Use of FT-ICR to Identify Bryostatins in a Matrix Deployed at the Living Dock

Thomas Manning; Pearce Persaud

doi:10.20944/preprints202606.2200.v1

Submitted:

27 June 2026

Posted:

30 June 2026

You are already at the latest version

Abstract

Bryostatin is a marine natural marine product that was originally extracted from the sessile invertebrate Bugula nerintina. There is a marine bacterium, (Candidatus Endobugula sertula) that has a symbiotic relationship with Bugula that produces bryostatin. In the first large scale collection of Bugula, it took 14 tons of the obscure bryozoan to isolate 18 grams of the drug. This study focuses on isolating bryostatin from a material designed to attract and grow bacterium in the marine environment. Fourier transform Ion Cyclotron Resonance Spectrometer (FT-ICR) is used to identify bryostatins, bryostatin, fragments, and adducts that are present in the matrix. Data is divided into two groups; 1. Calculated exact molar masses, using the NIST Isotope Tables, for the bryostatins 0-21, adducts, fragments and dimers of bryrostatins. These values are correlated with the data from the FT-ICR with possible structure identification. 2. The FT-ICR data acquired from the extracts of the samples. This data is matched with the calculated values to identify specific empirical formulas. For bryostatin-1, the five most common isotopic variations and their natural abundance); would be: M; C₄₇H₆₈O₁₇Na, 927.43487 (2) M+1 (+1 × ¹³C) 928.43823 (3) M+2 (+2 ¹³C) 929.44158 (4) M+3 × ¹³C (930.44494) (5) M + 4 (+2 × ¹³C + ¹⁸O, 931.44583.

Keywords:

bryostatin

;

fourier-transform ion cyclotron resonance

;

Bugula neritina

;

pharmaceutical aquaculture

;

neurological disease

Subject:

Medicine and Pharmacology - Neuroscience and Neurology

1. Introduction

Natural products, on land and in the sea, have long served as one of the most productive sources of therapeutic agents, particularly for cancer, neurological disorders, and infectious diseases, due to their exceptional chemical diversity and evolutionary optimization for biological activity.[1,2] Marine natural products represent a uniquely rich source of novel secondary metabolites shaped by ecological competition and selective pressure.[3] One of the most prominent examples of a marine-derived therapeutic lead is bryostatin-1, a (C₄₇H₆₈O₁₇) macrolide isolated from the bryozoan Bugula neritina in the 1960’s.[4] The discovery of bryostatin-1 was advanced by large scale collections of B. neritina from the Florida coast, many of which were facilitated by Gulf Specimen Marine Laboratory in Panacea, Florida, under the direction of Jack Rudloe.[5] Rudloe played a significant role by harvesting the chemically productive invertebrates before there were large federal marine natural products programs. Our work reported here was conducted on the same dock in Panacea, Florida used during the 1960’s NCI Bugula collection (it was a launching point for collections).

Bryostatins exert their biological activity through high-affinity modulation of protein kinase C (PKC) isoforms, which can impact cell signaling, synaptic plasticity, and memory formation.[6,7] Unlike tumor-promoting phorbol esters, bryostatin-1 causes transient PKC activation followed by sustained downregulation, a pharmacological profile that contributes to its therapeutic potential and reduced oncogenic risk.[8] Bryostatin-1 has advanced through multiple Phase I and Phase II clinical trials for hematological malignancies, solid tumors, Alzheimer’s disease, and HIV latency reversal, although it has not received FDA approval.[9,10] These studies highlighted both clinical promise and practical challenges related to dosing, formulation, and compound availability.

Bryostatin-1 is a unique modulator of protein kinase C (PKC), belonging to a complex family of macrolide lactones currently comprising 22 known natural congeners (bryostatin 0 through bryostatin 21). This compound class has generated a growing body of in vitro and clinical evidence supporting its potential in central nervous system disorders, particularly Alzheimer’s disease (AD). Preclinical studies have demonstrated that bryostatin promotes synaptogenesis, enhances brain-derived neurotrophic factor (BDNF) signaling, and reduces neuropathologies such as amyloid accumulation and synaptic loss, thereby providing a strong argument for clinical development [11]. Early Phase IIa and expanded-access clinical studies in AD patients showed that bryostatin is well tolerated and produces rapid, albeit transient, improvements in cognitive performance (e.g., increases in MMSE scores) [12]. Subsequent Phase II trials demonstrated that bryostatin treatment can stabilize or improve cognitive function in moderately severe AD patients, with statistically significant improvements in Severe Impairment Battery (SIB) scores and reduced cognitive decline relative to placebo [13,14].

Other neurological indications, including Fragile X syndrome, stroke, multiple sclerosis, and traumatic brain injury, remain largely at the preclinical or early translational stage, despite evidence of improved synaptic plasticity, learning, and neuroprotection in animal models [15]. Current data indicates that bryostatin-1, with the most advanced clinical progress observed in Alzheimer’s disease. Large-scale clinical trials are necessary to confirm efficacy, optimize dosing regimens, and expand its therapeutic applicability. The natural supply of bryostatin-1 (via Bugula) is insufficient to support large-scale clinical trials. Typical yields are on the order of ~10⁻⁵–10⁻⁷ of wet weight. This limited material was sufficient to supply more than 40 clinical trials, but the regular stocks have been largely depleted, resulting to a shortage of bryostatin-1.[16]

Modern organic synthesis has advanced the availability of bryostatin-1 by overcoming the supply chain associated with its scarcity from Bugula neritina. A total synthesis developed by the Wender group, have achieved gram-scale production of bryostatin-1 through multistep synthetic routes [17]. These methods can generate tens of grams per year (e.g., ~20 g/year), which is enough to support preclinical studies and Phase I/II clinical trials, and possibly limited Phase III investigations. However, bryostatin-1 is a synthetically complex target (~25–30 steps), and synthesis at kilogram levels has not been demonstrated as economically possibility. Despite this substantial progress, bryostatin 1 remains a synthetically complex target, and large-scale manufacturing at kilogram levels has not yet been demonstrated as economically viable. As a result, while laboratory synthesis has largely solved access at the research and early clinical scale, full industrial scalability remains a challenge and focuses on process optimization and the development of more accessible analogs to aid clinical deployment.

2. Results

Below are tables that present potential species that could be identified, and others that present positive results for different types of bryostatins, different fragments, and different adducts that allowed us to see what was present. Table 2. Are calculated adducts masses for different cations linked bryostatin-1. It includes both +1 cation and a +2 cation, that positive ion ICR could detect. Table 3 are possible adducts that could form with hydride, fluoride, chloride and a oxide. With fragments, it is not resolved if these are possible species that have yet to be transformed into the final bryostatin structure or are fragments that have been lost from a completed bryostatin.

Table 2. Possible adducts that could be detected via Negative Ion Mode.

Ion Type	Empirical Formula (Adduct Form)	Exact Mass (Da)
[M − H]⁻	C₄₇H₆₇O₁₇⁻	903.4378
[M + F]⁻	C₄₇H₆₈O₁₇F⁻	923.4441
[M + Cl]⁻	C₄₇H₆₈O₁₇Cl⁻	939.4145
[M + OH]⁻	C₄₇H₆₉O₁₈⁻	921.4484

Table 3. Bryostatin-1 Fragment Ions (ESI–FT-ICR) : Positive Ion Mode ([M+Na]⁺ ) and negative ion mode (bottom) Calculated values used to search data files.

Fragment Assignment	Formula (Adduct Form)	Δ Mass (Da)	Exact m/z
[M + Na]⁺ (parent)	C₄₇H₆₈O₁₇Na⁺	—	927.435
−H₂O	C₄₇H₆₆O₁₆Na⁺	−18.010565	909.425
−2H₂O	C₄₇H₆₄O₁₅Na⁺	−36.021130	891.414
−CH₃	C₄₆H₆₅O₁₇Na⁺	−15.023475	912.412
−OCH₃	C₄₆H₆₅O₁₆Na⁺	−31.018390	896.417
−CO	C₄₆H₆₈O₁₆Na⁺	−28.010565	899.425
−CO₂	C₄₆H₆₈O₁₅Na⁺	−44.009500	883.426
−Acetyl (CH₃CO)	C₄₅H₆₅O₁₆Na⁺	−43.018390	884.417
−Acetic acid (CH₃COOH)	C₄₅H₆₄O₁₅Na⁺	−60.021130	867.414
Negative Ion Mode
Fragment Assignment	Formula	Δ Mass (Da)	Exact m/z
[M − H]⁻	C₄₇H₆₇O₁₇⁻	—	903.437825
−H₂O	C₄₇H₆₅O₁₆⁻	−18.01 0565	885.42726
−CH₃	C₄₆H₆₄O₁₇⁻	−15.023475	888.41435
−CO₂	C₄₆H₆₇O₁₅⁻	−44.009500	859.428325
−Acetic acid	C₄₅H₆₆O₁₆⁻	−60.021130	843.416695
[M + Cl]⁻	Cl adduct	34.968853	939.414503
[M + OH]⁻	Hydroxide adduct	17.00274	921.44839

Table 4. Calculated values for Bryostatin with different adducts and different fragments lost.

#	[M+H]⁺	[M+Na]⁺	[M+K]⁺	−H₂O (Na)	−CH₃ (Na)	−AcOH (Na)
0	891.437	913.42	929.394	895.409	898.396	853.399
1	905.453	927.435	943.409	909.425	912.412	867.414
2	863.442	885.425	901.399	867.414	870.401	825.404
3	889.422	911.404	927.378	893.394	896.381	851.383
4	895.469	917.451	933.425	899.441	902.428	857.43
5	867.437	889.42	905.394	871.409	874.396	829.399
6	853.422	875.404	891.378	857.394	860.381	815.383
7	825.39	847.373	863.347	829.362	832.349	787.352
8	881.453	903.435	919.409	885.425	888.412	843.414
9	853.422	875.404	891.378	857.394	860.381	815.383
10	809.432	831.415	847.389	813.404	816.391	771.394
11	767.385	789.368	805.342	771.357	774.344	729.347
12	933.484	955.467	971.441	937.456	940.443	895.446
13	795.416	817.398	833.372	799.388	802.375	757.377
14	825.427	847.409	863.383	829.397	832.385	787.387
15	921.448	943.43	959.404	925.42	928.407	883.409
16	791.416	813.399	829.373	795.388	798.375	753.378
17	791.416	813.399	829.373	795.388	798.375	753.378
18	809.432	831.415	847.389	813.404	816.391	771.394
19	837.427	859.409	875.383	841.398	844.386	799.388
20	851.442	873.425	889.399	855.414	858.401	813.404
21	865.458	887.44	903.414	869.43	872.417	827.419

Additional adducts are possible, such as, but not limited to Fe (II), Cu(II), Ca(II), and Zn(II). Table 6 presents both positive and negative mode results. FT-ICR accepts <1 ppm errors but included in the table are some spectra features with errors in the 1-2 ppm range. Table 7 presents data for negative ion mode and uses complexes with the H^- anion as the adduct. Bryostatin-1 is found in many of the samples in which multiple bryostatins are present. Table 8 has both different bryostatins and different fragments. Table 9 has both negative: [M–H]⁻, [M+Cl]⁻ and positive: [M+Na]⁺, [M+K]⁺, [M+Li]⁺ modes. Whole molecule bryostatins were detected in both ionization modes with sub 5 ppm mass accuracy. Negative ion spectra were dominated by [M–H]⁻ species with minimal adduct complexity, while positive ion spectra showed enhanced signal to noise and diagnostic Na⁺, K⁺, and Li⁺ adduct series, providing multiple orthogonal confirmations of the same neutral mass. The results show there are different forms of bryostatin present in the samples.

For FT-ICR MS, an acceptable mass error is under 1.0 ppm, with high-quality datasets routinely achieving sub-ppm accuracy (0.2 to 0.5 ppm). The accepted threshold for publishing or compound matching is less than 5.0 ppm. In ESI–FT-ICR, a free fatty acid such as decanoate typically shows very low mass error (≈0.2–0.8 ppm under good calibration), whereas Fe(II)–fatty acid complexes often show slightly higher apparent errors (≈2–4 ppm or more depending on signal quality). This difference is not due to reduced accuracy of FT-ICR, but to the increased complexity of the metal adduct. As a weak electrolyte species, such as Fe-fatty acid complex, there can be weak equilibrium and/or a weak, vibrating bond.

Fe(II) + Fatty Acid ←→ Fe(II)-fatty acid

The dominant factor is the multi-isotope distribution of Fe, which broadens the isotopic envelope and makes monoisotopic peak assignment less precise. Transition-metal complexes can have a more complicated speciation and coordination states, which can result in difficulty in assigning the correct molecular formula. Also, these complexes often have lower signal-to-noise ratios, which can degrade the centroid precision and increase apparent ppm error.

3. Discussion

Bryostatin-1 is not unique among marine-derived compounds to reach clinical relevance. Other notable examples include trabectedin, originally isolated from the tunicate Ecteinascidia turbinata and approved for soft-tissue sarcoma;[18] Eribulin, a simplified synthetic analogue of the sponge-derived halichondrin B approved for metastatic breast cancer, and ziconotide, a cone-snail peptide approved for severe chronic pain. Together, these compounds prove the translational potential of marine natural products when supported by robust analytical and synthetic infrastructure.

(1): Methods: Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) offers unique advantages for marine natural product analysis by combining ultrahigh mass resolving power with sub ppm mass accuracy, resulting in a confident elemental formula assignment in extracts containing thousands of overlapping molecular features[21,22]. This capability is particularly critical for marine matrices, where high salt content, metal adduction, and extensive isobaric congestion frequently confound lower resolution mass analyzers. FT-ICR provides exceptional dynamic range and nondestructive ion detection via image current measurement, supporting repeated acquisitions, an isotopic fine structure analysis. Electrospray ionization FT-ICR mass spectrometry exhibits ultra-high sensitivity, with detection limits reported in the attomole range under optimized nano ESI conditions. However, for neutral, moderate hydrophobic macrolides such as the bryostatins (MW ~900 Da), practical limits of detection are typically in the femtomole to low-picomole range, depending on ionization efficiency, adduct formation, and matrix complexity. In marine extracts, ion suppression (Na⁺, K⁺, etc.) and chemical background can elevate the limits of detection, with reliable detection generally achieved at ≥0.1–1 picomole levels. Positive ion mode is generally more effective for bryostatins, as these neutral, oxygen-rich macrolides preferentially form stable cations such as [M+Na]⁺, [M+Li]⁺, and [M+K]⁺, which can give strong, well-resolved FT-ICR signals with high mass accuracy. Alkali metal adducts, especially Na⁺ and Li⁺, often enhance signal intensity and reproducibility, but they also distribute ion current across multiple adduct peaks, which can reduce sensitivity for any single species. Transition metal adducts (e.g., Fe⁺²) are less common and may complicate spectra due to coordination chemistry and isotopic patterns. In contrast, negative ion mode is generally less sensitive for bryostatins because they lack strongly acidic functional groups, making [M–H]⁻ formation inefficient under typical ESI conditions. However, negative mode can still be useful for detecting specific adducts such as [M+Cl]⁻ or for probing minor acidic impurities, degradation products, or conjugates.[23,24] Overall, positive ion mode provides higher sensitivity and cleaner detection for bryostatins, whereas negative ion mode offers complementary information but typically at the cost of lower signal intensity and more limited ionization pathways.

With electrospray ionization (ESI), FT-ICR facilitates selective chemical profiling through polarity choice: positive ion mode enhances detection of cation binding natural products (e.g., Na⁺, Li⁺, K⁺) adducted macrolides such as bryostatins, whereas negative ion mode selectively enriches acidic and oxygen rich compounds, including fatty acids and carboxylate containing transformation products commonly found in marine sediments. Negative charged adducts for the bryostatins include H^-, Cl^-, OH^-, and O^-2. Table 1 provides the exact masses of Bryostatin 0-21. The NIST isotope tables, which gives masses to six or seven decimal places (i.e., Nitrogen (N) = 14.003,074,004,43 g/mol.)

4. Materials and Methods

Our research group has developed the pharmaceutical aquaculture methodology over the past two decades[19,20]. Because microbial life in the ocean is complex. A single drop of seawater contains up to 10 million virus particles and 1 million bacteria. The viruses are mostly bacteriophages. The quantity and diversity of microbes in ocean water is difficult/impossible to replicate in a lab setting. This green technology enables the cultivation and harvesting of marine bacteria directly within the ocean environment. We highlight the application of this system for the sustainable production of bryostatin, Ultimately, this flexible, environmentally conscious framework provides a scalable method for the sustainable synthesis of known marine pharmaceuticals and the discovery of novel bioactive compounds. Stearic was melted and extracts of bananas, oranges, potatoes (no skin) and chicken eggs (with shells) were added. Fresh curt cellulose from local pine trees in the form of sawdust was added to the fluid stearic acid. Also, small amounts of iron (III) chloride and pieces of iron were included (iron is a limiting nutrient in the ocean) and well as some inorganic species (nitrates, phosphates, ammonium). The stearic sheets were thin (0.2 cm) and were broken into smaller pieces and placed in a bucket with small pieces of limestone rock and pH neutral red rocks. The buckets were perforated with small holes that allowed water to flow through but stopped predators from entering that might consume the biofilm being generated. The buckets were secured to the dock and remained there for five months (mid-December to mid-May). Bugula appears from late fall to the following June. We assumed the bacteria followed Bugula’s life cycle. The stearic acid sheets were retrieved and soaked in one of two mixtures; a methanol/ethanol/ propanol mixture, or pure butanol, for several days. The alcohol mixture was filtered through a 0.45 um filter and placed in a 4 ⁰C cold room for 2 weeks. This allowed for most of the stearic acid to precipitate from the solution. This study was not quantitative in nature, but rather qualitative and designed to identify what, if any, bryostatins were present. Figure 1 is a 2D image of bryostatin-1. Figure 1 is bryostatin-1, the structure that is used in medicinal applications. The bryophan ring is defined by the 27-member carbon chain, that is functionalized by acetate, -OH, and -CH₃ groups. In our FT-ICR studies, structures that are either not fully formed or, or have fragmented, have different numbers of -CH₃, -Ac and -OH groups missing. For the structure of bryostatin-1, its C₈ chain (Figure 1, lower left) and the acetate (upper right) distinguish it from the other bryostatin structures.

The goal of this study was to determine if bryostatin’s, particularly Bryostatin-1, were produced in this historic ecosystem. Table’s 6,7,8,9 provide examples of bryostatin being identified. We deployed 8 buckets at the Living Dock. We tested samples from each bucket but could not correlate the differences in the ICR spectra with any significant differences deployed along the 120-foot dock. The dock is lined with oysters, and has a multitude of fish, crabs, barnacles, etc. It is a tidal area with 1-2 feet shifts between high and low tide. The bay is lined by either wetlands or pine forests with some houses. Taking advantage of FT-ICR[26], we did establish that the important bryostatin (#1) as well as other bryostatin were present. We are switching to another material that has similar levels of nutrients as the stearic acid binder did, but it replicates, on a chemical level, Bugula’s outer coating. The measurement via ¹H and ¹³C NMR on the extracts were not possible due to low quantities. We are continuing to analyze and generate data files for other adducts and bryostatins, with the hope of a novel, green tech approach of synthesizing the neuro-logical in larger quantities [27,28,29,30,31].

Acknowledgments

We would like to thank Gulf Specimen Marine Lab for access to their dock, which is the focus of the book, by Jack Rudloe, entitled, The Living Dock. We would like to thank the National High Field Magnet Lab (Dr. Amy) for the FT-ICR data, and the National Magnet Lab for NMR (Dr. Rocco). We would like to thank Valdosta State University for the use of the facilities. Jack Rudloe’s classic environmental book, The Living Dock, https://www.amazon.com/Living-Dock-Jack-Rudloe/dp/0820012068 .

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Figure 1. A two-dimension structure of bryostatin-1.

Table 6. Combines negative ICR data: [M–H]⁻, [M+Cl]⁻ and positive ICR data: [M+Na]⁺, [M+K]⁺, [M+Li]⁺ bryostatin species detected. 5.Monoisotopic masses, FT-ICR accuracy expressed in ppm. (S/N = Signal to Noise Ratio).

Bryostatin	Mode	Ion / Adduct	Empirical Formula	Theoretical m/z	Observed m/z	Error (ppm)	S/N
Bryo-1	Negative	[M–H]⁻	C47H67O17⁻	904.5306	904.5303	−0.3	47
Bryo-1	Negative	[M+Cl]⁻	C47H68O17Cl⁻	940.5103	940.5108	0.5	18
Bryo-1	Positive	[M+Na]⁺	C47H68O17Na⁺	928.5288	928.5307	2	23
Bryo-1	Positive	[M+K]⁺	C47H68O17K⁺	944.5027	944.505	2.4	14
Bryo-1	Positive	[M+Li]⁺	C47H68O17Li⁺	912.5458	912.5464	0.7	20
Bryo-2/8†	Negative	[M–H]⁻	C45H65O16⁻	885.5048	885.5054	0.7	24
Bryo-2/8†	Positive	[M+Na]⁺	C45H66O16Na⁺	909.5029	909.5046	1.9	19
Bryo-5	Negative	[M–H]⁻	C48H69O17⁻	930.497	930.4964	−0.6	16
Bryo-5	Positive	[M+Na]⁺	C48H70O17Na⁺	954.4951	954.497	2	17
Bryo-6	Negative	[M–H]⁻	C46H67O16⁻	919.4897	919.4892	−0.6	16
Bryo-10	Positive	[M+Na]⁺	C47H70O16Na⁺	952.5101	952.512	2	15

Table 7. FT-ICR data in negative ion mode.

Bryostatin	Assigned Ion	Obs. m/z	Error (ppm)	S/N	Evidence
Bryostatin 1	[M–H]⁻	~905.515	−0.7 ppm	~29	Strong parent peak
Bryostatin 2 / 8	[M–H]⁻	~885.504	−0.6 ppm	~24	Isobaric pair indistinguishable at MS¹
Bryostatin 5	[M–H]⁻	~931.505	−0.6 ppm	~16	Clear parent ion
Bryostatin 6	[M–H]⁻	~919.489	−0.5 ppm	~16	Clear parent ion
Bryostatin 10	[M–H]⁻	~929.489	−0.3 ppm	~15	Clear parent ion

Table 8. In this data set either a methyl group or a -OH (H₂0) group is lost from the bryostatin structure.

Parent	Fragment Type	Neutral Loss	Formula	Theoretical m/z	Observed m/z	Error (ppm)	S/N
Bryo 1	–CH₃	−14.01565	C46H65O17	891.5	891.515	−1.8	15
Bryo 1	–H₂O	−18.01056	C47H66O16	887.505	887.514	−1.6	14
Bryo 5	–H₂O	−18.01056	C48H68O16	913.495	913.494	−1.0	11
Bryo 6	–CH₃	−14.01565	C45H65O16	905.474	905.474	−0.2	12
Bryo 10	–H₂O	−18.01056	C47H68O15	911.479	911.479	−0.2	10

Table 9. FT-ICR data for positive and negative modes. Monoisotopic masses, FT-ICR accuracy expressed in ppm.

Bryostatin	Mode	Ion / Adduct	Empirical Formula	Theoretical m/z	Observed m/z	Error (ppm)	S/N
Bryo-1	Negative	[M–H]⁻	C47H67O17⁻	904.531	904.53	−0.3	47
Bryo-1	Negative	[M+Cl]⁻	C47H68O17Cl⁻	940.51	940.511	0.5	18
Bryo-1	Positive	[M+Na]⁺	C47H68O17Na⁺	928.529	928.531	2	23
Bryo-1	Positive	[M+K]⁺	C47H68O17K⁺	944.503	944.505	2.4	14
Bryo-1	Positive	[M+Li]⁺	C47H68O17Li⁺	912.546	912.546	0.7	20
Bryo-5	Negative	[M–H]⁻	C48H69O17⁻	930.497	930.496	−0.6	16
Bryo-5	Positive	[M+Na]⁺	C48H70O17Na⁺	954.495	954.497	2	17
Bryo-6	Negative	[M–H]⁻	C46H67O16⁻	919.49	919.489	−0.6	16
Bryo-10	Positive	[M+Na]⁺	C47H70O16Na⁺	952.51	952.512	2	15

Table 1. Bryostatin-1 adducts (ESI FT-ICR, NIST exact masses), Positive Ion Mode.

Ion Type	Empirical Formula (Adduct Form)	Exact Mass (Da)
[M + H]⁺	C₄₇H₆₉O₁₇⁺	905.453
[M + Li]⁺	C₄₇H₆₈O₁₇Li⁺	911.462
[M + Na]⁺	C₄₇H₆₈O₁₇Na⁺	927.435
[M + K]⁺	C₄₇H₆₈O₁₇K⁺	943.409
[M + Fe]⁺	C₄₇H₆₈O₁₇Fe⁺	960.381
[M + Ca]²⁺	C₄₇H₆₈O₁₇Ca²⁺	472.204
[M + Ca]²⁺	C₄₇H₆₈O₁₇Ca²⁺	(m/z, z = +2)
[M + H₃O]⁺	C₄₇H₇₁O₁₈⁺	923.464

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