Natural products are structurally and biologically interesting metabolites, but they have been isolated in minute amounts. The syntheses of such natural products help in obtaining them in bulk amounts. The recognition of microbial biotransformation as important manufacturing tool has increased in chemical and pharmaceutical industries. In recent years, microbial transformation is increasing significantly from limited interest into highly active area in green chemistry including preparation of pharmaceutical products. This is the first review published on the usage of microbial biocatalysts for some natural product classes and natural product drugs.

Rumex dentatus L. and Rumex vesicarius L., of the family Polygonaceae, are edible herbs growing wild in Egypt. Their lipoid constituents were examined by both liquid chromatography/mass spectrometry (LC/MS) and by gas chromatography/mass spectrometry (GC/MS). Their essential oil compositions consisted mainly of thujene, limonene, fenchon, estragole, and anethole but at largely different concentration. Fatty acid compositions were similar among the two species and consisting of palmitic, oleic, linoleic and linolenic acids, with R. vesicarius containing much higher level of omega-3-fatty acids. Both of the crude lipid extracts of the two species showed strong antioxidant activity as a radical quenching agent against 2,2-diphenyl-1-picrylhydrazyl (DPPH) systems. Antioxidant activities were mostly associated with the polar lipid fractions. High performance thin layer chromatography (HPTLC), both in the normal and reversed phase,as well as liquid chromatography/mass spectrometry (LC/MS) in the positive and negative electrospray ionization (ESI), showed unique chemical profile for each species that can be useful for species identification and quality control of herbal drug formulations. R. vesicarius was characterized by abundances of flavonoids and R. dentatus was abundant in anthraquinones and chromones.

Centaurea is a value-ultimate genus of medicinal plants showing high diversification levels, especially within the Mediterranean basin, and is still traditionally recognized as a complicated taxon. So far, few studies utilizing molecular markers have been done on Centaurea spp. towards a better dissection of its phylogeny and accurate assessment of genetic diversity. Here, two functional marker systems, start codon targeted (SCoT) polymorphism and CAAT box-derived polymorphism (CBDP), were implemented to assess the genetic diversity between eight wild Centaurea species in Egypt. Seventeen SCoT and 19 CBDP primers generated 197 and 179 bands, respectively. These primers generated 158 (80.2%) and 131 (73.18%) polymorphic amplicons with an average of 9.29 and 6.89 amplicons per primer, respectively. SCoT primers exhibited higher levels in % of polymorphism, % of heterozygosity, effective multiplex ratio, discriminating power, resolving power parameters compared to the CBDP. In contrast, no significant differences were observed between SCoT and CBDP in polymorphism information content, marker index and mean heterozygosity parameters. The UPGMA (unweighted pair group method with arithmetic mean) dendrogram of the combined data classified the Centaurea species under two major clades; the first comprised two species, whereas the second grouped five species. C. pallescens was kept separated as the most diverged among the eight Centaurea species. Principal component analysis (PCA) topology revealed highly similar results to those obtained from the cluster analysis. Ultimately, our results represent the first report utilising two gene-targeting marker systems as powerful techniques for assessing the genetic variability and relatedness among these eight valuable Centaurea species.

Artemisia herba-alba is widely used in traditional medicines for the treatment of several diseases. From the aerial parts organic extract of A. herba-alba, two new compounds, 1,3,8-trihydroxyeudesm-4-en-7α,11βH-12,6α-olide (1) and 5-β-​_D-​glucopyranosyloxy​-​7-methoxy-​6H-​benzopyran-​2-​one (2), respectively, together with five known metabolites: 3α,8β-dihydroxygermacr-4(15),9(10)-dien-7β,11αH,12,6α-olide (3), 1β,8α-dihydroxy-11α,13-dihydrobalchanin (4), 11-epiartapshin (5), tomenin (6) and benzoic acid, p-​(β-​_D-​glucopyranosyloxy)​-​methyl ester (7), were isolated and identified. The chemical structures were proven depending upon spectroscopic analysis, including 1 D/2D NMR as and ESI-MS. Compound 1 inhibited Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus. Compounds 2 and 3 exhibited antibacterial activity against both gram-positive and gram-negative bacteria. Graphical Abstract

The essential oils of the aerial parts of cultivated and wild fennel (Foeniculum vulgare Mill) plants were obtained by hydrodistillation, examined by high performance thin layer chromatography (HPTLC) and characterized by gas chromatography -mass spectrometry (GC-MS). The essential oils of the wild and cultivated fennel showed great differences in their chemical contents, cultivated plants showed higher percentages of pinenes, fenchone, estragol, myrcene and camphene while the wild plants showed much higher level of limonene.