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Abstract We present continued analysis of a sample of low-redshift iron low-ionization broad-absorption-line quasars (FeLoBALQs). Choi et al. presentedSimBALspectral analysis of broad-absorption-line (BAL) outflows in 50 objects. Leighly et al. analyzed the optical emission lines of 30 of those 50 objects and found that they are characterized by either a high accretion rate (LBol/LEdd> 0.3) or low accretion rate (0.03 <LBol/LEdd< 0.3). We report that the outflow velocity is inversely correlated with the BAL location among the high-accretion-rate objects, with the highest velocities observed in parsec-scale outflows. In contrast, the low-Eddington-ratio objects showed the opposite trend. We confirmed the known relationship between the outflow velocity andLBol/LEddand found that the scatter plausibly originates in the force multiplier (launch radius) in the low(high)-accretion-rate objects. A log volume filling factor between −6 and −4 was found in most outflows but was as high as −1 for low-velocity compact outflows. We investigated the relationship between the observed [Oiii] emission and that predicted from the BAL gas. We found that these could be reconciled if the emission-line covering fraction depends on the Seyfert type and BAL location. The difference between the predicted and observed [Oiii] luminosity is correlated with the outflow velocity, suggesting that [Oiii] emission in high-Eddington-ratio objects may be broad and hidden under Feiiemission. We suggest that the physical differences in the outflow properties as a function of location in the quasar and accretion rate point to different formation, acceleration, and confinement mechanisms for the two FeLoBALQ types.
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Enzymatic Benzofuranoindoline Formation in the Biosynthesis of the Strained Bridgehead Bicyclic Dipeptide (+)‐Azonazine A
Abstract We uncovered and reconstituted a concise biosynthetic pathway of the strained dipeptide (+)‐azonazine A from marine‐derivedAspergillus insulicola. Formation of the hexacyclic benzofuranoindoline ring system from cyclo‐(l‐Trp‐N‐methyl‐l‐Tyr) is catalyzed by a P450 enzyme through an oxidative cyclization. Supplementing the producing strain with various indole‐substituted tryptophan derivatives resulted in the generation of a series of azonazine A analogs.
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- Award ID(s):
- 2153972
- PAR ID:
- 10448367
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 62
- Issue:
- 40
- ISSN:
- 1433-7851
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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