Ent-labdane-type diterpene glycosides obtained from Rubus chingii Hu and their inhibitory effects on PDE5A activity.

In this study, 16 new ent-labdane-type diterpene glycosides, designated as goshonosides J1-J16 (1-16), along with nine previously known diterpene glycosides (17-25) were extracted from the fruits of Rubus chingii Hu. The structures of goshonosides J1-J16 were elucidated using various analytical techniques, such as nuclear magnetic resonance, electron capture detector ECD, high-resolution electrospray ionization mass spectrometry HREIMS, single-crystal X-ray diffraction, and hydrolysis. Furthermore, the isolates' efficacy in inhibiting the activity of phosphodiesterase type 5 A was evaluated. Goshonosides J1, J2, and G effectively inhibited the activity of the aforementioned enzyme (IC50 values: 6.15 ± 1.76, 3.27 ± 0.65, and 9.61 ± 2.36 µM, respectively). Our findings highlight the remarkable structural diversity of bioactive compounds in R. chingii Hu and offer insights into the use of this shrub.

Anti-SARS-CoV-2 activities in vitro of Shuanghuanglian preparations and bioactive ingredients.

Human infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19) and there is no cure currently. The 3CL protease (3CLpro) is a highly conserved protease which is indispensable for CoVs replication, and is a promising target for development of broad-spectrum antiviral drugs. In this study we investigated the anti-SARS-CoV-2 potential of Shuanghuanglian preparation, a Chinese traditional patent medicine with a long history for treating respiratory tract infection in China. We showed that either the oral liquid of Shuanghuanglian, the lyophilized powder of Shuanghuanglian for injection or their bioactive components dose-dependently inhibited SARS-CoV-2 3CLpro as well as the replication of SARS-CoV-2 in Vero E6 cells. Baicalin and baicalein, two ingredients of Shuanghuanglian, were characterized as the first noncovalent, nonpeptidomimetic inhibitors of SARS-CoV-2 3CLpro and exhibited potent antiviral activities in a cell-based system. Remarkably, the binding mode of baicalein with SARS-CoV-2 3CLpro determined by X-ray protein crystallography was distinctly different from those of known 3CLpro inhibitors. Baicalein was productively ensconced in the core of the substrate-binding pocket by interacting with two catalytic residues, the crucial S1/S2 subsites and the oxyanion loop, acting as a "shield" in front of the catalytic dyad to effectively prevent substrate access to the catalytic dyad within the active site. Overall, this study provides an example for exploring the in vitro potency of Chinese traditional patent medicines and effectively identifying bioactive ingredients toward a specific target, and gains evidence supporting the in vivo studies of Shuanghuanglian oral liquid as well as two natural products for COVID-19 treatment.

Characterization and phylogenetic analysis of the complete chloroplast genome of Curcuma longa (Zingiberaceae).

Curcuma longa, a well-known traditional medicinal plant in China, belongs to the genus Curcuma family Zingiberaceae. In this study, we firstly assembled the complete chloroplast genome of C. longa based on sequences from Illumina and PacBio sequencing platforms. We obtained the complete chloroplast genome with the total length of 162,176 bp. It consisted of a large single-copy region (LSC, 86,984 bp), a small single-copy region (SSC, 15,694 bp), and a pair of inverted repeats (IRs, 29,749 bp each). Sequence analyses indicated that the chloroplast genome contained 111 distinct genes including 79 protein-coding genes, 28 tRNA genes, and four rRNA genes. The nucleotide composition was asymmetric (31.62% A, 18.42% C, 17.79% G, 32.18% T) with an overall AT content of 63.80%. The AT contents of the LSC, SSC and IR regions were 66.00%, 70.35% and 58.85%, respectively. Sixteen genes owned a single intron, while another two genes had two introns. The phylogenetic analysis indicated that C. longa was closely related to species Curcuma roscoeana within the genus Curcuma in family Zingiberaceae.