The potent antibiotics albofungin [systematic name: (1S,4R,8aR)‐13‐amino‐1,15,16‐trihydroxy‐4‐methoxy‐12‐methyl‐3,4,8a,13‐tetrahydro‐1H‐xantheno[4′,3′,2′:4,5][1,3]benzodioxino[7,6‐g]isoquinoline‐14,17(2H,9H)‐dione, C₂₇H₂₄N₂O₉, 1] and its chlorinated analogue chloroalbofungin (the 11‐chloro analogue, C₂₇H₂₃ClN₂O₉, 2) have been crystallized following their isolation from the bacterial strain Streptomyces chrestomyceticus and their structures determined by single‐crystal X‐ray diffraction. The novel N‐aminoquinolone molecular arrangement shows N—N bond lengths of 1.4202 (16) and 1.424 (2) Å in 1 and 2, respectively. The regiochemistry of chloro substitution in the A‐ring is para to the quinolone O atom, with a C—Cl bond length of 1.741 (2) Å. The absolute stereochemistry at three chiral centres of the xanthone rings (i.e. 10S, 13R and 19R) is confirmed. Both compounds crystallize in chiral Sohncke space groups consistent with enantiopurity, but are not fully isostructural. A preserved supramolecular construct (SC) confers two‐dimensional (2D) isostructurality, but the SC self‐associates via either a twofold screw operation in 1, giving a monoclinic P2₁ structure, or a twofold rotation in 2, affording a monoclinic C2 structure with a doubled unit‐cell axis.

中文翻译：

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Albofungin和chloroalbofungin：具有2D但不具有3D同构性的抗生素晶体

强效抗生素albofungin [系统名称：（1 S，4 R，8a R）‐13‐氨基‐1,15,16‐三羟基‐4‐甲氧基‐12‐甲基‐3,4,8a，13‐四氢‐1 H-黄原[4'，3'，2'：4,5] [1,3]苯并二恶英[7,6 - g ]异喹啉-14,17 （2 H，9 H）-二酮，C ₂₇ H ₂₄ N ₂ Ó ₉，1 ]及其类似物氯化chloroalbofungin（11-氯类似物，C ₂₇ ħ ₂₃ CLN ₂ ö ₉，2）已经被结晶从以下细菌菌株其隔离链霉菌及其结构通过单晶X射线衍射测定。新颖的N-氨基喹诺酮分子排列在1和2中分别显示1.4202（16）和1.424（2）Å的NN键长度。氯取代的区域化学甲形环是对位到喹诺酮的O原子，具有1.741（2）的C-Cl键的长度。an酮环的三个手性中心的绝对立体化学（即10 S，13 R和19 R）已确认。两种化合物均在与对映体纯度一致的手性Sohncke空间群中结晶，但并非完全同构。保留的超分子构造（SC）赋予二维（2D）同构性，但SC通过1中的双螺旋操作自缔合，提供单斜晶P 2 ₁结构，或通过2中的双重旋转自缔合，从而提供单斜C 2结构具有双晶胞轴。