Icariside 1

The α-L-rhamnosidase gene of T. petrophila DSM 13995 (TpeRha, GenBank accession: ABQ47687.1) was codon-optimized, synthesized and cloned into the vector pET-28a by General Biosystems Co., Ltd. (Anhui, China). Details of strains and plasmids used in this study are listed in Table 1. Primers are listed in the Supplementary Table S1. Competent cells of E. coli BL31(DE3) and E. coli DH5α were purchased from Weidi Biotechnology Co., Ltd. (Shanghai, China). Plasmid Mini Kit I was purchased from Omega Bio-tek Inc. (Georgia, United States). The PrimeSTAR^® Max DNA Polymerase, used for site-directed mutagenesis, was purchased from Takara Biomedical Technology Co., Ltd. (Dalian, China). Restriction enzymes were purchased from Thermo Fisher Scientific Co., Ltd. (Beijing, China). The HiPure Gel Pure DNA Micro Kit was acquired from Magen Co., Ltd. (Guangzhou, China). The standards epimedin C, naringin, rutin, hesperidin, naringin dihydrochalcone (NDHC), icariin, and icariside I were purchased from Shanghai yuanye Bio-Technology Co., Ltd. (Shanghai, China). The epimedin C and icariin was purchased from Tianben Bio-Engineering Co., Ltd. (Xian, China). Other general chemical reagents used in this study were obtained from standard suppliers.

Icariin (purity 98.0%) and baohuoside I (purity 98.0%) were purchased from Shanghai Aladdin Bio-chemical Technology Co., Ltd. (Shanghai, China). Icariside I (purity 98.0%), icaritin (purity 99.0%), epimedin A, B and C (purity 98.0%) were purchased from Shanghai Yuanye Bio-Technology Co., Ltd. (Shanghai, China). Crude icariin extracts (purity ~ 10%, ~ 20%, ~ 50% and ~ 70%) were purchased from Shanxi Sunrun Bio-tech. Co., Ltd. (Shanxi, China). All restriction enzymes, PrimeSTAR DNA polymerase, T4 DNA ligase and In-Fusion HD Cloning kit were purchased from Takara Co., Ltd. (Dalian, China). E. coli DH5α was used for plasmid propagation and construction. E. coli BL21 (DE3) was used for expression of heterologous genes.