A new phthalazinone derivative and a new isoflavonoid glycoside from lichen-associated Amycolatopsis sp.

Article abstract of DOI:10.1016/j.fitote.2019.04.011

A new phthalazinone derivative, named amycophthalazinone A (1), and a new isoflavonoid glycoside, 7-O-methyl-5-O-α-L-rhamnopyranosylgenestein (2), along with an isoflavonoid glycoside, 7-O-α-D-arabinofuranosyl daidzein (3) firstly found from natural sources, and eight known compounds (4–11), were isolated from the culture broth of the lichen-associated Amycolatopsis sp. YIM 130642. The structures of new compounds were elucidated on the basis of spectroscopic analysis. Compound 1 was the first example of naturally occurring phthalazinone derivative. The antimicrobial activities of all compounds towards five pathogenic strains were evaluated by a broth microdilution assay. Compound 1 exhibited the most potent inhibitory activity against Staphylococcus aureus, Salmonella typhi, and Candida albicans with MIC values of 32, 32, and 64 μg/mL, respectively.

Full text of DOI:10.1016/j.fitote.2019.04.011

Fitoterapia135(2019)85–89
Contents lists available at ScienceDirect
Fitoterapia
journal homepage: www.elsevier.com/locate/fitote
A new phthalazinone derivative and a new isoflavonoid glycoside from
lichen-associated Amycolatopsis sp.
Kai-Xuan Zhenga, Yi Jianga, Ju-Xing Jiangb, Rong Huangc, Jian Hed, Shao-Hua Wua,⁎
a Yunnan Institute of Microbiology, School of Life Sciences, Yunnan University, Kunming 650091, China
b R&D Center, China Tobacco Yunnan Industrial Co., Ltd., Kunming 650202, China
c School of Chemical Science and Technology, Yunnan University, Kunming 650091, China
d Group of Peptides and Natural Products Research, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China
A R T I C L E I N F O
A B S T R A C T
Keywords:
Amycolatopsis
Lichen
Phthalazinone
Isoflavonoid
Antimicrobial activity
A new phthalazinone derivative, named amycophthalazinone A (1), and a new isoflavonoid glycoside, 7-O-
methyl-5-O-α-L-rhamnopyranosylgenestein (2), along with an isoflavonoid glycoside, 7-O-α-D-arabinofuranosyl
daidzein (3) firstly found from natural sources, and eight known compounds (4–11), were isolated from the
culture broth of the lichen-associated Amycolatopsis sp. YIM 130642. The structures of new compounds were
elucidated on the basis of spectroscopic analysis. Compound 1 was the first example of naturally occurring
phthalazinone derivative. The antimicrobial activities of all compounds towards five pathogenic strains were
evaluated by a broth microdilution assay. Compound 1 exhibited the most potent inhibitory activity against
Staphylococcus aureus, Salmonella typhi, and Candida albicans with MIC values of 32, 32, and 64 μg/mL, re-
spectively.
1. Introduction
a number of publications have been reported on the cultivable bacterial
associated with lichens. However, only a few structurally identified
Actinobacteria has long been regarded as one of the important re-
sources of bioactive metabolites in discovery of natural drugs [1].
Among them, the genus of Streptomyces is the main contributor of
producing antibiotics in the past several decades. Over time, the ratio of
bioactive substances from “rare actinomycetes” had been gradually
increased [1]. The genus of Amycolatopsis is characterized as a rare
actinomycete group. Some Amycolatopsis species had been reported to
produce various structural types of antibiotics, such as glycopeptides
[2], cyclic thiazolyl peptides [3], vancoresmycin [4], pargamicin A [5],
and rifamorpholines [6]. Most notably, vancomycin and rifamycin with
strong antibacterial activity produced by Amycolatopsis sp. had been
used as the common clinical antibiotic drugs.
Lichen is a symbiotic community between fungi and a photo-
synthetic alga and/or cyanobacteria [7]. Most lichens are promising
sources of specific secondary metabolites possessing antioxidant, cyto-
toxic, and antimicrobial activities [7,8]. Up to now, very little study on
the chemical components of the lichen Squamarina had been reported.
A naphthoquinone named squamarone was isolated from the lichen
Squamarina cartilaginea [9]. Psoromic acid derived from Squamarina
cartilaginea showed potent antibacterial activity against the oral pa-
thogens Streptococcus gordonii and Porphyromonas gingivalis [10]. So far,
bioactive molecules are reported from several strains, especially most of
which are Streptomyces species [11]. In addition, several 21-membered
macrocyclic benzenoid ansamycins with antiproliferative and anti-
neuroinflammatory activity were isolated recently from moss-soil-de-
rived actinomycete Streptomyces cacaoi subsp. asoensis H2S5 [12]. Re-
cent studies revealed that lichen-associated bacteria represent
a
potential but under explored resource for discovery of new bioactive
natural products [11,13].
Our current research work is focused on investigating bioactive
secondary metabolite produced by lichen-associated actinobacteria.
During the course of our bioactive screening for the culture extract of
actinomycete strains isolated from lichens growing in Yunnan dry-hot
valley region, the strain Amycolatopsis sp. YIM 130642 showed potent
antimicrobial activity against several pathogens. Further phytochemical
studies on the culture broth of this strain led to the isolation of one new
phthalazinone derivative, amycophthalazinone A (1), and a new iso-
flavonoid glycoside, 7-O-methyl-5-O-α-L-rhamnopyranosylgenestein
(2), along with an isoflavonoid glycoside 7-O-α-D-arabinofur-
anosyldaidzein (3) firstly found from natural sources, and eight known
compounds, prunetin (4) [14], kakkatin (5) [15], isoformononetin (6)
[16], genistein (7) [17], formononetin (8) [18], turnagainolide B (9)
⁎ Corresponding author.
E-mail address: shwu123@126.com (S.-H. Wu).
https://doi.org/10.1016/j.fitote.2019.04.011
Received 14 March 2019; Received in revised form 23 April 2019; Accepted 23 April 2019
Availableonline24April2019
0367-326X/©2019ElsevierB.V.Allrightsreserved.

K.-X. Zheng, et al.
Fitoterapia135(2019)85–89
Fig. 1. Chemical structures of compounds 1–11.
[19], cyclo (L-Leu-L-Tyr) (10) [20], minaline (11) [21] (Fig. 1). Recent
research revealed that genistein could inhibit α-glucosidase in vitro,
more potent than the positive control, acarbose, and minaline could
inhibit the growth of radish (Raphanus sativus) seedlings, which was
comparable to the positive control glyphosate [22]. So far, a number of
bioactive substances had been isolated from Amycolatopsis strains de-
rived from various habitats, whereas there is no any report of secondary
metabolites from lichen-associated Amycolatopsis species till now. In
this paper, we describe the isolation, structural elucidation, and anti-
microbial activities of the isolated compounds from the strain Amyco-
latopsis sp. YIM 130642.
Institute of Microbiology, Yunnan University, China. The fresh myce-
lium of the strain was inoculated into 100 × 250 mL Erlenmeyer flasks,
each containing 40 mL of seed medium (yeast extract, 4 g; glucose, 4 g;
malt extract, 3 g; trace salt 1 g; multi-vitamins 3.5 mg; H2O, 1 L;
pH 7.2). After 3 d of the incubation at 28
1 °C on a rotary shaker at
200 r.p.m., each 40-mL of the culture liquid was transfered as seed into
2 L Erlenmeyer flasks (× 100) containing 400 mL of fermentation
medium (soybean extract, 20 g; peptone, 2 g; glucose, 20 g; starch, 5 g;
yeast extact, 2 g; NaCl, 4 g; K2HPO4, 0.5 g; MgSO4·7H2O, 0.5 g; CaCO3,
2 g; H2O, 1 L; pH 7.8). The cultivation was kept for 7 days at 28
on a rotary shaker at 200 r.p.m.
1 °C
2. Experimental
2.3. Extraction and isolation
2.1. General experimental procedures
The cultures were extracted with an equal volume of EtOAc for four
times. The combined organic phase was then concentrated in vacuo to
obtain a brown gum of crude extract (34 g). The extract was submitted
to silica gel CC, eluting with a gradient of CHCl3/MeOH from 1:0 to 0:1
(v/v) to obtain eight fractions (Frs. 1–7). Fr. 2 was purified by crys-
tallization to get compound 4 (440 mg). Fr. 3 was subjected to silica gel
CC (petroleum ether/EtOAc 4:1 → 1:1) to afford two subfractions (Frs.
3.1–3.2). Fr. 3.1 was further purified by silica gel CC (petroleum ether/
acetone 6:4, 1:1) to afford compound 5 (15 mg). Compound 11 (17 mg)
was yielded by crystallization from Fr. 3.2. Fr. 4 was subjected to silica
gel CC (CHCl3/MeOH 9:1) to afford compound 9 (15 mg). Fr. 5 was
purified by silica gel CC (CHCl3/MeOH 9:1, 85:15) and RP-18 CC
(MeOH/H2O, 3:7, 4:6, 1:1) to afford compounds 1 (7 mg) and 10
(10 mg). Fr. 6 was seperated by RP-18 CC, eluting with a gradient of
MeOH/H2O from 2:8 to 1:0 to afford three subfractions (Frs. 6.1–6.3).
Fr. 6.1 was then purified by crystallization to obtain compound 3
(15 mg). Fr. 6.2 was subjected to RP-18 CC (MeOH/H2O 3:7, 4:6, 1:1) to
afford compounds 6 (5 mg) and 8 (5 mg). Fr. 6.3 was purified by
Sephadex LH-20 (MeOH) to provide compound 2 (8 mg). Fr. 7 was
subjected to silica gel CC (CHCl3/MeOH 9:1, 8:2) to yield compound 7
Optical rotations were recorded on a Jasco P-2000 polarimeter. UV
spectra were detected on a U-4100 spectrophotometer. IR spectra were
collected on a Bio-Rad FTS spectrometer, with KBr pellets. NMR spectra
were recorded on a Bruker DRX-500 and Bruker Avance III-HD 600 NMR
spectrometers, using TMS as an internal standard. HRESIMS were ac-
quired by an Agilent 3250AA LC-MSD TOF mass spectrometer. Column
chromatography (CC) was employed on silica gel (200–300 mesh,
Qingdao Marine Chemical Inc., China), Sephadex LH-20 (Pharmacia),
and RP-18 silica gel (40–63 μm, Merck).
2.2. Cultivation of actinomycete strain
The strain YIM 130642 was isolated from the lichen Squamarina sp.
collected in dry and hot valley region of Jinsha River, Yunnan Province.
The specimen of the lichen was identified by Prof. Lisong Wang,
Kunming Institute of Botany, The Chinese Academy of Sciences,
Kunming, Yunnan, China. The strain was determined as Amycolatopsis
sp. by the partial 16S rRNA gene sequence and deposited in Yunnan
86

K.-X. Zheng, et al.
Fitoterapia135(2019)85–89
Table 1
1H and 13C NMR data of compounds 1 and 2.
Position
1a
2b
δH (J in Hz)
δC
δH (J in Hz)
δC
NH
NH
1
2
3
4
5
6
7
8
164.3, C
8.35, d (7.5)
6.81, t (7.5)
7.28, t (7.5)
7.04, d (8.0)
128.3, CH
117.4, CH
133.5, CH
114.9, CH
147.5, C
7.90, s
151.4, CH
126.0, C
176.0, C
157.3, C
100.9, CH
164.2, C
94.4, CH
160.0, C
110.0, C
6.64, d (2.4)
6.63, d (2.4)
116.0, C
68.6, C
O
9
1.94–2.01, m
1.60–1.65, m
1.27–1.31, m
1.60–1.65, m
1.94–2.01, m
38.1, CH2
21.7, CH2
25.1, CH2
21.7, CH2
38.1, CH2
1H−1H COSY
10
11
12
13
1′
2′, 6′
3′, 5′
4′
1″
2″
3″
4″
5″
6″
7-OCH3
1-NH
8-NH
HMBC (H→C)
Fig. 2. Selected 1He1H COSY and HMBC correlations of compound 1.
122.9, C
130.3, CH
114.8, CH
157.2, C
99.3, CH
70.4, CH
70.6, CH
72,5, CH
69.9, CH
16.6, CH
55.1, CH3
7.22, dd (7.2, 2.4)
6.72, dd (7.2, 2.4)
determined as the lowest concentrations at which the microorganism
did not demonstrate visible growth. The experiments were repeated
three times.
5.42, d (1.2)
4.08, dd (3.6, 1.8)
3.99, dd (9.6, 3.6)
3.36, t (9.6)
3.58, m
1.12, d (6.0)
3.81, s
3. Results and discussion
7.13, br s
8.73, br s
Compound 1 was obtained as a yellow powder. Its molecular for-
mula was determined to be C13H16N2O by the positive HRESIMS ion at
m/z 239.1159 [M + Na]+ (calcd 239.1160), indicating seven degrees
of unsaturation. The 1H NMR spectrum (Table 1) showed four aromatic
protons, including two doublet signals at δH 7.04 (J = 8.0 Hz) and 8.35
(J = 7.5 Hz), two triplet signals at δH 6.81 (J = 7.5 Hz) and 7.28
a
Measured in pyridine‑d5.
Measured in CD3OD.
b
(4 mg).
2.3.1. Amycophthalazinone A (1)
(J = 7.5 Hz). Interpretation of the H-1H COSY spectrum (Fig. 2) re-
l
vealed that these four protons were linked together, indicating an ortho-
disubstituted aromatic ring. The 13C NMR and HSQC spectra displayed
13 signals corresponding to one carbonyl carbon (δC 164.3), six olefinic
carbons (δC 147.5, 133.5, 128.3, 117.4, 116.0, 114.9), one aliphatic
quaternary carbon (δC 68.6), five aliphatic methylenes (δC 25.1, each
two signals at δC 38.1 and 21.7). The two exchangeable protons at δH
8.73 and 7.13 observed in the original 1H NMR spectrum were shifted
to δH 8.71 and 7.21, respectively, which were overlapped by the solvent
residual signals of pyridine‑d5 during the 2D-NMR experiment (see
Supplementary materials). These two exchangeable protons were cou-
Yellow powder; UV (MeOH) λmax (log ε) 272 (1.60), 350 (2.47) nm;
IR (KBr) νmax 3432, 2923, 2851, 1644, 1612, 1507, 1485, 1383, 1269,
1148, 1041, 754 cm−1 1H (500 MHz) and 13C (125 MHz) NMR data,
;
see Table 1; HRESIMS m/z 217.1344 [M + H]+, 239.1159 [M + Na]+
(calcd for C13H16N2ONa, 239.1160).
2.3.2. 7-O-Methyl-5-O-α-L-rhamnopyranosylgenestein (2)
Yellow gum; [α]2D0 − 21.7 (c 0.13, MeOH); UV (MeOH) λmax (log ε)
202 (2.51), 258 (3.68) nm; IR (KBr) νmax 3443, 1628, 1516, 1426, 1255,
1119, 1053, 1023 cm−1 1H (600 MHz) and 13C (150 MHz) NMR data,
;
pled with each other in the H-1H COSY spectrum, indicating the ex-
l
see Table 1; HRESIMS m/z 453.1168 [M + Na]+ (calcd for
22H22O9Na, 453.1162).
istence of acylhydrazine unit (O=C-NH-NH-) due to its atomic com-
position. This was further supported by the strong absorption bands for
NH group (3432 cm−1) and conjugated carbonyl group (1644 cm−1).
Since seven degrees of unsaturation were accounted for, it was implied
that compound 1 should contain two additional rings except for a
carbonyl group and a benzene ring. The coupling sequence of the ali-
phatic protons from H-9 to H-13 could be distinguished by tracking
correlations in the lH-1H COSY spectrum. In the HMBC spectrum
(Fig. 2), the quaternary carbon at δC 68.6 (C-8) showed strong long-
range correlations with two pairs of methylene protons at δH 1.94–2.01
(H-9, 13) and 1.60–1.65 (H-10, 12), indicating the cyclohexane ring
consisted of C-8 and five methylene groups. The weak HMBC correla-
tions from two extrangable protons at δH 8.71 and 7.21 to C-8 implied
the linkage of -NH-NH- group with C-8. Furthermore, the key HMBC
correlations could be observed from H-2 (δH 8.35) to C-1 (δC 164.3), C-4
(δC 133.5), and C-6 (δC 147.5), and from H-5 (δH 7.04) to C-1, C-3 (δC
117.4), and C-7 (δC 116.0). These above data readily confirmed that
compound 1 had a phthalazinone skeleton bearing a spiro cyclohexane
at C-8. Thus, its structure was formulated as in Fig. 1 and given its
trivial name of amycophthalazinone A.
C
2.4. Antimicrobial assays
Antimicrobial assays were performed by the broth microdilution
method in 96-well sterilized microplates as described previously [23].
The yeast Candida albicans (YM 2005) was grown in Sabouraud dex-
trose broth medium for 48 h at 28 °C with the test concentration of
1.0 × 105 spores/mL. The bacterial strains Staphylococcus aureus (YM
3105), methicillin-resistant Staphylococcus aureus (MRSA, YM 3106),
Salmonella typhi (YM 3115), and Escherichia coli (YM 3130) were grown
in LB medium (1.0% tryptone, 1.0% NaCl, 0.5% yeast extract, pH 7.0)
for 18 h at 37 °C, and the final suspensions were adjusted to 1.0 × 105
colony-forming units/mL. Each of 50 μL inoculum suspension was
added into the wells of 96-well plates. The test compounds were dis-
solved in a small volume of sterile DMSO and diluted in the appropriate
medium to afford the final concentrations ranging from 512.0 to 1 μg/
mL using 2-fold serial dilution method. The plates were incubated at
28 °C (48 h) for yeast and 37 °C (24 h) for bacteria. Nystatin and
chloramphenicol were used as positive control for yeast and bacteria,
respectively. The minimal inhibitory concentrations (MICs) were
Compound 2 was obtained as a yellow gum with the molecular
formula C22H22O9, deduced from HRESIMS ([M + Na]+ m/z 453.1168,
87

K.-X. Zheng, et al.
Fitoterapia135(2019)85–89
calcd 453.1162), indicating twelve degrees of unsaturation. The IR
spectrum exhibited absorption bands for hydroxy group at 3443 cm−1
and carbonyl group at 1628 cm−1. The 1H NMR spectrum showed seven
aromatic proton signals at δH 7.90 (1H, s), 7.22 (2H, dd, J = 7.2,
2.4 Hz), 6.72 (2H, dd, J = 7.2, 2.4 Hz), 6.64 (1H, d, J = 2.4 Hz), 6.63
(1H, d, J = 2.4 Hz); eight proton signals attributable to a sugar moiety
at δH 5.42 (1H, d, J = 1.2 Hz), 4.08 (1H, dd, J = 3.6, 1.8 Hz), 3.99 (1H,
dd, J = 9.6, 3.6 Hz), 3.58 (1H, m), 3.36 (1H, t, J = 9.6 Hz), 1.12 (1H, d,
J = 6.0 Hz), and one methoxy group at δH 3.81 (3H, s). It is notable that
the aromatic proton signal at δH 7.90 (1H, s) is characteristics of H-2 in
isoflavonoid skeleton. The 13C NMR and DEPT spectra showed 22
carbon signals including 15 carbons for the isoflavonoid aglycone and 6
carbons for a sugar moiety, along with a methoxy carbon (δC 55.1). Its
1H and 13C NMR data showed strong resemblance with those of re-
ported isoflavonoid glycosides [24]. The main difference is owing to the
substitution position of the sugar moiety and the methoxy group. The
quaternary carbon at δC 160.0 was assigned to be C-9 based on its
HMBC correlation with H-2. The two aromatic protons at δH 6.64 and
6.63 were coupled with a small constant of J = 2.4 Hz, indicating that
they are in meta position of aromatic ring. These two protons were
determined as H-6 (δH 6.64) and H-8 (δH 6.63), respectively, due to
both of their long-range correlations with C-10 and the only correlation
from H-8 to C-9. The two quaternary carbons at δC 157.3 and 164.2
were positioned in C-5 and C-7, respectively, on the basis of the HMBC
correlations from H-6 and H-8 to C-7, and from H-6 to C-5. Since the
unambiguous assignment of H-6, H-8, C-5 and C-7, the location of
glycosylation and the methoxy group could be easily determined by
analysis of the HMBC spectrum. The HMBC cross peaks were observed
from the anomeric proton H-1′′ (δH 5.42) to C-5 and from the methoxy
protons at δH 3.81 to C-7. Thus, the glycosylation and the methoxy
group were sited at C-5 and C-7, respectively. The chemical shifts of the
sugar signals and the small coupling constant of J = 1.2 Hz for the
anomeric proton clearly suggested the α-rhamnopyranoside moiety.
Acid hydrolysis of compound 2 refluxed with 2 N HCl for 2 h afforded L-
rhamnose ([α]2D0 + 9.8, H2O). The L-conformation of the rhamnose was
confirmed by its positive specific rotation. Therefore, the structure of
compound 2 was determined to be 7-O-methyl-5-O-α-L-rhamnopyr-
anosylgenestein.
Table 2
Antimicrobial activities of compounds 1–5 against different pathogens.
Compounds
MIC (μg/mL)
C. albicans
S. aureus
MRSA
S. typhi
E. coli
1
2
3
4
5
6
7
8
64
32
64
256
256
512
256
128
> 512
128
> 512
> 512
> 512
> 512
–
32
512
64
128
> 512
128
32
128
256
32
512
64
> 512
> 512
–
128
256
256
256
> 512
128
> 512
128
> 512
> 512
8
256
128
128
> 512
64
> 512
> 512
> 512
> 512
–
128
256
256
256
256
128
> 512
> 512
–
9
10
11
Nystatin
Chloramphenicol
–
8
16
8
8
a nitroso species, followed by cyclization and reduction. Nevertheless,
the detailed biosynthetic mechanisms for the formation of piperazic
acid are still not well understood currently [49]. Similarly, in our study,
some peptides and amino acid, such as compounds 9–11, were also
isolated. Therefore, a similar conversion from amino group to hy-
drazine moiety was also possibly existed in this microbial strain.
However, more extensive investigations are necessarily required to
clarify this biogenetic proposal.
All isolated compounds were tested for their antimicrobial activities
towards S. aureus, methicillin-resistant S. aureus, S. typhi, and E. coli by
using broth microdilution method. The results were shown in Table 2.
Among them, compound 1 exhibited the most potent inhibitory activity
against S. aureus, S. typhi, and C. albicans with MIC values of 32, 32, and
64 μg/mL, respectively. Compound 2 showed moderate inhibitory ac-
tivity towards S. aureus and E. coli with MIC value of 64 μg/mL. Com-
pound 3 displayed moderate activity against S. typhi with MIC value of
64 μg/mL. Besides, compounds 4 and 9 inhibited the growth of E. coli
with MICs of 32 and 64 μg/mL, respectively. Compound 7 showed
moderate inhibitory activity against S. aureus and E. coli with MICs of
64 and 32 μg/mL, respectively. The remaining compounds 5, 6, 8, 10,
and 11 showed weak or no antimicrobial activities towards the five
tested pathogenic strains.
To the best of our knowledge, the phthalazinone skeleton in 1 has
not been encountered in natural products previously, although a few
synthetic compounds with similar substructures have been reported
[25,26]. The related structures of phthalazine and tetra-
hydrophthalazine, containing a hydrazine moiety in the ring system,
are incorporated into important bioactive compounds, including ex-
amples of pseudopeptides and C-nucleosides [25]. Many synthetic de-
rivatives containing benzoylhydrazine skeleton had been reported.
Some of them possess a wide range of biological activities, such as
leishmanicidal activity [27], antiangiogenic activity [28], antichagasic
activity [29], insecticidal activity [30], and antifungal activity [31].
Compound 1 was the first example of naturally occurring phthalazinone
derivative.
Acknowledgments
This work was financially supported by the National Natural Science
Foundation of China (No. 81860634, 81460545, and 31460005), and
Program for Excellent Young Talents, Yunnan University. The authors
also thank Advanced Analysis and Measurement Center of Yunnan
University for the measurements of NMR and MS spectral data.
Appendix A. Supplementary data
Isoflavonoids were commonly occurred in various microorganism
sources, mainly obtained from Streptomyces. Recent reported examples
included isoflavone rhamnopyranosides from soil-derived Streptomyces
[24,32], chlorinated isoflavonoids from soil-derived Streptomyces
[33–35], and isoflavonoid glycosides from termite-associated Strepto-
myces [36,37]. In this paper, we firstly report the phthalazinone deri-
vative and isoflavonoids from the actinomycete Amycolatopsis.
The naturally occurring hydrazine compounds are rarely observed,
most of which are derived by synthetic approach. A number of struc-
turally related cyclic depsipeptides bearing such group had been re-
ported, e.g. polyoxypeptins [38], aurantimycins [39], citropeptin [40],
kettapeptin [41], azinothricin [42], diperamycin [43], pipalamycin
[44], variapeptin [45], and pargamicins [46,47]. As described in lit-
erature [48], the hydrazine moiety in these peptides was formed pos-
sibly by the conversion of ornithine into piperazic acid via oxidation to
1D and 2D NMR spectra of compounds 1 and 2 are available as
Supporting information.
References
[1] J. Bérdy, Thoughts and facts about antibiotics: where we are now and where we are
heading, J. Antibiot. 65 (2012) 385–395.
[2] S.J. Box, A.L. Elson, M.L. Gilpin, D.J. Winstanley, MM 47761 and MM 49721,
glycopeptide antibiotics produced by a new strain of Amycolatopsis orientalis.
Isolation, purification and structure determination, J. Antibiot. 43 (1990) 931–937.
[3] T. Sasaki, T. Otani, H. Matsumoto, N. Uneml, M. Hamada, T. Takeuchi, M. Horl,
MJ347-81F4 A & B, novel antibiotics from Amycolatopsis sp.: taxonomic char-
acteristics, fermentation, and antimicrobial activity, J. Antibiot. 51 (1998)
715–721.
[4] C. Hopmann, M. Kurz, M. Broenstrup, J. Wink, D. LeBeller, Isolation and structure
elucidation of vancoresmycin-a new antibiotic from Amycolatopsis sp. ST 101170,
Tetrahedron Lett. 43 (2002) 435–438.
88

K.-X. Zheng, et al.
Fitoterapia135(2019)85–89
[5] H. Hashizume, H. Adachi, M. Igarashi, Y. Nishimura, Y. Akamatsu, Biological ac-
tivities of pargamicin A, a novel cyclic peptide antibiotic from Amycolatopsis sp, J.
Antibiot. 63 (2010) 279–283.
[6] Y.S. Xiao, B. Zhang, M. Zhang, Z.K. Guo, X.Z. Deng, J. Shi, W. Li, R.H. Jiao,
R.X. Tan, H.M. Ge, Rifamorpholines A-E, potential antibiotics from locust-asso-
ciated actinobacteria Amycolatopsis sp. Hca4, Org. Biomol. Chem. 15 (2017)
3909–3916.
R. Lesniewski, 3-Amino-2-hydroxyamides and related compounds as inhibitors of
methionine aminopeptidase-2, Bioorg. Med. Chem. Lett. 14 (2004) 865–868.
[29] L.R. Dias, M.B. Santos, S. de Albuquerque, H.C. Castro, A.M. de Souza, A.C. Freitas,
M.A. DiVaio, L.M. Cabral, C.R. Rodrigues, Synthesis, in vitro evaluation, and SAR
studies of a potential antichagasic 1H-pyrazolo[3,4-b] pyridine series, Bioorg. Med.
Chem. 15 (2007) 211–219.
[30] S. Cao, X. Qian, G. Song, N'-tert-butyl-N'-aroyl-N-(alkoxycarbonylmethyl)-N- ar-
oylhydrazines, a novel nonsteroidal ecdysone agonist: syntheses, insecticidal ac-
tivity, conformational, and crystal structure analysis, Can. J. Chem. 79 (2001)
272–278.
[7] G. Shrestha, L.L.S. Clair, Lichens: a promising source of antibiotic and anticancer
drugs, Phytochem. Rev. 12 (2013) 229–244.
[8] V. Shukla, G.P. Joshi, M.S.M. Rawat, Lichens as a potential natural source of
bioactive compounds: a review, Phytochem. Rev. 9 (2010) 303–314.
[9] U. Himmelreich, S. Huneck, G.B. Feige, H.T. Lumbsch, Squamarone, a naphtho-
quinone from the lichen Squamarina cartilaginea, Z. Naturforsch. B 49 (1994)
1289–1291.
[31] J.L. Reino, L. Saiz-Urra, R. Hernández-Galán, V.J. Arán, P.B. Hitchcock,
J.R. Hanson, M.P. Gonzalez, I.G. Collado, Quantitative structure-antifungal activity
relationships of some benzohydrazides against Botrytis cinerea, J. Agric. Food Chem.
55 (2007) 5171–5179.
[10] A. Sweidan, M. Chollet-Krugler, A. Sauvager, P. van de Weghe, A. Chokr,
M. Bonnaure-Mallet, S. Tomasi, L. Bousarghin, Antibacterial activities of natural
lichen compounds against Streptococcus gordonii and Porphyromonas gingivalis,
Fitoterapia 121 (2017) 164–169.
[11] M.T. Suzuki, D. Parrot, G. Berg, M. Grube, S. Tomasi, Lichens as a natural source of
biotechnologically relevant bacteria, Appl. Microbiol. Biotechnol. 100 (2016)
583–595.
[12] D. Tang, L.L. Liu, Q.R. He, W. Yan, D. Li, J.M. Gao, Ansamycins with anti-
proliferative and antineuroinflammatory activity from moss-soil-derived
Streptomyces cacaoi subsp. asoensis H2S5, J. Nat. Prod. 81 (2018) 1984–1991.
[13] D. Parrot, S. Antony-Babu, L. Intertaglia, M. Grube, S. Tomasi, M.T. Suzuki, Littoral
lichens as a novel source of potentially bioactive actinobacteria, Sci. Rep. 5 (2015)
15839.
[14] A.A. Drenin, E.K. Botirov, E.V. Petrulyak, New genistein monogalactoside from the
aerial part of Trifolium pratense, Chem. Nat. Compd. 44 (2008) 178–181.
[15] R. Huang, Z.G. Ding, Y.F. Long, J.Y. Zhao, M.G. Li, X.L. Cui, M.L. Wen, A new
isoflavone derivative from Streptomyces sp. YIM GS3536, Chem. Nat. Compd. 48
(2013) 966–969.
[32] Y.S. Dong, J.S. Yang, X. Ren, H. Zhang, J.G. He, New aldose reductase inhibitors
N99-596 A and B from Streptomyces, J. Antibiot. 58 (2005) 737–739.
[33] K. Komiyama, S. Funayama, Y. Anraku, A. Mita, Y. Takahashi, S. Omura, Isolation
of isoflavonoids possessing antioxidant activity from the fermentation broth of
Streptomyces sp, J. Antibiot. 42 (1989) 1344–1349.
[34] I.O. Anyanwutaku, E. Zirbes, J.P.N. Rosazza, Isoflavonoids from Streptomycetes:
origins of genistein, 8-chlorogenistein, and 6, 8-dichlorogenistein, J. Nat. Prod. 55
(1992) 1498–1504.
[35] S. Funayama, Y. Anraku, A. Mita, K. Komiyama, S. Omura, Structural study of
isoflavonoids possessing antioxidant activity from the fermentation broth of
Streptomyces sp, J. Antibiot. 42 (1989) 1350–1355.
[36] H.R. Kang, D. Lee, R. Benndorf, W.H. Jung, C. Beemelmanns, K.S. Kang, K.H. Kim,
Termisoflavones A-C, isoflavonoid glycosides from termite-associated Streptomyces
sp. RB1, J. Nat. Prod. 79 (2016) 3072–3078.
[37] S.R. Lee, J.H. Song, J.H. Song, H.J. Ko, J.Y. Baek, T.A. Trinh, C. Beemelmanns,
N. Yamabe, K.H. Kim, Chemical identification of isoflavonoids from a termite-as-
sociated Streptomyces sp. RB1 and their neuroprotective effects in murine hippo-
campal HT22 cell line, Int. J. Mol. Sci. 19 (2018) 2640–2653.
[16] G.T. Maatooq, J.P.N., Rosazza, Metabolism of daidzein by Nocardia species NRRL
5646 and Mortierella isabellina ATCC 38063, Phytochemistry 66 (2005) 1007–1011.
[17] M.S. Cotroneo, W.A. Fritz, C.A. Lamartiniere, Dynamic profiling of estrogen re-
ceptor and epidermal growth factor signaling in the uteri of genistein- and estrogen-
treated rats, Food Chem. Toxicol. 43 (2005) 637–645.
[18] H.M.T.B. Herath, R.S. Dassanayake, A.M.A. Priyadarshani, S.D. Silva,
G.P. Wannigama, J. Jamie, Isoflavonoids and a pterocarpan from Gliricidia sepium,
Phytochemistry 49 (1998) 117–119.
[38] K. Umezawa, K. Nakazawa, T. Uemura, Y. Ikeda, S. Kondo, H. Naganawa,
N. Kinoshita, H. Hashizume, M. Hamada, T. Takeuchi, S. Ohba, Polyoxypeptin
isolated from Streptomyces: a bioactive cyclic depsipeptide containing the novel
amino acid 3-hydroxy-3- methylproline, Tetrahedron Lett. 39 (1998) 1389–1392.
[39] U. Grafe, R. Schlegel, M. Ritzau, W. Ihn, K. Dornberger, C. Stengel, W.F. Fleck,
W. Gutsche, A. Hartl, E.F. Paulus, Aurantimycins, new depsipeptide antibiotics from
Streptomyces aurantiacus IMET 43917. Production, isolation, structure elucidation,
and biological activity, J. Antibiot. 48 (1995) 119–125.
[19] D.H. Li, C. Gavin, Y.H. Zhang, E.D. Williams, A. Amlani, H. Bottriell, A.L.-F. Mui,
R.J. Andersen, Turnagainolides A and B, cyclic depsipeptides produced in culture
by a Bacillus sp.: isolation, structure elucidation, and synthesis, J. Nat. Prod. 74
(2011) 1093–1099.
[40] Y. Hayakawa, M. Nakagawa, Y. Toda, H. Seto, A new depsipeptide antibiotic, ci-
tropeptin, Agric. Biol. Chem. 54 (1990) 1007–1011.
[41] R.P. Maskey, S. Fotso, M. Sevvana, I. Uson, I. Grun-Wollny, H. Laatsch, Kettapeptin:
isolation, structure elucidation and activity of a new hexadepsipeptide antibiotic
from a terrestrial Streptomyces sp, J. Antibiot. 59 (2006) 309–314.
[42] H. Maehr, C.M. Liu, N.J. Palleroni, J. Smallheer, L. Todaro, T.H. Williams,
J.F. Blount, Microbial products. VIII. Azinothricin, a novel hexadepsipeptide anti-
biotic, J. Antibiot. 39 (1986) 17–25.
[43] N. Matsumoto, I. Momose, M. Umekita, N. Kinoshita, M. Chino, H. Iinuma, T. Sawa,
M. Hamada, T. Takeuchi, Diperamycin, a new antimicrobial antibiotic produced by
Streptomyces griseoaurantiacus MK393-AF2. I. Taxonomy, fermentation, isolation,
physico-chemical properties and biological activities, J. Antibiot. 51 (1998)
1087–1092.
[20] Z.G. Ding, J.Y. Zhao, P.W. Yang, M.G. Li, R. Huang, C.X. Long, M.L. Wen, 1H and
13C NMR assignments of eight nitrogen containing compounds from Nocardia alba
sp. nov (YIM 30243T), Magn. Reson. Chem. 47 (2009) 366–370.
[21] A. Dieter, A. Hamm, H.P. Fiedler, M. Goodfellow, W.E.G. Müller, R. Brun, W. Beil,
G. Bringmann, Pyrocoll, an antibiotic, antiparasitic and antitumor compound pro-
duced by a novel alkaliphilic Streptomyces strain, J. Antibiot. 56 (2003) 639–646.
[22] J. Wei, X.Y. Zhang, S. Deng, L. Cao, Q.H. Xue, J.M. Gao, α-Glucosidase inhibitors
and phytotoxins from Streptomyces xanthophaeus, Nat. Prod. Res. 31 (2017)
2062–2066.
[23] I. Wiegand, K. Hilpert, R.E.W. Hancock, Agar and broth dilution methods to de-
termine the minimal inhibitory concentration (MIC) of antimicrobial substances,
Nat. Protoc. 3 (2008) 163–175.
[44] Y. Uchihata, N. Ando, Y. Ikeda, S. Kondo, M. Hamada, K. Umezawa, Isolation of a
novel cyclic hexadepsipeptide pipalamycin from Streptomyces as an apoptosis- in-
ducing agent, J. Antibiot. 55 (2002) 1–5.
[24] J.F. Hu, D. Wunderlich, I. Sattler, R. Thiericke, S. Grabley, X.Z. Feng, New 2-o-
methylrhamno-isoflavones from Streptomyces sp, Nat. Prod. Res. 17 (2003)
451–458.
[25] D. Marosvölgyi-Haskó, A. Petz, A. Takács, L. Kollár, Synthesis of tetrahydro-
phthalazine and phthalamide (phthalimide) derivatives via palladium-catalysed
carbonylation of iodoarenes, Tetrahedron 67 (2011) 9122–9128.
[26] G. Strappaghetti, C. Brodi, G. Giannaccini, L. Betti, New 4- (4-methylphenyl)
phthalazin-1(2H)-one derivatives and their effects on α1-receptors, Bioorg. Med.
Chem. Lett. 16 (2006) 2575–2579.
[27] K.M. Khan, M. Rasheed, Zia-Ullah, S. Hayat, F. Kaukab, M.I. Choudhary, Atta-ur-
Rahman, S. Perveen, Synthesis and in vitro leishmanicidal activity of some hy-
drazides and their analogues, Bioorg. Med. Chem. 11 (2003) 1381–1387.
[28] G.S. Sheppard, J. Wang, M. Kawai, N.Y. BaMaung, R.A. Craig, S.A. Erickson,
L. Lynch, J. Patel, F. Yang, X.B. Searle, P. Lou, C. Park, K.H. Kim, J. Henkin,
[45] M. Nakagawa, Y. Hayakawa, K. Adachi, H. Seto, A new depsipeptide antibiotic,
variapeptin, Agric. Biol. Chem. 54 (1990) 791–794.
[46] M. Igarashi, R. Sawa, N. Kinoshita, H. Hashizume, N. Nakagawa, Y. Homma,
Y. Nishimura, Y. Akamatsu, Pargamicin A, a novel cyclic peptide antibiotic from
Amycolatopsis sp, J. Antibiot. 61 (2008) 387–393.
[47] H. Hashizume, R. Sawa, K. Yamashita, Y. Nishimura, M. Igarashi, Structure and
antibacterial activities of new cyclic peptide antibiotics, pargamicins B, C and D,
from Amycolatopsis sp. ML1-hF4, J. Antibiot. 70 (2017) 699–704.
[48] C.S. Neumann, W. Jiang, J.R. Heemstra, E.A. Gontang, R. Kolter, C.T. Walsh,
Biosynthesis of piperazic acid via N5-hydroxy-ornithine in Kutzneria spp. 744,
Chembiochem 13 (2012) 972–976.
[49] Y.H. Du, Y.M. Wang, T.T. Huang, M.F. Tao, Z.X. Deng, S.J. Lin, Identification and
characterization of the biosynthetic gene cluster of polyoxypeptin A, a potent
apoptosis inducer, BMC Microbiol. 14 (2014) 30–42.
89