Definition: In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.
Input: From an aqueous decoction of the traditional Chinese medicine "ban lan gen" (the Isatis indigotica root), an antiviral natural product CI -39 was isolated as an NNRTI (non-nucleoside reverse transcriptase inhibitor) (EC 50 ¼ 3.40 mM). Its novel structure was determined as methyl (1-methoxy-1H-indol-3-yl) acetamidobenzoate by spectroscopic data and confirmed by single crystal X-ray diffraction. Through synthesis and structure-activity relationship (SAR) investigation of CI -39 and 57 new derivatives (24 with EC 50 values of 0.06e8.55 mM), two optimized derivatives 10f and 10i (EC 50 : 0.06 mM and 0.06 mM) having activity comparable to that of NVP (EC 50 ¼ 0.03 mM) were obtained. Further evaluation verified that 10f and 10i were RT DNA polymerase inhibitors and exhibited better activities and drug resistance folds compared to NVP against seven NNRTI-resistant strains carrying different mutations. Especially, 10i (EC 50 ¼ 0.43 mM) was more active to the L100I/K103N double-mutant strain as compared to both NVP (EC 50 ¼ 0.76 mM) and EFV (EC 50 ¼ 1.08 mM). The molecular docking demonstrated a possible binding pattern between 10i and RT and revealed activity mechanism of 10i against the NNRTI-resistant strains. a Chemical shift values (d) were measured at 500 MHz for 1 H and at 125 MHz for 13 C, respectively. Proton coupling constants (J) in Hz are given in parentheses. The assignments were based on DEPT, 1 He 1 H COSY, HSQC, and HMBC experiments. C. Xu et al.

Discovery, synthesis, and optimization of an N-alkoxy indolylacetamide against HIV-1 carrying NNRTI-resistant mutations from the Isatis indigotica root