Actinobacteria are the rich source of natural products while the large parts of biosynthetic gene clusters (BGCs) are silent under the standard culture conditions. The authors previously demonstrated that co-culture with mycolic acid-containing bacterium (MACB) effectively activates the silent BGCs in actinobacteria. In this study, the authors investigated the actinobacterium which produces a polyene macrolactam, mirilactam A. The authors tested co-culture of the mirilactam A producer strain with MACB, and successfully obtained three novel polycyclic macrolactams, mirilactams C-E, by activating silent biosynthetic genes responsible for the epoxidation and cyclization of the polyene mirilactam A.
The genus Dendrobium (Orchidaceae) is comprised of more than 1,000 species and divided into two major groups, Asian and Australasian clades. There are many ethnobotanical important species in this genus and various phenanthrenes and bibenzyl derivatives have been isolated from Dendrobium in previous studies. Secondary metabolites produced by species of the Australasian clade have not been studied well, even though several species of this group have also been used as traditional herbal remedies. The authors provide an overview of secondary metabolites of Dendrobium by combined non-target metabolomics and multivariate analysis, and identified characteristic compounds from several closely related Australasian species.
article describes the estimation of the diffusion coefficients of sugars and a
related compound. A simple and handy
experimental system with agar-gel was built and used to observe diffusion of small
molecules. The correlation formulas derived from computer simulations of the
experimental diffusion system were then applied to estimate diffusion
coefficients. The values obtained for these coefficients agree reasonably well
with those published in the literature. This finding supports the efficacy of the
approach for estimating diffusion coefficients, leading to the elucidation of
the diffusion coefficients of galactose, trehalose and glycerol.
The antiparallel triplex DNA is formed by the interaction between purine-rich triplex forming oligonucleotides (TFOs) and the homo-purine region within a duplex DNA. The formation of such a structure with the genome DNA promises to control the gene expression in a living cell. In this paper, in an attempt to enhance the stability of the triplex DNAs, the authors have designed and synthesized the N2-arylated deoxyguanosine derivatives. The TFOs containing N2-phenyl-2′-deoxyguanosine (PhdG) showed a stable and selective triplex DNA formation with the GC base pair as compared to the natural dG/GC triplet.
Dolastatin 16 is a cyclic depsipeptide isolated from cyanobacterium Lyngbya majuscula, however, its bioactivity has been a historical question. In this study, FKBP1A was predicted as a potential target of dolastatin 16 via PharmMapper as well as verified using chemical-protein interactome (CPI) and molecular docking. The lowest binding energy of dolastatin 16-FKBP1A complex was -7.4 kcal/mol. The ligand dolastatin 16 formed three hydrogen bonds and seven hydrophobic interactions within the active site residues. And the pharmacophore model was shown feasibly matching with the molecular feature of dolastatin 16.
Use of Mixer Torque Rheometer to Clarify the Relationship between the Kneading States of Wet Mass and the Dissolution of Final Product in High Shear Granulation
Released: May 01, 2018 | Volume 66 Issue 5 Pages 554-561
Tomoko Otsuka, Yosuke Kuroiwa, Kazunari Sato, Kazunari Yamashita, Tadashi Hakomori, Shin-ichiro Kimura, Yasunori Iwao, Shigeru Itai