Identification of the key flavonoid and lipid synthesis proteins in the pulp of two sea buckthorn cultivars at different developmental stages.

BACKGROUND: Sea buckthorn is an economically important woody plant for desertification control and water soil conservation. Its berry pulp is rich in flavonoids and unsaturated fatty acids. Cultivars containing high oil and flavonoid contents have higher economic value and will increase in the planting area. However, the cause of the differences in oil and flavonoid contents among cultivars is still unclear. The influence of key enzymes in the lipid and flavonoid synthesis pathways on their content needs to be explored and clarified. RESULTS: The flavonoid content in XE (Xin'e 3) was 54% higher than that in SJ (Suiji 1). Rutin was the main flavonoid in sea buckthorn pulp, and the differences in the rutin content could cause flavonoid differences between the two cultivars. The oil content of XE was 31.58% higher than that of SJ, and the difference in oil content was highest at 50-70 DAF. High-throughput proteomics was used to quantify key enzymes of flavonoid and lipid synthesis pathways in two cultivars at three developmental stages. By functional annotation and KEGG analysis, 41 key enzymes related to phenylpropanoid biosynthesis, flavonoid biosynthesis, flavone and flavonol biosynthesis, fatty acid biosynthesis and TAG biosynthesis were quantified. CHS, F3H, ANS, fabD, FATA, FAB2, LPIN and plcC showed significant differences between the two cultivars. In addition, we quantified 6 oleosins. With the exception of a 16 kDa oleosin, the other oleosins in the two cultivars were positively correlated with oil content. CONCLUSIONS: In the flavonoid synthesis pathway, CHS and F3H were the main enzymes responsible for the difference in flavonoid content between the two cultivars. In the lipid synthesis pathway, LPIN, plcC and MGD were the main enzymes with different contents in the middle to late stages. Higher contents of LPIN and plcC in XE than in SJ could cause DAG to generate TAG from PC, since the difference in DGAT between the two cultivars was not significant. Investigating the causes of flavonoid and oil content differences among different cultivars from the perspective of proteomics, could provide a basis for understanding the regulatory mechanism of flavonoids and lipid synthesis in sea buckthorn pulp.

[Research progress on chemical constituents and pharmacological activities of seabuckthorn and prediction of its Q-markers].

Seabuckthorn contains flavonoids, tannins, terpenoids, polysaccharides, and vitamins, which have anti-inflammation,anti-oxidation, liver protection, anti-cardiovascular disease, anti-aging, immune enhancing, anti-tumor, and anti-bacterial activities.We reviewed the papers focusing on the chemical constituents, pharmacological activities, and utilization of seabuckthorn. The quality markers(Q-markers) of seabuckthorn were predicted and analyzed based on original plant phylogeny, chemical composition correlation, traditional medicinal properties, pharmacodynamic correlation, traditional and extended efficacy, pharmacokinetics, metabolic processes, and measurable components. With this review, we aim to provide theoretical reference for the quality control and quality standard establishment of seabuckthorn, so as to promote the rational exploitation and utilization of seabuckthorn resources, and improve the healthy and sustainable development of seabuckthorn industry.

Inhibitory effects of the constituents of Hippophae rhamnoides on 3T3-L1 cell differentiation and nitric oxide production in RAW264.7 cells.

Three new flavonol glycosides, hippophaeosides A-C (1-3), together with 27 known constituents, were isolated from Hippophae rhamnoides L. leaves. Their structures were determined by spectroscopic analyses. Their inhibitory activities on 3T3-L1 preadipocyte differentiation and triglyceride accumulation in maturing adipocytes, and nitric oxide production in RAW264.7 cells were examined.

Identification and Characterization of the Bioactive Polyphenols and Volatile Compounds in Sea Buckthorn Leaves Tea Together With Antioxidant and α-Glucosidase Inhibitory Activities.

Sea buckthorn leaves have been used for tea making in food field gradually. This study was carried out to characterize the bioactive polyphenols and volatile compounds in sea buckthorn leaves (SL), sea buckthorn leaves green tea (SGT), and sea buckthorn leaves black tea (SBT) by using high-performance liquid chromatography with an UV detector (HPLC-UV), the liquid chromatography-mass spectrometry (LC-MS), and headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS), in combination with multivariate analysis. A total of 48 non-volatile metabolites and 295 volatile metabolites were identified. Then, the total polyphenol and total flavonoid contents in SL, SGT, and SBT were also analyzed. Moreover, SL and SGT showed greater antioxidant activities based on 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), and oxygen radical absorbance capacity (ORAC) results. At the concentration of 0.1 mg/ml, their DPPH and ABTS radical scavenging ratios were 66 to 95%, while SBT exhibited lower antioxidant activity of 26 to 44%. SL, SGT, and SBT displayed moderate α-glucosidase inhibitory activity.

Nontargeted metabolomic and multigene expression analyses reveal the mechanism of oil biosynthesis in sea buckthorn berry pulp rich in palmitoleic acid.

Sea buckthorn berry pulp (SBP) oil is abundant in palmitoleic acid (C16:1). However, metabolic mechanisms of oil biosynthesis in SBP (non-seed tissues) are not clear. Thus, comparative nontargeted metabolomic analysis of the four developmental stages of berry pulp in two lines, Za56 and TF2-36, was performed. The results revealed that glycerol-3-phosphate (G3P) was critical for high oil accumulation in the mid-early developmental stages. In particular, the metabolism of phosphatidylcholine (PC) (16:0/16:0), PC (16:0/16:1), and PC (16:1/16:1) was also significantly altered. Sufficient supply of G3P and 16:1-CoA, coupled with upregulated expression of the glycerol-3-phosphate dehydrogenase (GPD1) and delta-9 desaturase (Δ9D) genes, were associated with high oil content enriched in C16:1 in SBP. Our results provide a scientific basis for the development of metabolic engineering strategies to increase the oil content in SBP with a high level of C16:1.

Triterpenoids from Hippophae rhamnoides L. and their nitric oxide production-inhibitory and DPPH radical-scavenging activities.

In our investigation on the chemical constituents of Hippophae rhamnoides L., the chloroform-soluble fraction of the 80% acetone extract of branch bark was observed to inhibit nitric oxide (NO) production in a lipopolysaccharide and recombinant mouse interferon-gamma-activated murine macrophage-like cell line, RAW 264.7 cells. Two new triterpenoids, 2-O-trans-p-coumaroyl maslinic acid (1) and 2-O-caffeoyl maslinic acid (2), and three known triterpenoids, oleanolic acid (3), 3-O-trans-p-coumaroyl oleanolic acid (4), and 3-O-caffeoyl oleanolic acid (5), and 6-methoxy-2H-1-benzopyran (6) and beta-sitosterol (7) were isolated from the branch bark extract. Their inhibitory activities on the production of NO in RAW 264.7 cells and radical-scavenging activities were examined.