English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

A new antibiotic called FR-900109 was obtained from streptomyces identified as Streptomyces prunicolor and its producing strain, fermentation, isolation procedures, chemical and biological properties have been reported in a previous paper'). In this paper, the crystal structure of FR-900109p-bromophenyl ester will be described. Prismatic crystals of FR-900109p-bromophenyl ester were obtained from ethyl acetate. The crystal data of this compound are: C33H36O9Br, monoclinic, a=15.732 (2), b=8.936 (1), c= 11.245 (2) A, ;3=106.6°, space group P21, D°gl°d_ = 1.44 g/cm3 and Z=2. Intensity data were collected on a Rigaku automated four-circle diffractometer with graphite monochromated Cu-Ka radiation and 2160 independent reflections were used for the structure determination. The structure was solved by the heavy atom method. Least-squares refinement with anisotropic temperature factors for all the atoms (except hydrogen) converged the conventional R factor to 0.065. The stereochemistry of the molecule together with its molecular structure is shown in Fig. 1. The bond distances and angles within the molecule are presented in Figs. 2 and 3, respectively. There are four rings in the FR-900109 molecule of which the main framework is composed of three rings, A, B and C. The five membered ring D is just attached to C(18) of ring C. The six membered ring A adopts a chair form but the form of ring B is slightly distorted owing to the double bond between C(14) and C(15). Ring C consists of six atoms, C(16), C(17), C(18), 0(3), C(19) and C(20), and adopts a boat form of which the prows, C(18) and C(20), are bridged by oxygen atom, 0(4). This complex ring can also be regarded to consist of a dioxolane ring, C(18)-O(3)-C(19)-C(20)-O(4), which is attached to ring B through bonds, C(16)-C(20) and C(17)C(18). The elongation of bond length such as C(16)C(17) (1.60 A) and the acute angle such as C(16)C(17)-C(18) (95.8°) seem to be caused by a tension in this complex ring system.

Studies on a new antibiotic FR-900109. 2. X-ray structure determination of FR-900109 p-bromophenyl ester.