LC-MS/MS-QTOF dataset of compounds detected in kelulut honey of the stingless bees, Heterotrigona itama and Tetrigona binghami from Kuantan, Pahang, Malaysia

Honey is a sustainable nutritious substance which has been incorporated into the human diet since ancient times for its health and remedial benefits. Stingless bee honey or kelulut honey (KH) is well-known in Malaysia and has received high demand in the market due to its distinctive unique flavour. Its composition, colour, and flavour are majorly affected by the geographical location, floral source, climate, as well as the bee species. This data article presents the nontargeted metabolite profiling of the extracts of KH of Heterotrigona itama and Tetrigona binghami bee species. The KH was collected from three nests in Kuantan, Pahang, which is situated in the east coast of Peninsular Malaysia. The extracts were prepared using sugaring-out assisted liquid-liquid extraction (SULLE) method and the Liquid Chromatography–Tandem Mass Spectrometry with Quadrupole Time-of-Flight, operated in the negative ion mode, was used to identify compounds in the extracts. The data processing revealed the presence of 35 known compounds in the KH1 extract by Heterotrigona itama collected from Bukit Kuin, 38 compounds in the KH2 extract by H. itama collected from Indera Mahkota, whilst 50 known compounds were present in KH3 extract by Tetrigona binghami species from Indera Mahkota. This data article contains the m/z values, retention times, and the METLIN database search hit identities of the compounds and their respective classes.


a b s t r a c t
Honey is a sustainable nutritious substance which has been incorporated into the human diet since ancient times for its health and remedial benefits. Stingless bee honey or kelulut honey (KH) is well-known in Malaysia and has received high demand in the market due to its distinctive unique flavour. Its composition, colour, and flavour are majorly affected by the geographical location, floral source, climate, as well as the bee species. This data article presents the nontargeted metabolite profiling of the extracts of

Value of the Data
• This dataset presented the chemical profiles of Kelulut honey of the stingless bees, Heterotrigona itama and Tetrigona binghami , collected from three locations in Kuantan region of the eastcoast Malaysia. • As honey composition can be impacted by geographical locations and stingless bee species [3 , 4] , this data provide information on the compositions of KH in this particular region which would greatly benefit the researchers of traditional and complementary medicine and natural products.
• This dataset would also be useful in postulating the potential bioactive compounds that may contribute to the numerous health benefits of KH. The health-promoting effects of KH have been linked to its biological properties such as its antioxidant, anti-inflammatory, anti-diabetic, anti-ageing, antimicrobial, anti-cancer, and hypolipidemic effects as demonstrated in many of the previous in vitro and in vivo studies [5 , 6] . All in all, these will aid in future identification of the KH potential biomarker with regard to any particular therapeutic applications.

Objective
Kelulut honey (KH) is a type of honey that derived from stingless bee with a distinctive unique flavour. KH is known to possess numerous biological activities such as anti-inflammatory, antioxidant, anti-diabetic, anti-ageing, antimicrobial, anti-cancer and also hypolipidemic effects [5 , 6] . There are approximately 500 stingless bee species which dwell in the warm and humid forests worlwide. KH composition and properties depend on the bee species, the floral sources and the nectar that the bees collected, storage conditions, environmental factors, processing methods and also the geographical origin; due to these factors, there were some variations found across KH samples from around the globe in terms of its composition [3 , 4] . As there are still a dearth of information regarding KH compositions from Malaysia, this study aimed to provide a dataset on the phytochemical compositions in KH which derived from two stingless bee species, Heterotrigona itama and Tetrigona binghami , collected from Kuantan region of the eastcoast Malaysia.  Tables 1 , 2 , and 3 . The raw data of all the identified compounds from the KH samples can be found in the Mendeley data repository at this link: http://dx.doi.org/10.17632/ w9wtvf52vd.1 [2] . After removing duplicate detection of similar compounds found in each extract, there were a total of 35 known compounds identified from KH1, followed by 38 known compounds identified from KH2, and 50 known compounds identified from KH3. Table 4 tabulates the variation in composition for a total of individual 110 compounds accross KH samples.

Sugaring-out assisted liquid-liquid extraction (SULLE)
The extraction of compounds from KH was performed according to the SULLE method adopted from Zhu et al. [1] . This method is rapid, easy to perform and can provide good extraction efficiency with less consumption of organic solvents and samples. Initially, a total of 0.5 g KH sample was added with 1 mL of acidified water (adjusted the pH to 2.0 using the concentrated hydrochloric acid solution), followed by a vigorous mix until the honey was completely dissolved. Then, 1 mL of acetonitrile was added and vortexed for 1 minute. The mixture was centrifuged (Eppendorf, Germany) at 40 0 0 rpm for 1 minute and the upper organic layer was collected. The chemical extraction using acetonitrile was repeated twice and the collected organic phase was dried in an incubator (TECH-LAB, Malaysia) at 40 • C overnight. To ensure the complete drying of acetonitrile, the dried extracted samples were further dried under gentle nitrogen flow for 1 hour. The extracts for KH1, KH2, and KH3 were then kept at 4 • C chiller (Samsung, Malaysia) prior to the subsequent chemical analysis.

Chemical profiling analysis using LC-MS QTOF
The chemical profiling of KH1, KH2, and KH3 was conducted using an Agilent 1290 Infinity LC system coupled to Agilent 6520 Accurate-Mass Q-TOF mass spectrometer with dual ESI source (Agilent Technologies Inc, USA) using the parameters shown in Table 5 . Each of the three extracted honey samples was dissolved with 200 μL of methanol/water solution (v/v, 1:1) before being injected into the column. One μL of each extracted sample was injected into an Eclipse XDB-C18 Narrow-bone column (150 mm x 2.1 mm, 3.5-micron, Agilent Technologies Inc, USA). A gradient system consisting of mobile phase A (0.1% formic acid in deionised water) and B (0.1% formic acid in acetonitrile) was used at the flow rate of 0.5 mL/min and column temperature of 25 °C. The total runtime was 25 min and the concentration gradient was varied as shown in Table 6 .

Data acquisition, processing, and reporting
Data was processed with the Agilent MassHunter Qualitative Analysis B.07.00 (Agilent Technologies, United States) software. The raw data of identified compound was processed and the tentative identification of the target compound was performed using the Agilent MassHunter METLIN Metabolomics Database and Library (Metlin_AM_PCDL-N-170502.cdb) by matching mass values with a match tolerance of 5 ppm.

Ethics Statement
This research work does not require ethical approval.