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Phytochemical studies of the 70 % ethanol extract of Tinospora cordifolia stems led to the isolation of two new neo -clerodane diterpenoids, including tinocordifoliols C (1) and D (2). Their structures were determined by experimental 1D and 2D NMR, HR-ESI-MS, ECD, and statistical analyses, including DP4+ probability based on DFT calculations of NMR chemical shifts. According to the previous report for two neo -clerodane diterpenoids, tinocordifoliols A and B, the inhibitory activities of 1 and 2 against human arginases I and II were also evaluated. In contrast to the previously reported two neo -clerodane diterpenoids, 1 and 2 did not show inhibitory activities against human arginases I and II. These results provide insight into the structure-activity relationship of neo -clerodane diterpenoids. [Display omitted] • Two new neo -clerodane diterpenoids were isolated from Tinospora cordifolia. • The structures of the two new compounds were elucidated by spectroscopic analyses. • The inhibitory activities of the two new compounds against arginases-I and -II were evaluated. [ABSTRACT FROM AUTHOR]

We describe activity-based protein profiling for analyzing the adenylation domains of non-ribosomal peptide synthetases (ABPP-NRPS) in bacterial proteomes. Using a range of non-proteoinogenic amino acid sulfamoyladenosines, the competitive format of ABPP-NRPS provided substrate tolerance toward non-proteinogenic amino acids. When coupled with precursor-directed biosynthesis, a non-proteinogenic amino acid (O-allyl- L -serine) was successfully incorporated into gramicidin S. [ABSTRACT FROM AUTHOR]

The biosynthetic gene cluster of goadsporin, a polypeptide antibiotic containing thiazole and oxazole rings, was cloned from Streptomyces sp. TP-A0584. The cluster contains a structural gene, godA, and nine god (goadsporin) genes involved in post-translational modification, immunity and transcriptional regulation. Although the gene organization is similar to typical bacteriocin biosynthetic gene clusters, each goadsporin biosynthetic gene shows low homology to these genes. Goadsporin biosynthesis is initiated by the translation of godA, and the subsequent cyclization, dehydration and acetylation are probably catalysed by godD, godE, godF, godG and godH gene products, godI shows high similarity to the 54 kDa subunit of the signal recognition particle and plays an important role in goadsporin immunity. Furthermore, four goadsporin analogues were produced by site-directed mutagenesis of godA, suggesting that this biosynthesis machinery is used for the heterocyclization of peptides.

Keywords: 13C; 1H; antibiotic complex; combined culture; L-156,587; NMR; streptogramin B; Streptomyces albogriseolus; Tsukamurella pulmonis EN 13C 1H antibiotic complex combined culture L-156,587 NMR streptogramin B Streptomyces albogriseolus Tsukamurella pulmonis 261 270 10 01/19/22 20220201 NES 220201 The complete SP 1 sp H and SP 13 sp C NMR characterization of streptogramin B ( B 1 b ), the major component of a clinically important synergistic antibiotic complex, was presented for the first time, along with those of L-156,587 ( B 2 b ), a dehydrated congener of streptogramin A ( B 3 b ). NMR spectra were obtained in 5-mm outer diameter thin wall Symmetrical MICRO NMR Tubes (Shigemi Co., Ltd.) at 295 K on a Bruker AVANCE II 500 operated at 500.13 MHz for SP 1 sp H or on an AVANCE NEO spectrometer operated at 500.29 and 125.80 MHz for SP 1 sp H and SP 13 sp C, respectively. Because the available NMR data for reference were an SP 1 sp H NMR spectrum in 300 MHz and an enumerated list of SP 13 sp C resonances in CD SB 2 sb Cl SB 2, sb SP [ sp 21 SP ] sp we engaged in the full assignment of SP 1 sp H and SP 13 sp C resonances for B 2 b . NMR characterization of streptogramin B and L-156,587, a non-synergistic pair of the streptogramin family antibiotic complexes produced inductively by a combined culture of Streptomyces albogriseolus and Tsukamurella pulmonis. [Extracted from the article]