Seaweeds are abundant and are an important renewable resource for the coastal community since they are rich sources of minerals and natural bioactive compounds. Among them, the Caulerpa species under green seaweeds is widely consumed by locals in Southeast Asia. Edible seaweeds are often associated with various health benefits. However, in Malaysia, limited studies have been done on the mineral and antioxidant levels of seaweeds, especially for the Caulerpa species. Thus, the present study aimed to evaluate the variations of minerals and antioxidants of selected Caulerpa species in Malaysia. The samples were collected in two study sites, which were Blue Lagoon, Port Dickson and Merambong Shoal, Johor. Two species, C. racemosa and C. manorensis were recorded from Merambong Shoal, Johor, while five species were recorded namely C. sertularioides, C. racemosa var lamourouxii, C. lentillifera, C. racemosa var cylindracea and C. racemosa at Blue Lagoon, Port Dickson. Among all the Caulerpa species from both study sites, C. manorensis possessed the highest phosphorus content (139.54 mg/100g) while C. racemosa from both Merambong and Blue Lagoon Port Dickson's calcium (Ca) content was significantly highest at 2318.33-2406.66 mg/100g. All the Caulerpa species possessed high sodium (Na) content ranging 9338.30-21748.30 mg/100g. For micronutrients, the highest zinc content was recorded in C. manorensis (3.40 mg/100g) while the copper content was significantly highest in C. racemosa from Port Dickson (1.05 mg/100g). The methanol extract of C. sertularioides possessed phytochemical attributes of high antioxidant activity (DPPH EC50 = 24.16 mg/mL) with a high FRAP value being recorded in C. lentillifera (27.09 mg TE/100g). The TPC and TFC were highest in C. lentillifera with 57.95 mg GAE/100g and 1506.41 mg QE/100g respectively. The present study revealed that Caulerpa species contained constituents with significant mineral compositions and phytochemical attributes suitable for pharmaceutical and nutraceutical uses.

Rosmarinic acid (RA) is present in a broad variety of plants, including those in the Lamiaceae family, and has a wide range of pharmacological effects, particularly antioxidant activity. To extract RA from Orthosiphon stamineus (OS) leaves, a Lamiaceae plant, a suitable extraction process is necessary. The present study used a green extraction method of supercritical carbon dioxide (SCCO2) extraction with the addition of ethanol as a modifier to objectively measure and correlate the solubility of RA from OS leaves. The solubility of RA in SCCO2 was determined using a dynamic extraction approach, and the solubility data were correlated using three density-based semi-empirical models developed by Chrastil, del Valle-Aguilera, and Gonzalez. Temperatures of 40, 60, and 80 °C and pressures of 10, 20, and 30 MPa were used in the experiments. The maximum RA solubility was found at 80 °C and 10 MPa with 2.004 mg of rosmarinic acid/L solvent. The RA solubility data correlated strongly with the three semi-empirical models with less than 10% AARD. Furthermore, the fastest RA extraction rate of 0.0061 mg/g min−1 was recorded at 80 °C and 10 MPa, and the correlation using the Patricelli model was in strong agreement with experimental results with less than 15% AARD.

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The leaves of Melastoma malabathricum were dried and ultrasonicated to produce a high‐quality extract. The optimum drying temperature was determined to obtain the highest yield, total phenolics, and flavonoids, especially quercetrin content with antiradical capacity. The Midilli model could explain the drying kinetics satisfactorily. The effective diffusivity of moisture ranged between 2.16 and 10.22 × 10−11 m2s−1, and the activation energy was 49.81 kJ mol−1. The dried leaves were extracted under optimized conditions in terms of particle size, solid‐to‐solvent ratio, solvent concentration, extraction time, and ultrasonic amplitude of the ultrasound‐assisted system. The quadratic model was applied to predict reasonably the yield and quercetrin content in the extract.

Plants Zingiber officinale (ginger) and Zingiber zerumbet (lempoyang) of Zingiberaceae family have been traditionally used as treatment for stomach problems, nausea, vomiting, epilepsy, sore throat, muscular pains and several other disorders. In this study, essential oils from both plants were investigated for their efficacy on antibacterial activity against two Gram positive (Staphylococcus aureus, and Bacillus cereus) and two Gram negative (Pseudomonas aeruginosa and Escherichia coli) bacteria species using the disc diffusion assay. A zone of inhibition was compared with the standard antibiotic chloramphenicol, whilst a blank disc impregnated with the methanol was used as negative control. At concentration 20 mL/disc, Z. officinale essential oil produced zone of inhibition ranging from 16 to 36 mm, while Z. zerumbet essential oil produced zone inhibition ranging from 11 to 14 mm. These findings showed Z. officinale essential oil inhibited the growth of all tested bacteria with large zone of inhibition. The most susceptible bacteria was B. cereus while the lowest was P. aeruginosa. It can be concluded that, Z. officinale and Z. zerumbet essential oils might provide potential therapeutic agents against bacterial infection.