Bioactive natural products from fungicolous Hawaiian isolates: secondary metabolites from a Phialemoniopsis sp.

Figures & data

Table 1. ¹H and ¹³C NMR data for gabusectin (4) in CDCl₃^a.

Position	δC	δH, mult (J in Hz)	HMBC
1	49.4
1-Me	21.0	1.23, s	1, 2, 14
		1.22, s
2	46.1, 46.0	3.34, br d (10)	3, 4, 12
3	133.20, 133.17
3-Me	23.5	1.66, s	2, 3, 4
4	130.3	5.01, br s	2, 3-Me, 5, 6, 10
5	37.9
5-Me	32.1	0.67, s	4, 5, 6
6	52.0	1.34, m	7 (wk), 10 (wk)
		0.87, m	4, 5, 5-Me, 7, 7-Me, 8
7	29.7	1.26, m
7-Me	22.6, 22.5	0.77, d (6.8)	6, 7, 8
8	35.3	1.61, m
		0.87, m	5- Me, 7
9	25.8	1.80, m	7 (wk), 8 (wk), 10 (wk)
		1.29, m	10 (wk)
10	42.5, 42.4	2.64, dd (12, 4.2)	1, 2, 4, 5, 5-Me, 9, 14
		2.54, dd (12, 4.2)	1, 2, 4, 5, 9, 14
11	132.7	5.29, m	2 (wk), 12, 13
12	129.0	5.40, m	2, 11, 13
13	18.0	1.67, s	12, 13
14	203.4, 203.3
15	99.2, 99.1
16	177.5, 177.4
N-Me	27.4	2.97, s	16, 18
18	64.7	3.68, m	19, 20, 21
19	190.5, 190.4
20	23.9, 23.8	2.28, m	18, 22
		2.04, m	18, 19, 21, 22 (wk)
21	28.0	2.28, m	18, 20, 22
22	177.9, 177.7

Notes: ^aData were collected at 600 MHz (¹H, HSQC, and HMBC) and 125 MHz (¹³C); wk = weak correlation. Signals listed with dual entries were those that showed discernible doubling due to the presence of a tautomeric mixture. Mult refers to multiplicity.

Figure 1. X-ray crystal structure (ORTEP image) of the p-bromobenzoate derivative of oxirapentyn B.

Figure 2. Key HMBC (→) and COSY (▬) correlations for gabusectin (4).

Figure 3. X-ray crystal structure (ORTEP image) of gabusectin (4).