Okaramine molecular formula

An inactive okaramine-related compound was isolated from the okara culture of A. aculeatus KF-428. This compound, okaramine I (10), had a molecular formula of C27H24N4O3. The H- and 13C-NMR spectra of 10 were the same as those of depentenylokaramine A, which was formed by hydrogenolysis of 1 with Pd/C [15, 20]. 

Okaramine J (11) had a molecular formula of C32H36N4O3, which is identical to the molecular formula of okaramine C (4). The H-NMR spectrum of 11 is shown in Fig. (4). The critical differences were the absence of one of two reverse-prenyl groups that were observed in 4 and the appearance of a new prenyl group and one exchangeable proton coupled to the methine proton at C-8a. The HMBC spectrum of 11 indicated that the prenyl group was bound to C-7 in the pyrroloindole ring [21]. 

Okaramine K (12), C32H34N4O3, had a molecular formula identical to that of okaramine G (8) [21]. The essential difference between the H-NMR spectra of 8 and 12 was the absence of a reverse-prenyl group... 

Okaramine N (15) had a molecular formula of C32H34N4O3, indicating that 15 had two more hydrogen atoms than okaramine A (1). The precise analysis of NMR experiments suggested that the C-r=C-2 double bond... 

Okaramine P (17), C32H34N4O4, had the same molecular formula as 16. The H-NMR spectrum of 17 is characterized by the disappearance of the reverse-prenyl signals in 16 and the appearance of a prenyl group. The HMBC spectrum indicated that the prenyl group was connected to C-l. The relative stereochemistry of 17 was the same as that of 16 at all chiral... 

Okaramine Q (18) had a molecular formula of C32H32N4O4. The UV spectrum (Xmax 234, 288, 376 nm) indicated the presence of an indole chromophore with an expanded conjugation. The H-NMR spectrum of 18 resembled that of okaramine B (2), except for the absence of the methoxyl proton signal in 2 and the presence of signals due to isolated methylene protons. A precise comparison between the NMR spectra of 18 and 2 led to the conclusion that 18 is a demethoxyl derivative of 2 [23]. 

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