distribution in related genera within the labiatae