Sesquiterpenoids with a cage-like multiring frame are rarely found in nature. Mining of the isopod-derived fungus Aspergillus parasiticus SDU001 by the one strain−many compounds (OSMAC) strategy unexpectedly led to the discovery of fungal drimane-type sesquiterpenoids astellolide R (1), featuring an unusual cage-like 6/6/5/6/5 pentacyclic ring system, astellolide S (2), possessing a rare nicotinic acid building block, and astellolides T−W (3−6). Their structures were comprehensively assigned by spectroscopic data analysis, single-crystal X-ray diffraction, and electronic circular dichroism calculations. Furthermore, compounds 3 and 5 exhibited anti-inflammatory activity by inhibiting the lipopolyssacharide-induced NO production in RAW264.7 macrophages with IC 50 values of 6.1 ± 0.8 and 6.8 ± 0.8 μM, respectively. A putative biosynthetic pathway for 1 is proposed. Our results enlarge the chemical space of the drimane-type sesquiterpenoids generated from endophytic fungi.

Compared to other orthodontic acceleration methods such as drug, electric current, and laser, vibratory loading is less invasive and easier to use. But the optimal duration for vibratory load application has not been determined, nor can the alveolar bone parameters be predicted after vibratory load application. Therefore, this work examined the mechanism of vibration-accelerated alveolar bone reconstruction and established a numerical model for simulating alveolar bone damage caused by vibration loads. That is, the role of vibration load in orthodontic acceleration was analyzed, and a finite element model was established to validate the vibra-tion-accelerated orthodontic mechanism with a simulated numerical model of alveolar bone damage. The optimal duration of application was obtained for the right anterior incisor under vibratory loading of 5 N orthodontic force, 50 Hz in the gingival orientation and 0.2 cm amplitude for 120 to 140 minutes. This work is of guidance and reference significance in promoting the development of orthodontic treatment and shortening the orthodontic treatment cycle.

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