In this entreviewy, information about the common metabolites of the Callyspongia genus were grouped, as well as studies of the biological activity of these compounds. Through NMR data, 212 metabolites were identified from genus Callyspongia (15 species and Callyspongia sp.), belonging to classes such as polyacetylenes, terpenoids, steroids, alkaloids, polyketides, simple phenols, phenylpropanoids, nucleosides, cyclic peptides, and cyclic depsipep-tides. A total of 109 molecules have been reported with bioactive activity, mainly cytotoxic and antimicrobial (antibacterial and antifungal) action.
1. Introduction
The genus Callyspongia (Callyspongiidae) encompasses a group of demosponges including 261 described species, of which approximately 180 have been accepted after taxonomic reviews. The marine organisms of Callyspongia are distributed in tropical ecosystems, especially in the central and western Pacific, but also in the regions of the Indian, the West Atlantic, and the East Pacific Oceans. The reason for the interest in the genus Callyspongia is related to its potential production of bioactive compounds. In this review, we group the chemical information about the metabolites isolated from the genus Callyspongia, as well as studies of the biological activity of these compounds. Through NMR data, 212 metabolites were identified from genus Callyspongia (15 species and Callyspongia sp.), belonging to classes such as polyacetylenes, terpenoids, steroids, alkaloids, polyketides, simple phenols, phenylpropanoids, nucleosides, cyclic peptides, and cyclic depsipeptides. A total of 109 molecules have been reported with bioactive activity, mainly cytotoxic and antimicrobial (antibacterial and antifungal) action.
2. Chemical Aspects of Callyspongia species
NMR spectroscopy-based studies on Callyspongia unidentified species (Callyspongia sp.) along with other 15 identified species (C. abnormis, C. aerizusa, C. bilamellata, C. californica, C. diffusa, C. fibrosa, C. fistularis, C. flammea, C. implexa, C. lindgreni, C. pseudoreticulata, C. siphonella, C. spinosissima, C. truncata and C. vaginalis) resulted in the structural characterization of 212 isolated metabolites from different classes: polyacetylenes; terpenoids and steroids; alkaloids; simple phenols and phenylpropanoids; nucleosides; cyclic peptides and cyclic depsipeptides; polyketides; and miscellaneous.
These substances were described according to the extract used in the isolation, relevant structural characteristics, and the elucidation data based on NMR data. This information is presented in together with additional information such as chemical formula, type of metabolite, one-dimensional NMR data, geographic location, and references related to the compound obtention in Callyspongia species. Regarding the 1D NMR data, the chemical shifts, the solvent and frequency used in process, and the coupling constant of all compounds, were investigated. In addition, although NMR was the only spectroscopic information reported in this study, mainly due to the large volume of data, other techniques were used in the primary studies to support structural identification and elucidation, such as: specific rotation, X-ray crystallography, Thin-Layer Chromatography (TLC), melting point, two-dimensional NMR spectroscopy, Mass Spectrometry (EM), and spectroscopy in the infrared (IR) and ultraviolet (UV) regions.
2.1. Polyacetylenes
The polyacetylenes aikupikanynes A (
1), B (
2) and C (
3), D (
4), E (
5) and F (
6) and octahydrosiphonochalyne (
7) were isolated from methanol (MeOH) extract of
Callyspongia sp., a red sea sponge
[27][1]. Other metabolites were also isolated: callimplexen A (
8) from
Callyspongia implexa (MeOH/Dichloromethane (CH
2Cl
2) 1:1 extract)
[28][2]; callyberynes A (
9), B (
10) and C (
11) from
Callyspongia sp. (MeOH/CH
2Cl
2 3:1 extract)
[21][3];
9 and
11 from
Callyspongia truncata (MeOH extract)
[29][4]; and the diacetylene Callydiyne (
12) from
Callyspongia flammea (MeOH extract)
[30][5]. Polyacetylenes
1–
12 (
Figure 1) were elucidated by
1H and
13C NMR and have unsaturated hydrocarbon moieties associated with olefinic and alkynyl double and triple bonds, respectively. The only symmetrical compound is
12 and structures
4,
5 and
6 have characteristics of fatty acyls.
Figure 1. Structures of polyacetylenes isolated from Callyspongia species.
Six polyacetylene diols were obtained from studies based on
Callyspongia genus. 14,15-dihydrosiphonodiol (
13), Callyspongidiol (
14) and siphonodiol (
15) were isolated from Ethyl acetate (EtOAc) extract of
Callyspongia sp.
[31][6];
13 and
15 from ethanol (EtOH) extract of
Callyspongia lindgreni [32][7]; from these later, only
15 from
Callyspongia lindgreni (CH
2Cl
2 extract)
[33][8] and
Callyspongia truncata (MeOH extract)
[29][4]. Two isomeric structures were isolated from
Callyspongia sp. (EtOH extract): (3
S,18
S,4
E,16
E)-eicosa-1,19-diyne-3,18-diol-4,16-diene (
16a) and (−)-(4
E,16
E)-icosa-4,16-diene-1,19-diyne-3,18-diol (
16b). Compound
16a has also been identified in
Callyspongia pseudoreticulata (MeOH extract)
[34,35][9][10]. In addition, callyspongendiol (
17) was isolated from
Callyspongia siphonella (CH
2Cl
2/MeOH 1:1 extract)
[8[11][12],
36], and Tetrahydrosiphonodiol (
18) from
Callyspongia lindgreni (EtOH extract)
[32][7]. Polyacetylene Diols
13–
18 are open chain unsaturated hydrocarbons (
Figure 1) that have their structures elucidated by
1H and
13C NMR. The regiochemistry patterns for the two hydroxyls in the structures vary considerably depending on the metabolite, having close proximity in
13,
14,
15 and
18. Isomers
16a and
16b are the only structures with symmetric atom connectivity; they differ from each other according to the configuration of stereogenic centers.
A total of 12 polyacetylene alcohols were obtained from
Callyspongia species: (3
R,4
E,28
Z)-hentriacont-4,28-diene-1,23,30-triyn-3-ol (
19), Callyspongenols A (
20), B (
21), C (
22) and D (
23), Callysponynes A (
24) and B (
25), dehydroisophonochalynol (
26), siphonellanols A (
27), B (
28) and C (
29) and siphonchalynol (
30) (
Figure 1). Studies involving
Callyspongia sp. afforded different metabolites depending on the solvent used in the extraction: acetone (
19)
[37][13], MeOH/CH
2Cl
2 1:1 (
20–
22 and
26)
[38][14] and EtOAc (
24 and
25)
[39][15] extracts; while those related to
Callyspongia siphonella were obtained from MeOH/CH
2Cl
2 1:1 (
23 and
26)
[8,36][11][12] and MeOH (
26–
30)
[40][16] extracts. The polyacetylene alcohols were elucidated by
1H and
13C NMR, but only
19–
29 present elucidative data.
Studies involving
Callyspongia truncata resulted in obtaining the acetylenic sulfate fatty acid callysponginol sulfate A (
31) from a mixture of H
2O, MeOH, CHCl
3, and EtOAc extracts
[41][17]. The methanolic extract provided callyspongins A (
32) and B (
33)
[29[4][18],
42], as well as callytriols A (
34), B (
35), C (
36), D (
37), and E (
38)
[29][4]. The polyacetylene lipids callyspongynes A (
39) and B (
40) were also isolated from an ethanolic extract of
Callyspongia sp.
[43][19]. The metabolites
32–
40 were elucidated by
1H and
13C NMR and have an oxygenated and unsaturated aliphatic structure with double and triple bonds (
Figure 1). Compounds
32 and
33 are derived from siphonodiol and along with
31 are classified as sulfated compounds. Metabolites
34–
38 have three hydroxyls, while
39 and
40 are simple monoalcohol.
Four metabolites were isolated from ethanolic extracts from different species: (6
Z,9
Z,12
Z,15
Z)-1,6,9,12,15-octadecapenten-3-one (
41) (
Callyspongia sp.)
[17][20], (4
Z,7
Z,10
Z,13
Z)-4,7,10,13-hexadecatetraenoic acid (
42) (
Callyspongia sp.)
[17][20], petroselenic acid (
43) (
Callyspongia siphonella)
[7][21], and callyspongynic Acid (
44) (
Callyspongia truncata)
[44][22]. In addition, glycerolipid 3-octadecyloxy-propane-1,2-diol (
45) was obtained from 95% EtOH + MeOH/CH
2Cl
2 1:1 extracts
[45][23], and batyl alcohol (
46) from methanolic extract, both from
Callyspongia fibrosa [23][24]; the polyacetylenic amide callyspongamide A (
47) was isolated from
Callyspongia fistularis (MeOH/CH
2Cl
2 1:1 extract)
[46,47,48][25][26][27]. Among the elucidated compounds, only
41,
44,
45, and
47 have
1H and
13C NMR data reported. Compound
46 was characterized by
1H NMR only, while
41 and
44–
47 present the spectroscopic data. The metabolites are structurally distinct, but some similarities are visible (
Figure 1). Substance
41 has a conjugated ketone system, while
42–
44 have carboxyl groups, among which
44 also has a hydroxyl unit. Glycerolipids
45 and
46 are the only saturated compounds having hydroxyls and ether oxygen, with the only structural difference between them being the presence of an additional methylene unit in
45. Double and triple bonds, an aromatic unit, and an amide form compound
47.
2.2. Terpenoids and Steroids
The diterpenes callyspinol (
48) and isocopalanol (
49) were isolated, respectively, from
Callyspongia spinosissima (MeOH extract)
[49][28] and
Callyspongia sp. (acetone extract)
[50][29]. Compounds
48 and
49 were elucidated by
1H and
13C NMR and are structurally different (
Figure 2):
48 has only one ring and a double bond, and is monooxygenated, while
49 has a three-membered ring and is saturated and polyoxygenated. Four
Callyspongia sp. triterpenes were also isolated: akaterpin (
50) from an acetone extract
[51][30] and ilhabelanol (
51), ilhabrene (
52), and isoakaterpin (
53) from an extraction with EtOH followed by MeOH
[11][31]. The molecules
50–
53 (
Figure 2) were characterized by
1H and
13C NMR and they are oxygenated, sulfated, and formed by cyclic and aromatic units.
Figure 2. Structures of terpenoids and steroids from Callyspongia species.
A total of 38 sipholane triterpenoids were isolated from
Callyspongia sipholena (
Siphonochalina Siphonela): (2
S,4a
S,5
S,6
R,8a
S)-5-(2-((1
S,3a
S,5
R,8a
S,
Z)-1-hydroxy-1,4,4,6-tetramethyl-1,2,3,3a,4,5,8,8a-octahydroazulen-5-yl)-ethyl)-4a,6-dimethyloctahydro-2H-chromene-2,6-diol (
54)
[52][32]; dahabinone A (
55)
[53][33]; neviotives A (
56)
[54[34][35][36][37],
55,56,57], B (
57)
[53][33], C (
58)
[55][35], and D (
59)
[57][37]; sipholenols A (
60)
[7[21][11][38][35][36][37][39][40][41][42],
8,25,55,56,57,58,59,60,61], B (
61)
[61][42], C (
62)
[61][42], D (
63)
[61][42], E (
64)
[61][42], F (
65)
[53][33], G (
66)
[53][33], H (
67)
[53][33], I (
68)
[59][40], J (
69)
[52][32], K (
70)
[52][32], L (
71)
[55][35], L (
72)
[8[11][32][36],
52,56], M (
73)
[52][32], N (
74)
[57][37], and O (
75)
[57][37]; sipholenones A (
76)
[7[21][11][38][35][36][39][40][41][42],
8,25,55,56,58,59,60,61], B (
77)
[61][42], C (
78)
[61][42], D (
79)
[53][33], and E (
80)
[52][32]; sipholenosides A (
81)
[53][33] and B (
82)
[53][33]; siphonellinol (
83)
[62][43] and siphonellinols B (
84)
[53][33], C (
85)
[59][40], C-23-hydroperoxide (
86)
[52][32], D (
87)
[52[32][37],
57], and E (
88)
[52][32]. The extracts studied were: EtOAc (
54,
60,
69,
70,
72,
73,
76,
80, and
86–
88), EtOAc/MeOH 1:1 (
55,
57,
65–
67,
79,
81–
82, and
84), petroleum ether (
60–
64,
76–
78, and
83), chloroform (
56), CH
2Cl
2/MeOH 1:1 (
56,
58,
60,
71,
72, and
76), MeOH (
60,
68,
76, and
85), EtOH (
56,
59,
60,
74–
76, and
87) and EtOH 70% (
56,
60,
72, and
76) extracts. Molecules
63 and
67 present elucidating
1H NMR data, and the other metabolites are fully characterized by both
1H and
13C NMR. Sipholane triterpenoids have distinct structures (
Figure 2 ), which are composed of monocyclic and polycyclic rings, unsaturation, epoxy oxygen, ether, alcohol, and carbonyls.
Fifteen sterols were isolated from
Callyspongia species: 24
S-24-methyl-cholestane-3
β,5
α,6
β,25-tetraol-25-mono acetate (
89), 24
S-24-methyl chelestane-3
β,5
α,6
β,12
β,25-pentaol-25-
O-acetate (
90), 24
S-24-methyl cholest-25-ene-3
β,5
α,6
β,12
β-tetrol (
91), 24
S-24-methyl cholestane-3
β,6
β,25-triol-25-
O-acetate (
92), 24S-24-methyl cholestane-3
β,6
β,8
β,25-tetraol-25-
O-acetate (
93) and 24
S-24-methylcholesterol (
94),
5α-cholestanone (
95), callysterol (
96 and
97) or ergosta-5,11-dien-3
β-ol (
97), cholestenone (
98), Stigmasta-4,22-dien-3,6-dione (
99), stigmasterone (
100), gelliusterol E (
101),
β-sitosterol (
102), siphonocholin (
103), and ergosta-5,24(28)-dien-3
β-ol (
104). The obtainment of these metabolites is associated with the following extracts:
89–
94 to MeOH extract from
Callyspongia fibrosa [23][24];
95,
96 [7][21],
98–
100 [7][21], and
103 [63,64][44][45] to EtOH extract from
Callyspongia siphonella;
97 [19][46] and
104 [8][11] to MeOH/CH
2Cl
2 1:1 extract from
Callyspongia siphonella and,
101, and
102 to MeOH/CH
2Cl
2 1:1 extract from
Callyspongia implexa [28][2]. Compounds
89–
94,
97, and
101 were elucidated by
1H and
13C NMR, while remaining compounds of this set do not present NMR data, but are compared with information from other studies. These compounds are four-ring sterols (
Figure 2), with
89–
103 being formed by three six-membered rings and one of five, while in
104 a four six-membered ring system is present.
2.3. Alkaloids
Several alkaloids were isolated and properly characterized from
Callyspongia species. The bromopyrrole alkaloids 2-bromoaldisine (
105), callyspongisines A (
106), B (
107), C (
108), and D (
109) and hymenialdisine (
110) were obtained from the hydroalcoholic extract from
Callyspongia sp.
[65][47]. The bicyclic structures of compounds
105–
110 were elucidated by
1H and
13C NMR and are formed by a seven-membered cyclic amide and a pyrrole attached to a bromine atom (
Figure 3).
Figure 3. Structures of alkaloids isolated from Callyspongia species.
Some alkaloids were obtained from EtOH 95% extract of
Callyspongia sp.: callyimine A (
111)
[18][48], callylactam A (
112)
[18][48], clathryimine B (
113)
[18][48], 3-(2-(1
H-indol-3-yl)-2-oxoethyl)-5,6-dihydropyridin-2(1
H)-one (
114)
[18][48], 3-(2-(4-hydroxyphenyl)-2-oxoethyl)-5,6-dihydropyridin-2(1
H)-one (
115)
[18][48], (1
R,3
R)-1-methyl-2,3,4,9-tetrahydro-1
H-pyrido[3,4-b]indole-3-carboxylic acid (
116a)
[66][49], (1
R,3
S)-1-methyl-2,3,4,9-tetrahydro-1
H-pyrido[3,4-b]indole-3-carboxylic acid (
116b)
[66][49], C
2-
α-
D-mannosylpyranosyl-tryptophan (
117)
[66][49], Ethyl 2-(1
H-indol-3-yl) acetate (
118)
[67][50], and the indol derivative 1
H-indole-3-carbaldehyde (
119)
[67][50] (
Figure 3). Molecules
111 and
113 are structurally similar due to the presence of aromatic rings and nitrogen as a heteroatom, while
112 and
115 are only differentiated by the presence of a hydroxyl group in
115; and the structures
114 and
116a-
119 are formed by an indol heterocycle. Metabolites
111–
119 not present NMR data, but compare with information from others studies.
The isomers 5-bromo trisindoline (
120) and 6-bromo trisindoline (
121) were isolated from the ethanolic extract of
Callyspongia siphonella [7][21], and they are differentiated by the position of bromine in the aromatic ring of the indole unit of the molecules. In addition, from
Callyspongia sp. were isolated the untenines A (
122), B (
123), and C (
124), from the methanolic extract
[68][51], and niphatoxin C (
125), from the mixture of CH
2Cl
2/MeOH 4:1 and MeOH extracts
[69][52]. The
122–
125 structures have the pyridine group in the molecule. Metabolites
120–
125 (
Figure 3) were determined by
1H and
13C NMR.
Studies of some sponges
Callyspongia sp. resulted in the isolation of Callysponine (
126), cyclo-(
S-Pro-
R-Tyr) (
127), cyclo-(
S-Pro-
R-Val) (
128), cyclo-(
S-Pro-
R-Ala) (
129), cyclo-(
S-Pro-
R-Leu) (
130), callysponine A (
131), cyclo-(Gly-Pro) (
132), cyclo-(Ile-Pro) (
133), cyclo-(Pro-Pro) (
134), cyclo-(Thr-Pro) (
135), cyclo-(
R-Pro-6-hydroxyl-
R-Ile) (
136), cyclo-(
R-Pro-
R-Phe) (
137), cyclo-(
R-Tyr-
R-Phe) (
138), cyclo-(
S-Pro-
S-Phe) (
139), Staphyloamide A (
140), dysamide A (
141), callyspongidipeptide A (
142), cyclo-((
S)-Pro-(
R)-Ile) (
143), seco-((
S)-Pro-(
R)-Val) (
144), (3
R)-methylazacyclodecane (
145), and callyazepin (
146) (
Figure 3). The analyzed metabolites were obtained from the following extracts: EtOH for
126–130 [70][53] and
141 [6][54], EtOH 95% for
129 and
130 [66,71][49][55],
136–
140 [66][49] and
142–
144 [71][55], EtOH/H
2O 9:1 for
131–
135 [72[56][57][58][59][60][61][62][63],
73,74,75,76,77,78,79], and MeOH + CH
2Cl
2 for
145 and
146 [5][64]. Only
126,
130,
131,
136,
141,
142, and
144–
146 present
1H and
13C NMR data. The structures of
138,
141,
144, and
145 are monocyclic, while
126–
137,
139,
140,
142,
143, and
146 are bicyclic.
3. Biological Aspects of Metabolites Isolated in Callyspongia species
3.1. Polyacetylenes
The aikupikanynes E (
5) and F (
6) from
Callyspongia sp. showed moderate activity (with IC
50 values of 5 and 10 μg/mL) against the cancer cell lines studied
[27][1]. Other polyacetylenes obtained from
Callyspongia truncata showed a potent metamorphosis-inducing activity in the ascidian
Halocynthia roretzi larvae (with ED
100 values of 0.13–1.3 μg/mL) for
9,
11,
15, and
32–
38, and antifouling activity against the barnacle
Balanus amphitrite larvae (with ED
50 values of 0.24–4.5 μg/mL) for
15 and
32–
38 [29][4]. In addition, the inhibitory effect of the fertilization of starfish gametes of
32 and
33 in concentrations of 6.3 and 50 μM, respectively,
[42][18].
Three polyacetylene diols were isolated from
Callyspongia sp. and have driving Th1 polarization and antiproliferative effect against HL-60 (IC
50 values: 6.5 μg/mL for
13,
14 and 2.8 μg/mL for
15) and HCT-15 (IC
50 values: 21 μg/mL for
13, 22 μg/mL for
14 and 34 μg/mL for
15)
[31][6].
13,
15 and
18 exhibited strong inhibitory activity against gastric H,K-ATPase (IC
50 1.0 × 10
−5 M)
[32,96][7][65]. The
16a and
16b isomers are weakly cytotoxic, with IC
50 values of 0.47 for
16a natural, 1.5 (± 0.29) for
16a synthetic, 0.11 for
16b natural and 0.35 (± 0.13) for
16b synthetic against TR-LE and 1.8 (± 5.0) for
16a and 5.3 (± 1.1) for
16b synthetics against HeLa
[35][10]. Other activities have been attributed to siphonodiol (
15): medium antibacterial effect against
S. aureus (MIC 12.5 μg/mL) and
S. pyrogenes C-203 (MIC 6.2 μg/mL), and weak antifungal activity against
T. asteroids (MIC 25.0 μg/mL)
[33,96][8][65].
The metabolites
17 and
23 from
Callyspongia siphonella proved to be weakly cytotoxic active against HCT-116. In addition,
17 and
26 were found to be weak cytotoxic against cells of MCF-7 with IC
50 values of 65.7 and 73.6 μM, respectively, while
23 (IC
50: 11.7 μM) presented greater activities
[36][12].
The compound (3
R,4
E,28
Z)-hentriacont-4,28-diene-1,23,30-triyn-3-ol (
19) has been reported to be cytotoxic against the NBT-II cell line at concentrations of 5 and 10 μg/mL
[37][13]. The metabolites
20–
22 and
26 are moderately cytotoxic against the P388 cell lines (IC
50 values in μg/mL: 2.2 for
20,
22, and
26 and 10.0 for
21) and HeLa (IC
50 values in μg/mL: 4.5 for
20, 10.0 for
21, 3.9 for
22, and 5.1 for
26)
[38][14]. Cytotoxic compounds
26–
30 also have moderate activity against HeLa (IC
50 values 23.9–26.5 μM), MCF-7 (IC
50 values 54.9–69.2 μM), and A549 (IC
50 values 58.5–63.4 μM) cell lines
[40][16]. In vitro cytotoxicity activities of compounds
24 and
25 were evaluated and verified to fight MOLT-4 cell lines (IC
50 values: 1.9 μM for both), K-562 (IC
50 values 5.6–6.1 μM), and HCT 116 (IC
50 values 5.4–7.0 μM), only
24 against T-47D (IC
50 value: 8.9 μM) and
25 against MDA-MB-231 (IC
50 value: 9.9 μM)
[39][15].
Two interesting compounds were isolated from
Callyspongia truncata, the Callysponginol sulfate A (
31), which was found to inhibit MT1-MMP with an IC
50 of 15.0 μg/mL
[41][17], and Callyspongynic Acid (
44), a α-glucosidase inhibitor with an IC
50 of 0.25 μg/mL
[44][22]. The glycerolipid Batyl alcohol
46 showed biofilm inhibition capacity for
Alteromona macleodii,
Ochrobactrum pseudogrignonense,
Vibrio harveyi, and
Staphylococcus aureus at 0.5 and 0.025 mg/mL
[97][66]. The polyacetylenic amide callyspongamide A (
47) was shown to be moderately cytotoxic against HeLa (IC
50 of 4.1 μg/mL)
[46][25].
3.2. Terpenoids and Steroids
The metabolites
60,
72,
76, and
104, from
Callyspongia siphonella, proved to be weakly cytotoxic active against HCT-116, but
60,
72, and
76 were found to have moderate activity (at the respective IC
50 values of 14.8 ± 2.33, 19.8 ± 3.78, and 95.8 ± 1.34 μM)
[8][11]. In addition,
60 presented high cytotocix activity against cells of MCF-7 with IC
50 values of 8.8 μM
[36][12]. The effects on Reversing P-gp-Mediated MDR to colchicine involving the KB-3-1 cell lines were also tested (IC
50 values in μM: 5.6 ± 0.5 for
54, 4.8 ± 0.1 for
60, 5.1 ± 0.3 for
72, 4.7 ± 0.3 for
73, 4.7 ± 0.4 for
80, 4.2 ± 0.1 for
87 and 4.6 ± 0.6 for
88) and KB-C2 (IC
50 values in μM: 390 ± 40 for
54, 140 ± 30 for
60, 150 ± 10 for
72, 780 ± 60 for
73, 62 ± 11 for
80, 180 ± 10 for
87 and 560 ± 50 for
88)
[52][32].
The isocopalanol (
49) showed inhibition ability for the PANC-1 cell line with an IC
50 of 0.1 μg/mL
[50][29]. akaterpin (
50) has been proven to inhibit PI-PLC (IC
50 of 0.5 μg/mL) and neural sphingomyelinase (IC
50 of 30 μg/mL)
[51][30]. The sulfated meroterpenoids
51–53 are inhibitors of L-APRT at IC
50 of 0.7, 0.7 and 1.05 μM, respectively,
[11][31].
The metabolites
56,
58,
60, and
71 showed activity against PC-3 (IC
50 7.9 ± 0.12–71.2 ± 0.34 μM) and A549 (IC
50 8.9 ± 0.01–87.2 ± 1.34 μM) cell lines, with compound
60 being the most active
[55][35]. The cell lines MCF-7 (IC
50 3.0 ± 0.4–19.2 ± 0.6 μM) and HepG-2 (IC
50 2.8 ± 0.4–18.7 ± 0.9 μM) were tested for
56,
60,
71, and
76, and
76 had the most significant effect
[56][36] (also obtained MCF-7 IC
50 values of 1.162 for
60 and 0.9 μM for
76 [58][39]). In the same study, antiviral activity against HAV-10 was also weak for
56 and
71 (which also showed weak effectiveness against HSV-1) and moderate for
60 [56][36] (
60 is an inhibitor of P-gp too)
[98][67]. In addition, the antimicrobial activities of
56 and
71 were measured , in which
56 obtained the greater result (12.7 ± 0.58–17.2 ± 0.58 mm) and
71 obtained a moderate one against gram positive bacteria only (12.3 ± 0.72–14.5 ± 0.72 mm)
[56][36]. Compounds
56 and
59 also strongly inhibit RANKL-induced osteoclastogenesis with IC
50 values of 32.8 and 12.8 μM, respectively,
[57][37].
Sipholenol A (
60) and sipholenone A (
76) exhibited antiproliferative activity against +SA mouse mammary epithelial cells. While compound
76 was found to be a potential inhibitor (IC
50 20–30 μM),
60 had lower activity (IC
50 70 μM)
[58][39]. Substances
60 and
76, in addition to
85, showed Reversal effects for KB-C2
[59][40], and
76 had both anti-angiogenic activity in CAM assay (0.026 μM per pellet)
[58][39] and antibacterial activity
[56][36]. In another study, substances
89–
92 were associated with moderate antimalarial activity against
Plasmodium falciparum [23][24], in which
89 showed the best result. Callysterol (
97) showed an anti-inflammatory effect
[19][46] and cholestenone (
98) had an anti-metastatic effect on lung adenocarcinoma
[98,99][67][68]. Gelliusterol E (
101) inhibited the formation and growth of
chlamydial trachomatis (IC
50 value 2.3 μM)
[28][2], and siphonocholin (
103) inhibited the production of violacein, being an Anti-QS and Anti-biofilm compound
[63][44]. β-Sitosterol (
102) was found to exhibit anthelminthic
[100][69], antimutagenic (at 0.5 mg/kg inhibited the mutagenicity of tetracycline)
[100][69], angiogenic
[101][70], antibacterial
[102[71][72][73],
103,104], antifungal against
Fusarium spp.
[104][73], antidiabetic
[102[71][74],
105], analgesic
[100,106][69][75], antipyretic
[107][76], anti-inflammatory
[100[69][75][76][77][78][79][80][81][82][83],
106,107,108,109,110,111,112,113,114], cytotoxic
[108[77][78][79][80][81][82][83],
109,110,111,112,113,114], hypocholesterolemic
[115][84], and immunomodulatory activities
[116][85].