Acta Cryst. (2001). E57, o909-o912  [ doi:10.1107/S1600536801014234 ]

Cycloechinulin, a Trp-Ala-derived alkaloid from the fungus Aspergillus ochraceus

L. K. Hansen, F. C. Størmer, D. Petersen and A. J. Aasen

Online 11 September 2001

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean (C-C) = 0.011 Å
• R factor = 0.064
• wR factor = 0.209
• Data-to-parameter ratio = 13.4

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level B:



SHFSU_01  Alert B The absolute value of parameter shift to su ratio > 0.10      
          Absolute value of the parameter shift to su ratio given   0.121       
          Additional refinement cycles may be required.                         

PLAT_213  Alert B Atom  C119   has ADP max/min Ratio ...........       4.20

 Alert Level C:



STRVAL_01                                                                       
         From the CIF: _refine_ls_abs_structure_Flack    2.700                  
         From the CIF: _refine_ls_abs_structure_Flack_su    1.900               
           Alert C Chirality of atom sites is inverted?                         

PLAT_213  Alert C Atom  O102   has ADP max/min Ratio ...........       3.40

PLAT_213  Alert C Atom  N116   has ADP max/min Ratio ...........       3.50

PLAT_213  Alert C Atom  C115   has ADP max/min Ratio ...........       3.70

PLAT_213  Alert C Atom  C121   has ADP max/min Ratio ...........       3.10

General Notes



REFLT_03                                                                        
         From the CIF: _diffrn_reflns_theta_max           25.01                 
         From the CIF: _reflns_number_total              13028                  
         Count of symmetry unique reflns         6796                           
         Completeness (_total/calc)            191.70%                          
         TEST3: Check Friedels for noncentro structure                          
         Estimate of Friedel pairs measured      6232                           
         Fraction of Friedel pairs measured     0.917                           
         Are heavy atom types Z>Si present           no                         
          ALERT: MoKa measured Friedel data cannot be used to                   
                 determine absolute structure in a light-atom                   
                 study EXCEPT under VERY special conditions.                    
                 It is preferred that Friedel data is merged in such cases.     


 0 Alert Level A = Potentially serious problem

 2 Alert Level B = Potential problem

 5 Alert Level C = Please check

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