Artemisinin (1) was transformed by Mucor polymorphosporus and Aspergillus niger. Five products were identified as 9β-hydroxyartemisinin (2), 3β-hydroxyartemisinin (3), deoxyartemisinin (4), 3β-hydroxydeoxyartemisinin (5), and 1α-hydroxydeoxyartemisinin (6). Products 2, 3, and 6 are new compounds.

Ginkgo biloba cell suspension cultures were used to bioconvert sinenxan A, 2α, 5α, 10β, 14β-tetra-acetoxy-4 (20), 11-taxadiene, a taxoid isolated from callus tissue cultures of Taxus spp. Besides two major products, 9α-hydroxy-2α, 5α, 10β, 14β-tetra-acetoxy-4 (20), 11-taxadiene 1 and 9α, 10β-dihydroxy-2α, 5α, 14β-triacetoxy-4 (20), 11-taxadiene 2, additional six minor products were obtained and five of them identified as new compounds. On the basis of chemical and spectral data, their structures were identified as 9α,14β-dihydroxy2α, 5α, 10β-triacetoxy-4 (20), 11-taxadiene 3, 6α, 10β-dihydroxy-2α, 5α, 14β-triacetoxy-4 (20), 11-taxadiene 4, 6α, 9α, 10β-trihydroxy2α, 5α, 14β-triacetoxy-4 (20), 11-taxadiene 5, 9α, 10β-O-(propane-2, 2-diy1)-2α, 5α, 14β-triacetoxy-4 (20), 11-taxadiene 6, 9α-hydroxy2α, 5α, 10β, 14β-tetra-acetoxy-4 (20), 11-taxadiene formate 7, 10β-hydroxy-2α, 5α, 9α, 14β-tetra-acetoxy-4 (20), 11-taxadiene formate 8, respectively. Investigation of the properties of the enzymes responsible for the biocatalysis process of sinenxan A to 1 and 2 revealed that the enzymes were extracellular and constitutive. Using sinenxan A and the two major products (1 and 2) as indicators, the stage and concentration of sinenxan A added and the kinetics of the biotransformation reaction were investigated. The results showed that: (1) the optimal stage for sinenxan A addition was the logarithmic phase of the cell growth period, in which sinenxan A was almost completely bioconverted, and the biotransformation rates were up to 60 and 20% for 1 and 2, respectively; (2) the optimal concentration of sinenxan A added was 60mg/L; (3) the substrate was mainly converted into 1 and 2 in the first 48h after addition and then into the minor products.

Microbial transformations of artemisinin 1 by Cunninghamella echinulata (AS 3.3400) and Aspergillus niger (AS 3.795) were carried out. Two products, 10β-hydroxyartemisinin 2 and 3α-hydroxydeoxyartemisinin 3, were obtained. Their structures were identified on the basis of chemical and spectroscopic data. 10β-Hydroxyartemisinin is a new compound.

Ginkgo biloba cell suspension cultures were used to biotransform 2α, 5α, 10β, 14β-tetra-acetoxy-4 (20),11-taxadiene. Two novel compounds were obtained and their structures were identified as 9α-hydroxyl-2α, 5α, 10β, 14β-tetra-acetoxy-4 (20), 11-taxadiene 1 and 9α, 10β-dihydroxyl-2α, 5α, 14β-tri-acetoxy-4 (20), 11-taxadiene 2, respectively, on the basis of their physical and chemical data. Compound 1 was subsequently used as a substrate for the bioconversion by Ginkgo cell cultures, and the product obtained was confirmed to be the same as 2, which suggested that 2 is biosynthesized from 1. Investigation on properties of the related enzymes responsible for the biotransformation reaction through the experimental techniques of cell-free culture and substrate/product concentration analysis revealed that the enzymes were extracellular and constitutive.

Nine new triterpenoid saponins, conyzasaponins I-Q (1-9), were isolated from the aerial parts of Conyza blinii. Their structures were established on the basis of extensive 1D and 2D NMR spectra as well as by chemical degradations. Among these compounds, conyzasaponins M-O (5-7) share a common pentasaccharide unit attached to C-28 of the aglycon, 28-O-β-D-apiofuranosyl-(1→3)-β-D-xylopyranosyl-(1→4)-[β-D-apiofuranosyl-(1→3)]-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl ester, which contains two apiofuranosyl residues. To the best of our knowledge, they are among the few examples of natural products possessing two apiofuranose units in a single sugar chain.